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1.
Article in Chinese | WPRIM | ID: wpr-879831

ABSTRACT

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.


Subject(s)
Adsorption , Child , Humans , Liver Failure, Acute/therapy , Plasma , Plasma Exchange , Prospective Studies
2.
Article in Chinese | WPRIM | ID: wpr-828727

ABSTRACT

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.


Subject(s)
Adenoviridae , Bronchitis , Female , Fever , Humans , Infant , Male , Pneumonia, Viral , Retrospective Studies
3.
Article in Chinese | WPRIM | ID: wpr-774040

ABSTRACT

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.


Subject(s)
Child , Dexmedetomidine , Humans , Hypnotics and Sedatives , Prospective Studies , Respiration, Artificial , Ventilator Weaning
4.
Article in Chinese | WPRIM | ID: wpr-706565

ABSTRACT

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.

5.
Article in Chinese | WPRIM | ID: wpr-279944

ABSTRACT

<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>


Subject(s)
Calcitonin , Blood , Calcitonin Gene-Related Peptide , Case-Control Studies , Child, Preschool , Female , Humans , Infant , Infant, Newborn , Lithostathine , Blood , Male , Prognosis , Prospective Studies , Protein Precursors , Blood , Sepsis , Blood , Severity of Illness Index
6.
Article in English | WPRIM | ID: wpr-636706

ABSTRACT

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.

7.
Article in English | WPRIM | ID: wpr-636607

ABSTRACT

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.

8.
Article in English | WPRIM | ID: wpr-351082

ABSTRACT

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.


Subject(s)
China , Clinical Trials as Topic , Humans , Quality Control , Research Personnel , Surveys and Questionnaires
9.
Article in English | WPRIM | ID: wpr-351055

ABSTRACT

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.


Subject(s)
Adult , Alanine Transaminase , Metabolism , Antitubercular Agents , Therapeutic Uses , Asian Continental Ancestry Group , Aspartate Aminotransferases , Metabolism , Bilirubin , Chemical and Drug Induced Liver Injury , China , Evidence-Based Medicine , Female , Glucuronates , Therapeutic Uses , Glutathione , Therapeutic Uses , Humans , Liver , Pathology , Liver Function Tests , Male , Medicine, Chinese Traditional , Middle Aged , Treatment Outcome , Tuberculosis, Pulmonary , Drug Therapy , Ethnology
10.
Article in Chinese | WPRIM | ID: wpr-269510

ABSTRACT

<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>


Subject(s)
CD4-CD8 Ratio , Child, Preschool , Female , Hemofiltration , Humans , Male , Sepsis , Allergy and Immunology , Therapeutics , T-Lymphocyte Subsets , Allergy and Immunology
11.
Article in Chinese | WPRIM | ID: wpr-260169

ABSTRACT

<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>


Subject(s)
Crowns , Dental Porcelain , Chemistry , Dental Restoration Failure , Materials Testing , Molar
12.
Chinese Journal of Stomatology ; (12): 225-228, 2012.
Article in Chinese | WPRIM | ID: wpr-281626

ABSTRACT

<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>


Subject(s)
Ceramics , Crowns , Dental Porcelain , Dental Restoration Failure , Dental Veneers , Equipment Failure Analysis , Humans , Microscopy, Electron, Scanning , Porosity
13.
Journal of Medical Biomechanics ; (6): E349-E354, 2011.
Article in Chinese | WPRIM | ID: wpr-804161

ABSTRACT

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.

14.
Article in Chinese | WPRIM | ID: wpr-286961

ABSTRACT

<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>


Subject(s)
C-Reactive Protein , Calcitonin , Blood , Calcitonin Gene-Related Peptide , Child , Child, Preschool , Female , Humans , Infant , Leukocyte Count , Male , Protein Precursors , Blood , Sepsis , Blood , Serum Albumin
15.
Chinese Journal of Stomatology ; (12): 483-487, 2009.
Article in Chinese | WPRIM | ID: wpr-274546

ABSTRACT

<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>


Subject(s)
Bicuspid , Ceramics , Crowns , Dental Porcelain , Dental Restoration Failure , Dental Stress Analysis , Methods , Materials Testing , Maxilla , Nickel , Resin Cements , Titanium
16.
Chinese Journal of Stomatology ; (12): 680-683, 2008.
Article in Chinese | WPRIM | ID: wpr-250971

ABSTRACT

<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>


Subject(s)
Ceramics , Dental Porcelain , Dental Stress Analysis , Finite Element Analysis , Materials Testing , Stress, Mechanical
17.
Article in Chinese | WPRIM | ID: wpr-348098

ABSTRACT

<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>


Subject(s)
Aluminum Oxide , Ceramics , Dental Porcelain , Materials Testing , Zirconium
18.
Chinese Journal of Hepatology ; (12): 370-373, 2005.
Article in Chinese | WPRIM | ID: wpr-349108

ABSTRACT

<p><b>OBJECTIVE</b>To evaluate the clinical efficacy and study the mechanism of combining plasma exchange and continuous veno-venous hemofiltration in treating patients with chronic severe viral hepatitis B in their mid- and late stages.</p><p><b>METHODS</b>94 patients suffering from chronic severe viral hepatitis B were divided into three groups. 29 patients were treated with plasma exchange plus continuous veno-venous hemofiltration (group A). 31 patients were treated with plasma exchange alone (group B). 34 patients received routine treatment (group C). The efficacy of treatment and survival rate of the three groups was investigated. Before and after artificial liver support system treatment the levels of cytokine were examined.</p><p><b>RESULTS</b>In group A, hyponatremia improved, the levels of interleukin 8 (IL-8) obviously decreased, the level of IL-10 increased, 5 of the 10 patients in coma regained normal consciousness (50.0%) and their survival rate was 48.3%. In group B, hyponatremia did not change, the level of IL-8 and IL-10 did not change. 2 of 11 patients in coma regained normal consciousness (18.2%) while survival rate was 22.6%. In group C, 1 of 11 patients in coma regained normal consciousness (9.1%) while survival rate was 20.6%.</p><p><b>CONCLUSIONS</b>It shows that plasma exchange with continuous veno-venous hemofiltration in treating patients with mid- and late stage chronic severe viral hepatitis B can increase the survival rate. IL-8 can be significantly removed, IL-10 significantly increased. This combined therapy is easy to practice, and should be used as an artificial liver support system.</p>


Subject(s)
Adult , Female , Hemofiltration , Hepatitis B, Chronic , Therapeutics , Humans , Interleukin-10 , Blood , Interleukin-8 , Blood , Liver, Artificial , Male , Middle Aged , Plasma Exchange , Severity of Illness Index , Treatment Outcome
19.
Chinese Journal of Biotechnology ; (12): 725-729, 2004.
Article in Chinese | WPRIM | ID: wpr-249946

ABSTRACT

It was constructed that a genomic DNA library from Lactobacillus sp. MD-1 yielding D, L-lactic acid. The gene encoding L-lactate dehydrogenase (L-LDH) was cloned from the genomic library of strain MD-1 by complementation in E. coli FMJ144 which was lactate dehydrogenase and pyruvate-formate lyase double defective mutant. The nucleotide sequence of the ldhL gene predicted a protein of 316 amino acid starting with ATG. The putative molecular weight of the L-LDH amino acid sequence was 33.84kD. A putative typical promoter (-35 and -10 boxes) had been observed in the 5' noncoding region. An rho-independent transcriptional terminator has been observed in the 3' noncoding region. Three highly conserved regions (Gly13 approximately Asp50, Asp73 approximately Ileul00 and Asn123 approximately Arg154) with several conserved residues had been identified. Gly13 approximately Asp50 was NADH-binding site domain. Asp73 approximately Ileu100 and Asn123 approximately Arg154 were reported to be the active site domains. The ldhL and the L-LDH of Lactobacillus sp. MD-1 showed the low identity and similarity with other Lactobacilli, and the highest percentage were 61.9% and 68.9% respectively. All the above indicated this gene is a novel ldhL.


Subject(s)
Amino Acid Sequence , Base Sequence , Cloning, Molecular , L-Lactate Dehydrogenase , Chemistry , Genetics , Physiology , Lactobacillus , Genetics , Molecular Sequence Data
20.
Article in Chinese | WPRIM | ID: wpr-279575

ABSTRACT

<p><b>BACKGROUND</b>To develop a capturing-ELISA for the detection of anti-HCMV-IgM antibody in serum.</p><p><b>METHODS</b>The anti-HCMV-IgM antibody was detected in 68 patients with HCMV infection by the capturing-ELISA, and the results were compared with those of indirect ELISA.</p><p><b>RESULTS</b>The specificity and sensitivity of the capturing-ELISA were shown to be significantly higher than those of indirect ELISA, and its results were not affected by RF factor.</p><p><b>CONCLUSION</b>The capturing ELISA is specific, sensitive, convenient and reliable method which may be feasible for clinical use.</p>


Subject(s)
Antibodies, Viral , Blood , Cytomegalovirus , Allergy and Immunology , Cytomegalovirus Infections , Allergy and Immunology , Virology , Enzyme-Linked Immunosorbent Assay , Methods , Humans , Immunoglobulin M , Blood
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