Objective The biomechanical performance of Ilizarov fixator models with different configurations for humeral shaft defect was compared,so as to provide a biomechanical basis for selecting the appropriate circular external fixation structure for the clinical treatment of humeral shaft defects using Ilizarov technology.Methods Based on CT data of the humerus from a healthy volunteer,the external fixators with three configurations,namely,hybrid frame,semi-ring frame and 90° fan frame were established.The finite element method was used to simulate the displacement and stress distribution under different loading conditions,and the finite element results were validated by biomechanical tests.Results Finite element analysis results:in terms of displacement,under compression,tensile and torque conditions,the displacement of 90° fan model was smaller than that of hybrid and semi-ring models.In terms of stress,the 90° fan model had the smallest displacement under tensile condition.In compression and torque tests,the semi-annular model had the lowest stress.Biomechanical test results:the semi-ring model exhibited the smallest displacement under axial compression,but there was no significant difference between the three models(P＞0.05).Conclusions The semi-ring and 90° fan frames can achieve a similar stability as the traditional hybrid frame through the strategy of'reducing the ring and increasing the stem'.The unilateral structure of the 90° fan frame has the advantages of small size,light weight,and structural stability,as well as a small impact on the shoulder and elbow joints,which makes it more valuable in clinical applications.

Objective The biomechanical performance of Ilizarov fixator models with different configurations for humeral shaft defect was compared,so as to provide a biomechanical basis for selecting the appropriate circular external fixation structure for the clinical treatment of humeral shaft defects using Ilizarov technology.Methods Based on CT data of the humerus from a healthy volunteer,the external fixators with three configurations,namely,hybrid frame,semi-ring frame and 90° fan frame were established.The finite element method was used to simulate the displacement and stress distribution under different loading conditions,and the finite element results were validated by biomechanical tests.Results Finite element analysis results:in terms of displacement,under compression,tensile and torque conditions,the displacement of 90° fan model was smaller than that of hybrid and semi-ring models.In terms of stress,the 90° fan model had the smallest displacement under tensile condition.In compression and torque tests,the semi-annular model had the lowest stress.Biomechanical test results:the semi-ring model exhibited the smallest displacement under axial compression,but there was no significant difference between the three models(P＞0.05).Conclusions The semi-ring and 90° fan frames can achieve a similar stability as the traditional hybrid frame through the strategy of'reducing the ring and increasing the stem'.The unilateral structure of the 90° fan frame has the advantages of small size,light weight,and structural stability,as well as a small impact on the shoulder and elbow joints,which makes it more valuable in clinical applications.

Pulmonary fluid refers to a thin and continuous liquid layer mainly consisting of airway mucus and lining liquid on the inner surface of alveoli, which is essential for maintaining a healthy lung. The clinical significance of rheological properties of pulmonary fluid in airway stability, pulmonary barrier and clearance functions, ventilator induced lung injury and surfactant replacement therapy in infant respiratory distress syndrome was introduced in this paper. Furthermore, a variety of classical methods for measuring surface tension and liquid viscosity, such as Langmuir-Wilhelmy balance, captive bubble method, glass capillary viscometer and rotational viscometer, and emerging techniques (e.g. particle tracking microrheometer and axisymmetric drop shape analysis) were reviewed, and their advantages and drawbacks were also compared, in order to provide an important reference for the assisted diagnosis and treatment of lung diseases in clinical practice.

Objective: To study the clinical value of serum cystatin C, neutrophil gelatinase-associated lipocalin (NGAL) and matrix metalloproteinase (MMP)-9/NGAL-1 measurements for early diagnosis of acute kidney injury (AKI) in patients with acute-on-chronic liver failure (ACLF). Methods: This study included 102 patients with hepatitis B virus related ACLF and 31 patients with chronic hepatitis B (CHB) were enrolled as controls. Biomarkers including serum cystatin C, NGAL and MMP-9/NGAL-1 were measured twice in the patients with ACLF at admission and at the time progressed to AKI and once in the controls. Results: In patients with ACLF, serum cystatin C levels was higher than that of the CHB control (t=3.609, P=0.000), whereas NGAL and MMP-9/NGAL-1 levels were lower in patients with ACLF than that of CHB controls (t=3.016, P=0.003; t=7.514, P=0.000, respectively). Thirty-three patients (32.4%) progressed to AKI during hospitalization period. In AKI group of the patients serum cystatin C levels was higher than that of non-AKI group of the patents (t=4.543, P=0.000). MMP-9/ NGAL-1 and NGAL levels were not different in patients with and without AKI (t=0.905, P=0.368; t=0.061, P=0.952). Serum cystatin C in patients with mild AKI (serum creatinine<1.5 mg/dl) and AKI serum creatinine>1.5 mg/dl were 33.59± 9.19 ng/ml and 43.32±9.02 ng/ml respectively. That was higher than that of non-AKI patients (27.94±7.93 ng/ml, P=0.022, 0.000, respectively). Serum cystatin C was the independent risk factors associated with development of AKI by a multivariate logistic regression in patients with ACLF. Conclusions Serum cystatin C measurement may contribute to more earlier diagnosis of AKI even in patients with S. creatinine<1.5 mg/dl. NGAL and MMP-9/NGAL-1 may be the biomarker of progress for ACLF.

NS2 is a nonstructural protein of Periplaneta fuliginosa densovirus(PfDNV) with a molecular mass of 30 kD,whose function is not yet clearly understood. In order to study the expression,subcellular distribution and the function of NS2 protein,the coding region of NS2 was amplified from the hindgut tissue of cockroaches infected with PfDNV by RT-PCR and then the recombinant prokaryotic expression vector pET28a-NS2 was constructed. The recombinant plasmid was transformed into E. coli BL21(DE3) to express the 6?His fusion protein in the bacteria. After purification,the fusion protein was injected into New Zealand rabbits to prepare polyclonal antibody. The specificity of the anti-NS2 antibody was successfullyproved by western blotting on the eukaryotic expressed products of NS2 protein.Meanwhile,the full sequence of ns2 gene was also cloned into the eukaryotic expression vector pAC. The recombinant plasmid pAC-NS2 was then transfected into Schneider line 2(S2) cells to express NS2 protein in the insect cells. The subcellular localization of NS2 in the insect cells was then investigated by indirect immunofluorescence technique using the anti-NS2 polyclonal antiserum. The confocal laser scanning microscope observation showed that NS2 protein was located primarily in the cytoplasm with some punctate nuclear staining.

The ultrastructural characteristics of the mouse mammary adenocarcinoma cell line (MA782/5S-8102) have been studied by transmission electron microscope. The results show that the cells were irregular in the shape, with abundant microvilli on cell surface. The nucleus was abnormal in shape with the nuclear membrane sunk or swollen, the nucleus/cytoplasmic ratio (N/C) was high. There were many free ribosomes, abundant mitochondrias, dilated rough endoplasmic reticulum in the cytoplasm. Golgi apparatus, lysosomes and lipid droplets were present. Moreover, many cytoplasmic type-A particles and a few immatural type-B particles at the surface of the cell were observed.