One-Step Solvothermal Synthesis of Black TiO2 Films for Enhanced Visible Absorption.

An economic and facile solvothermal method was reported to prepare black TiO2 films on Ti foils that possessed the property of optical absorption in the visible region. The UV-vis spectra showed that the black TiO2 samples exhibited highly enhanced visible-light absorption from 400-600 nm. The black TiO2 films were compact and uniform, composed of nanoparticles and nanosheets. Moreover, a mixed structure of anatase and rutile was present in black TiO2 films. The electron paramagnetic resonance (EPR) spectra confirmed the presence of Ti3+ in samples, which accounted for longer wavelength optical absorption. The results showed that the TiO2 films had retained their black color upon storage in ambient atmosphere for more than one month. Therefore, it was supposed that the ethylene glycol in solvothermal reaction was the key factor for the extension of the absorption spectrum.

Rounded Cu2ZnSnS4 nanosheet networks as a cost-effective counter electrode for high-efficiency dye-sensitized solar cells.

Semi-transparent rounded Cu2ZnSnS4 (CZTS) nanosheet networks were in situ grown on a FTO glass substrate, via an effective solution method, without any post-treatments. An improved power conversion efficiency of 6.24% was obtained by applying CZTS nanosheet networks as a counter electrode for dye-sensitized solar cells. When assisted by a mirror reflection, the PCE increased to 7.12%.

[Synthesis and anti-inflammatory activity of ursolic acid derivative-chalcone conjugates].

A series of novel conjugates with ursolic acid core and different chalcone ligands were synthesized via ursolic acid, 4-hydroxyacetophenone and aromatic aldehydes. All of the conjugates were confirmed by the application of IR, (1)H NMR, (13C) NMR and HR-MS. The anti-inflammatory effect was observed for the target compounds in xylene-induced mouse ear edema and carrageenan-induced paw edema in rats. The preliminary bioassay test demonstrated that these compounds had potent anti-inflammatory activities, and their activities were better than that of the parent ursolic acid. Among them, 1-en-3-oxoursolic acid-chalcone conjugates (6a-6g) exhibited higher activities than analogues 5a-5g and 7a-7g.

Anti-icing potential of superhydrophobic Ti6Al4V surfaces: ice nucleation and growth.

On the basis of the icing-delay performance and ice adhesion strength, the anti-icing potential of the superhydrophobic surface has been well-investigated in the past few years. The present work mainly emphasized the investigations of ice nucleation and growth to fully explore the anti-icing potential of the superhydrophobic surface. We took the various surfaces ranging from hydrophilic to superhydrophobic as the research objects and, combining the classical nucleation theory, discussed the ice nucleation behaviors of the water droplets on these sample surfaces under the condition of supercooling. Meanwhile, the macroscopical growth processes of ice on these surfaces were analyzed on the basis of the growth mechanism of the ice nucleus. It was found that the superhydrophobic surface could greatly reduce the solid-liquid interface nucleation rate, owing to the extremely low actual solid-liquid contact area caused by the composite micro-nanoscale hierarchical structures trapping air pockets, leading to the bulk nucleation dominating the entire ice nucleation at the lower temperatures. Furthermore, ice on the superhydrophobic surface possessed a lower macroscopical growth velocity as a result of the less ice nucleation rate and the insulating action of the trapped air pockets.

Relationship between Wetting Hysteresis and Contact Time of a Bouncing Droplet on Hydrophobic Surfaces.

The contact time of impacting water droplets on superhydrophobic surfaces directly reflects the extent of thermal and energy conversions between the water droplet and the surface, which is also considered to be crucial to the practical applications. The purpose of this study was to reveal the relationship between the contact time and the wetting hysteresis. We designed and fabricated six classes of surfaces with different extent of hydrophobicity through modifying the microscale/nanoscale hierarchical textured titanium surfaces with 1H,1H,2H,2H-perfluorodecyltrimethoxysilane, and we filmed the contact process of the water droplet impacting on these surfaces using a high-speed camera. It can be concluded that wetting hysteresis played a significant role in determining how long the impacting water droplet can bounce off the surface, based on the interfacial wetting mechanism and the work done against the resistance force generated by contact angle hysteresis during the dynamic process.

Nanostructures in superhydrophobic Ti6Al4V hierarchical surfaces control wetting state transitions.

This paper mainly reports the wetting state of liquid droplets on a Ti6Al4V micro-nanoscale hierarchical structured hydrophobic surface. In this work, the detailed action mechanism of the secondary nanostructure in the hierarchical structure on the wetting-state transition (from the Wenzel state to the Cassie state) was revealed and discussed. The variation of micro-morphology of the sample surface was observed using a field emission scanning electron microscope (FE-SEM). Furthermore, the apparent contact angle and sliding angle of the droplets on the surfaces were measured via a contact angle measurement instrument. The theoretical and experimental results indicated that the one-dimensional nanowire structure, which was planted on the microstructure surface by the hydrothermal method, effectively changed the wetting state of liquid droplets on the surface from the Wenzel state to the Cassie state owing to its good size synergies with microscale structure. This process not only increased the apparent contact angle of liquid droplets on the solid surface (to 161°), but also decreased the sliding angle significantly (to 3°) and contact angle hysteresis (to ∼2°), demonstrating the robust non-wetting property.

Delayed primary closure versus primary closure for wound management in perforated appendicitis: a prospective randomized controlled trial.

BACKGROUND: It is still a matter of debate whether delayed primary closure (DPC) of contaminated abdominal incisions reduces surgical site infections compared with a primary closure (PC). The aim of this study was to determine the optimal method of wound closure for patients with perforated appendicitis. METHODS: A total of 70 patients with perforated appendicitis were included. They were randomized to have their surgical incisions (skin and subcutaneous tissue) either PC or left open with Betadine-soaked gauze packing for DPC on the fifth postoperative day or later if the wound conditions were inappropriate for closure. A wound was considered infected if pus discharged from the incision site. The main outcome measures were the incidence of wound infection and the length of hospital stay (LOS). RESULTS: In the entire series, wound infection developed after incision closure in 21.4% of the patients. The PC group had a higher incidence of wound infection (38.9% vs. 2.9%, p<0.001) and longer LOS (8.4 days vs. 6.3 days, p=0.038). CONCLUSION: Delayed primary closure is the optimal management strategy for perforated appendicitis wounds. It significantly reduces the wound infection rate and length of stay.

Nerve invasion by epithelial cells in benign breast diseases.

Nerve invasion by glandular epithelial cells in a lesion is usually regarded as invasive carcinoma. However, some benign conditions in the pancreas, prostate, breast and other organs may show involvement of nerve bundles by benign epithelial cells. We report an 18-year-old female with nerve invasion in benign breast disease. The lesion in her right breast revealed fibrocystic changes with ductal hyperplasia and stromal sclerosis. Perineural and intraneural involvement by bland-looking small ducts lined by 2 layers of cells including an outer layer of myoepithelial cells were found, suggestive of benign nerve invasion. There was no evidence of malignant cells in any of the sections. The patient remains well after 31 months of follow-up. About 44 cases of nerve invasion in benign breast diseases have been reported in the literature. It is necessary to carefully evaluate nerve involvement in breast lesions to avoid over-diagnosis and inappropriate operation.

Comparison of primary wound closure versus open wound management in perforated appendicitis.

BACKGROUND/PURPOSE: Open wound management has long been the most common practice after appendectomy for perforated appendicitis. Primary closure, however, has recently been advocated to reduce cost and morbidity. The aim of this study was to compare the results of open wound management and primary wound closure in adult patients (age, > or =15 years) with perforated appendicitis. METHODS: Hospital records of 390 patients (age, > or =15 years) who underwent appendectomy between January 2002 and December 2004 were reviewed to identify surgical wound infection (SWI) and pathologic diagnosis. Perforated appendicitis was the indication for appendectomy in 65 of these patients. The incision wounds in these 65 patients were closed primarily in 41 and left open at the end of the operation in 24. The duration of symptoms, white blood cell count, operative time, incidence of SWI, length of stay (LOS) and readmission rate were compared between patients with these two different methods of wound management. RESULTS: Patients whose wounds were closed primarily had a higher incidence of SWI (43.9% vs. 4.2%, p < 0.001) and longer LOS (10 days vs. 7.9 days, p = 0.044). The readmission rate was also higher for patients whose wounds were closed primarily; however, this difference was not significant. CONCLUSION: Open wound management may be preferable to primary wound closure for perforated appendicitis in adults because of a lower incidence of SWI and a shorter LOS. Randomized clinical trials, however, are needed to establish these findings.