Rheology of graphene oxide stabilized Pickering emulsions.

Pickering emulgels stabilized by graphene oxide (GO) with didodecyldimethylammonium bromide (DDAB) as an auxiliary surfactant and liquid paraffin as the oil phase have proved to be an excellent 3D printable ink. This paper elucidates the structure of such emulgels by a combination of microscopy before and after intensive shear as well as broadband dielectric spectroscopy and rheology in the linear and nonlinear regime. An increase of the DDAB surfactant and GO-contents leads to a systematic increase of modulus and viscosity, a reduction of the limits of the nonlinear regime and a more complicated variation of the normal forces, with negative normal forces at high shear rate  for low GO-contents and positive normal forces at high GO-contents. The interfacial jamming behavior studied by morphology, rheology and dielectric spectroscopy is explained based on droplet deformation, jamming and recovery phenomena.

Influence of Cellulose Nanofibers on the Behavior of Pickering Emulsions. Part 1. Microscopy and Startup Flow Test.

The dispersibility of flexible polymer chains present at the emulsion's interface between the dispersed and continuous phase has obvious effects on rheology and dielectric properties of the whole emulsion. Cellulose nanofiber (CNF)-based Pickering emulsions are good systems to research these properties with respect to their microscopic phase structure, dielectric, and rheological properties by using CNF as a water-dispersible Pickering emulsifier, liquid paraffin as an oil phase, and didodecyldimethylammonium bromide (DDAB) as a cationic auxiliary surfactant. The CNF and DDAB contents were systematically varied while the water-to-paraffin oil ratio was kept constant to discern the influence of the Pickering emulsifiers. Polarized optical microscopic images reveal that the droplets tend to shrink at higher CNF content but grow bigger when increasing the DDAB content, which is proved by fluorescence analysis of the CNF dispersibility with varying DDAB content. The dielectric damping exhibits a minimum, whose value decreases with increasing DDAB and CNF content. Increasing the DDAB content promotes the solubilization of CNF in the aqueous phase, which will increase the overall viscosity and yield points. Similarly, a higher CNF content leads to a higher viscosity and yield point, but at high DDAB contents, the viscosity function exhibits an S-shape at intermediate CNF contents. To evaluate the results further, they were compared with CNF dispersions (without oil phase), which showed a surfactant effect slightly on maximum stress but strongly on yield stress τy, indicating that DDAB can promote the formation of a CNF network rather than the viscosity of the whole system. This paper provides information on how a systematical variation of the composition influences morphology and physico-chemical interactions as detected by broadband dielectric spectroscopy and rheological behavior.

External fixation and bone grafting for collapsed and comminuted distal radius fracture.

OBJECTIVE: To study the therapeutic effect of collapsed and comminuted distal radius fracture. METHODS: Twenty-six patients with collapsed and comminuted distal radius fracture were hospitalized from July 1998 to June 2003. All fractures were treated by the methods of open reduction, sustained bone grafting and passing joint external fixator to restore the anatomic shape of distal radius. RESULTS: All 26 cases were followed up, and the results showed that the fractures have been united radiographically. The joint surfaces were intact and there was no length discrepancy occurred in patient's radius. The average volar tilt was 6 to 15 degrees and the average ulnar tilt was 18 to 25 degrees. According to the Dieust criterion, 19 cases were rated as excellent and 7 as good. CONCLUSIONS: The method that applying passing joint external fixator and bone grafting for the treatment of collapsed and comminuted distal radius fracture could maintain the stability of fracture and restore the length of radius and the intact of joint surface.

Comparison of restrictive and liberal transfusion strategy on postoperative delirium in aged patients following total hip replacement: a preliminary study.

Few studies have examined the association between perioperative blood transfusion and postoperative delirium (POD) in aged patients undergoing total hip replacement surgery. In this prospective study, 186 patients older than 65 years undergoing elective unilateral total hip replacement surgery were enrolled. Of those, 94 patients were randomly assigned to the restrictive strategy transfusion strategy group, in which red blood cells were transfused in order to maintain 10.0 g/dL>hemoglobin≧8.0 g/dL. Ninety-two patients were randomly assigned to the liberal transfusion strategy group, in which red blood cells were transfused in order to maintain hemoglobin≧10.0 g/dL. POD was diagnosed by confusion assessment method. The baseline characteristics of patients, the length of hospital stay, the incidence of POD, myocardial infarction, stroke, wound infection, pulmonary embolism, and the transfusion volume were recorded. No difference was observed in the baseline characteristics, the length of hospital stay, and the incidence of POD, myocardial infarction, stroke, wound infection, and pulmonary embolism between the two groups (P>0.05). The proportion of patients transfused with red blood cell and frozen plasma was decreased in the restrictive transfusion group compared with the liberal transfusion group (P<0.05). In conclusion, restrictive transfusion does not influence the incidence of POD but reduces blood transfusion. Thus, restrictive transfusion may serve as an effective and safe strategy for aged patients following total hip replacement.

Cannabinoid receptor-2 selective antagonist negatively regulates receptor activator of nuclear factor kappa B ligand mediated osteoclastogenesis.

BACKGROUND: The cannabinoid receptor-2 (CB2) is important for bone remodeling. In this study, we investigated the effects of CB2 selective antagonist (AM630) on receptor activator of nuclear factor kappa B (RANK) ligand (RANKL) induced osteoclast differentiation and the underlying signaling pathway using a monocyte-macrophage cell line-RAW264.7. METHODS: RAW264.7 was cultured with RANKL for 6 days and then treated with AM630 for 24 hours. Mature osteoclasts were measured by tartrate-resistant acid phosphatase (TRAP) staining using a commercial kit. Total ribonucleic acid (RNA) was isolated and real-time reverse transcriptase-polymerase chain reaction (RT-PCR) was done to examine the expression of RANK, cathepsin K (CPK) and nuclear factor kappa B (NF-κB). The extracellular signal-regulated kinase (ERK), phosphorylation of ERK (P-ERK) and NF-κB production were tested by Western blotting. The effect of AM630 on RAW264.7 viability was determined using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide (MTT) assay. RESULTS: AM630 did not affect the viability of RAW264.7. However, this CB2 selective antagonist markedly inhibited osteoclast formation and the inhibition rate was dose-dependent. The dose of ≥ 100 nmol/L could reduce TRAP positive cells to the levels that were significantly lower than the control. AM630 suppressed the expression of genes associated with osteoclast differentiation and activation, such as RANK and CPK. An analysis of a signaling pathway showed that AM630 inhibited the RANKL-induced activation of ERK, but not NF-κB. CONCLUSION: AM630 could inhibit the osteoclastogenesis from RAW264.7 induced with RANKL.

[Application of the island flap at the dorsum of the middle phalange with the pedicel of the digital proper artery].

OBJECTIVE: To explore a method for the treatment of the skin defects at the distal phalanges of 2-5th fingers. METHODS: The island flap at the dorsum of the middle phalange was designed with the pedicle of dorsal branches from the digital proper artery. When the flap was used to repair defect at finger pulp, the dorsal branch of the digital proper nerve in the flap was kept to be anastomosed to the digital proper nerve at the recipient finger. From Feb. 2005 to May. 2010, 54 cases with skin defects at the distal phalanges of 61 fingers were treated with the flap, including 35 defects at finger pulp and 26 defects at finger tip. RESULTS: The maximum size of defects and flaps was 2.2 cm x 2.5 cm and 2.4 cm x 2.7 cm, respectively. 61 flaps survived completely. Blister was happened in 3 flaps 2 days after operation, which healed spontaneously without necrosis. 54 cases were followed up for 5 to 22 months (average, 11 months). The flaps had good texture and color match with normal sensation (grade S4). The 2-point discrimination distance was 6-9 mm. The interphalangeal joint had normal movement. CONCLUSIONS: The island flap at the dorsum of the middle phalange is an ideal method for the skin defect at the distal phalange of finger.

Arterioles in cerebral amyloid angiopathy and vascular dementia.

BACKGROUND: Small cerebrovascular lesions are one of the most important factors in cerebral amyloid angiopathy (CAA) and vascular dementia (VaD). We analyzed the difference of arteriolar pathology between CAA patients (CAAs) and vascular dementia patients without CAA (VaDs). METHODS: Ten deceased CAAs and twelve deceased VaDs were available for this study. Five deceased patients without known cerebrovascular diseases served as controls. These patients were all autopsy cases. All transversely cut arterioles in the gray matter and white matter with an external diameter equal to or larger than 30 microm and with a maximum of 300 microm were examined. The internal and external diameters of arterioles were measured. RESULTS: The external diameter of gray matter arterioles in the CAAs was significantly greater than in controls. In gray matter arterioles, the diameter of the lumen in VaDs was markedly smaller than in the CAAs, whereas there was no significant difference between CAAs and controls. CAAs and VaDs may cause remarkable thickening of the arteriolar walls in either white matter or gray matter. The sclerotic index of arterioles in VaDs was significantly greater than in CAAs and controls. CONCLUSIONS: Stenosis of arterioles occurred in both CAA and VaD, but the tendency was greater in VaD. Arterioles of CAA were also expanded in gray matter, which may be related to lobar hemorrhage. The loss and/or degeneration of vascular smooth muscle cells was predominant in CAA, while the over-proliferation of vascular smooth muscle cells was greater in VaD.