Simhypo-sand: a simple hypoplastic model for granular materials and SPH implementation.

This paper introduces a new hypoplastic model characterized by a simple and elegant formulation. It requires only 7 material parameters to depict salient mechanical behaviors of granular materials. The numerical implementation employs an explicit integration method, enhanced by a best-fit stress correction algorithm in a smoothed particle hydrodynamics code. The performance of this model in capturing soil behavior across a range of scenarios is demonstrated by conducting various numerical tests, including triaxial and simple shear at low strain rates, as well as granular collapse, rigid penetration and landslide process at high strain rates.

A case report of Schatzker type VI tibial plateau fracture treated with double reverse traction closed reduction combined with minimally invasive percutaneous plate osteosynthesis technique: A case report.

RATIONALE: The knee joint is an important weight-bearing joint, tibial plateau fractures affect knee function and stability. High-energy intra-articular fractures involving the tibial plateau can cause management-related problems such as wound dehiscence; severe comminution leading to malalignment; and delayed complications such as varus collapse, implant failure, and arthritis of the knee joint. The treatment of severe or complex tibial plateau fractures can be quite difficult. Traditional methods of open reduction and plating require extensive exposures, which may further compromise soft tissue and devascularize bone fragments, leading to infection. In this case, a novel device, double reverse traction combined with MIPPO technique, was used and provided the possibility of minimally invasive and personalized orthopedic surgery to treat severe comminuted Schatzker type VI tibial plateau fracture and tibial shaft fracture and got satisfactory results. PATIENT CONCERNS: A previously healthy 56-year-old man presented to the emergency room after a fall from a height, who lost the movement of the left knee with pain and swelling. DIAGNOSES: X-rays showed a tibial plateau comminuted fracture, Schatzker type VI, and tibial shaft fracture. INTERVENTIONS: Applying less extensile exposure and the indirect reduction technique of double reverse traction and closed reduction combined with minimally invasive percutaneous plate osteosynthesis (MIPPO) technique, we got satisfactory recovery of the severe comminuted Schatzker type VI tibial plateau fracture and tibial shaft fracture. OUTCOMES: This severe comminuted fracture and tibial shaft fracture were successfully reduced and got satisfactory recovery of knee joint function. LESSONS: Double reverse traction combined with MIPPO technique can reduce the risk of surgical complications, such as bleeding, oozing, and wound infection. It can be applied in patients with comorbidities such as cardiac disease, hypertension, and heart failure who may otherwise not be candidates for surgery. The cost burden is lower than that of the traditional traction table.

Bactericidal properties of ZnO-Al(2)O (3) composites formed from layered double hydroxide precursors.

ZnO-Al(2)O(3) composites with different Zn/Al molar ratios (R) have been prepared using zinc-aluminium layered double hydroxides (LDHs) Zn( R )Al-CO(3) as precursor. The samples were characterized by XRD, ICP, EDX, EPR and FT-IR. The results show that ZnO is highly dispersed in all of the ZnO-Al(2)O(3) composites. Bactericidal experiments against Staphylococcus aureus ATCC 6538 and Bacillus subtilis var. niger ATCC 9372 were carried out by contacting the bacteria and spores with the ZnO-Al(2)O(3) composites. The composites all showed high bactericidal activity against Staphylococcus aureus ATCC 6538, and the bactericidal efficiency against Bacillus subtilis var. niger ATCC 9372 increased with increasing content of ZnO. The mechanism of bactericidal activity of ZnO-Al(2)O(3) has also been investigated. It is suggested that highly active O(2) (-) and *OH species generated on the surface of ZnO-Al(2)O(3) particles react with the peptide linkages in the cell walls of bacteria or spores resulting in their destruction.

Controllable preparation of Nano-MgO and investigation of its bactericidal properties.

Samples of nano-MgO with varying particle sizes were prepared by four different methods using Mg(NO3)2.6H2O, Na2CO3, urea and ammonia as raw materials and characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), low temperature N2 adsorption-desorption measurements and FT-IR spectroscopy. Bactericidal experiments with Bacillus subtilis var. niger and Staphylococcus aureus were carried out using as-synthesized nano-MgO samples and the bactericidal mechanism was also investigated. The results showed that the bactericidal efficacy of nano-MgO increases with decreasing particle size. The bactericidal efficacy of the samples was compared with that of TiO2, a common photoactive bactericidal material. The nano-MgO has better bactericidal activity, both when used directly and as an additive in an interior wall paint. Furthermore, nano-MgO is active even in the absence of irradiation.

Preparation and bactericidal property of MgO nanoparticles on gamma-Al2O3.

After being impregnated in the solution containing Mg(NO3)2 x 6H2O, gamma-Al2O3 was dried and calcined at 500 degrees C which results in the production of a bactericide, highly dispersed MgO loaded on the surface of gamma-Al2O3. The threshold value of the monolayer dispersion of MgO on gamma-Al2O3 is 14.97%, and MgO crystal formed when the load amount beyond this value. The samples with different load amount were characterized by X-ray Diffraction (XRD), Low-temperature N2 adsorption-desorption, Inductively Coupled Plasma (ICP) and High Resolution Scan Electronic Microscope (SEM). The results showed that these MgO microcrystals are highly dispersed and have regular size in the range of 4 to 10.8 nm. The specific surface, pore volume and pore size of the sample decreases with the increase of load amount. It is demonstrated that gamma-Al2O3 with highly dispersed MgO on the surface is efficient bactericide, and the one with 20% load amount of MgO can kill more than 99% bacteria and spore cells.

[The role of intercellular adhesion molecule-1 in binding of acute myeloid leukemic blasts cells to human umbilical vein endothelial cells].

OBJECTIVE: To evaluate the adhesion of acute myeloid leukemia (AML) blasts to human umbilical vein endothelial cells (HUVECs) and the roles of intercellular adhesion molecule-1 (ICAM-1) and its ligand lymphocyte function associated antigen-1 (LFA-1) in binding of leukemic blasts to HUVECs. METHODS: AML blasts attachment to unactivated or tumor necrosis factor alpha (TNF alpha) activated-endothelial cell monolayers was investigate in vitro; The adhesion of leukemic blasts co cultured with unactivated endothelial cells under static conditions at 37 degrees C for 24 hours was observed;The binding of neutrophils and unactivated endothelial cell monolayers exposed to supernatant of blasts were tested. ICAM-1 on endothelial cell surface and sICAM-1 of endothelial cell supernatant were determined by flow cytometry and ELISA detection. We also observed the adhesion of leukemic blasts in the presence of the adhesion blocking mAbs anti-ICAM-1 and anti-LFA-1. RESULTS: This study has shown that the blast cells attached to unactivated endothelium was little (24.33 +/- 2.87)% and increased after exposure of endothelium to TNF alpha (81.87 +/- 4.08)% (n = 21, P < 0.001); The binding of blasts to endothelium also increased significantly after 24 hours co cultured with unactivated HUVEC (82.06 +/- 7.05)%, (n = 21, P < 0.001); The adhesion of neutrophils and unactivated endothelial cell monolayers exposed to supernatant of blasts was increased significantly (83.99 +/- 3.86)%, (n = 21, P < 0.001). Lower levels of ICAM-1 and sICAM-1 expression was detected on unactivated HUVECs (55.81 +/- 4.11)%, (0.839 +/- 0.236) microg/L respectively. Treatment of HUVECs with AML blasts supernatant for 24 hours increased the expression of ICAM-1 (65.36 +/- 5.97)%, (1.424 +/- 0.469) microg/L respectively (n = 21, P < 0.05) and anti-ICAM-1 and anti-LFA-1 significantly inhibited the adhesion of AML blasts attachment to TNF alpha activated-endothelial cell monolayers (20.12 +/- 1.73)%, (n = 10, P < 0.001). CONCLUSION: Our results indicate that leukemic blasts have the ability to generate some factors that stimulate endothelial cell to secrete ICAM-1 ane to promote their own adhesion to vascular endothelium, interaction of ICAM-1 and its ligand LFA-1 has a key role in adhesion of leukemic blasts and HUVECs.