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To investigate the mass absorption efficiency (MAE) of elemental carbon (EC) at Chengdu in China’s Sichuan Basin, daily PM2.5 filter samples were collected during the typical month for each season in 2011. PM2.5 samples were subject to chemical analysis for water-soluble inorganic ions, organic carbon and EC, as well as biomass burning organic tracer (i.e., levoglucosan). Additionally, PM2.5 samples were further conducted for aerosol absorption coefficient (bap) measurement at the wavelengths of 370 and 880 nm. To evaluate the seasonal variations of MAEs of EC, linear regression analyses were applied to EC (determined by thermal method), black carbon (BC, determined by optical method) and bap for four seasons. The average BC concentration was 10 µg m−3 when using the manufacturer’s recommended value (16.6 m2 g−1 at the wavelength of 880 nm), which was 1.4 times the mean EC concentration. The MAE of EC at 880 nm was estimated to be 6.1 m2 g−1 in autumn, which was evidently lower than 6.7–6.9 m2 g−1 in other seasons. The higher MAE in other seasons was likely due to more effective light absorption by internally mixed EC with both transparent coatings (e.g., sulfate and nitrate) and organic matters coatings.

Orthopedic surgeons sometimes combine recombinant, human BMP-2 with autograft bone when dealing with problematic osseous fractures. Although some case reports indicate success with this off-label strategy, there have been no randomized controlled trials. Moreover, a literature search revealed only one pre-clinical study and this was in a cranial defect model. The present project examined the consequences of combining BMP-2 with particles of living bone in a rat femoral defect model. Human bone particles were recovered with a reamer-irrigator-aspirator (RIA). To allow acceptance of the xenograft as surrogate autograft, rats were administered an immunosuppressive cocktail that does not interfere with bone healing. Implantation of 200 µg living bone particles generated a small amount of new bone and defects did not heal. Graded amounts of BMP-2 that alone provoked no healing (1.1 µg), borderline healing (5.5 µg), or full healing (11 µg) were added to this amount of bone particles. Addition of BMP-2 (1.1 µg) increased osteogenesis, and produced bridging in 2 of 7 defects. The combination of BMP-2 (5.5 µg) and bone particles made healing more reliable and advanced the maturation of the regenerate. Bone formation with BMP-2 (11 µg) and bone particles showed improved maturation. Thus, the combination of autograft and BMP-2 may be helpful clinically under conditions where the healing response is suboptimal. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:2137-2145, 2016. Clinical significance These data support the clinical use of recombinant, human BMP-2 with autograft bone when treating large segmental osseous defects. The combination leads to greater bone formation and accelerates the maturation of the regenerate.

The calcitonin receptor (CTR) is expressed in a wide variety of tissues and cell types. In bone, its expression is restricted to osteoclasts, the cells that mediate bone resorption. The human CTR (hCTR) gene has a complex structural organization that exhibits similarity to the porcine (pCTR) and mouse (mCTR) CTR genes. In these species, alternative splicing of a single gene generates multiple CTR isoforms that are distributed in both tissue-specific and species-specific patterns. However, the structural organization of the 5' putative regulatory region and transcriptional mechanisms responsible for tissue-specific expression of the different CTR isoforms are not fully defined. The present studies were undertaken to characterize the structural organization of the 5'-region of the hCTR and identify the regulatory regions involved in osteoclast-specific transcriptional activation. Analysis of mRNA prepared from human osteoclasts using reverse transcription-polymerase chain reaction (RT-PCR) and transient transfection of hCTR promoter-luciferase reporter constructs identified two regions in the 5'-flanking sequence of the hCTR gene that regulated CTR gene expression in osteoclasts. Both of these putative promoters were responsive to the osteoclast-inducing cytokine, receptor activator of NF-kappaB ligand (RANKL) and demonstrated trans-activation by the RANKL-induced transcription factor nuclear factor of activated T cells (NFATc1), consistent with a role in regulating CTR gene expression in osteoclasts.