Clinical analysis of pneumocystis pneumonia after kidney transplantation: a report of 13 cases / 中华器官移植杂志

Objective:To explore the clinical characteristics of pneumocystis carinii pneumonia (PCP) after kidney transplantation.Methods:From January 2020 to January 2022, clinical data were retrospectively reviewed for 13 renal transplant recipients with pneumocystis pneumonia diagnosed by metagenomics next generation sequencing (mNGS). There were 3 females and 10 males with an age range of (46±10) years.The median time of postoperative onset was 10(2-21) months; The major clinical manifestations included fever ( n=11), cough ( n=7), expectoration ( n=6) and dyspnea ( n=11). Paired t-test was employed for analyzing the laboratory results at admission and discharge. Results:The diagnosis was confirmed by the detection of NGS in alveolar lavage fluid or venous blood.The levels of G test, LDH test, total T lymphocyte absolute count (CD3+ Abs), inhibitory/cytotoxic T lymphocyte count (CD3+ CD8+ Abs) and auxiliary/induced T lymphocyte absolute count (CD3+ CD4+ Abs) were (543.27±440.49) pg/ml, (529.98±222.43)U/L and (191.92±119.42)/μl, (87.33±50.59)/μl and (106.92±87.42)/μl at admission and (69.58±50.21) pg/ml, (285.38±46.62 U/L), (888.58±672.99)/μl, (336.83±305.21)/μl and (520.08±388.76)/μl at discharge.The differences were statistically significant ( P<0.001, P=0.002, 0.006, 0.017, 0.005). All of them received compound sulfamethoxazole and caspofungin.Except for one death due to septic shock after 21-day treatment, 12 cases were cured. Conclusions:mNGS test is one of the important tool for an early diagnosis of PCP.Combined use of compound sulfamethoxazole and caspofungin is an effective anti-infective regimen.And immune function monitoring is vital for adjusting antibiotic and immunosuppressive regimens.

Proliferation, Differentiation and Immunoregulatory Capacities of Brown and White Adipose-Derived Stem Cells from Young and Aged Mice

Background and Objectives@#Adipose tissue is a source of mesenchymal stem cells, which have the potential to differentiate into various types of cells. Adipose-derived stem cells (ADSCs) are now recognized as an accessible, abundant, and reliable stem cells suitable for tissue engineering and regenerative medicine applications. However, few literatures gave a comprehensive report on the capacities of ADSCs harvested from different sites. Especially, the capacities of ADSCs from aged mice remained unclear. In this study, we investigated several main capacities of brown adipose derived stem cells (B-ADSCs) and white adipose derived stem cells (W-ADSCs) from both young and aged mice. @*Methods@#and Results: When isolated from young mice, B-ADSCs showed a stronger proliferation rate and higher osteogenic, adipogenic and myocardial differentiation ability than W-ADSCs. Carboxy fluorescein diacetate succinimidyl ester (CFSE) labeling test suggested no significant difference in immunosuppression capacity between B-ADSCs and W-ADSCs. Similarly, no difference between these two were found in several immune related molecules, such as programmed death-ligand 1 (PD-L1), intercellular cell adhesion molecule (ICAM-1), vascular cell adhesion molecule (VCAM-1), inducible nitric oxide synthase (iNOS), tumour necrosis factor-α (TNF-α), interleukin 10 (IL10), and suppressor of cytokine signaling 1 (socs1). When isolated from aged mice, B-ADSCs also showed a stronger proliferation rate and higher osteogenic, adipogenic and myocardial differentiation ability than W-ADSCs; however, it demonstrated an attenuated immunosuppression capacity compared to W-ADSCs. @*Conclusions@#In summary, our data showed that ADSCs’ characteristics were tissue source dependent and changed with age. It provided evidence for choosing the right tissue-specific ADSCs for clinical application and fundamental research.

Performance and comparison of assessment models to predict 30-day mortality in patients with hospital-acquired pneumonia / 中华医学杂志(英文版)

BACKGROUND@#Hospital-acquired pneumonia (HAP) is the most common hospital-acquired infection in China with substantial morbidity and mortality. But no specific risk assessment model has been well validated in patients with HAP. The aim of this study was to investigate the published risk assessment models that could potentially be used to predict 30-day mortality in HAP patients in non-surgical departments.@*METHODS@#This study was a single-center, retrospective study. In total, 223 patients diagnosed with HAP from 2012 to 2017 were included in this study. Clinical and laboratory data during the initial 24 hours after HAP diagnosis were collected to calculate the pneumonia severity index (PSI); consciousness, urea nitrogen, respiratory rate, blood pressure, and age ≥65 years (CURB-65); Acute Physiology and Chronic Health Evaluation II (APACHE II); Sequential Organ Failure Assessment (SOFA); and Quick Sequential Organ Failure Assessment (qSOFA) scores. The discriminatory power was tested by constructing receiver operating characteristic (ROC) curves, and the areas under the curve (AUCs) were calculated.@*RESULTS@#The all-cause 30-day mortality rate was 18.4% (41/223). The PSI, CURB-65, SOFA, APACHE II, and qSOFA scores were significantly higher in non-survivors than in survivors (all P < 0.001). The discriminatory abilities of the APACHE II and SOFA scores were better than those of the CURB-65 and qSOFA scores (ROC AUC: APACHE II vs. CURB-65, 0.863 vs. 0.744, Z = 3.055, P = 0.002; APACHE II vs. qSOFA, 0.863 vs. 0.767, Z = 3.017, P = 0.003; SOFA vs. CURB-65, 0.856 vs. 0.744, Z = 2.589, P = 0.010; SOFA vs. qSOFA, 0.856 vs. 0.767, Z = 2.170, P = 0.030). The cut-off values we defined for the SOFA, APACHE II, and qSOFA scores were 4, 14, and 1.@*CONCLUSIONS@#These results suggest that the APACHE II and SOFA scores determined during the initial 24 h after HAP diagnosis may be useful for the prediction of 30-day mortality in HAP patients in non-surgical departments. The qSOFA score may be a simple tool that can be used to quickly identify severe infections.

Interpretation of Guide to the Quality and Safety of Organs for Transplantation(6th edition): identification and referral of potential donors / 器官移植

Organ shortage is one of the important factors restricting the development of human organ transplantation. The identification and referral of potential donors determine the total scale of organ donation. Whether potential donors can be identified and referred is the most important reason for the difference of organ donation rates in different regions. This paper interprets the chapter of the identification and referral of potential donors in the Guide to the Quality and Safety of Organs for Transplantation (6th edition) issued by European Union in order to provide reference for the staff of organ procurement organization and related medical personnel in China and improve the organ donation rate in China.

Synthesis and Evaluation of a Novel Small-molecule Compound as an Anticancer Inhibitor of CD147 / 生物医学与环境科学（英文）

OBJECTIVE@#Cancer is a serious threat to human health. Despite extensive research on cancer treatment, there is a growing demand for new therapies. CD147 is widely involved in tumor development, but it is unclear whether cancer cell malignancy is affected by CD147 expression level. The first compound (AC-73) targeting CD147 could only act on advanced tumors and inhibit metastasis. Therefore, new compounds with better anticancer activity should be explored.@*METHODS@#Wst-1 assays were used to confirm the effect of novel compounds on proliferation. Apoptosis tests were used to evaluate their proapoptotic capacity. A nude mouse model was used to demonstrate in vivo anticancer activity and safety of the compounds. Western blots were used to suggest a molecule mechanism.@*RESULTS@#There is a positive correlation between CD147 expression and tumor cell proliferation. A new compound, HA-08, was synthesized and proved to be more active than AC-73. HA-08 could inhibit cancer cell viability and promote cancer cell apoptosis both in vitro and in vivo. HA-08 induces cancer apoptosis, mainly by disrupting the CD147-CD44 interaction and then down-regulating the JAK/STAT3/Bcl-2 signaling pathway.@*CONCLUSION@#Our results have clarified the tumor specificity of CD147 and its drug target characteristics. The biological profile of HA-08 suggests that this compound could be developed as a potential anticancer agent.

Clinical study of single kidney transplantation from young pediatric donors after death: 86 cases report / 中华器官移植杂志

Objective By analyzing the perioperative management in our hospital to explore the clinical effect and safety of single kidney transplantation from deceased juveniles' donors.Methods We retrospectively analyze 86 cases of kidney transplantations from deceased juveniles' donors in our hospital from 2007 December to 2015 August.Results The success rate of the operations was 100％.The postoperative complications occurred as fellows:7 cases of acute rejection (8.14％);10 cases of drug intoxication (11.62％);21 cases of DGF (24.44％),4 cases of leakage of urine (4.65％),7 cases of lung infection (8.14％).Two cases (2.32％) died after the operation because of serious lung infection,and by corresponding treatment 47 cases recovered after 2-4 weeks.The creatinine level in 37 cases without any complications was 131.88 ± 44.20 μmol/L during discharge.Conclusion With strict selection,the organ from a deceased juvenile donor is safe and practicable.

The immunomodulatory function and clinical applications of mesenchymal stem cells / 中国组织工程研究

BACKGROUND: Mesenchymal stem cells (MSCs) have the abilities of self-renewal, multidirectional differentiation and immunomodulation, and have become the focus of current research. OBJECTIVE: To summarize the immunomodulation of MSCs to different immune cells and the clinical applications of MSCs in the treatment of immune-related diseases. METHODS: The first author searched the PubMed and the CKNI databases for relative articles from January 1974 to December 2016. The key words were mesenchymal stem cells, immunomodulation, MSC1 and MSC2, autoimmune diseases in English and Chinese, respectively. Finally, 52 representative articles were included. RESULTS AND CONCLUSION: MSCs can inhibit the function of T lymphocytes, reduce the activation, proliferation and antibody secretion of B lymphocytes, affect the polarization of macrophages, inhibit the maturation of dendritic cells, inhibit the proliferation and toxicity of NK cells, so MSCs have the great potential in the treatment of immune-related diseases. However, MSCs exhibit the opposite immunomodulatory abilities under different inflammatory microenvironments, and moreover the definite and controllable mechanism of this phenomenon is still unclear, Therefore, future investigations may focus on the specific mechanism of MSCs in the clinical treatment of immune-related diseases.

Correlation between hyperuricemia and type 2 diabetes mellitus with vascular complication / 国际检验医学杂志

Objective To investigate the risk factors of hyperuricemia and type 2 diabetes mellitus(T2DM ) with vascular com‐plication .Methods 97 individuals undergoing the physical examination were included into the control group ,103 patients with pure T2DM and 78 patients with T2DM complicating hyperuricemia were selected .The fasting plasma glucose(FPG) ,glycosylated he‐moglobin(HbA1c) ,total cholesterol(TC) ,triglycerides(TG) ,high density lipoprotein cholesterol (HDL‐C) ,low density lipoprotein cholesterol (LDL‐C) ,apolipoprotein A1(ApoA1) ,apolipoprotein B (ApoB) ,serum creatinine (Cr) and uric acid (UA ) were com‐pared among 3 groups ,meanwhile the first morning urine was collected for detecting urine microalbumin (UMA) ,and the body mass index(BMI) was detected .Then the correlation between hyperuricemia with the diabetes related complications was investigated .Re‐sults The levels of FPG ,TG ,Cr ,UMA and HbA1c in the pure T2DM group were higher than those in the control group(P < 0 . 05) ;BMI ,FPG ,TG ,TC ,LDL‐L ,UMA ,Cr and HbA1c in the T2DM complicating hyperuricemia group were higher than those in the control group (P < 0 .05) ;BMI ,TG ,Cr ,UMA and HbA1c in the T2DM complicating hyperuricemia group were higher than those in the pure T2DM group(P < 0 .05) .The incidence rates of diabetic nephropathy (DN ) ,limb arterial plaques in the T2DM complicating hyperuricemia group were significantly higher than those in the T 2DM group ,the differences were statistically signifi‐cant (P< 0 .05) .Conclusion The patients with T2DM complicating hyperuricemia are easier to develop dyslipidemia ,and their inci‐dence rates of DN and lower limb arterial plaque are also significantly higher than those in patients with pure T 2DM .

Effect of rat endothelial progenitor cell on proliferation and apoptosis of bone marrow mesenchymal stem cell / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the effect of endothelial progenitor cell (EPC) on regulating proliferation and apoptosis of bone marrow mesenchymal stem cell (BMSC) in the indirect co-culture system.</p><p><b>METHODS</b>BMSC and EPC were cultivated and identified in vitro.Using transwell inserts to establish EPC and BMSC indirect co-culture system.Experimental groups were prepared as follows: BMSC/EPC indirect co-culture: BMSC were co-cultured with EPC that were separated in transwell insert.</p><p><b>CONTROL</b>BMSC/BMSC were indirect co-cultured at the same cell counts with the experimental groups. Colony forming unit-fibroblast(CFU-F) assay was studied with three types of EPC/BMSC ratios (1: 1, 10: 1, 100: 1) to assess the capacity and efficiency for cell self-renewal.In addition, flow cytometry technique was used to detect the cell cycle at co-cultured 3 days and the cell apoptosis at co-cultured 3, 7, 10 d.</p><p><b>RESULTS</b>Under indirect co-culture condition,EPC could significantly promote cell cycle progress and enhance capacity of cell self-renewal. Co-cultured EPC resulted in an accumulation of BMSC at S phase [experimental group: (15.72 ± 2.93)%, control group: (2.02 ± 0.66)%, P < 0.01]. CFU-F assay showed that the self-renewal capacity of EPC: BMSC/10: 1 group [(50.98 ± 6.32)%] and 100:1 group[(57.87 ± 14.06)%] were significantly higher than that in control group [(33.07 ± 9.60)% and (30.06 ± 7.20)%](P < 0.01). However,EPC had a slight but non-significant down-regulated effect on BMSC apoptosis(P > 0.05).</p><p><b>CONCLUSIONS</b>Under indirect co-culture condition, EPC could enhance the proliferation of BMSC, but could not regulate cell apoptosis in vitro.</p>

A new method for isolating and culturing mouse bone marrow mesenchymal stem cells / 中国实验血液学杂志

This study was purposed to establish a convenient and efficient method for isolating and culturing mouse bone marrow mesenchymal stem cells (MSC). The femurs and tibias of mouse were taken under sterile condition. MSC were isolated and cultured with flushing- out bone marrow or collagenase-digested bone fragment or bone marrow plus bone fragment. MSC colony number and size were compared. Immunophenotype and differentiation ability were tested to identify MSC. The results showed that colonies from bone marrow plus bone fragment group came out earliest and the colony number was 20 ± 4 at day 4; there were 11.5 ± 2.5 colonies in collagenase-digested bone fragment group and 9.5 ± 1.5 in flushing- out bone marrow group. The total cell yields of MSC after passaging showed best in bone marrow plus bone fragment group. Flow cytometry data showed the cultured cells expressed Sca-1, CD44 and CD29, not expressed pan-leukocyte surface marker CD45 and endothelial cell marker CD31. The isolated and cultured MSC could differentiate into osteoblast at the osteogenic differentiation condition, or adipocyte at adipogenic differentiation condition. It is concluded that the method of bone marrow plus bone fragment is convenient and efficient for isolating and culturing MSC.

Influence of background color on four veneered dental ceramic core material / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the influence of background color on veneered In-Ceram and Cercon dental ceramics including Vita In-Ceram Electroformed Alumina (AL2), Electroformed Zirconia (Z21), Cercon base color Zirconia and Cercon base Zirconia.</p><p><b>METHODS</b>The colorimetric values of all the materials on noble metal, Ni-Cr alloy, silver amalgam and resin background were measured with a spectrocolorimeter, and the color difference among the groups was calculated.</p><p><b>RESULTS</b>After veneered, the color difference of Z21 Electroformed Zirconia was more distinct against the background of silver amalgam than against the backgrounds of noble metal and resin, but the color differences of the 4 veneered dental ceramics against different backgrounds were unidentifiable by human eyes (δE<1.5).</p><p><b>CONCLUSION</b>After veneered, AL2 electroformed alumina, Z21 electroformed zirconia, Cercon base Zirconia and Cercon base color Zirconia are less influenced by the background color, and covering the background color is therefore not necessary.</p>

Infinite optical thickness of dentine porcelain of IPS E.max A color series / 南方医科大学学报

<p><b>OBJECTIVE</b>To determine the infinite optical thickness of dentine porcelain of IPS E.max A color series.</p><p><b>METHODS</b>Cylindrical dentine porcelain specimens of the IPS E.max A color series were prepared with a diameter of 13 mm and thickness of 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, and 5.0 mm. The chromatic value of all the specimens was determined with CM-5 spectrometer against standard black and white background. The chromatic aberration (deltaE) was calculated by regression equation.</p><p><b>RESULTS</b>The infinite optical thickness of dentine porcelain of the IPS E.max A color series ranged from 2.341 to 3.333 mm for a deltaE of 1.0, and from 2.064 to 2.904 mm for a deltaE of 1.5. As the chromaticity or thickness increased, the influence by the background color decreased, and the color of specimens became gradually close to the intrinsic color.</p><p><b>CONCLUSION</b>The thickness of the background dentine porcelain specimens must exceed its infinite optical thickness to represent the intrinsic color and avoid the influence by the extrinsic color.</p>

Research on the osteogenic ability of 3-Ds interconnected porous titanium / 中国骨伤

<p><b>OBJECTIVE</b>To evaluate the osteogenic ability of the three-dimensional interconnected porous titanium(TDIPT) coated with bonelike apatite, by the test of the culture of osteoblast in vitro.</p><p><b>METHODS</b>The pure TDIPT was prepared by the high temperature insostatic pressing (HIP) and was divided into two groups. One group of TDIPT was dipped into the 1.5 simulated body fluid (1.5 SBF) and developed the TDIPT coated with bone-like apatite (The test group). Another group was control group (pure TDIPT). The porous titanium of the two groups were all made into standard parts (5 mm x 5 mm x 4 mm) and placed into the 24-hole plates. The osteoblasts were extracted from SD rat. After the primary culture and subculture of the osteoblast in vitro, the osteoblasts were inoculated into the samples in the 24-pole plate and cultured continually. MTT Cell Proliferation Assay was done on the 1st, 3rd, 5th, 7th and 9th day respectively after inoculating. The ALP activity was tested on the 7th, 14th and 21st day, respectively. The collected data were analyzed by use of the student t test.</p><p><b>RESULTS</b>The MTT value and the ALP activity increased with the increasing of the culture time in the two group, but those of the test group was more significant than those of the control group (P < 0.05). Moreover, the osteoblast tachyauxesis and stable adhesion were observed in test group by SEM at the 7th day after culturing.</p><p><b>CONCLUSION</b>The bioactivity of the TDIPT improves significantly after coating with the bone-like apatite onto the surface of the TDIPT.</p>

Apoptosis and oxidative injury of donor islets during isolation and purification / 中华器官移植杂志

Objective To observe the changes of islet cell apoptosis and oxidation-antioxidation before the transplantation, and to explore the pathways of islet protection. Methods Fifteen human pancreases were perfused with the Hanks solution containing collagenase, then digested and isolated. During the procedure, islet cell apoptosis was detected by TUNEL, SOD and MDA in the pancreas were measured by colorimetric method, and the morphologic changes were observed by H-E staining and dithizone staining. Results In the procedure of human islet isolation, especially in the stage of digestion, the apoptosis of human islet cells occurred. In the stages of perfusion and digestion, the MDA contents reached the high levels (6. 18 ± 2. 38 and 9. 21 ± 2. 75 umol/mg protein respectively),and the structures of the islets and tissues around the islets were damaged. Conclusion In the stages of perfusion and digestion, apoptosis of islet cells can be caused by oxidation. It suggests that antioxidation is a pathway for protection of islets before transplantation.

Study on the setting property and compressive strength of β-TCP/α-CSH combined bone graft / 医用生物力学

Objective To investigate the setting property and compressive strength of β-TCP (β-tricalcium phosphate)/α-CSH (α-calcium sulphate hemihydrate) combined bone graft. Method β TCP/α CSH combined bone graft and distilled water were mixed with different ratio: 1 g∶0.1 mL、1 g∶0.2 mL、1 g∶0.3 mL、1 g∶0.4 mL、1 g∶0.5 mL, respectively. The initial setting time (Ti), final setting time (TF), compressive strength were recorded, and the X-ray diffraction (XRD) and the scanning electron microscope (SEM) were examined. Results The initial and final setting time of combined bone graft increased along with the increase of solid/liquid ratio. The Ti and TF were (4.6±1.3) min and (13.1±2.9) min respectively when the solid/liquid ratio was 1 g∶0.2 mL. The average compressive strength was 7.86 MPa in one day after setting, which was about two times higher than that of β-TCP alone. The XRD results showed that no other materials were produced except that α-CSH was transformed to CSD in the setting process. The SEM results indicated that thick CSD granules were adhered to the porous surfaces of β-TCP granules after setting. Conclusions The setting time and compressive strength of β-TCP/α-CSH combined bone graft could be adjusted by the different solid/liquid ratio.

Effects of three types of veneering porcelain on bending strength of KAVO(TM) Y-TZP/porcelain bilayered structure / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the effect of three types of veneering porcelain on the bending strength of KAVO Y-TZP/porcelain layered structure.</p><p><b>METHODS</b>KAVO zirconia ceramics were used as the substructure. To form Y-TZP/porcelain bilayered structure, a leucite-based veneering porcelain was fired on the zirconia substructures by slip-casting technique with dentin washbake, and two nano-fluorapatite-based veneering porcelains were fired on the zirconia substructures by either slip-casting or pressed-on technique with or without liner coverage. The bending strength was tested according to ISO 6872 standard, and the veneered surfaces of the fracture samples were analyzed by scanning electron microscopy (SEM).</p><p><b>RESULTS</b>For covering KAVO zirconia core material, the conventional veneering slurry-porcelain combined with liner or wash firing had significant higher bending strength than pressed-on porcelain. SEM showed that the main failure type at the interface was adhesive failure.</p><p><b>CONCLUSION</b>Thin layer sintering using washbake program or liner on KAVO zirconia surface increases the surface wettability, and this procedure may be indispensable when veneering on the surface of dental zirconia.</p>

Near infrared Raman spectral character and diagnostic value of squamous cell carcinoma of oral mucosa / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To evaluate the value of the near infrared Raman spectroscope in diagnosing oral squamous cell carcinoma (OSCC).</p><p><b>METHODS</b>Near infrared Raman spectra of ten normal mucosa, twenty OSCC and thirty oral leukoplakia (OLK) cases were collected in the research. Based on the previous researches, the information of the subtracted spectra of compared group was gained by the characteristic band in them. A Gaussian radial basis function support vector machine was used to classify spectra and establish the diagnostic models. The efficacy and validity of the algorithm were evaluated.</p><p><b>RESULTS</b>By analyzing the subtracted mean spectra, the increasing peak intensity in wavenumber range of 500-2 200 cm(-1) hinted us of the high contents of DNA, protein and lipid in OSCC, which elucidate the high proliferative activity. The increasing peak intensity in the wavenumber range of 500-2 200 cm(-1) hinted us of the high contents of DNA, protein and lipid in OSCC, which elucidate the high proliferative activity, but the difference between OLK and OSCC was not as much as that between normal and OSCC. The Gaussian radial basis function support vector machine showed powerful ability in grouping and modeling of normal and OSCC, and the specificity, sensitivity and accuracy were 100%, 97.44% and 98.81% correspondingly. The algorithm showed good ability in grouping and modeling of OLK and OSCC, the specificity, sensitivity and accuracy were 95.00%, 86.36% and 96.30%.</p><p><b>CONCLUSION</b>Combined with support vector machines, near infrared Raman spectroscopy could detect the biochemical variations in oral normal, OLK and OSCC, and establish diagnostic model accurately.</p>

Effect of pigmentation on the strength of dental Y-TZP/porcelain bilayered structure / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the effect of two methods of pigmentation on the flexural strength of dental Y-TZP/porcelain layered structure.</p><p><b>METHODS</b>KaVo zirconia substructures were pigmented by dipping presintered blocks in the coloring solution VITA LL1 and LL5, and colored TZ-3YS zirconia substructures were fabricated by adding pigments before isostatic pressing. The colors No.1 and No.5 were used for the test. The specimens were made in monolithic or bilayered forms, and the flexural strength was tested. XRD and SEM with EDX were used to analyze the characteristics of the surface structure.</p><p><b>RESULTS</b>In KaVo group, no significant differences were found in the flexural strength between white and LL1 and LL5 colored monoclinic materials, nor in bilayered structures. While in TZ-3YS group, significant differences were noted in the flexural strength between color No.5 white and color No.1 monoclinic materials, but not between the latter two subgroups. The flexural strength was significantly lowered by veneering with porcelain in both zirconia groups, and similar findings were observed with the monoclinic materials. Only the tetragonal phase was detected in both of the zirconia groups.</p><p><b>CONCLUSION</b>Pigmentation has no apparent effects on the bonding strength between the veneering porcelain and zirconia. Both coloring methods are appropriate when the concentration of the pigments is under deliberate control.</p>

Detection Rate of Oral Candida albicans with Different Sampling Methods among Elderly:A Comparative Study / 中华医院感染学杂志

0.05).CONCLUSIONS There is high frequency of C.albicans in the elderly.There is no significant difference rate of detection rate among three groups.Mucosa swab sampling method may be a convenient and effective method for clinical study.

Structure and properties of colored dental tetragonal zirconia stabilized by yttrium ceramics / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the structure, mechanical and low temperature aging properties of colored dental zirconia ceramics.</p><p><b>METHODS</b>5 graded colored dental zirconia ceramics were made by adding colorants and their combinations into a 3Y-TZP (tetragonal zirconia stabilized by 3mol% yttrium) powder, the green body were compacted at 200 MPa, pre-sinter at 1,050 degrees C and maintained for 2 h, then densely sintered at 1,500 degrees C for 2 h. Specimens were cut from each of the 5 graded colored blocks. Physical, mechanical properties as well as chemical stability were tested, microstructure were observed, crystalline phase were identified by X-ray diffraction (XRD), aging properties were assessed by measurement of the relative content of monoclinic phase and bending strength testing.</p><p><b>RESULTS</b>The overall density of colored zirconia ceramics was over 99.7%, linear shrinkage was about 20%, while thermal expansion coefficient was about 11 x 10(-6) x degrees C(-1), the crystalline phase was tetragonal, bending strength was over 900 MPa which was slightly lowered than that of the uncolored zirconia, fracture toughness was slightly higher. Good chemical stability in acetic acid was observed. After aging treatment, tetragonal-to-monoclinic phase transformation was detected up to 40%, while bending strength was not significantly degraded.</p><p><b>CONCLUSION</b>The results showed that colored 3Y-TZP ceramics presented good mechanical properties even after aging treatments, and was suitable for dental clinical use.</p>