ABSTRACT
OBJECTIVE: To explore curative effects of external fixation combined with single hip plaster in treating children with femoral subtrochanteric fracture. METHODS: Form March 2009 to July 2016, 15 children with femoral subtrochanteric fracture were treated with external fixation combined with single hip plaster, including 9 males and 6 females with a mean age of 8.5 years old ranging from 5 to 14 years old. According to fracture classification of Seinsheimer, 3 cases were type IIA, 4 cases were type IIB, 3 cases were type IIC, 2 cases were type IIIA, 1 case was type IIIB, 1 case was type IV, 1 case was type V. Complications and radiographs were retrospectively reviewed. Postoperative function of hips were evaluated according to Sanders criteria. RESULTS: All children were followed up from 16 to 48 months with an average of 32 months. No early closure of epiphysis, bone nonunion and breakage of screw occurred. According to the Sanders score standard of hip function, the result was excellent in 14 cases, good in 1 case. There were no hip inversion, limb shortening, excessive growth and other malformations. CONCLUSIONS: External fixation combined with single hip plaster for the treatment of children is a safe and effective fixation, which provide a new choice of femoral subtrochanteric fracture.
Subject(s)
Casts, Surgical , Femoral Fractures/surgery , Fracture Fixation/methods , Adolescent , Bone Screws , Child , Child, Preschool , Female , Femoral Fractures/classification , Hip , Humans , Male , Treatment OutcomeABSTRACT
Quasi-phase-matching (QPM) has enriched the capacity of parametric down-conversion (PDC) in generating biphotons for many fundamental tests and advanced applications. However, it is not clear how the nonidealities and randomness in the QPM grating of a parametric down-converter may affect the quantum properties of the biphotons. This paper intends to provide insights into the interplay between PDC and nonideal or random QPM structures. Using a periodically poled nonlinear crystal with short periodicity, we conduct experimental and theoretical studies of PDC subject to nonideal duty cycle and random errors in domain lengths. We report the observation of biphotons emerging through noncritical birefringent-phasematching, which is impossible to occur in PDC with an ideal QPM grating, and a biphoton spectrum determined by the details of nonidealities and randomness. We also observed QPM biphotons with a diminished strength. These features are both confirmed by our theory. Our work provides new perspectives for biphoton engineering with QPM.
ABSTRACT
Matrix metalloproteinases (MMP) play a pivotal role in the pathogenesis of cardiovascular diseases. Their expressions are altered in response to a variety of stimuli, including growth factors, inflammatory markers, and cytokines. In this study, we demonstrated that platelet-derived growth factor-BB (PDGF-BB) induces a dose- and time-dependent increase in MMP-2 expression in rat vascular smooth muscle cells (VSMC). Treatment with either the Rho-associated protein kinase (ROCK) inhibitor Y-27632 or suppression of ROCK-1/2 by small interfering RNA technology significantly reduced the MMP-2 expression, thus suggesting that ROCK regulates such expression. Similar results were observed when VSMC were pretreated with either U0126 or SB203580, which are selective inhibitors of extracellular signal-regulated kinase and p38 mitogen-activated protein kinase, respectively, thus suggesting that these kinases are important for the induction of MMP-2 expression by PDGF-BB. In conclusion, these results described a novel mechanism in atherosclerosis through PDGF-BB signaling in VSMC, in which MMP-2 expression is induced via extracellular signal-regulated kinases and p38 mitogen-activated protein kinase phosphorylation, as well as ROCK.
