Strong transmission and reflection of edge modes in bounded photonic graphene.

The propagation of linear and nonlinear edge modes in bounded photonic honeycomb lattices formed by an array of rapidly varying helical waveguides is studied. These edge modes are found to exhibit strong transmission (reflection) around sharp corners when the dispersion relation is topologically nontrivial (trivial). An asymptotic theory is developed that establishes the presence (absence) of typical edge states, including, in particular, armchair and zigzag edge states in the topologically nontrivial (trivial) case. In the presence of topological protection, nonlinear edge solitons can persist over very long distances.

Effect of Sevoflurane postconditioning on gene expression in brain tissue of the middle cerebral artery occlusion rat model.

Ischemic postconditioning has been described in both heart and brain. The first aim of this study was to evaluate the effects of Sevoflurane postconditioning (SP) on brain biochemical parameters, Bcl-2, Bax, c-Fos and Caspase-3 protein levels and Bcl-2, Bax, TNF-α and Caspase-3 mRNA expression in the middle cerebral artery occlusion model. Results showed that SP markedly decreased cerebral oxidative injury and improved immunity activity. In addition, SP significantly enhanced cerebral Bcl-2, c-Fos and decreased Bax, Caspase-3 proteins positive expression. Reverse transcription polymerase chain reaction analysis showed that SP markedly enhanced Bcl-2, and decreased Bax, TNF-α and Caspase-3 mRNA expression. Our results confirm that SP can play the protective action against cerebral ischemia reperfusion-induced brain injury by regulating cerebral antioxidant enzymes activities, Bcl-2, Bax, c-Fos and Caspase-3 protein positive expression levels and Bcl-2, Bax, TNF-α and Caspase-3 mRNA expression.

[A comparative study of vancomycin loaded bone cement in the treatment of Wagner â ¡-â £ diabetic foot].

OBJECTIVE: To investigate the clinical effect of vancomycin bone cement in the treatment of diabetic foot ulcer (DFU) ruptured Wagner gradeⅡ-Ⅳ. METHODS: From March 2019 to April 2021, 32 patients with Wagner gradeⅡ-Ⅳ diabetic foot were divided into vacuum sealing drainage (VSD) group and bone cement group according to different treatment methods. There were 16 cases in VSD group, 8 males and 8 females;the age ranged from 66 to 81 (70.50±7.20) years, and the course of disease ranged from 8 to 40 (27.56±8.55) months;Wagner gradeⅡin 2 cases, grade Ⅲin 7 cases and grade Ⅳin 7 cases;debridement and VSD were used. There were 16 cases in the bone cement group, 9 males and 7 females;the age ranged from 63 to 79 (69.56±7.29) years, and the course of disease ranged from 11 to 39(22.75±11.43) months;Wagner gradeⅡ in 2 cases, grade Ⅲin 5 cases and grade Ⅳ in 9 cases;vancomycin loaded bone cement was used for treatment. The types of bacteria, negative time of bacterial culture, skin healing time, hospital stay, operation times and complications were observed and compared between two groups. RESULTS: All patients were followed up for 3 to 6 (4.00±1.07) months. The bacterial negative time, skin healing time and hospital stay in bone cement group were significantly lower than those in VSD group (P<0.05). The median number of operations in both groups was 2, and there was no significant difference (P>0.05). According to the analysis of pathogens in two groups, there were 13 cases of G+ patients, 14 cases of G- patients and 5 cases of mixed bacteria. The number of G+, G- and mixed bacteria in bone cement group was 6, 7 and 3 cases respectively, and the number of G+, G- and mixed bacteria in VSD group was 7, 7 and 2 cases respectively. The wounds of 32 patientsin two groups healed completely without complications. CONCLUSION: Vancomycin loaded bone cement is effective in the treatment of Wagner grade Ⅱ-Ⅳ diabetic foot ulceration wounds. It can reduce the length of hospital stay, shorten the healing time of skin and kill pathogens as soon as possible. It is one of the effective methods to treat Wagner gradeⅡ-Ⅳdiabetic foot ulceration.

[Modified Metaizeau's technique for the treatment of radial neck fractures of Judet III or IV in children].

OBJECTIVE: To explore the clinical effect of modified Metaizeau's technique for radial neck fractures of Judet II or IV in children, summarizing the value of clinical application. METHODS: From May 2014 to March 2017, 32 children of Judet III or IV radial neck fractures were treated with percutaneous Kirschner wire poking reduction and closed reduction with elastic intramedullary nailing fixation, including 21 boys and 11 girls, aged from 5.7 to 10.6 years old with a mean of 7.2 years old. The modified An-Morrey functional rating index were used to evaluate elbow range of motion, myodynamia, stability, and pain preoperatively and 1 year postoperatively in all the patients. RESULTS: All patients were available for an average follow-up from 12 to 15 months. No complications such as incision infection, wire or nail tail irritation and avascular necrosis of radial head and epiphyses was occurred. The fracture achieved solid healing at 8 to 10 weeks after operation. The modified An and Morrey functional score improved from 58.69±5.80 before operation to 99.13±1.79 at 1 year after operation, there was obvious difference of scores between preoperative and postoperative at 1 year. CONCLUSIONS: Modified Metaizeau's technique is a reliable and good treatment for Judet III or IV radial neck fractures in children, which has advantages of few complication, minimal invasion, quick fracture union and good recovery of elbow joint.

[Clinical effect of minimally invasive technique on the treatment of osteoporotic humeral shaft fractures in elderly patients with locking plates].

OBJECTIVE: To explore the clinical effect of minimally invasive technique combined with locking plates for the treatment of osteoporotic humeral shaft fractures in elderly patients. METHODS: From July 2012 to December 2016, 26 patients were treated by minimally invasive technique combined with the locking plate for osteoporotic humeral shaft fractures, including 10 males and 16 females, ranging in age from 61 to 81 years old, with an average of 70.3 years old. The T-score of mean bone density was -2.74. All 26 patients had closed fractures, including 6 cases of type A, 7 cases of type B and 13 cases of type C. All patients were followed up for 12 months after surgery, and the Constant shoulder joint score and Mayo elbow score were calculated before surgery and 12 months after surgery. RESULTS: All 26 patients were followed up, and the duration ranged from 12 to 16 months, with an average of 13.2 months. All fractures healed within 16 weeks, with an average healing time of 14.3 weeks. The average Constant shoulder joint score before surgery and 12 months after surgery was 54.61±2.09, 88.50±2.47. The average score of Mayo elbow joint before surgery and 12 months after surgery was 58.19±2.74, 90.30±2.16. CONCLUSIONS: The shoulder and elbow joint function of elderly patients with osteoporotic humeral fractrues treated with minimally invasive technology combined with locking plate recovered well postoperatively. It is an effective method for the treatment of osteoporotic humeral shaft fractures in elderly patients.

Conical wave propagation and diffraction in two-dimensional hexagonally packed granular lattices.

Linear and nonlinear mechanisms for conical wave propagation in two-dimensional lattices are explored in the realm of phononic crystals. As a prototypical example, a statically compressed granular lattice of spherical particles arranged in a hexagonal packing configuration is analyzed. Upon identifying the dispersion relation of the underlying linear problem, the resulting diffraction properties are considered. Analysis both via a heuristic argument for the linear propagation of a wave packet and via asymptotic analysis leading to the derivation of a Dirac system suggests the occurrence of conical diffraction. This analysis is valid for strong precompression, i.e., near the linear regime. For weak precompression, conical wave propagation is still possible, but the resulting expanding circular wave front is of a nonoscillatory nature, resulting from the complex interplay among the discreteness, nonlinearity, and geometry of the packing. The transition between these two types of propagation is explored.

A novel missense KIT mutation causing piebaldism in one Chinese family associated with café-au-lait macules and intertriginous freckling.

Piebaldism is a rare autosomal dominant genodermatosis, manifesting as congenital and stable depigmentation of the skin and white forelock. It has been found to be associated with mutations in the KIT or SLUG genes. We report a Chinese piebaldism family including a 28-year-old woman and her 3-year-old son with characteristics of white patches and forelock associated with numerous brown macules and patches. Genomic DNA samples of the proband and her son were extracted from their peripheral blood. One hundred unrelated healthy individuals were used as controls. All coding regions of KIT, SLUG, and NF1 genes were amplified by polymerase chain reaction using exon flanking intronic primers and Sanger sequencings were performed. DNA sequencing revealed heterozygous missense c.2431T>G mutation in exon 17 of the KIT gene in the proband and the affected son. No potentially pathogenic variant was identified in SLUG or NF1 genes. The nucleotide substitution was not found in 100 unrelated control individuals. This study reveals a novel KIT mutation in piebaldism, and it further supports that café-au-lait macules and intertriginous freckling of piebaldism are parts of pigmented anomaly in piebaldism, which does not necessarily represent coexistence of neurofibromatosis type 1 (NF1).

[Unilateral external fixation assisted with closed reduction and interlocking intramedullary nail fixation for the treatment of comminuted fracture of femoral shaft].

OBJECTIVE: To introduce the use of single arm external fixation assisted reduction and closed complex intramedullary nail fixation for the treatment of femoral shaft fracture operation method and to study its effects. METHODS: From June 2008 to October 2012, 24 patients with femoral shaft fractures were treated with unilateral external fixation assisted by closed reduction, interlocking intramedullary nail fixation. Among the patients, 19 patients were male and 5 patients were female, ranging in aged from 20 to 68 years,with an average of 45.6 years old. The fracture was caused by traffic accidents in 14 cases, by falling in 6 cases, by heavy bruising in 4 cases. Admission diagnosis was femoral shaft fracture. Operation was performed after traction from tibial tubercle for about 1 week. RESULTS: All the patients were followed up, and the duration ranged from 6 to 24 months, with a mean of 16.2 months. The X-ray showed fracture healing time ranging from 11 to 17 weeks, with an average of 13.8 weeks. All fractures healed without nails broken or close joint dysfunction. According to femoral shaft efficacy evaluation standards, 23 patients got an excellent result, 1 good. CONCLUSION: Unilateral fixator assisted closed reduction and interlocking intramedullary nail fixation for the treatment of femoral shaft fracture has following advantages: less trauma, simple operation, effective reduction, high rate of fracture healing, and low complication rate.

[Clinical application of blocking screws and rooting technique in the treatment of distal tibial fracture with interlocking intramedullary nail].

OBJECTIVE: To introduce the clinical method of blocking screws and rooting technique in the treatment of distal tibial fracture with interlocking intramedullary nails. METHODS: From June 2006 to March 2011, 26 patients with distal tibial fracture were treated with interlocking intramedullary nails using blocking screws and rooting technique, included 18 males and 8 females with an average age of 46.2 years old ranging from 24 to 64 years. According to AO classification: 10 cases of type A1, 4 cases of type A2, 8 cases of type B1, 4 cases of type B2. The average distance of the fractures end to the ankle joint was 85 mm ranging from 55 to 125 mm, the mean time between injured and operation was 4.5 days. The patients were evaluated with pain, range of motion, walking. RESULTS: All cases were followed-up for 6 to 22 months (averaged 15 months). According to Iowa ankle joint grading system,the score was improved from preoperative (66.8 +/- 8.2) to postoperative (94.6 +/- 4.8). All fractures had united, and got satisfactory reduction and stable fixation with no complications had happen such as breakage of screw. CONCLUSION: Fixation with interlocking intramedullary nail using blocking screws and rooting technique in treating distal tibial fracture, is a safe and effective technique for the improvement of stability.