Objective To explore the characteristics of fluid flow within loaded osteons under different boundary conditions.Methods The COMSOL Multiphysics software was used to establish a three-dimensional(3D)finite element model of osteons with different boundary conditions,and the variation rules of pore pressure and flow velocity of osteons under different inner wall pulsating blood pressures and outer wall elastic constraint conditions were analyzed.Results As the pulsatile blood pressure inside the osteon increased from 0 mmHg(1 mmHg=0.133 kPa)to 300 mmHg,the peak pore pressure within the osteon correspondingly increased from 26 kPa to 68 kPa.As the elastic constraint on the outer wall of osteons changed from being completely elastic to completely constrained,the peak pore pressure within osteons increased from 15 kPa to 26 kPa,and the peak flow velocity increased from 0.04 um/s to 0.07 um/s.Conclusions This study reveals the influence laws of changes in boundary conditions such as the pulsatile blood pressure on the inner wall and the elastic constraint on the outer wall of osteons on fluid flow characteristics within loaded osteons.These findings are conducive to a deeper understanding of the mechanical response mechanisms of bone tissues in both physiological and pathological states,and provide an important theoretical basrs for further researches on bone mechanotransduction.

The visual crowding effect refers to the phenomenon that the observers' ability to identify the target object significantly decreases when it is flanked by surrounding objects.A variety of ophthalmic diseases,including amblyopia,strabismus,glaucoma,macular degeneration and nystagmus,involve structural or functional abnormalities in different parts of the visual system.These abnormalities will exacerbate the visual crowding effect,thereby impairing the ability in multi-line visual identification,reading and other daily visual activities of patients.Since intervention on visual crowding can im-prove patients' ability to process complex visual information,optimize the use of residual vision and improve prognosis,it is of great clinical value to develop targeted intervention methods.This article systematically reviews the characteristics of visual crowding in patients with oculopathy and its impact on functional vision,and summarizes the current intervention strategies,in order to provide theoretical basis and practical guidance for future clinical practice.

The visual crowding effect refers to the phenomenon that the observers' ability to identify the target object significantly decreases when it is flanked by surrounding objects.A variety of ophthalmic diseases,including amblyopia,strabismus,glaucoma,macular degeneration and nystagmus,involve structural or functional abnormalities in different parts of the visual system.These abnormalities will exacerbate the visual crowding effect,thereby impairing the ability in multi-line visual identification,reading and other daily visual activities of patients.Since intervention on visual crowding can im-prove patients' ability to process complex visual information,optimize the use of residual vision and improve prognosis,it is of great clinical value to develop targeted intervention methods.This article systematically reviews the characteristics of visual crowding in patients with oculopathy and its impact on functional vision,and summarizes the current intervention strategies,in order to provide theoretical basis and practical guidance for future clinical practice.

Objective To explore the characteristics of fluid flow within loaded osteons under different boundary conditions.Methods The COMSOL Multiphysics software was used to establish a three-dimensional(3D)finite element model of osteons with different boundary conditions,and the variation rules of pore pressure and flow velocity of osteons under different inner wall pulsating blood pressures and outer wall elastic constraint conditions were analyzed.Results As the pulsatile blood pressure inside the osteon increased from 0 mmHg(1 mmHg=0.133 kPa)to 300 mmHg,the peak pore pressure within the osteon correspondingly increased from 26 kPa to 68 kPa.As the elastic constraint on the outer wall of osteons changed from being completely elastic to completely constrained,the peak pore pressure within osteons increased from 15 kPa to 26 kPa,and the peak flow velocity increased from 0.04 um/s to 0.07 um/s.Conclusions This study reveals the influence laws of changes in boundary conditions such as the pulsatile blood pressure on the inner wall and the elastic constraint on the outer wall of osteons on fluid flow characteristics within loaded osteons.These findings are conducive to a deeper understanding of the mechanical response mechanisms of bone tissues in both physiological and pathological states,and provide an important theoretical basrs for further researches on bone mechanotransduction.

Objective To investigate the conduction behavior of fluid flow induced by physiological loads at different scales of bone. Method sThe multiscale bone models were established by using the COMSOL Multiphysics software, and the fluid behaviors were investigated at macro-, meso- and micro-scale. Results At macro-meso scale，the distribution of pore pressure and fluid velocity of osteon near the periosteum and endoosteum were different from that in other parts. Due to the different structure and material parameters at different layers, the loading and fluid pressure caused different biomechanical responses in the process of transferring from macro-scale to micro-scale. Conclusions The multi-scale layered modeling of bone structure-osteon-lacunae-bone canaliculi was established, which provided the theoretical reference for deeper understanding of fluid stimulation and mechanotransduction.

Subglottic pleomorphic adenoma is a rare disease . Surgery is the main curative treatment. To review some clinical cases and to summarize the characteristics and treatment experience of this disease,it is expected that we can provide more clinical thought and therapeutic strategy for subglottic pleomorphic adenoma.
Adenoma, Pleomorphic ; therapy ; Humans ; Hypothermia, Induced ; Rare Diseases

BACKGROUNDTo elucidate relationship between amino acid sequence of non-structural protein 5A (NS5A) and outcome of HCV (1 b) patients after interferon (IFNa) therapy.

METHODSSera of 24 patients were collected before, during and after IFNa therapy. Pretreatment RNA levels and the sequences of HCV NS5A interferon sensitivity determining region (ISDR) were determined. NS5A full-length sequences of 5 HCV isolates from 3 patients with different response types were also analyzed. Phylogenetic tree analysis and protein secondary structure prediction were undertaken.

RESULTSPretreatment RNA levels of sustained response group were significantly lower than that of non-response group and relapse group (4.50X104 copies/ml versus 1.82X107 copies/ml, P < 0.01).ISDR sequences of NS5A from pretreatment sera were compared with HCV-J strain (prototype). Thirteen of 24 isolates were wild type,11 of 24 were intermediate type and none of them was mutant type. 3 of 6 sustained responders were infected with wild-type isolates, the rest with intermediate type isolates. Phylogenetic tree based on NS5A full-length sequences classified 5 isolates with 3 different response types into 3 groups. Non-response isolates belonged to the same group as HCV-J. Secondary structure prediction of 5 isolates revealed significant differences existing in 2 255- 2 289. This region was partly overlapped with PKR-binding domain.

CONCLUSIONSLow HCV RNA levels in serum are associated with favorable outcome of IFNa therapy. ISDR sequence alone could not predict outcome of IFN treatment. Combination of determination of HCV RNA levels in serum with sequence analysis of PKR-binding domain may be helpful in predicting the efficacy of IFN therapy.

Amino Acid Sequence ; Antiviral Agents ; therapeutic use ; Hepacivirus ; drug effects ; genetics ; Hepatitis C, Chronic ; drug therapy ; virology ; Humans ; Interferon-alpha ; therapeutic use ; RNA, Viral ; blood ; Viral Nonstructural Proteins ; genetics

Objective To study the correlation of replication efficiency and antigen expression of hepatitis B virus (HBV) strains in patient sera and transfected cells. Methods Quantification of five maternal serum HBV DNA was carried out using dot hybridization and polymerase chain reaction-enzyme linked immunosorbent assay (PCR-ELISA), hepatitis B surface antigen (HBsAg) and hepatitis B e antigen (HBeAg) levels in the sera were determined by ELISA. Full-length genomes of HBV strains cloned from five pregnant women were separately used to transfect HepG2 cells. The levels of HBsAg and HBeAg in the supernatant of transfected cells were determined with Abbott EIA kits, the replication efficiency of intracelluar replicative intermediates and extracellular HBV DNA of viral particles was analyzed by Southern blot and hybridization. Results Intracellular and extracellular HBV replication and antigen expression of cloned HBV strains showed positive correlation tendency with the HBV DNA and antigen levels in serum samples. Conclusions Virus replication efficiency and expression of HBsAg and HBeAg by full-length HBV clones are in relative coincidence with the biological characteristics of HBV strains in patients. Cell transfection can be used to study the biological characteristics of individual isolates.

Aim To study the mechanism and inhibitory effect of aspirin on U251 cells in vitro.Methods The effects of aspirin on proliferation of U251 cells were assessed using the MTT assay.Cell cycle analysis was done by flow cytometry.AnnexinⅤ-FITC Apoptosis Detection Kit was used to detect apoptosis of cells.Western blot was employed to analyze expression of apoptosis-related protein Bcl-2 and Caspase-3.Results The growth inhibiton of U251 cells by aspirin was in a time-and-dose-dependent manner.After treatment with 8 mmol?L-1,cell cycle was arrested at G2/M phase.Aspirin also significantly enhanced apoptosis of U251 cells with down-regulated anti-apoptotic protein Bcl-2,and activation of Caspase-3.Conclusions Aspirin can significantly inhibit the growth of U251 cells through inducing cell apoptosis in vitro.