A new amide from the marine sponge Haliclona baeri.

A new amide, baeriamide (1), along with nine known diketopiperazines (2-10), was isolated from the marine sponge Haliclona baeri. Their structures were identified by the means of UV, IR, MS and NMR. The absolute configuration of 1 was established by Marfey's method and comparing the specific optical rotation with the known compound HCO-Val-Gly methyl ester. Compound 1 was derived from dehydration of formylated L-valine with γ-amino-butanoic acid methyl ester. Compounds 2-10 were isolated from the genus of Haliclona for the first time. The absolute confirmation of 7 was confirmed first by the means of single-crystal X-ray diffraction. The cytotoxic, antibacterial, antiviral and antifouling activities of these compounds were also tested. However, none of them exhibited significant bioactivities.

Gas permeation through graphdiyne-based nanoporous membranes.

Nanoporous membranes based on two dimensional materials are predicted to provide highly selective gas transport in combination with extreme permeance. Here we investigate membranes made from multilayer graphdiyne, a graphene-like crystal with a larger unit cell. Despite being nearly a hundred of nanometers thick, the membranes allow fast, Knudsen-type permeation of light gases such as helium and hydrogen whereas heavy noble gases like xenon exhibit strongly suppressed flows. Using isotope and cryogenic temperature measurements, the seemingly conflicting characteristics are explained by a high density of straight-through holes (direct porosity of ∼0.1%), in which heavy atoms are adsorbed on the walls, partially blocking Knudsen flows. Our work offers important insights into intricate transport mechanisms playing a role at nanoscale.

Three-dimensional printing of patient-specific plates for the treatment of acetabular fractures involving quadrilateral plate disruption.

BACKGROUND: Complicated acetabular fractures comprise the most challenging field for orthopedists. The purpose of this study was to develop three-dimensional printed patient-specific (3DPPS) Ti-6Al-4 V plates to treat complicated acetabular fractures involving quadrilateral plate (QLP) disruption and to evaluate their efficacy. METHODS: Fifty patients with acetabular fractures involving QLP disruption were selected between January 2016 and June 2017. Patients were divided into a control group (Group A, 35 patients) and an experimental group (Group B, 15 patients), and were treated by the conventional method of shaping reconstruction plates or with 3DPPS Ti-6AL-4 V plates, respectively. The efficacy of Ti-6AL-4 V plates was evaluated by blood loss, operative time, reduction quality, postoperative residual displacement, and complications. RESULTS: The operative time and blood loss in Group B were reduced compared to Group A, and the difference was statistically significant (P < 0.05). There was no significant difference in reduction quality between the two groups (P > 0.05). Reduction quality in Group B was anatomic in 10 (66.7%), satisfactory in four (26.7%), and poor in one (6.7%). In Group A, they were anatomic in 18 (51.4%), satisfactory in 13 (37.1%), and poor in four (11.4%). Residual displacement in Group B was less than that in Group A, and the difference was statistically significant (P < 0.05). In Group B, one case exhibited loosening of the pubic screw postoperatively. In Group A, there was one case of wound infection, one of deep vein thrombosis (DVT) in the ipsilateral lower limb, one case of traumatic arthritis and two obturator nerve injuries. CONCLUSIONS: The 3DPPS Ti-6AL-4 V plate is a feasible, accurate and effective implant for acetabular fracture treatment.

Comparative biomechanical testing of customized three-dimensional printing acetabular-wing plates for complex acetabular fractures.

BACKGROUND: Three-dimensional (3D) printing of an acetabular wing-plate is a new minimally invasive surgical technique for complex acetabular fractures. OBJECTIVES: To investigate the biomechanical stability of 3D printing acetabular wing-plates. The results were compared with 2 conventional fixation systems. MATERIAL AND METHODS: Eighteen fresh frozen cadaveric pelvises with both column fractures were randomly divided to 3 groups: A - iliosciatic plates fixation system; B - 3D printing plates; C - 2 parallel reconstruction plates fixation system. These constructions were loaded onto a biomechanical testing machine. Longitudinal displacement and stiffness values of the constructs were measured to estimate their stability. RESULTS: When the load force reached 700 N, Group A was superior to Group B in the longitudinal displacement of point 1 (p > 0.05). The longitudinal displacement of point 2 showed no significant differences among Groups A, B and C, and the displacement of the fracture line over point 3 showed no significant differences between Groups A and B (p > 0.05). The axial stiffness of Groups A, B and C were 122.4800 ±8.8480 N/mm, 168.4830 ±14.8091 N/mm and 83.1300 ±3.8091 N/mm, respectively. Group B was significantly stiffer than A and C (p < 0.05). Loads at failure of internal fixation were 1378.83 ±34.383 N, 1516.83 ±30.896 N and 1351.00 ±26.046 N for Groups A, B and C, respectively. Group B was significantly superior to Groups A and C (p > 0.05). CONCLUSIONS: Customized 3D printing acetabular-wing plates provide stability for acetabular fractures compared to intraspecific buttressing fixation.

Internal fixation of acetabular fractures in an older population using the lateral-rectus approach: short-term outcomes of a retrospective study.

PURPOSE: This study aims to examine the clinical efficacy and surgical techniques of the lateral-rectus approach for treatment of acetabular factures in elderly patients. METHODS: After appropriate exclusion, 65 elderly patients with an acetabular fracture who was treated through the lateral-rectus approach from January 2011 and October 2016 were selected retrospectively. By analyzing the medical records retrospectively, the patients' characteristics, fracture type, mechanism of injury, comorbid conditions, ASA class, operative time, intra-operative blood loss, and post-operative complications were assessed. Clinical examination radiographs have been taken, align with the Matta evaluation system. Functional outcomes were evaluated using surveys including SF-36, Harris hip score, and modified Merle D'Aubigne-Postel. RESULTS: All 65 patients had undergone the single lateral-rectus approach successfully. Surgery duration was 101.23 min on average (45-210), and intra-operative bleeding was 798.46 ml on average (250-1800). According to the Matta radiological evaluation, the quality of reduction evaluated 1 week after surgery was rated as "anatomical" in 41 (63.1%) cases, "imperfect" in 12 (18.5%) cases, and "poor" in 12 (18.5%) cases. The modified Merle D'Aubigne-Postel score performed 18 months after surgery was categorized as excellent in 40 (61.5%) cases, good in 10 (15.4%) cases, and fair in 15 (23.1%) cases. The mean Harris Hip score was similar as present researches, being 87.18. The mean SF-36 score was 69.12 which was considered as normal for the group age 60 and older. Several complications were found, including screw loosening in 10 cases, fat liquefaction of incision in 2 cases, deep vein thrombosis in 2 cases, and temporary weakness of hip adductors in 5 cases. None of the patients had heterotopic ossification. CONCLUSIONS: The lateral-rectus approach is a valuable alternative to the ilioinguinal and modified Stoppa approach, being the treatment of acetabular fractures in elderly patients.

A Single Lateral Rectus Abdominis Approach for the Surgical Treatment of Complicated Acetabular Fractures: A Clinical Evaluation Study of 59 Patients.

BACKGROUND This study aimed to evaluate outcome following a single lateral rectus abdominis surgical approach for complicated acetabular fractures, involving anterior and posterior columns. MATERIAL AND METHODS From January 2012 to March 2016, 59 patients, including 36 anterior column hemitransverse fractures, 18 two-column fractures, and five T-type complicated acetabular fractures, were treated with a single lateral rectus abdominis approach and fixed by plates and cannulated lag screws. Anterior column fractures were fixed with 3.5 mm reconstruction plates; posterior column fractures were fixed with 6.5 mm cannulated lag screws. The quality of surgical reduction (using the Matta criteria), functional outcome (using the modified Merle d'Aubigné and Postel scoring system), and postoperative complications were assessed with 24-month follow-up. RESULTS Fifty-nine patients (mean age, 45 years; range, 18-64 years) including 39 men and 20 women underwent surgery. Mean intraoperative blood loss was 514.6 ml (range, 150-830 ml) and mean operating time was 86.3 min (range, 42-145 min). Anatomical reduction was good in 40 cases (67.8%), fair in 15 cases (25.4%), and poor in four cases (6.8%). The modified Merle d'Aubigné score was excellent in 39 cases (66.1%), good in 14 cases (23.7%), fair in five cases (8.5%), and poor in one case (1.7%). At follow-up, there were five cases of peritoneal damage, eight cases of obturator nerve dysfunction, and four cases of postoperative traumatic arthritis. CONCLUSIONS The single lateral rectus abdominis surgical approach for the treatment of complicated acetabular fractures was minimally invasive with good anatomical exposure and good outcomes.

Central dislocation of femoral head without involvement of acetabular anterior and posterior columns.

Objective This study was performed to explore the treatment of central dislocation of the femoral head without involvement of the acetabular columns. Methods Preoperatively, a three-dimensionally printed model of the patient's pelvis was manufactured according to the patient's computed tomography data. An all-locking anatomical plate was designed based on the mirror of the ipsilesional semi-pelvis. The fracture was reduced using reduction forceps and femoral traction via the lateral rectus approach. The customized plate was used as a template for reduction of the quadrilateral plate fracture. Results Reduction and fixation of this patient's fracture was achieved with a customized all-locking anatomical plate with a propeller shape via the lateral rectus approach. Conclusions This report describes an isolated quadrilateral plate fracture with central dislocation of the femoral head without involvement of the columns, which is a rare injury that has not yet been classified. It was effectively treated using a customized all-locking anatomical plate with propeller shape via the lateral rectus approach.

Biocompatibility of Bespoke 3D-Printed Titanium Alloy Plates for Treating Acetabular Fractures.

Treatment of acetabular fractures is challenging, not only because of its complicated anatomy but also because of the lack of fitting plates. Personalized titanium alloy plates can be fabricated by selective laser melting (SLM) but the biocompatibility of these three-dimensional printing (3D-printed) plates remains unknown. Plates were manufactured by SLM and their cytocompatibility was assessed by observing the metabolism of L929 fibroblasts incubated with culture medium extracts using a CCK-8 assay and their morphology by light microscopy. Allergenicity was tested using a guinea pig maximization test. In addition, acute systemic toxicity of the 3D-printed plates was determined by injecting extracts from the implants into the tail veins of mice. Finally, the histocompatibility of the plates was investigated by implanting them into the dorsal muscles of rabbits. The in vitro results suggested that cytocompatibility of the 3D-printed plates was similar to that of conventional plates. The in vivo data also demonstrated histocompatibility that was comparable between the two manufacturing techniques. In conclusion, both in vivo and in vitro experiments suggested favorable biocompatibility of 3D-printed titanium alloy plates, indicating that it is a promising option for treatment of acetabular fractures.