Photocatalytic and adsorption property of ZnS–TiO2/RGO ternary composites for methylene blue degradation

The visible light–driven ZnS–TiO2/RGO nanocomposites, with good visible light–driven photocatalytic activity, utilizing graphene oxide as precursor, were successfully synthesized via a facile solvothermal thermal method with graphene oxide as precursor. Ti4+ ions were derived from titanium dioxide powder (TiO2, P25) and tetrabutyl titanate. S2− ions and Zn2+ ions were provided by sodium sulfide and zinc acetate, respectively. The photocatalytic and absorbance activity of the nanocomposites was investigated through the photocatalytic degradation of methylene blue in aqueous solution. The results showed that the ZnS–TiO2/RGO nanocomposite prepared by tetrabutyl titanate exhibited better photocatalytic and adsorbance activity for methylene blue under visible light irradiation and its photocatalytic efficiency reached 90% in 60-min light irradiation, almost 1.5 times that of the synthesized ZnS–TiO2/RGO by P25, which was attributed to a cooperative reaction because of an increase of photo-absorption effect of graphene sheets and photocatalytic effect of ZnS nanoparticles. The adsorbance activity for ZnS–TiO2/RGO–tetrabutyl titanate) reached 48%, which was almost 1.7 times higher than that of ZnS–TiO2/RGO-P25 and almost 3.7 times higher than that of ZnS/RGO.

Effect of cysteamine hydrochloride supplementation on the growth performance, enterotoxic status, and glutathione turnover of broilers fed aflatoxin B1 contaminated diets

This study aimed to investigate the effect of cysteamine hydrochloride (CSH) supplementation on the growth performance, opportunistic bacteria and enterotoxic markers, visceral lesions, glutathione turnover, and inflammatory factors of broilers fed diets contaminated with aflatoxin B1 (AFB1). One-day-old Arbor Acres broilers (n = 480) were randomly allocated to 4 treatments with 6 replicates of 20 chicks each for a 2 × 2 design with CSH (0 or 200 mg/kg) and AFB1 (0 or 40 μg/kg). The trial lasted for 42 d. Results showed that AFB1 negatively affected (P < 0.05) growth performance, opportunistic bacteria and enterotoxic markers, intestinal lesions, glutathione turnover, and inflammatory factors. The CSH increased (P < 0.05) feed intake and body weight gain. The enterotoxic status was relieved in the CSH treatments by reducing (P < 0.05) the populations of gut Escherichia coli, Gram-negative bacteria, serum diamine oxidase, and intestinal lesions. The CSH also increased (P < 0.05) serum reduced glutathione, glutathione s-transferases, and glutathione reductase, and decreased (P < 0.05) the mRNA levels of tumor necrosis factor-α, interleukin-6, and interleukin-1β. Significant interactions (P < 0.05) were found on Gram-negative bacteria, diamine oxidase, and glutathione s-transferases. The results suggest that the CSH can improve glutathione turnover and reduce the risk of enterotoxic disease induced by AFB1 in broilers.

[Clinical characteristic and prognostic analyses of 117 cases of head and neck mucosal melanoma]

Objective: To study the clinical characteristics of mucosal melanoma in the head and neck, including the risk factors affecting distant metastasis, recurrence and survival rate, and to provide the basis for the individualized treatment of mucosal melanoma in the head and neck. Methods: The clinical data of 117 cases of mucosal melanoma in the head and neck treated from January 2004 to June 2016 in Beijing Tongren Hospital were analyzed retrospectively, and the risk factors affecting the prognosis, distant metastasis and local recurrence were analyzed.Kaplan-Meier analysis was used for survival analysis, and Log-Rank test was used for comparison between groups. Results: The follow-up time was 5-139 months, with a median of 32 months, and the median survival time was 34 months.The 3 and 5 year cumulative survival rates were 47.0% and 25.0%, respectively.Local recurrence occurred in 27 patients (23.1%), and distant metastasis in 37 cases (31.6%). After the operation, 50 patients received radiotherapy.Multiple factor Cox regression analysis showed that distant metastasis, AJCC staging, and two operations were risk factors affecting survival (P<0.05), and immunologic/targeted therapy was a protective factor affecting survival prognosis(P=0.008). Postoperative radiotherapy and distant metastasis were important factors affecting recurrence (P<0.05). AJCC staging, pigmentation, and postoperative recurrence were risk factors for distant metastasis (P<0.05). Conclusion: The 3 and 5 year survival rates of primary mucosal melanoma in head and neck are low, and the incidence of local recurrence and distant metastasis are high. Surgery is the first choice and the integrity of the initial operation has an important impact on the prognosis of the patients. Postoperative adjuvant radiotherapy is recommended to improve the local control rate, and immunotherapy and targeted therapy should be applied in time to improve survival.

[The clinical significance of CD(4)(+)CD(69)(+) T lymphocytes in patients with autoimmune hemolytic anemia/Evans syndrome]

Objective: To investigate the significant of peripheral CD(4)(+) CD(69)(+) T lymphocytes in patients with autoimmune hemolytic anemia (AIHA)/Evans syndrome (ES). Methods: In this study peripheral blood samples from 32 patients with AIHA/ES (15 hemolytic episode patients, 17 remission patients) and 13 healthy controls were collected. Patients with AIHA/ES were recruited in Tianjin Medical University General Hospital from October 2015 to May 2016. The percentages of CD(69)(+) T lymphocytes were analyzed by flow cytometry. The expression of CD(69) mRNA in CD(4)(+) T lymphocytes which was sorted from peripheral blood by magnetic activated cell sorting (MACS) was detected using real-time PCR. Soluable CD(69) was measured by ELISA. Results: In hemolytic episode patients, the ratio of CD(3)(+)CD(69)(+)/CD(3)(+)T lymphocytes [(3.08±1.48)%] was significantly higher than that in healthy controls [(1.28±0.83)%, P<0.01] and in remission group[(1.96±1.33)%, P<0.05]. The absolute count of CD(3)(+)CD(69)(+)T lymphocytes in hemolytic episode group [(2.94±1.81)×10(7)/L] was higher than that in healthy controls [(1.48±1.42)×10(7)/L, P<0.05]. The ratio of CD(3)(+)CD(4)(+)CD(69)(+)/CD(3)(+)CD(4)(+)T cells in hemolytic episode group [(2.16±1.56)%] was significantly higher than that in remission group [(1.16±0.62)%, P<0.05] and healthy controls[(0.94±0.78)%, P<0.05]. The quantity of CD(3)(+)CD(4)(+)CD(69)(+)T lymphocytes in hemolytic episode group[(1.04±0.98)×10(7)/L] was higher than in healthy controls [(0.44±0.38)×10(7)/L, P<0.05]. The ratio of CD(3)(+)CD(8)(+)CD(69)(+)/CD(3)(+)CD(8)(+)T lymphocyte in hemolytic episode group [(4.87±2.56)%] was significantly higher than that in healthy controls[(1.83±1.27)%, P<0.01]. The quantity of CD(3)(+)CD(8)(+)CD(69)(+)T lymphocytes in three groups did not show significant difference. The ratio of CD(3)(+)CD(4)(+)CD(69)(+)/CD(3)(+)CD(4)(+) T lymphocytes in hemolytic episode group was negatively correlated with hemoglobin (Hb) (P<0.01) , positively correlated with the percentage of reticulocytes (Ret%) (P=0.01) total bilirubin(TBil), indirect bilirubin(IBil) (P<0.01) and not correlated with absolute reticulocytes count, lactic dehydrogenase (LDH), complement 3(C3), complement 4 (C4). The ratio of CD(3)(+)CD(4)(+)CD(69)(+)/CD(3)(+)CD(4)(+)T lymphocytes in remission group was negatively correlated with Hb (P<0.05). In hemolytic episode patients CD(69) mRNA (32.26±35.11) was significantly higher than that in remission group(6.05±5.87) (P<0.05) and healthy controls (1.76±1.85)(P<0.01). CD(69) mRNA in remission group was significantly higher than healthy controls (P<0.05). Serum CD(69) in hemolytic episode patients [(494.21±16.06) ng/L] was significantly higher than that in healthy controls [(441.39±104.6) ng/L, P<0.05]. Conclusion: Our findings suggest that the proportion of CD(4)(+)CD(69)(+) T lymphocytes increase in AIHA/ES patients, which is correlated with the severity of disease.

A novel, tunable, multimodal microwave system for microwave reflectometry system

Based on a new technique, a tunable, multi-channel system that covers the Q-band (33-55 GHz) is presented in this article. It has a potential use of the Doppler backscattering system diagnostic that can measure the turbulence radial correlation and the perpendicular velocity of turbulence by changing the incident angle. The system consists primarily of a double-sideband (DSB) modulation and a multiplier, which creates four probing frequencies. The probing frequency enables the simultaneous analysis of the density fluctuations and flows at four distinct radial regions in tokamak plasma. The amplitude of the probing frequency can be adjusted by the initial phase of the intermediate frequency (IF) input from the double-sideband, and the typical flatness is less than 10 dB. The system was tested in the lab with a rotating grating, and the results show that the system can operate in the frequency range of 33-55 GHz with a Q-band multitude and that the power of each channel can be adjusted by the phase of the IF input of DSB.

[Polymorphisms of mTORC1 genes and risk of primary colorectal adenocarcinoma in Chinese populations]

Objective: To study the associations between variants of mTORC1 of PI3K/AKT/mTOR pathway and colorectal cancer. Methods: In this hospital-based case-control study, at the First Affiliated Hospital, Xinjiang Medical University from 2000 to 2013, 665 primary colorectal cancer cases and 695 cancer-free controls were genotyped at 10 potentially functional single nucleotide polymorphism (SNPs) loci of mTORC1 (mTOR: rs1034528, rs2295080; Raptor: rs1062935, rs3751934; mLST8: rs3160, rs26865; DEPTOR: rs2271900, rs4871827; AKT1S1: rs2290774, rs2353005) to assess their associations with risk of colorectal cancer by Logistic regression analysis. Results: In single-locus analysis, found a significantly decreased risk of colorectal cancer associated with mLST8 rs26865 by recessive genetic model, especially in populations of ≤68 years of age (OR=0.64; 95%CI=0.43-0.96, P=0.031), female (OR=0.61; 95%CI=0.38-0.99, P=0.046), non-smoking (OR=0.55; 95%CI=0.35-0.87, P=0.010). mTOR rs1034528 CC genotypes were associated with higher risk of colorectal cancer in >68-year-old populations (OR=3.34; 95%CI=1.12-9.91, P=0.030). Raptor rs3751934 CA/AA genotypes were associated with lower colorectal cancer risk in population of body mass index(BMI)>25 kg/m(2) (OR=0.68; 95%CI=0.47-0.98, P=0.038); and AKT1S1 rs2290774 CC genotypes were associated with lower colorectal cancer risk in non-smoking population (OR=0.67; 95%CI=0.45-0.99, P=0.048). Furthermore, found that populations carrying more than two low-risk genotypes were associated with lower colorectal cancer risk, compared with that of populations carrying less than two low-risk genotypes (OR=0.74, 95%CI=0.58-0.95, P=0.017), especially in population of ≤68 years of age, male and BMI>25 kg/m(2,) and non-smoking. Conclusions: SNPs of mTORC1-related genes individually or jointly contribute to colorectal cancer susceptibility in Chinese. Further studies of larger cohorts are needed to validate the findings.

[Effect of neuroglobin on oxygen-glucose deprivation and reoxygenation induced autophagy in a human neuroblastoma cell line]

Objective: To investigate the effect of neuroglobin on oxygen-glucose deprivation and reoxygenation (OGD/R) induced autophagy in a human neuroblastoma cell line (SH-SY5Y). Methods: SH-SY5Y cells were transfected with plasmids (or vector) to establish a stable cell line of NGB overexpression (OE). After treated with OGD/R, cells were collected for the analyses of mRNA (Atg5, Atg7, BECN1 and FUNDC1) and protein levels of LC3. Furthermore, mitochondrial and cytosolic fractions were isolated for protein levels of PINK1 and Parkin. Results: Treatment of OGD/R significantly increased the levels of mRNA of Atg5, Atg7, BECN1 and FUNDC1 (peak levels were 4.90±0.71, 6.72±0.75, 2.71±0.39 and 3.96±0.78 fold, all P<0.05). The protein level of Parkin increased in mitochondria and decreased in cytoplasm after the treatment. Compared with the vector group, Ngb OE group showed a significant higher level of FUNDC1 mRNA (3.96±0.78 versus 6.86±0.63 fold, P<0.05), while Atg5, Atg7 and BECN1 mRNA levels showed no significant difference. Moreover, the mitochondrial or cytosolic protein levels of PINK1 or Parkin showed no significant difference between Ngb OE and vector group. Conclusions: Overexpression of Ngb can not affect autophagy or mitohpagy in OGD/R treated SH-SY5Y cells. Overexpression of Ngb can increase the mRNA level of FUNDC1 and the mechanism needs further study.

[Expert consensus on the diagnosis and treatment of cryptococcal meningitis]

Cryptococcal meningitis is a common and refractory central nervous system infection, with high rates of mortality and disability. The experts of the Society of Infectious Diseases of Chinese Medical Association have reached this consensus after a thorough discussion. Based on the current situation of cryptococcal meningitis in China, the management of cryptococcal meningitis includes 6 aspects: introduction, microorganism identification, clinical manifestations and diagnosis, principles of antifungal therapy, treatment of refractory and recurrent meningitis, treatment of intracranial hypertension. There is not a separate consensus on human immunodeficiency virus (HIV) infection in patients with cryptococcal meningitis. This article focuses on different antifungal regimens and reducing intracranial pressure by reference to Infectious Disease Society of America (IDSA) guidelines. The importance of early diagnosis, combined long-term antifungal therapy, control of intracranial hypertension are emphasized.

[Clinicopathologic and molecular features of cribriform morular variant of papillary thyroid carcinoma]

Objective: To investigate the clinicopathologic and molecular features of the rare cribriform morular variant of papillary thyroid carcinoma (CMV-PTC). Methods: The clinicopathologic data of 10 patients with CMV-PTC were retrospectively reviewed. Immunohistochemical (IHC) staining was done using LSAB method. DNA sequencing for APC were applied using Sanger method. BRAF V600E mutation was examined using ARMS method. The cytological, morphological, IHC and molecular features were analyzed. Results: All patients were female at an average age of 27 years old. The tumors were mostly located in the right lobe of thyroid. Fine needle aspiration cytology was performed in three patients; two were diagnosed as suspicious for PTC and one as PTC. Nine tumors presented as solitary nodule and two as multiple nodules in both lobes. Infiltration was demonstrated in three cases. The average size was 2.6 cm. The neoplastic cells were arranged in papillary, cribriform, solid and glandular patterns, with rare or without colloid inside the lumen. The number of morula varied, ranging from zero to many. The neoplastic cells were variably enlarged, showing round, oval or spindle shape. Nuclear irregularity was identified as irregular membrane, nuclear grooves or pseudoinclusion, but no typical ground glass feature. Peculiar nuclear clearing could be observed in the morular cells. IHC staining showed the neoplastic cells were negative for thyroglobulin and p63, but positive for TTF1, cytokeratin 19 and estrogen receptor. Diffuse staining with cytokeratin was seen in the neoplastic cells and the morula. Specific cytoplasmic and nuclear staining of β-catenin was seen in the neoplastic cells but not the morula. Ki-67 proliferation index was 1%-30%. No recurrence or metastasis was observed. One patient was demonstrated to harbor both somatic and germline mutations of the APC gene, who was found to have adenomatous polyposis and her mother died of colonic carcinoma. No BRAF V600E mutation was detected. Conclusions: CMV-PTC is rare and shows atypical cytological and clinicopathological features, and it is easily misdiagnosed.TG, TTF1, ER and β-catenin are specific IHC markers for CMV-PTC. The morula is negative for cytokeratin 19, in contrast to squamous metaplasia. Although CMV-PTC has indolent clinical behavior, a definite diagnosis is necessary to rule out the possibility of APC gene mutation and related extra-thyroidal neoplasm, such as FAP and Gardner syndrome.

[Staged transcranial and transsphenoidal surgery for giant pituitary adenomas: a retrospective study of 21 cases]

Objective: To investigate the effect of the second-stage transcranial and transsphenoidal approach for giant pituitary tumors. Methods: A retrospective review of 21 patients, who had undergone the transcranial surgery and then transsphenoidal surgery for giant pituitary adenomas from 2012 to 2015 in the neurosurgery department of West China Hospital, was performed. Visual findings, endocrine presentation, complications, and tumor types were collected. All data were based on clinical feature, MRI, and follow-up. Results: Among the 21 cases, gross total resection of tumor was achieved in 7 of all patients, subtotal in 11, and partial in 3. No intracranial hemorrhage or death occurred postoperatively. Postoperative infectionoccurred in one patient and cerebrospinal fluid leakage occurred in 3 patients. Four patients recovered after treatment. Conclusion: According to the clinical feature and MRI, it is safe and effective to choose the transcranial surgery and then transsphenoidal surgery for specific giant pituitary adenomas, which can improve treatment effects and reduce postoperative complications.

[Evaluation of pelvic floor function of postpartum pelvic floor ultrasound in pregnant women with multiple pregnancies]

Objective: To probe the effect of multiple pregnancy on pelvic floor function of pregnant women, Pelvic floor ultrasonography was performed on the 42 day postpartum women.And the bladder neck mobility, bladder and urethral posterior angle and pelvic diaphragmatic hiatus area were measured. Methods: Collect 200 cases 42 day postpartum women who visited the second hospital of Jilin University from July 2015 to June 2017, of which 100 cases of primipara belong to group A, 100 cases of multiple pregnancy belong to group B, and 100 cases without maternal at the same age belong to the control group, ultrasound measurement of the bladder neck mobility, bladder and urethral posterior angle and pelvic diaphragmatic hiatus area were measured.t test were proformed respectively between the three groups, P<0.05 was considered statistically significant difference. Results: In the control group, the bladder neck mobility is (2.59±0.51) cm , the bladder neck mobility in A group is (2.99±0.69) cm, the bladder neck mobility in B group is (3.36±0.71) cm; the bladder and urethral posterior angle in the control group is (112.56±13.61)°, the bladder and urethral posterior angle in the control group after Valsalva action angle is(135.37±12.17)°, the bladder and urethral posterior angle in A group is(119.26±15.80)°, the bladder and urethral posterior angle in group A after Valsalva action is(141.79±12.08)°, the bladder and urethral posterior angle in B group is(123.62±16.20)°, the bladder and urethral posterior angle in group B after Valsalva action is (148.92±13.60)°; the pelvic diaphragmatic hiatus area in the control group is (13.35±2.86) cm(2,) the pelvic diaphragmatic hiatus area in the control group after Valsalva action is(15.28±3.15) cm(2,) the pelvic diaphragmatic hiatus area in A group is(17.52±3.19) cm(2,) the pelvic diaphragmatic hiatus area in A group ater Valsalva action is (18.06±5.13_the pelvic diaphragmatic hiatus area) cm(2,) the pelvic diaphragmatic hiatus area in B group is (18.26±4.18) cm(2,) the pelvic diaphragmatic hiatus area in B group after Valsalva action is (20.3±3.53) cm(2).In group A, group B and the control group, the measured value of the bladder neck mobility, bladder and urethral posterior angle and pelvic diaphragmatic hiatus area were examined by t test, and P<0.05, which means the difference was statistically significant. Conclusion: Pregnancy can affect the function of female pelvic floor, and the effect of parturient is more significant than that of the primipara.

[Role of endoplasmic reticulum stress-mediated glycogen synthase kinase 3β activity in pathogenesis of acute liver failure in mice]

Objective: To study the role of endoplasmic reticulum (ER) stress-mediated glycogen synthase kinase 3β (GSK3β) activity in the pathological process of liver injury in acute liver failure (ALF) mice. Methods: ALF model was established by intraperitoneal injection of D-galactosamine/lipopolysaccharide (D-GalN/LPS) in C57BL/6 mice. The mice were divided into control group (n=10), ALF model group (n=18), 4-phenylbutyrate (4-PBA, an ER stress inhibitor) group (n=18) and SB216763 (a specific inhibitor of GSK3β) group (n=16). The serum alanine transaminase (ALT) and aspartate transaminase (AST) levels were measured to reflect the liver function, liver injury was assessed by observing pathological changes of liver tissue, the levels of proteins in liver tissue were analyzed by Western blotting, the activity of GSK3β in liver tissue was detected using GSK3β activity assay kit, and the survival rate of hepatocyte was measured by methyl thiazolyl tetrazolium (MTT) assay. Results: In in vivo experiment, the expression levels of ER stress markers, glucose-regulated protein 78 (GRP78) and CCAAT/enhancer-binding protein homologous protein (CHOP), were upregulated during the progression of D-GalN/LPS-induced ALF, indicating activation of severe ER stress and increased activity of GSK3β. Compared with the model group, inhibition of ER stress by 4-PBA improved liver function[ALT: (365.4±58.6) U/L vs (1 094.5±201.5) U/L, P<0.05; AST: (555.1±60.8) U/L vs (1 444.3±533.7) U/L, P<0.05)and pathological injury, also decreased the activity of GSK3β (2.6±0.3 vs 4.6±1.3, P<0.05). Inhibition of GSK3β activity was shown to alleviate liver injury in ALF by reducing the expression levels of GRP78 and CHOP. The in vitro experiment of tunicamycin-induced hepatocyte apoptosis showed that inhibition of GSK3β activity increased the cell survival rate. Conclusion: In ALF induced by D-GalN/LPS, severe ER stress may accelerate the development and progress of ALF by upregulating the activity of GSK3β.

[Research progress of ocular sustained-release corticosteroid delivery systems]

Ocular drug delivery by conventional routes of administration cannot reach or maintain therapeutic drug concentrations in the target tissues for a long duration due to the presence of various anatomical and physiological barriers. Treatment of chronic ocular diseases especially posterior segment of ocular diseases requires novel drug delivery systems that is capable overcome these barriers for efficacious delivery. In recent years, the ocular sustained-release drug delivery system, as a new drug delivery approach, has drawn tremendous attention for its advantages of improving local drug concentration, prolonging action time and reducing frequency of injection. Researchers have been devoted to the developing more effective sustained-release drug delivery systems in order to achieve better clinical efficacy. This article discusses various current sustained-release corticosteroids delivery systems. (Chin J Ophthalmol, 2018, 54: 154-160).

Ultrafast consolidation of bulk nanocrystalline titanium alloy through ultrasonic vibration

Nanocrystalline (NC) materials have fascinating physical and chemical properties, thereby they exhibit great prospects in academic and industrial fields. Highly efficient approaches for fabricating bulk NC materials have been pursued extensively over past decades. However, the instability of nanograin, which is sensitive to processing parameters (such as temperature and time), is always a challenging issue to be solved and remains to date. Herein, we report an ultrafast nanostructuring strategy, namely ultrasonic vibration consolidation (UVC). The strategy utilizes internal friction heat, generated from mutually rubbing between Ti-based metallic glass powders, to heat the glassy alloy rapidly through its supercooled liquid regime, and accelerated viscous flow bonds the powders together. Consequently, bulk NC-Ti alloy with grain size ranging from 10 to 70 nm and nearly full density is consolidated in 2 seconds. The novel consolidation approach proposed here offers a general and highly efficient pathway for manufacturing bulk nanomaterials.

[Introduction and interpretation of guidelines on thromboprophylaxis in the perioperative period of urological surgery]

Venous thromboembolism had drawn great attention of global experts, as it is the third leading cause of cardiovascular-associated death, ranking after coronary heart disease and stroke. Numerous health care organizations had introduced guidelines for thromboprophylaxis during the perioperative period in their own fields. The paper reviewed the available guidelines pertaining to urological surgery from America Urological Association, American College of Chest Physicians and European Association of Urology. Compared with the first two guidelines, the European Association of Urology guideline is a milestone which recommended the most detailed prophylactic measures for the procedure-specific and patient-specific according to the evidence-based medicine. Meanwhile, there was still no reliable evidence in fields of the effect of new oral anticoagulants in urology, needing further study. Although they were similar in patient management and prophylaxis principles, there are still some differences in risk factors, assessments, and recommendations of prophylactic measures. In this context, we planed to summarize the highlights and compare the differences of three guidelines addressing the use of thromboprophylaxis in urology, in order to provide reference for Chinese urologists to select the best prevention strategies for patients in the perioperative period.

Surface integrity and corrosion performance of biomedical magnesium-calcium alloy processed by hybrid dry cutting-finish burnishing

Biodegradable magnesium-calcium (MgCa) alloy is a very attractive orthopedic biomaterial compared to permanent metallic alloys. However, the critical issue is that MgCa alloy corrodes too fast in the human organism. Compared to dry cutting, the synergistic dry cutting-finish burnishing can significantly improve corrosion performance of MgCa0.8 (wt%) alloy by producing a superior surface integrity including good surface finish, high compressive hook-shaped residual stress profile, extended strain hardening in subsurface, and little change of grain size. A FEA model was developed to understand the plastic deformation of MgCa materials during burnishing process. The measured polarization curves, surface micrographs, and element distributions of the corroded surfaces by burnishing show an increasing and uniform corrosion resistance to simulated body fluid.

A Dynamic Biochemomechanical Model of Geometry-Confined Cell Spreading

Cell spreading is involved in many physiological and pathological processes. The spreading behavior of a cell significantly depends on its microenvironment, but the biochemomechanical mechanisms of geometry-confined cell spreading remain unclear. A dynamic model is here established to investigate the spreading of cells confined in a finite region with different geometries, e.g., rectangle, ellipse, triangle, and L-shape. This model incorporates both biophysical and biochemical mechanisms, including actin polymerization, integrin-mediated binding, plasma viscoelasticity, and the elasticity of membranes and microtubules. We simulate the dynamic configurational evolution of a cell under different geometric microenvironments, including the angular distribution of microtubule forces and the deformation of the nucleus. The results indicate that the positioning of the cell-division plane is affected by its boundary confinement: a cell divides in a plane perpendicular to its minimal principal axis of inertia of area. In addition, the effects of such physical factors as the adhesive bond density, membrane tension, and microtubule number are examined on the cell spreading dynamics. The theoretical predictions show a good agreement with relevant experimental results. This work sheds light on the geometry-confined spreading dynamics of cells and holds potential applications in regulating cell division and designing cell-based sensors.

[Evaluation of the modified test system for children sound localization]

Objective: To evaluate the feasibility of modified test system for sound localization (SL) in children. Methods: Modified system (6 male, 9 female) and traditional method ( 5 male, 5 female) were used for evaluation of minimum audible angle(MAA) and root-mean-square error(RMS) error of 4 to 6 years old children, and the results were compared to verify the accuracy and effectiveness of the modified test system for children sound localization.SPSS 17.0 software was used to analyze the data(t test). Results: (1) Comparison of veracity of modified system and traditional test: when tested at the positive front position using modified system, MAA and RMS error were(3.23±1.00)° and (13.68±5.18)° respectively.When using traditional method, MAA and RMS error were(3.17±0.59)°and (13.96±4.56)° respectively. No statistical differences were found between two groups(t value was 0.16, -0.14, both P>0.05). (2) Comparison of time used were as followed: when using modified system, it was (14.67±1.95) min for MAA, and (6.67±1.35) min for RMS error. When using traditional method, it was (36.30±6.81) min for MAA, and (21.00±3.50) min for RMS error. Time used were significant shorter in modified system than in traditional method (t value was-9.78, -12.37, both P<0.05). Conclusion: Modified test system for children sound localization is useful and reliable in children's horizontal SL test.The time used of modified test system is shorter than that of traditional test system.