Carbon/carbon composites have excellent biocompatibility with human hard tissue and elasticity modulus similar with that of human bones, which endow them great potential applications in substitution for human loaded bones. The current research situations and applications of carbon/carbon composites in human loaded bones are reviewed. The coating technologies of bioactive layers on carbon/carbon composites are discussed. The problems to be solved and the prospects of carbon/carbon composites in human loaded bones are analyzed and predicted. It is believed that bioactive layers coating on carbon/carbon composites should play an important role in human loaded bones.
Biocompatible Materials ; chemistry ; Bone Substitutes ; chemistry ; Bone and Bones ; physiology ; Carbon ; chemistry ; Coated Materials, Biocompatible ; chemistry ; Composite Resins ; Durapatite ; chemistry ; Humans ; Stress, Mechanical ; Tensile Strength

Objective To observe the dynamic changes of myocardial structure and dysfunction during post-resuscitation period in order to establish a rat mode of post-resuscitation myocardial dysfunction after cardiac arrest resulted from electric stimulation-induced ventricular fibrillation (VF) and cardiopulmonary resuscitation (CPR).Methods A total of 40 male Sprague-Dawley (SD) rats were randomly (random number) assigned into post-resuscitation (PR) 4 h,PR 12 h,PR 24 h,PR 72 h and sham groups.VF was induced by an alternating electric current delivered to the right ventricular endocardium and untreated for 8 min.Biphasic waveform defibrillation was attempted and mechanical ventilation was synchronized after 6 min of CPR.Myocardial function was assessed with serum myocardial enzyme activity,echocardiography,mitochondrial respiratory function and histopathologic findings at different intervals.Results Thirty-two animals were successfully resuscitated with restoration of spontaneous circulation (ROSC) in 86％ (32/37) rats.Compared with sham group,severe systolic and diastolic heart failure were found at 4 h after ROSC and then gradually improved without significant difference (P ＞0.05) in ejection fraction at PR 72 h after ROSC was found,whereas thickened ventricular wall and increased myocardial performance index as well as interstitial proliferation were observed at 72 h after ROSC.Conclusions A rat model of post-resuscitation myocardial dysfunction after cardiac arrest resulted from electric stimulation-induced VF and CPR was successfully established.

Objective To determine the influence of continuous mild sedation versus usual sedation on the sedative effect and inflammatory factor level in ICU patients with multiple trauma.Methods In this prospective, randomized double-blind investigation, 58 multiple trauma patients hospitalized from October 2013 to April 2015 were randomized into continuous mild sedation group (continuous group, n =30) and conventional sedation group (conventional group, n =28) using the sealed envelopes.Between-group differences were made on the duration of mechanical ventilation, length of stay in the ICU, ratio of inception of continuous renal replacement therapy (CRRT), tracheotomy rate, accidental extubation rate, sepsis rate, multiple organ failure (MOF) rate and mortality.Serum inflammatory factor levels of the patients were recorded.Results There were 3 deaths (10％) in continuous group versus 4 deaths (14％) in conventional group (P ＞ 0.05).Patients in continuous group showed significantly less time spent on mechanical ventilation [(4.8 ±2.7) vs.(8.9 ±3.1)d] and in the ICU [(10.7 ± 5.4) vs.(16.9 ± 7.3) d] compared with conventional group (P ＜ 0.01).Between-group differences were insignificant regarding the ratio of CRRT inception, tracheotomy rate, accidental extubation rate, sepsis rate and MOF rate (P ＞ 0.05).Serum levels of interleukin (IL)-6, tumor necrosis factor (TNF)-α, Creactive protein (CRP) were lower in continuous group than those in conventional group at 24 h, 48 h and 72 h post-ICU, but significant differences were only observed at 48 h (P ＜ 0.05).At these time periods, serum IL-10 levels in continuous group were significantly higher than those in conventional group (P ＜0.05).In receiver operative characteristic curve (ROC) analysis, the area under the curve for IL-6, IL-10, TNF-α and CRP in continuous group was 0.726, 0.608, 0.729 and 0.757 respectively at 48 h post-ICU, indicating a predictive value of these markers for sepsis.Conclusion Continuous mild sedation results in shortened length of stay in the ICU and decreased inflammatory response in the treatment of patients with multiple trauma.

A simple plasma spraying method was employed in coating hydroxyapaptite (HA) on to carbon/carbon composites (C/C composites). The morphology of the coating was examined under scanning electron microscope (SEM). The phase constitutions of the HA coating were determined by X-ray diffractometer (XRD). The shear strength of the HA coating-C/C composite substrates was detected. A hydroxyapatite coating with rough surface was observed. A considerable amount of amorphous phase appeared as a result from the coating process, which could be transformed into the morphous phase crystalline HA after subsequent heat treatment. The shear strength between the HA coating and C/C composite substrates was 7.15 MPa.
Bone Substitutes ; chemistry ; Carbon ; chemistry ; Carbon Compounds, Inorganic ; chemistry ; Coated Materials, Biocompatible ; chemistry ; Durapatite ; pharmacology ; Humans

Objective To investigate the clinical therapeutic value of CRRT on severe sepsis coincidence with capillary leak syndrome in surgical patients. Methods 38 patients suffering from severe sepsis coincidence with capillary leak syndrome were random divided into routine group ( n = 18 ) and CRRT group ( n =20). Both groups were given routine treatment, while the patients of CRRT group were given CRRT in addition. Red blood cell count (RBC), haematoglobin level, blood platelets count, leukocyte count, hematocrit (HCT), plasma-albumin level, central venous pressure ( CVP), arterial blood pressure ( ABP), urinary production change of every hour, oxygenation index condition ( PO2\FiO2 ) were measured at 0, 12, 24, 48,72 hour following routine treatment or CRRT. Additionally, serum levels of tumor necrosis factor- a (TNF-α), interleukin-6 (IL-6) and interleukin-8(IL-8) were determined at the same time. Results Blood platelets count, HCT, plasma-albumin level in CRRT group were significantly higher than those of routine group [72 h: (211. 75 ± 45. 23 ) × 109 vs ( 135.67 ± 41.45 ) × 109 ;0. 43 ± 0. 05 vs 0. 35 ±0. 04; (48. 60 ±4. 76) g/L vs (41.17 ±4. 64) g/L, P <0. 01 ]. WBC were significantly lower than those of routine group[72 h:(7.58 ±2.31) ×109 vs (13.77 ±2.67) × 109, P <0.01]. Change of ABP, PO2\FiO2, urinary production for every hour was notably increased than those of routine group [72 h: (94. 25 ±8.60) mmHg vs ( 84. 22 ± 7. 37 ) mmHg; 345. 25 ± 35. 21 vs 304. 22 ± 38. 74; ( 80. 15 ± 14. 54 ) ml vs (62. 72 ± 12. 33) ml, P <0. 01 ]. The serum levels of TNF-α, IL-6 and IL-8 of CRRT group were markedly decreased compared with those of routine group(72 h:249. 55 ±99. 60 vs 368. 83 ±97. 11 ;600. 75 ±98. 31 vs 718. 94 ± 92. 00 ;665. 35 ±138. 44 vs 843. 22 ±123. 95 , P <0. 01,P <0.05). Conclusions CRRT can significantly improve patient's condition, which may be an effective nechanism to treat the surgical patients with severe sepsis coincidence with capillary leak syndrome.

Objective To determine the effect of calmodulin-dependent kinase Ⅱ (CaMK Ⅱ ) -ryanodinereceptor pathway signaling in rabbits with left ventricular bypertrophy (LVH) and triggered ventricular arrhythmia.Methods Forty New Zealand rabbits were randomized into four groups ( n =10 per group):the sham operation group,LVH group,KN-93 (CaMKⅡ inhibitor) group (LVH + KN-93),and the ryanodinegroup ( LVH + ryanodine).Rabbits in the LVH,KN-93,and ryanodinegroups were used to establish a left ventricular hypertrophy model by the coarctation of the abdominal aorta,while the rabbits in the sham operation group did not have the coarctation.After eight weeks,action potentials (APs) were recorded simultaneously in the endocardium and epicardium,and transmural electrocardiogram (ECG) was also recorded in the wedge shaped models of rabbits' left ventricular myocardium.Drugs were administered to animals in the KN-93 and ryanodinegroups respectively,and the frequency of triggered APs and ventricular tachycardia were recorded after isoprenaline ( 1 μmol/L),and high-frequency electrical stimulation were given to rabbits.Results The incidences (animals/group) of triggered APs were:sham,0/10 ; LVH,10/10; KN-93,4/10; and ryanodine,1/10.The incidences of ventricular tachycardia induced were 0/10,9/10,3/10,and 1/10,respectively.The incidences of triggered ventricular arrhythmias in the KN-93 group and ryanodine groups tachycardia or ventricular fibrillation were 0/10,7/10,2/10,and 1/10,respectively.The incidences of triggered ventricular arrhythmias in the KN-93 group and ryanodine groups were much lower than that in the LVH group (P ＜ 0.05).Conclusions KN-93 and ryanodinecan effectively reduce the occurrence of triggered ventricular arrhythmia in rabbits with LVH.The CaMK Ⅱ-ryanodine signaling pathway can be used as a novel target site of treating ventricular arrhythmia.

Porous hydroxylapatite (HA) has excellent osseous inductive ability. It has been prepared by gel-casting process, which is feasible and can make complex ceramic material. According to the result of orthogonal test based on the compressive strength, the order and the level of the factors, including monomer HA, initiator MBAM, catalyst APS and water, were dealt with. The effects of drying and sintering technique on the properties of porous hydroxylapatite were also researched. The results showed that the order of every factor in the gel-casting process is as follows, AM-APS, MBAM, H2O. Based on the determined level of each factor, the suitable slurry constituents and drying and sintering technologies were selected, and the porous hydroxylapatite with compressive strength of 6-7 MPa was produced.
Biocompatible Materials ; chemistry ; Bone Substitutes ; chemistry ; Compressive Strength ; Durapatite ; chemical synthesis ; chemistry ; Gels ; Humans ; Materials Testing ; methods ; Porosity ; Surface Properties