Stereoisomeric coordination polymers based on facial and meridional six-coordinate dysprosium(III ).

Due to the small differences in the chemical properties of facial (fac) and meridional (mer) stereoisomers, selective synthesis of one of the isomers is challenging, especially for lanthanide complexes. By using a flexible bidentate phosphine oxide ligand, we managed to isolate three stereoisomeric 2D and 3D coordination polymers, in which six-coordinate Dy(III) ions possess fac- or mer-Cl3O3 coordination environments. Structural studies indicate that the stereochemistry differences result from their various supramolecular interactions (e.g., hydrogen bonding and π⋯π stacking). Magnetic property measurements reveal the different static and dynamic magnetic behaviours of the three stereoisomers. Ab initio CASSCF calculations were then performed which indicated that their distinct magnetic behaviours arise from their fac/mer configurations. Compared to fac-Dy(III), mer-Dy(III) possesses more axial ground-state KDs and higher first excited KDs.

[Treatment of extensive cervicomandibular scar in children and adolescent patients with bilateral expanded scapular flaps: report of 7 consecutive cases].

PURPOSE: To explore the feasibility of applying bilateral free expanded scapular flaps to treat extensive cervicomandibular scar in children and adolescents. METHODS: This study reviewed 7 children and adolescent patients who received bilateral expanded scapular flaps to treat extensive cervicomandibular scars in the Pediatric Plastic Surgery Ward from August 2018 to December 2020. The scars in all patients involved neck, mandible, and anterior chest. The cervical scars involved the anterior neck and one or both sides of the lateral neck, and there were varying degrees of cervical dysfunction and mandibular dysplasia. The operation was completed into two stages. In the first stage, the expanded circumflex scapular artery perforator flaps were designed on both sides of the back and soft tissue expanders were implanted. The expansion process lasted for 6-14 months. In the second stage, the scar tissue was removed and contracture was released, and the expanded flaps were harvested. The cervical wound was repaired with free flap transplantation by anastomosing the facial artery and vein with the circumflex scapular artery and vein. The donor sites were closed directly. RESULTS: In this series of 7 patients, one patient had poorly healed incision after the expander was implanted. One expanded flap ruptured before the second-stage surgery, which was successfully treated by secondary surgery. One patient had expansion problem due to the blockage of the internally placed injection bottle, which was treated by placing the injection bottle externally. One patient developed a small area of ischemic necrosis at the distal end of the flap after transplantation, which was treated conservatively with dressing change. The postoperative follow-up was 6 months to 2 years. The cervico-mandibular angle restored to normal range, the cervical extension, flexion, and rotation were significantly improved. Two patients underwent flap thinning and scar releasing. CONCLUSIONS: The route of the circumflex scapular artery is constant. Bilateral expanded scapular flap transplantation can be used to repair extensive cervicomandibular scar in children and adolescent patients. The flap donor site is concealed and secondary damage is minimal.

Phosphine Oxide Ligand Based Tetrahedral CoII Complexes with Field-induced Slow Magnetic Relaxation Behavior Modified by Terminal Ligands.

Two isostructural mononuclear CoII complexes, [Co(xantpo)(NCE)2 ] (E=S (1) and O (2); xantpo=9,9-dimethyl-4,5-bis(diphenylphosphoryl) xanthene), supported by a bidentate phosphine oxide ligand are reported. The cobalt complexes exhibit characteristic tetrahedral structures coordinated with two oxygen and two nitrogen atoms. Magnetic property measurements show their similar static magnetic behaviours but very different dynamic magnetic behaviours. Both complexes show field-induced slow magnetic relaxation behaviours, but the relaxation of 2 is much slower than that of 1. Fittings to the magnetic data and ab initio CASSCF calculations reveal significant changes in the zero field splitting (ZFS) parameters (D and E), which can be attributed to the small geometrical changes of the Co ions and the different ligand field strength of the two terminal ligands.

[Anatomy and clinical application of posterior calf fasciocutaneous flap].

OBJECTIVE: To investigate the blood supply and the clinical application of the posterior calf fasciocutaneous flap for repairing the frontal defect of knee joint. METHODS: Based on the article review and the anatomical study of the posterior calf in 8 cadavers (16 sides), 10 cases with frontal defects of knee joints were repaired with island fasciocutaneous flaps which had pedicles of lateral superficial sural artery and the lateral sural nerve. RESULTS: The anatomical study showed there were three systems of superficial sural blood supply- medial, middle and lateral systems. They are originated from popliteal artery or from the bilateral sural artery. The lateral superficial sural artery was present in 100% of the cadavers. The flaps survived completely in 9 cases, except one case with partial necrosis at the one-fourth distal end of the flap. The patients were followed up for 6-12 months with good aesthetic and functional results. CONCLUSIONS: The posterior calf island fasciocutaneous flap has an reliable blood supply and protective sense nerve. The flap is ideal for the reconstruction of soft tissue defect around knee joint.

[Microsurgical reconstruction of the nasal subunit defects].

OBJECTIVE: The nose is composed of several delicate subunits, some of which are difficult to reconstruct if they have been injured. The paper presents the microsurgical technique to repair the nasal subunit defects with the free combined preauricular and auricular flap which well match the nasal tissues in texture, contour and color. METHODS: The nasal subunit defects were repaired with the combined preauricular and auricular flap which were vascularized by the superficial temporal vascular system. The flap was harvested from the contralateral preauricular and the region of helix crus. The superficial temporal vessels were anastomosed to facial vessels via the vascular grafts harvested from the lateral circumfluent femoral vessels, which were about 10 to 14 cm in length. The helix crus of donor ear was reconstructed with the post-auricular flap. RESULTS: 28 cases were treated, including 3 cases of nasal tip defects, 9 cases of combined nasal alar and sidewall defects, and 16 cases of nasal alar defects. In these cases, the size of the subunit defects varied from 2.5 cm x 1.5 cm to 4 cm x 2.5 cm. 27 cases were successfully repaired with satisfactory results. The contour of reconstructed helix crus in donor site was acceptable. No walking dysfunction of the donor thigh was complained. There is one failed case, and the possible reason is the insufficient blood perfusion to the flaps, which may due to the patient's longtime-smoking status and the hypertension. CONCLUSIONS: The technique of free combined preauricular and auricular flap is ideal for the reconstruction of nasal subunit defects.

[Nasal alar reconstruction with a vascularized free auricular composite flap].

OBJECTIVE: The plastic surgeons prefer to reconstruct nasal alar with free auricular composite flap because it well matches nasal tissue in contour, texture and color. However, the size of the free composite flap should be less than 1. 0 cm x 1.5 cm due to the limitation of revascularization. Our aim is to search for a surgical method which could be used to repair full-layer larger nasal alar defects. METHODS: A surgical technique was presented to repair nasal alar defect with a free auricular composite flap, which was vascularized by branches of superficial temporal artery. Briefly, the contralateral auricular composite tissue pedicled by superficial temporal vessels (3 to 4 cm in length) was harvested from region of helix crus and preauricular skin, which matched the arc of the nasal rim, and then transplanted onto the recipient area. The superficial temporal vessel pedicles were anastomosed to facial vessels via vessel grafts harvested from lateral circumflex femoral vessels, which were about 10 to 12 cm in length. RESULTS: Twelve cases were treated, among them, 11 cases were successfully repaired with satisfactory results, one case failed, possibly due to the bad condition of the patient's blood vessels. In our cases, the size of alar defect varied from 1.5 cm x 2.5 cm to 2.0 cm x 3.8 cm. The minimal auricular donor site deformities and inconspicuous scar were acceptable and could easily be hidden by hair. CONCLUSIONS: The technique of free auricular composite flap, which is vascularized by superficial temporal vessels, is ideal for nasal alar reconstruction.

[Inhibiting scar formation in rat cutaneous wounds by blocking TGF-beta signaling].

OBJECTIVE: TGF-beta plays a key role in wound scarring. This study explored the possibility of using gene therapy to inhibit wound scarring by blocking TGF-beta signaling. METHODS: In vitro, human normal dermal fibroblasts were infected with recombinant adenoviruses of truncated TGF-beta receptor II (tTGF-betaRII, 100 pfu/cell) and beta-galactosidase (beta-gal, 100 pfu/cell), and their effects on regulating TGF-beta1 gene expression were analyzed by Northern blot. For gene therapy, beta-gal and tTGF-betaRII viruses (1 x 10(9) pfu)were injected intradermally at left and right side of dorsal skin of newborn Sprague-Dawley rats (n = 15) respectively. A full-thickness incisional wound (0.5 cm long) was created at the injection sites of each rat 2 days post-injection. An incisional wound was similarly created in the middle part of the dorsal skin of tTGF-betaRII transgenic mice (n = 5) and control mice (n = 5). Wound tissues of rats and mice were harvested at various time points post-wounding for histological and immunohistochemical analysis. Scar area in tissue section was measured by Image-Pro Plus software. RESULTS: Over-expression of tTGF-betaRII markedly reduced TGF-beta1 gene expression in dermal fibroblasts. Adenovirus mediated gene expression in skin reached a peak level 2 - 3 days post-injection, and decreased gradually at 5 - 7 days. Two weeks post-wounding, histology and quantitative analysis demonstrated that relative scar area in the wounds of transgenic mice and control mice were 136,969.8 +/- 66,339 and 474,641.6 +/- 227,396 respectively, the scar area of transgenic wounds was 29 percent of control area (P < 0.05). In all rats, wounds transfected with tTGF-betaRII gene healed with much less scarring (relative scar area 128,311.2 +/- 36,764.6) than control wounds (251,189.1 +/- 62,544.7) of the same rat, with a 45% reduction of scar area in average (P < 0.001). In addition, the tTGF-betaRII expression also decreased inflammation and TGF-beta1 production in treated wounds, and promoted the repair of panniculus muscle in treated wounds. CONCLUSIONS: Adenovirus mediated over-expression of tTGF-betaRII can block TGF-beta signaling and inhibit wound scarring, and thus can serve as a gene therapy strategy to control wound scarring.