BACKGROUND:Silicon carbide-carbon (C/C-SiC) composite materials are widely used, but no relevant experimental studies on medical prosthesis materials have been reported.
OBJECTIVE: To demonstrate the feasibility of C/C-SiC composite materials as a substitute for facet joint prosthesis based on the biomechanical research and three-dimensional finite element analysis.
METHODS:The predetermined size C/C-SiC composites and traditional carbon/carbon(C/C) composite materials were placed in an electronic universal testing machine, to measure and calculate material compressive elastic modulus, compressive strength, maximal anticompression force, flexural modulus, bending strength and maximal antibending force. Afterwards friction coefficient, wear volume and weight wear rate were measured. Using three-dimensional finite element analysis, finite element models of the third metacarpal bone were defined as C/C and C/C-SiC composite element types, respectively. 200 N axial force was applied to analyze the total displacement and node stress.
RESULTS AND CONCLUSION:Compressive elastic modulus, compressive strength,maximal anticompression force, flexural modulus, bending strength and maximal antibending force of C/C-SiC composites were significantly higher than those of the C/C materials (P < 0.05); friction coefficient, wear volume, weight wear rate, total displacement as wel as node stress of C/C-SiC composites were significantly lower than those of C/C materials (P < 0.05). These results prove that C/C-SiC composite has favorable mechanical properties, antiwear ability, compression resistance and stress resistance.

Birth Weight ; Female ; Gastrointestinal Diseases ; etiology ; therapy ; Gestational Age ; Humans ; Infant, Newborn ; Male

Objective To explore the clinical application and outlook of anterior segment observation with Stratus optical coherence tomography(Stratus OCT).Design Prospective case series.Participants 56 eyes in 38 patients with primary angle closure glaucoma (PACG).Methods Morphological changes of anterior chamber angle (ACA) were observed with Stratus OCT before and 4 weeks after laser iridectomy.Opening status of ACA were described and measured with Photoshop software.Main Outcome Measures Opening degree of ACA and ratio of anterior chamber depth to thickness of cornea.Results To a great deal of extent,Stratus OCT could be used to observe the appearance of ACA. Clear images of ACA could be acquired.The ACA before laser was (15.67?5.33) degree and significantly reopened to(26.56?8.17) degree after laser iridectomy (P=0.000).The ratio of anterior chamber depth to thickness of cornea was also changed from (0.39?0.13) pre-treatment to (0.89?0.32) pest-treatment(P=0.000).Conclusions Stratus OCT could be applied to observe the changes of opening degree of ACA easily.The standard of quantization should be consummated in the future.

High performance liquid chromatography-time-off-flight mass spectrometer (HPLC-TOFMS) technology coupled with partial least squares discriminant analysis (PLS-DA) processed by SIMCA-P software was applied to investigate serum endogenous metabolites alternations of valsartan in spontaneous hypertension rats (SHR). And MetPA platform was used to connect identified potential biomarkers in corresponding metabolic pathways to find possible therapeutic mechanism of valsartan. Valsartan significantly declined the blood pressure of SHRs (P < 0.05) at fourth week. The metabolic profiling significantly changed and four metabolites involved in G protein-coupled pathway were identified. Metabolomics is able to detect holistic and microcosmic alternations in organism, so as to elucidate therapeutic mechanism of drugs.
Animals ; Biomarkers ; blood ; Blood Pressure ; Chromatography, High Pressure Liquid ; Discriminant Analysis ; Least-Squares Analysis ; Mass Spectrometry ; Metabolome ; Metabolomics ; Rats ; Rats, Inbred SHR ; Valsartan ; pharmacology

ObjectiveTo observe the effects of Jiuqiang Naoliqing(JNQ) on the microcirculation of the cheek pouch of golden hamsters. MethodsAutomatic measuring device was used to evaluate the changes of microcirculation. ResultsAfter the disorder of microcirculation of cheek pouch made by noradrenaline(NA), the JNQ group recovered better and more rapidly than other groups. ConclusionJNQ can prevent and reverse the disorder of microcirculation made by NA, and do better than NQ.

Objective To investigate the epidemiological characteristics of incipient neonatal hyperbilirubinemia. Methods The clinical data of admitted neonates with hyperbilirubinemia were retrospectively analyzed from June 2012 to May 2013. Results Two hundred and eight-four neonates with hyperbilirubinemia were enrolled and the ratio of male:female was 1.51:1. For the causes of hyperbilirubinemia, the incidences of ABO hemolytic and sepsis were higher in term infants than those in preterm infants, and the incidences of pneumonia, necrotizing enterocolitis and intracranial hemorrhage were higher in preterm infants than those in term infants (P<0.05). Compared with the preterm infants, the term infants had jaundice appearance and peak at earlier time, shorter duration of jaundice, faster decline rate of jaundice, higher levels of albumin and indirect bilirubin at the peak of jaundice (P<0.01). In the term infants, the time of jaundice appearance and peak were earlier in hemolytic group than those in non-hemolytic group (P<0.05). In preterm infants, the peak of transcutaneous bilirubin was higher in hemolytic group than that in non-hemolytic group (P<0.05). Six cases with bilirubin encephalopathy had abnormalities cranial MRI imaging, and the MRI was not entirely consistent with the peak level of bilirubin. Conclusions There are clinical differences between hemolytic and non-hemolytic hyperbilirubinemia in both term and preterm infants.

Thirty SHRs were obtained randomly to hypertension, model group, captopril group and Qingre jiangya capsule group. Ten Wistar rats were used as control group. The hippocampus tissue was removed to explore the damage of spontaneously hypertensive rats (SHR) and the protective effect of Qingre jiangya capsule after continuously administered for 14 days. And then the data were processed by principal component analysis (PCA) and partial least squares discriminant analysis (PLS-DA). The research results revealed captopril group was significantly different from the other three groups. The classification of other three groups is also very clear after captopril group removed. This suggested that Qingre jiangya capsule could improve the overall metabolism compared with captopril. Four metabolites were identified: dimethylglycine, glycerophosphocholine, aldosterone and noradrenaline. Hypertension hippocampus damage may mainly be expressed in tyrosine metabolism, aldosterone-regulated sodium, vascular smooth muscle contraction reabsorption, and Qingre jiangya capsule could reverse the hippocampus tissue damage of SHR.
Animals ; Capsules ; pharmacology ; Drugs, Chinese Herbal ; pharmacology ; Hippocampus ; drug effects ; Hypertension ; drug therapy ; Male ; Rats ; Rats, Inbred SHR ; Rats, Wistar

Adult ; Foot Diseases ; diagnostic imaging ; Humans ; Male ; Melorheostosis ; diagnostic imaging ; Radiography ; X-Rays

The purity of 4,4′-dimethoxy-5,6,5′,6′-bis (methylenedioxy)-2′-morpholine methylenebiphenyl-2-methyl formate methanesulfonate (IMH), a new drug for fatty liver treatment, was determined through differential scanning calorimetry (DSC). Analysis of two-factor non repeatability method was performed in the investigation the effects of two factors (heating rate and sample weight) on purity determination. The DSC experimental parameters were optimized as follows: heating rate was 10 ℃·min^-1, temperature range was 150-300 ℃, sample weight was 2.0-4.1 mg, and N₂ flow rate was 80 mL·min^-1. The linear correlation coefficient (r) of this DSC method was 0.999 8. The RSD value (n = 6) of precision was 0.03%. The standard value and uncertainty of the purity results of the multiple batches of IMH drugs were (99.74 ± 0.29)%, (99.91 ± 0.28)%, (99.90 ± 0.28)%, and (99.81 ± 0.28)% with inclusion factor (K) of 2 and confidence probability (P) of 0.95. The results were basically consistent with the results of the mass balance method. The DSC mehod is a simple, rapid and accurate method, and provides a new reference method for determining the purity of IMH drugs, improves the accuracy and reliability of purity determination.

AIM: To investigate the expression of EMMPRIN, MMP1, MMP9 and TIMP2 in retinoblastoma (RB) and normal retinal tissues and their clinicopathological significance and interrelationship.METHODS: Envision immunohistochemistry stainings of EMMPRIN, MMP1, MMP9 and TIMP2 were performed in 30 enucleated eyeballs with retinoblastoma and 15 specimens of normal retina tissue, which had been routinely imbedded with paraffin.RESULTS: Positive rate of EMMPRIN, MMP1, MMP9 expression was higher in RB tissue than in normal control (P<0.01), while TIMP2 expression was lower in RB than in normal retinal tissue (P<0.01). Samples from RB cases of clinical stage Ⅰ, differentiated type, and life span≥2 years had lower positive rate in expression of EMMPRIN, MMP1, MMP9 than those from RB cases of clinical stage Ⅲ, undifferentiated type, and life span<2 years (P<0.05 or P<0.01), while samples from RB cases of differentiated type, optic nerve unaffected, and life span≥2 years had markedly higher positive rate in expression of TIMP2 than those from RB cases of undifferentiated type, optic nerve involved and life span<2 years (P<0.05 or P<0.01). In RB tissues, EMMPRIN, MMP1, MMP9 expressions were highly consistent (P<0.05), whereas TIMP2 expression is highly inconsistent with EMMPRIN, MMP1, MMP9 expression levels (P<0.05).CONCLUSION: The expression level of EMMPRIN, MMP1, MMP9 and TIMP2 may be an important marker of RB progression, invasion and prognosis. There exist internally mutual regulation relations among them.