Zinc-Doped BiOBr Hollow Microspheres for Enhanced Visible Light Photocatalytic Degradation of Antibiotic Residues.

Photocatalysis represents an effective technology for environmental remediation. Herein, a series of Zn-doped BiOBr hollow microspheres are synthesized via one-pot solvothermal treatment of bismuth nitrate and dodecyl ammonium bromide in ethylene glycol along with a calculated amount of zinc acetate. Whereas the materials morphology and crystal structure remain virtually unchanged upon Zn-doping, the photocatalytic performance toward the degradation of ciprofloxacin is significantly improved under visible light irradiation. This is due to the formation of a unique band structure that facilitates the separation of photogenerated electron-hole pairs, reduced electron-transfer resistance, and enhanced electron mobility and carrier concentration. The best sample consists of a Zn doping amount of 1%, which leads to a 99.2% degradation rate of ciprofloxacin under visible photoirradiation for 30 min. The resulting photocatalysts also exhibit good stability and reusability, and the degradation intermediates exhibit reduced cytotoxicity compared to ciprofloxacin. These results highlight the unique potential of BiOBr-based photocatalysts for environmental remediation.

Defect Engineering of Bi2 WO6 for Enhanced Photocatalytic Degradation of Antibiotic Pollutants.

Infiltration of excessive antibiotics into aquatic ecosystems plays a significant role in antibiotic resistance, a major global health challenge. It is therefore critical to develop effective technologies for their removal. Herein, defect-rich Bi2 WO6 nanoparticles are solvothermally prepared via epitaxial growth on pristine Bi2 WO6 seed nanocrystals, and the efficiency of the photocatalytic degradation of ciprofloxacin, a common antibiotic, is found to increase markedly from 62.51% to 98.27% under visible photoirradiation for 60 min. This is due to the formation of a large number of structural defects, where the synergistic interactions between grain boundaries and adjacent dislocations and oxygen vacancies lead to an improved separation and migration efficiency of photogenerated carriers and facilitate the adsorption and degradation of ciprofloxacin, as confirmed in experimental and theoretical studies. Results from this work demonstrate the unique potential of defect engineering for enhanced photocatalytic performance, a critical step in removing antibiotic contaminants in aquatic ecosystems.

Alkyne-Functionalized Platinum Chalcogenide (S, Se) Nanoparticles.

Metal chalcogenide nanoparticles play a vital role in a wide range of applications and are typically stabilized by organic derivatives containing thiol, amine, or carboxyl moieties, where the nonconjugated particle-ligand interfaces limit the electronic interactions between the inorganic cores and organic ligands. Herein, a wet-chemistry method is developed for the facile preparation of stable platinum chalcogenide (S, Se) nanoparticles capped with acetylene derivatives (e.g., 4-ethylphenylacetylene, EPA). The formation of Pt-C≡ conjugated bonds at the nanoparticle interfaces, which is confirmed by optical and X-ray spectroscopic measurements, leads to markedly enhanced electronic interactions between the d electrons of the nanoparticle cores and π electrons of the acetylene moiety, in stark contrast to the mercapto-capped counterparts with only nonconjugated Pt-S- interfacial bonds, as manifested in spectroscopic measurements and density functional theory calculations. This study underscores the significance of conjugated anchoring linkages in the stabilization and functionalization of metal chalcogenides, a unique strategy for diverse applications.

[Bone remodeling after total hip arthroplasty with anatomic medullary locking prosthesis and its long-term effectiveness].

OBJECTIVE: To investigate the femoral bone remodeling and long-term effectiveness of total hip arthroplasty (THA) with anatomic medullary locking (AML) prosthesis. METHODS: The clinical data of 24 cases (26 hips) who were treated with THA with AML prosthesis between November 1997 and January 2003 were retrospectively analyzed. There were 12 males and 12 females with an age of 32-69 years (mean, 53.7 years). There were 5 cases (5 hips) of avascular necrosis of the femoral head, 6 cases (7 hips) of secondary osteoarthritis of the hip dysplasia, 6 cases (6 hips) of femoral neck fracture, 2 cases (2 hips) of primary osteoarthritis, 3 cases (3 hips) of revision surgery, 1 case (2 hips) of ankylosing spondylitis, 1 case (1 hip) of femoral head fracture. The patients were followed up at immediate, 6 weeks, 3 months, 6 months, 1 year, and then every year after operation for imaging evaluation (X-ray film was taken immediately after operation to evaluate the femoral isthmus compression, Engh standard was used to evaluate the biological fixation of the femoral shaft prosthesis, and Brooker method was used to evaluate the occurrence of heterotopic ossification); bone reconstruction evaluation [reconstruction of prosthesis and bone interface (type of bone reaction, Gruen zone, incidence, and occurrence time were recorded), reconstruction of bone around prosthesis (proximal femur stress shielding bone absorption was evaluated according to Engh and Bobyn methods, and bone mineral density change rate was measured)]; clinical efficacy evaluation [Harris score for efficacy, visual analogue scale (VAS) score for thigh pain]. RESULTS: All patients were followed up 15 years and 2 months to 20 years and 4 months, with a median of 16 years and 6 months. At immediate after operation, 24 hips (92.3%) had good femoral isthums compression, 24 hips (92.3%) had good bone ingrowth. Heterotopic ossification occurred in 2 patients with degree 1, 2 patients with degree 2, and 1 patient with degree 3 at 3-6 months after operation. Hyperplastic bone reactions were more common in Gruen 2, 3, 4, 5, 6, 10, 11, and 12 zones, mainly occurring at 6-20 months after operation, with the incidence of 3.8%-69.2%, with the highest incidence of spot welding. All absorptive bone reactions were osteolysis, which was common in Gruen 1 and 7 zones, and mainly occurred at 8 years after operation, with an incidence of 42.3%. No clear line (area) or enlarged sign of medullary cavity was observed. Twenty-one hips (80.8%) had 1 degree stress shieding, and 5 hips (19.2%) had 2 degree stress shieding. It mainly occurred at 10-24 months after operation in Gruen 1 and 7 zones. Dual energy X-ray absorptiometry showed that bone mineral density mainly decreased in Gruen 1, 2, 6, and 7 zones, mainly increased in Gruen 3, 4, and 5 zones. Bone mineral density loss progressed slowly after 2 years of operation, and it was stable in 5-8 years, but decreased rapidly in 8-9 years, and stabilized after 10 years. The Harris score increased from 51.1±6.2 before operation to 88.3±5.1 at last follow-up ( t=-21.774, P=0.000). Mild thigh pain occurred in only 2 cases (7.7%) with the VAS score of 2. No aseptic loosening or revision of femoral prosthesis occurred during the follow-up. CONCLUSION: The application of AML prosthesis in THA has a good bone remodeling and a good long-term effectiveness.

[Becker V-shaped lateral rotation osteotomy in total hip arthroplasty for Crowe type IV development dislocation of hip].

OBJECTIVE: To summarize the surgical technique and the effectiveness of Becker V-shaped lateral rotation osteotomy in total hip arthroplasty (THA) for Crowe type IV development dislocation of the hip (DDH). METHODS: Between January 2000 and December 2009, 18 patients (22 hips) with Crowe type IV DDH underwent THA. There were 3 males and 15 females with an average age of 54 years (range, 41-75 years). The unilateral hip was involved in 14 cases and bilateral hips in 4 cases. All patients had over anteversion of the femoral neck, with the acetabular anteversion angle of (21.28 +/- 4.87) degrees, the femoral neck anteversion angle of (59.06 +/- 1.44) degrees, and combined anteversion angle of (80.33 +/- 1.55) degrees. All the patients had limb-length discrepancy, ranged from 1.0 to 3.5 cm (mean, 2.5 cm). Before operation, gluteus medius muscle strength was grade 2 in 17 hips and grade 3 in 5 hips; severe or moderate claudication was observed in 13 and 5 patients, respectively. Trendelenburg sign was positive in all patients. Preoperative Harris score was 30.00 +/- 6.32. Cementless prosthesis was used. Becker V-shaped lateral rotation osteotomy and subtrochanteric shortening with overlapping femoral resection were performed, and proximal femoral shaft splitting was performed on 21 hips having narrow bone marrow cavity. RESULTS: All the cases achieved primary healing of incision. No complication of anterior dislocation, deep infection, nerve traction injury, or femoral uncontrolled fracture occurred. All the cases were followed up 3-12 years (mean, 8 years). Postoperative X-ray films showed that the initial fixation result of femoral prosthesis was excellent in 18 hips and good in 4 hips. Bone healing of osteotomy stump was obtained at 3-6 months (mean, 5 months) after operation. Affected limb prolonged for 2.5-3.5 cm (mean, 3.0 cm) at 1 year after operation; limb-length discrepancy was 0.5-1.5 cm (mean, 1.0 cm). The gluteus medius muscle strength was restored to grade 4 in 5 hips and grade 5 in 17 hips. At last follow-up, 13 patients had no claudication, and 5 patients had mild claudication; Trendelenburg sign was negative in 15 cases and was positive in 3 cases; the Harris score was significantly improved to 91.89 +/- 3.22; all showing significant difference when compared with preoperative ones (P < 0.05). At last follow-up, the acetabular anteversion angle, the femoral neck anteversion angle, and combined anteversion angle were (19.33 +/- 4.49), (13.33 +/- 5.70), and (32.67 +/- 5.35) degrees, respectively, all showing significant differences when compared with preoperative ones (P < 0.05). No aseptic loosening, osteolysis, or rediolucent line was found around the femoral component. No implant subsidence, stem varus, or revision occurred. CONCLUSION: Becker V-shaped lateral rotation osteotomy is a safe and predictable method to treat type Crowe type IV DDH.