Clinical application of plasma exchange combined with continuous veno-venous hemofiltration dialysis in children with refractory Kawasaki disease shock syndrome / 中国当代儿科杂志

OBJECTIVES@#To study the role of plasma exchange combined with continuous blood purification in the treatment of refractory Kawasaki disease shock syndrome (KDSS).@*METHODS@#A total of 35 children with KDSS who were hospitalized in the Department of Pediatric Intensive Care Unit, Hunan Children's Hospital, from January 2019 to August 2022 were included as subjects. According to whether plasma exchange combined with continuous veno-venous hemofiltration dialysis was performed, they were divided into a purification group with 12 patients and a conventional group with 23 patients. The two groups were compared in terms of clinical data, laboratory markers, and prognosis.@*RESULTS@#Compared with the conventional group, the purification group had significantly shorter time to recovery from shock and length of hospital stay in the pediatric intensive care unit, as well as a significantly lower number of organs involved during the course of the disease (P<0.05). After treatment, the purification group had significant reductions in the levels of interleukin-6, tumor necrosis factor-α, heparin-binding protein, and brain natriuretic peptide (P<0.05), while the conventional group had significant increases in these indices after treatment (P<0.05). After treatment, the children in the purification group tended to have reductions in stroke volume variation, thoracic fluid content, and systemic vascular resistance and an increase in cardiac output over the time of treatment.@*CONCLUSIONS@#Plasma exchange combined with continuous veno-venous hemofiltration dialysis for the treatment of KDSS can alleviate inflammation, maintain fluid balance inside and outside blood vessels, and shorten the course of disease, the duration of shock and the length of hospital stay in the pediatric intensive care unit.

Application of transport ventilator in the inter-hospital transport of critically ill children / 中国当代儿科杂志

OBJECTIVES@#To study the application value of transport ventilator in the inter-hospital transport of critically ill children.@*METHODS@#The critically ill children in Hunan Children's Hospital who were transported with or without a transport ventilator were included as the observation group (from January 2019 to January 2020; n=122) and the control group (from January 2018 to January 2019; n=120), respectively. The two groups were compared in terms of general data, the changes in heart rate, respiratory rate, and blood oxygen saturation during transport, the incidence rates of adverse events, and outcomes.@*RESULTS@#There were no significant differences between the two groups in sex, age, oxygenation index, pediatric critical illness score, course of disease, primary disease, heart rate, respiratory rate, and transcutaneous oxygen saturation before transport (P>0.05). During transport, there were no significant differences between the two groups in the changes in heart rate, respiratory rate, and transcutaneous oxygen saturation (P>0.05). The incidence rates of tracheal catheter detachment, indwelling needle detachment, and sudden cardiac arrest in the observation group were lower than those in the control group during transport, but the difference was not statistically significant (P>0.05). Compared with the control group, the observation group had significantly shorter duration of mechanical ventilation and length of stay in the pediatric intensive care unit and significantly higher transport success rate and cure/improvement rate (P<0.05).@*CONCLUSIONS@#The application of transport ventilator in the inter-hospital transport can improve the success rate of inter-hospital transport and the prognosis in critically ill children, and therefore, it holds promise for clinical application in the inter-hospital transport of critically ill children.

Efficacy of plasma exchange in children with severe hemophagocytic syndrome: a prospective randomized controlled trial / 中国当代儿科杂志

OBJECTIVES@#To investigate the efficacy and application value of plasma exchange as an adjuvant therapy in children with hemophagocytic syndrome (HPS).@*METHODS@#A prospective randomized controlled trial was designed. Forty children with severe HPS were enrolled, who were treated in the pediatric intensive care unit (PICU) of Hunan Children's Hospital from October 2018 to October 2020. The children were randomly divided into a plasma exchange group and a conventional treatment group using a random number table, with 20 children in each group. The children in the conventional treatment group received etiological treatment and conventional symptomatic supportive treatment, and those in the plasma exchange group received plasma exchange in addition to the treatment in the conventional treatment group. The two groups were compared in terms of general information, clinical symptoms and signs before and after treatment, main laboratory markers, treatment outcome, and prognosis.@*RESULTS@#Before treatment, there were no significant differences between the two groups in gender, age, course of the disease before admission, etiological composition, pediatric critical illness score, involvement of organ or system functions, and laboratory markers (P>0.05). After 7 days of treatment, both groups had remission and improvement in clinical symptoms and signs. After treatment, the plasma exchange group had significantly lower levels of C-reactive protein, procalcitonin, and serum protein levels than the conventional treatment group (P<0.05). The plasma exchange group also had significantly lower levels of alanine aminotransferase and total bilirubin than the conventional treatment group (P<0.05). The length of stay in the PICU in the plasma exchange group was significantly shorter than that in the conventional treatment group (P<0.05). The plasma exchange group had a significantly higher treatment response rate than the conventional treatment group (P<0.05). There were no significant differences between the two groups in the total length of hospital stay and 3-month mortality rate (P>0.05).@*CONCLUSIONS@#Plasma exchange as an adjuvant therapy is effective for children with severe HPS. It can improve clinical symptoms and signs and some laboratory markers and shorten the length of stay in the PICU, and therefore, it may become an optional adjuvant therapy for children with severe HPS.

Application of double plasma molecular adsorption system in children with acute liver failure / 中国当代儿科杂志

OBJECTIVE@#To study the efficacy and safety of double plasma molecular absorption system (DPMAS) in the treatment of pediatric acute liver failure (PALF).@*METHODS@#A prospective analysis was performed on the medical data of children with PALF who were hospitalized in the Intensive Care Unit (ICU), Hunan Children's Hospital, from March 2018 to June 2020. The children were randomly divided into two groups:plasma exchange group (PE group) and DPMAS group (@*RESULTS@#Compared with the PE group, the DPMAS group had a significantly lower number of times of artificial liver support therapy and a significantly shorter duration of ICU stay (@*CONCLUSIONS@#DPMAS is safe and effective in the treatment of PALF and can thus be used as an alternative to artificial liver support therapy.

Clinical features of severe type 7 adenovirus pneumonia: an analysis of 45 cases / 中国当代儿科杂志

OBJECTIVE@#To study the clinical features of severe type 7 adenovirus pneumonia in children.@*METHODS@#A retrospective analysis was performed for the clinical data of children who were diagnosed with severe type 7 adenovirus pneumonia from February to June, 2019.@*RESULTS@#Among the 45 children, the male/female ratio was 3:2 and the median age was 14 months. All children had repeated fever, cough, and pulmonary moist rales, and the mean duration of fever was 14±4 days. The median time from fever to dyspnea was 8 days, and the time from fever to mechanical ventilation was 11.6±2.5 d. There was no significant increase in white blood cell count, with neutrophils as the main type. There were slight reductions in hemoglobin and albumin, while platelet and fibrinogen remained normal. There were increases in aspartate aminotransferase, lactate dehydrogenase, procalcitonin, and C-reaction protein. The detection rate of mixed pathogens was 84%. Effusion in both lungs was the major change on chest imaging (64%). Bronchoscopic manifestations were endobronchitis, tracheomalacia, and plastic bronchitis. The incidence rate of respiratory complications was 100%, and extrapulmonary complications mainly involved the circulatory system (47%), digestive system (36%), and nervous system (31%). Among the 45 children, 16 were administered with 400 mg/kg intravenous immunoglobulin (IVIG) daily for 5 days, with a mean duration of fever of 16±5 days, and 29 were administered with 1 g/kg IVIG daily for 2 days, with a mean duration of fever of 13±4 days; there was a significant difference in the mean duration of fever between the two groups (P=0.046). The overall mortality rate was 11%.@*CONCLUSIONS@#Severe type 7 adenovirus pneumonia in children has severe conditions, with a high incidence rate of complications and a high mortality rate, so it should be diagnosed and treated as early as possible.

Application of dexmedetomidine in children with agitation during ventilator weaning / 中国当代儿科杂志

OBJECTIVE@#To study the clinical effect and safety of dexmedetomidine in children with agitation during ventilator weaning.@*METHODS@#A prospective open observational study was performed for children who were admitted to the intensive care unit and experienced mechanical ventilation between March 2017 and August 2018. They were given dexmedetomidine due to the failure in the spontaneous breathing test (SBT) caused by agitation. A sedation-agitation scale score of ≥5 was defined as agitation. The children were observed in terms of the sedation state at 0.5, 1, 2, 6, and 12 hours after the administration of dexmedetomidine, blood gas parameters before extubation and at 1, 24, and 48 hours after extubation, vital signs (heart rate, respiratory rate and mean arterial pressure) before SBT, before extubation, and at 10, 60, and 120 minutes and 24 hours after extubation, and incidence rates of adverse events related to the use of dexmedetomidine.@*RESULTS@#A total of 19 children were enrolled in this study. All the children were in a state of agitation at the time of enrollment. At 0.5, 1, 2, 6, and 12 hours after the administration of dexmedetomidine, 12, 17, 17, 18, and 18 children respectively reached the sedation state. There were no significant differences in the oxygenation index, arterial partial pressure of carbon dioxide, heart rate, respiratory rate, and mean arterial pressure at each time point before and after extubation (P>0.05). No adverse events were observed, such as severe hypotension and respiratory depression, and only one child experienced reversible bradycardia.@*CONCLUSIONS@#Dexmedetomidine is safe and effective in children with agitation during ventilator weaning, but prospective randomized controlled trials are needed for verification.

Study on the Stakeholders of Drug Supply Support Reform in Sanming City / 中国医院管理

Government departments,pharmaceutical enterprises,health providers and patients were the four main stakeholders who involved in drug supply support reform in Sanming City.The paper centered on stakeholders' role and basic appeal,their influence on the reform or the influence of reform on them and the probable problems of reform,to make the motivation and resistance of the reform clearly and provide evidence for the sustainability and reproducibility of the reform.

Value of pancreatic stone protein/regenerating protein in severity evaluation and prognosis prediction for children with sepsis / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To evaluate the value of pancreatic stone protein/regenerating protein (PSP/reg) in severity evaluation and prognosis prediction for children with sepsis.</p><p><b>METHODS</b>In this prospective case-control study, 159 children with sepsis (106 cases in the sepsis group; 53 cases in the severe sepsis group, including 12 cases of septic shock) and 20 children without sepsis (control group) were enrolled. ELISA was applied to measure plasma PSP/reg levels on days 1, 3, and 7 of admission to the PICU. The Spearman rank correlation test was applied to assess the correlations between plasma PSP/reg level and serum procalcitonin (PCT), CRP, WBC count, and pediatric critical illness score (PCIS). The area under the receiver operating characteristic curve (AUC) was used to assess the value of each index in determining severity and predicting prognosis for children with sepsis.</p><p><b>RESULTS</b>On day 1 of admission to the PICU, plasma PSP/reg levels in the sepsis and severe sepsis groups were significantly higher than in the control group (P<0.05), and the severe sepsis group had a significantly higher plasma PSP/reg level than the sepsis group (P<0.05). On day 1 of admission to the PICU, the survival group (n=132) had a significantly lower plasma PSP/reg level than the non-survival group (n=27) (P<0.05). On day 1 of admission to the PICU, plasma PSP/reg level in children with sepsis was positively correlated with WBC count and serum PCT level (rs=0.212 and 0.548, respectively; both P<0.05), and negatively correlated with PCIS score (rs=-0.373; P<0.05). The AUCs of plasma PSP/reg level and serum PCT for determination of severe sepsis, septic shock, and death were higher than 0.7 (P<0.05).</p><p><b>CONCLUSIONS</b>PSP/reg is closely related to infection, and has a certain clinical value in risk stratification of sepsis and prognosis evaluation.</p>

Development and influencing factors of compliance behaviors of investigators in clinical trials / 华中科技大学学报（医学）（英德文版）

The development and influencing factors of compliance behavior of investigators in clinical trials were explored. According to literature review, a hypothetical model of development of compliance behavior of investigators in clinical trials was established, and the influencing factors of compliance behavior of investigators and their interrelationships were studied based on questionnaire survey of five hundred investigators sampled randomly from one hundred clinical trial institutions in China. Cronbach's alpha coefficient and structural equation modeling were adopted to empirically analyze the results. Six variables in the hypothetical model were included: compliance behavior of investigators, credibility of clinical trial, capability of government regulation, quality control of sponsor, quality control of clinical institution and compliance intention of investigators. Empirical analysis showed that the compliance behavior of investigators in clinical trial was directly affected by compliance intention of investigators, quality control of sponsor and quality control of clinical institution. In addition, credibility of clinical trial and capability of government regulation indirectly affected the compliance behavior of investigators in clinical trial through influencing the compliance intention of investigators, quality control of sponsor and quality control of clinical institution. Quality control of sponsor was affected by credibility of clinical trial and capability of government regulation while quality control of clinical institution was only influenced by capability of government regulation.

Efficacy of Jian'ganle () versus Hugan Pian (), glucuronolactone and reduced glutathione in prevention of antituberculosis drug-induced liver injury / 华中科技大学学报（医学）（英德文版）

Evidence-based medicine is advocated by WHO and adopted by developed countries for many years. In China, however, the selection of essential medicine and various medical insurance reimbursement schemes medicine is usually based on experts' experience of prescription practice which is under heavy critics resulting from the lack of related comparative efficacy and evidence-based research. The efficacy of Jian'ganle in prevention of drug-induced liver injury (DILI) caused by antituberculotics was evaluated in this study by comparison with Hugan Pian, glucuronolactone and reduced glutathione. Evidence was provided for relevant sectors such as Ministry for Human Resources and Social Security of the People's Republic of China and National Health and Family Planning Commission of the People's Republic of China to select and renew the Essential Medicine List (EML), the new rural cooperative medical scheme in China (NRCMS) list or the reimbursement list of industrial injury insurance. A total of 189 patients with initial pulmonary tuberculosis were divided into four groups who took antituberculotics combined with Jian'ganle, Hugan Pian, glucuronolactone and reduced glutathione respectively. Their liver function profile including alanine aminotransferase (ALT), aspartate aminotransferase (AST), total bilirubin (TBIL), direct bilirubin (DBIL), total protein (TP), albumin (A) and globulin (G) were detected at admission as baseline and after treatment. The Jian'ganle group was compared with the three others by chi-square tests. In an aspect of maintaining bilirubin indexes normal, Jian'ganle was more efficacious than glucuronolactone. And Jian'ganle had a little more efficacy than reduced glutathione to maintain protein indexes normal as well. And the therapeutic regimen of antituberculotics combined with Jian'ganle was the best in treating tuberculosis and preventing DILI at the same time. The study showed that among the four hepatinicas which demonstrated similar prevention of DILI caused by antituberculotics, Jian'ganle has more advantages over the three others to some extent, which provides a reliable basis for health sectors to select and renew the EML, NRCMS List or the reimbursement list of industrial injury insurance.

Efficacy of Jian'ganle () versus Hugan Pian (), glucuronolactone and reduced glutathione in prevention of antituberculosis drug-induced liver injury / 华中科技大学学报（医学）（英德文版）

Evidence-based medicine is advocated by WHO and adopted by developed countries for many years. In China, however, the selection of essential medicine and various medical insurance reimbursement schemes medicine is usually based on experts' experience of prescription practice which is under heavy critics resulting from the lack of related comparative efficacy and evidence-based research. The efficacy of Jian'ganle in prevention of drug-induced liver injury (DILI) caused by antituberculotics was evaluated in this study by comparison with Hugan Pian, glucuronolactone and reduced glutathione. Evidence was provided for relevant sectors such as Ministry for Human Resources and Social Security of the People's Republic of China and National Health and Family Planning Commission of the People's Republic of China to select and renew the Essential Medicine List (EML), the new rural cooperative medical scheme in China (NRCMS) list or the reimbursement list of industrial injury insurance. A total of 189 patients with initial pulmonary tuberculosis were divided into four groups who took antituberculotics combined with Jian'ganle, Hugan Pian, glucuronolactone and reduced glutathione respectively. Their liver function profile including alanine aminotransferase (ALT), aspartate aminotransferase (AST), total bilirubin (TBIL), direct bilirubin (DBIL), total protein (TP), albumin (A) and globulin (G) were detected at admission as baseline and after treatment. The Jian'ganle group was compared with the three others by chi-square tests. In an aspect of maintaining bilirubin indexes normal, Jian'ganle was more efficacious than glucuronolactone. And Jian'ganle had a little more efficacy than reduced glutathione to maintain protein indexes normal as well. And the therapeutic regimen of antituberculotics combined with Jian'ganle was the best in treating tuberculosis and preventing DILI at the same time. The study showed that among the four hepatinicas which demonstrated similar prevention of DILI caused by antituberculotics, Jian'ganle has more advantages over the three others to some extent, which provides a reliable basis for health sectors to select and renew the EML, NRCMS List or the reimbursement list of industrial injury insurance.

Development and influencing factors of compliance behaviors of investigators in clinical trials / 华中科技大学学报（医学）（英德文版）

The development and influencing factors of compliance behavior of investigators in clinical trials were explored. According to literature review, a hypothetical model of development of compliance behavior of investigators in clinical trials was established, and the influencing factors of compliance behavior of investigators and their interrelationships were studied based on questionnaire survey of five hundred investigators sampled randomly from one hundred clinical trial institutions in China. Cronbach's alpha coefficient and structural equation modeling were adopted to empirically analyze the results. Six variables in the hypothetical model were included: compliance behavior of investigators, credibility of clinical trial, capability of government regulation, quality control of sponsor, quality control of clinical institution and compliance intention of investigators. Empirical analysis showed that the compliance behavior of investigators in clinical trial was directly affected by compliance intention of investigators, quality control of sponsor and quality control of clinical institution. In addition, credibility of clinical trial and capability of government regulation indirectly affected the compliance behavior of investigators in clinical trial through influencing the compliance intention of investigators, quality control of sponsor and quality control of clinical institution. Quality control of sponsor was affected by credibility of clinical trial and capability of government regulation while quality control of clinical institution was only influenced by capability of government regulation.

Impact of continuous blood purification on T cell subsets in children with severe sepsis / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To investigate the impact of continuous blood purification (CBP) on T-cell subsets and prognosis in children with severe sepsis.</p><p><b>METHODS</b>A total of 42 children with severe sepsis were randomly divided into a control group (n=22) and a CBP group (n=20). The patients in the control group received conventional treatment, while those in the CBP group underwent continuous veno-venous hemofiltration daily 12-24 hours for 3 days besides conventional treatment. Changes in clinical variables and in peripheral blood regulatory T cell subsets were assessed 3 and 7 days after treatment.</p><p><b>RESULTS</b>The pediatric intensive care unit length of stay and duration of mechanical ventilation were significantly shortened and the 28-day mortality rate was significantly lower in the CPB treatment group as compared with the control group (P<0.05). In the CBP treatment group, the percentage of CD3(+), CD4(+), CD8(+) T cell populations and PCIS scores were significantly higher at 3 and 7 days after treatment than before treatment (P<0.05). At 7 days after treatment, the percentage of CD3(+), CD4(+), CD8(+) T cell populations, CD4(+)/CD8(+) ratio and PCIS scores were significantly higher in the CBP group than in the control group (P<0.05).</p><p><b>CONCLUSIONS</b>The CBP treatment may counteract the suppression of immune function and thus improve prognosis in children with severe sepsis.</p>

Influence of veneer application on failure behavior and reliability of lithium disilicate glass-ceramic molar crowns / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To evaluate the influence of veneer application on failure behavior and reliability of lithium disilicate glass-ceramic (LDG) crowns of maxillary first molar, and thus to reveal the failure mechanism of bilayered LDG crowns.</p><p><b>METHODS</b>Twenty-six LDG maxillary first molar crowns were fabricated in a dental laboratory using IPS e. max Press or IPS e. max Press/Ceram. The crowns were randomly assigned into two groups (with or without veneer application) with thirteen in each group. The crowns were cemented on composite resin dies. After storage in water for one week, the sliding-contact fatigue test was performed by sliding the steatite ceramic ball indenter (6 mm in diameter) from central fossa up to the lingual surface of disto-buccal cusp, cyclic loaded 1 200 000 times with a weight of 100 N at 2 Hz with a fatigue chewing simulator. Survived specimens were subjected to single-load-to-fracture testing using a steatite ceramic ball of 6 mm in diameter at a cross-head speed of 0.5 mm/min in a universal testing machine. Fracture load values were recorded and analyzed with t test. Weibull modulus was calculated to evaluate structure reliability. Fractographic analysis was carried out to determine fracture modes of the failed specimens by a stereomicroscope and a scanning electron microscope (SEM).</p><p><b>RESULTS</b>Statistical analysis results indicated a significant difference of the fracture load values between monolithic group [(2071.23 ± 397.05) N] and bilayered group [(1483.41 ± 327.87) N] (P < 0.001). Monolithic and bilayered groups present similar Weibull modulus (95% confidence interval) as 6.15 (5.15 ∼ 7.15) and 5.54 (4.01 ∼ 7.08) respectively, with no significant difference (the confidence bounds overlapped with each other). Bulk fracture initiating from the middle of oblique ridge of the first maxilla molar was the primary failure mode of monolithic/bilayered LDG crowns. Crack propagation initiated from core-veneer interfacial defects was another major failure mode of bilayered all-ceramic crowns.</p><p><b>CONCLUSIONS</b>Veneer application has some influence on fatigue failure of LDG crowns, but shows no effect on structure reliability. Accumulated damage combined with tensile stress concentration on the surface of veneer layer and defects within core-veneer interface lead to initiating of cracks. The mechanical property of veneering materials should be increased, and procedure of veneer application should be standardized and improved in order to reduce the failure rate of LDG molar crowns.</p>

Fractographic analysis of clinically failed anterior all ceramic crowns / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To identify the site of crack initiation and propagation path of clinically failed all ceramic crowns by fractographic analysis.</p><p><b>METHODS</b>Three clinically failed anterior IPS Empress II crowns and two anterior In-Ceram alumina crowns were retrieved. Fracture surfaces were examined using both optical stereo and scanning electron microscopy. Fractographic theory and fracture mechanics principles were applied to disclose the damage characteristics and fracture mode.</p><p><b>RESULTS</b>All the crowns failed by cohesive failure within the veneer on the labial surface. Critical crack originated at the incisal contact area and propagated gingivally. Porosity was found within the veneer because of slurry preparation and the sintering of veneer powder.</p><p><b>CONCLUSIONS</b>Cohesive failure within the veneer is the main failure mode of all ceramic crown. Veneer becomes vulnerable when flaws are present. To reduce the chances of chipping, multi-point occlusal contacts are recommended, and layering and sintering technique of veneering layer should also be improved.</p>

Effect of different porosities on mechanical properties and ion release of porous NiTi alloy / 医用生物力学

Objective To prepare the porous NiTi alloy with good biocompatibility for jaw bone implantation and compare the amount of the nickel ion release from NiTi alloy with TiO2 or HA coatings, respectively. Methods The porous NiTi samples were fabricated by powder metallurgy and the morphological characteristics were observed by metallographic microscope and X ray dispersive spectroscopy (XRD). The elastic modulus and fracture strength of the porous NiTi samples were recorded after the compression test. By sol-gel method, TiO2 or HA coatings were obtained on the porous NiTi samples, and the amount of nickel ion release from the samples was measured at 1，3，7，15 d, respectively. Results The pores were interconnected with the pore size of 50~200 μm and ~50 μm. The porosities of porous NiTi samples ranged from (23.5±5.24)% to (38.8±1.82)%, the elastic modulus from (9.55±0.19) GPa to (4.28±0.32) GPa, the fracture strength from (133±6.75) MPa to (80.5±5.58) MPa (P0.05). Conclusions The mechanical properties of porous NiTi alloy declined with the increase of pore-forming agent and porosity. Coating treatment could effectively inhibit the release of nickel ion from the porous NiTi alloy.

Correlation of hypoproteinemia with C-reactive protein and procalcitonin in children with sepsis / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To investigate the correlation of hypoproteinemia with inflammation parameters C-reactive protein (CRP), procalcitonin (PCT) and WBC in children with sepsis.</p><p><b>METHODS</b>Seventy-three children with sepsis (including 22 severe sepsis) and 40 non-sepsis children (control group) were enrolled. Serum albumin levels were measured on admission. Based on the level of serum albumin, 73 cases of sepsis were classified into three groups: mild hypoproteinemia, severe hypoproteinemia and normal albumin. Blood CRP, PCT and WBC levels were compared in the three groups. The correlation of CRP, PCT and WBC with serum albumin level was evaluated.</p><p><b>RESULTS</b>Serum albumin levels in the sepsis groups (severe or non-severe) were significantly lower than those in the control group (P<0.05), and the severe sepsis group showed more decreased albumin levels compared with the non-severe sepsis group (P<0.05). Blood CRP, PCT and WBC levels in the mild hypoproteinemia group were higher than those in the normal albumin group (P<0.05), and the severe hypoproteinemia group showed more increased blood CRP, PCT and WBC levels compared with the mild hypoproteinemia group (P<0.05). The incidence of multiple organ failure in the severe hypoproteinemia group was significantly higher than that in the normal albumin group (P<0.05). Serum albumin levels were negatively correlated with blood CRP, PCT and WBC levels.</p><p><b>CONCLUSIONS</b>Serum albumin levels decrease in children with sepsis, and the more serious the illness, the lower serum albumin levels, resulting in a worse prognosis. CRP, PCT and WBC are negatively correlated to serum albumin levels in children with sepsis.</p>

Effects of different die materials on fracture and failure behaviors of all-ceramic crowns / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the influence of different die materials on fracture strength and failure mode of IPS e.max Press crowns in mechanical test.</p><p><b>METHODS</b>Thirty-six IPS e.max Press crowns were divided into 3 groups. They were cemented to extracted maxillary first premolars in Group 1, to epoxy dies in Group 2, and to porous NiTi alloy dies in Group 3 respectively. All the crowns were subjected to compressive load in an universal mechanical testing machine. The maximum fracture strength(N) was recorded and fracture modes of the tested crowns were classified. Fractographies of the failed crowns were observed with a stereomicroscope.</p><p><b>RESULTS</b>Statistical analysis results showed that the mean fracture strength of the IPS e.max Press crowns on extracted natural teeth [(1159.7 +/- 256.0) N] and porous NiTi alloy dies [(1229.6 +/- 326.7) N] were obviously higher than that of epoxy dies [(883.5 +/- 198.1) N, P = 0.016 and 0.003]. Observations of the fractographies of failed crowns showed that the crowns on epoxy die fractured mesio-distally and no plastic deformation and characteristic cracks were observed. However, crowns in the other groups showed cone cracks at the contact area on occlusal surface and radical cracks initiated from the adhesive interfaces.</p><p><b>CONCLUSIONS</b>Die material has a significant influence on fracture resistance and fracture mode of the IPS e.max Press crowns. The crowns cemented to porous NiTi alloy dies show a similar fracture mode as those on extracted natural teeth.</p>

A comparative study of mechanical experiment and three-dimensional finite element analysis on fracture mode of all-ceramic molar crowns / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the influence of indenter diameter on fracture strength and fracture mode of IPS e. max all-ceramic crowns using mechanical experiments and three-dimensional finite element (3-DFE) method, to validate the 3-DFE model using mechanical experiments, and to provide a guideline for occlusal surface design for IPS e. max all-ceramic crowns.</p><p><b>METHODS</b>A 3-DFE model of an all-ceramic crown on a molar was established using ANSYS10.0 software. The 3-DFE crown was loaded occlusally at three points to simulate the contact points of a hemispherical indenter loading on the crown. Two indenter diameters (4 mm and 10 mm) were designed by changing loading point, load level and its direction. The stress distribution and the principal stress in the 3-DFE model were calculated. Meanwhile, IPS e. max ceramic crowns were made on a laboratory model and loaded with indenters. The diameters of the indenters were also 4 mm and 10 mm respectively. Fracture mode and fracture-resistance of the crowns were recorded.</p><p><b>RESULTS</b>The principal stress increased as load increases for both small and large indenters. Stress concentrated in the central fossa of the 3-DFE crown when loaded with the small indenter. Stress concentration appeared in the middle area of the occlusal surface mesio-distally when 3-DFE crown was loaded with large indenter. The fracture-resistance load was 600 N to 700 N for 4 mm diameter indenter, and 2500 N to 2750 N for 10 mm diameter indenter. Mechanical experiments indicated the same results as those from 3-DFE analysis.</p><p><b>CONCLUSIONS</b>Both the three-dimensional finite element analysis and the mechanical experiment showed the same results. When loaded with 4 mm diameter indenter, fracture occurred in the central fossa of the crown, however, 10 mm diameter indenter usually caused extensive crown damage.</p>

Effect of zirconia content on flexural strength and fracture toughness of dental zirconia toughened composite alumina ceramic / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To evaluate mechanical properties of zirconia toughened composite alumina (ZTCA) ceramic used for dental application, characterize the effect of different zirconia contents on mechanical properties of ZTCA.</p><p><b>METHODS</b>Dental alumina ceramic powder was prepared by sol-gel method, and four groups of ZTCA powders with different zirconia contents were prepared via surface-induced precipitation method. All five groups of powders were dry-pressed and then sintered to make standard specimens for mechanical tests. The flexural strength and fracture toughness of these specimens were evaluated, and the fractography was characterized by scanning electronic microscope (SEM). Phases of ZTCA were also determined using X-ray diffraction (XRD).</p><p><b>RESULTS</b>It was found that the flexural strength of ZTCA ceramics increases with ZrO2 content up to 30%, and decreases thereafter. ZTCA specimens containing 30% ZrO2 show the highest flexural strength, and the corresponding fracture toughness was 1.85 MPa x m(1/2). The XRD results of ZTCA ceramics showed the phase constituents of alpha-Al2O3, t-ZrO2 and a small amount of m-ZrO2.</p><p><b>CONCLUSION</b>The strengthening and toughening mechanisms of ZTCA depend on ZrO2 content. In the range of 15%-30% ZrO2, the stress-induced phase transformation toughening mechanism is dominant, while microcrack and deflection exist as the additional toughening mechanism when ZrO2 addition amount is above 30%.</p>