A Cantilever Beam-Based Triboelectric Nanogenerator as a Drill Pipe Transverse Vibration Energy Harvester Powering Intelligent Exploitation System.

Measurement While Drilling (MWD) is the most commonly used real-time information acquisition technique in offshore intelligent drilling, its power supply has always been a concern. Triboelectric nanogenerators have been shown to harvest low-frequency vibrational energy in the environment and convert it into electricity to power small sensors and electrical devices. This work proposed a cantilever-beam-based triboelectric nanogenerator (CB-TENG) for transverse vibration energy harvesting of a drill pipe. The CB-TENG consists of two vibrators composed of spring steel with PTFE attached and Al electrodes. The structurally optimized CB-TENG can output a peak power of 2.56 mW under the vibration condition of f = 3.0 Hz and A = 50 mm, and the electrical output can be further enhanced with the increased vibration parameters. An array-type vibration energy harvester integrated with eight CB-TENGs is designed to fully adapt to the interior of the drill pipe and improve output performance. The device can realize omnidirectional vibration energy harvesting in the two-dimensional plane with good robustness. Under the typical vibration condition, the short-circuit current and the peak power can reach 49.85 µA and 30.95 mW, respectively. Finally, a series of demonstration experiments have been carried out, indicating the application prospects of the device.

CUL4A expression in pediatric osteosarcoma tissues and its effect on cell growth in osteosarcoma cells.

Osteosarcoma (OS) is the most common bone malignancy in the pediatric population, and it comprises about 3 % of all pediatric tumors. Aberrant expression of the Cullin 4A (CUL4A) is found in many tumor types, but the role of CUL4A in OS progression remains largely unknown. The aim of this study was to investigate the expression and function of CUL4A in OS. CUL4A expression was detected in 30 samples of surgically resected OS and matched tumor-adjacent tissues using quantitative reverse transcription polymerase chain reaction (qRT-PCR) and Western blot. Cell proliferation was assessed by MTT, and migration and invasion were analyzed by Transwell and Matrigel assays after CUL4A knockdown in OS in vitro. Our result showed increased CUL4A expression in OS tissues. CUL4A knockdown inhibited the proliferation of MG63 cells. Furthermore, CUL4A siRNA ameliorated the migration and invasion of MG63 cell lines with altered expression of epithelial-mesenchymal transition (EMT)-associated molecules. Taken together, our findings indicate that CUL4A plays a pivotal role in OS progression and may serve as a potential marker for clinical diagnosis and target for therapy.

Comparison of titanium elastic intramedullary nailing versus injection of bone marrow in treatment of simple bone cysts in children: a retrospective study.

BACKGROUND: Simple bone cysts are common benign lytic bone lesions in children. The main goals of treatment for bone cysts are to prevent pathological fractures, support the healing process, and prevent recurrence. This retrospective study compared fixation with titanium elastic intramedullary nailing (TEN) versus aspiration and injection of autogenous bone marrow (ABM) for the treatment of simple bone cysts in children. METHODS: Forty-six patients (mean follow-up, 62 months; range, 34-71 months) who presented with bone cysts (30 in the humerus, 16 in the femur) from January 2006 to December 2012 were retrospectively evaluated. Patients were treated with either TEN or ABM injection. Radiographs were evaluated according to previously established criteria. Clinical evaluations of pain, infection, additional fractures, and range of motion were performed. RESULTS: After treatment, all patients were pain-free and had normal range of motion in adjacent joints. In the ABM group, 14 (60.9 %) bone cysts completely healed, six (26.1 %) healed with small residuals after two injections, and three (13.0 %) recurred. In the TEN group, 16 (69.6 %) bone cysts completely healed, four (17.4 %) healed with small residuals, and three (13.0 %) recurred. There were no significant differences in radiographic outcomes between groups at the final follow-up (P > 0.05). Three patients developed skin irritation as a result of the nail ends. Additional fractures occurred in four patients who underwent ABM injection and in two patients who underwent TEN. No significant associations were found between pathological fractures and cyst activity, location, or treatment outcomes in the patients studied. CONCLUSIONS: Both TEN and ABM injection are safe and effective treatment for bone cysts. ABM injection promotes osteogenic differentiation of bone marrow stromal cells; multiple injections can reduce the likelihood of recurrence. TEN stabilizes the affected bone and thus allows early limb mobilization. It also reduces pressure in the capsule wall by continuous decompression to promote cyst healing. ABM injections can be used to treat cyst recurrence after previous TEN, with favorable results.

Electroacupuncture ST36 prevents postoperative intra-abdominal adhesions formation.

BACKGROUND: We have recently proved electroacupuncture (EA) ST36 exerted an anti-inflammatory effect in the early phase of intra-abdominal adhesion formation. Evidences indicate that the anti-inflammatory effect of EA ST36 involves a cholinergic anti-inflammatory pathway-dependent mechanism via the vagus nerve. However, the exact effects and accurate vagal modulation of acupuncture in prevention of postoperative intra-abdominal adhesion formation has not been thoroughly evaluated. MATERIALS AND METHODS: Sprague-Dawley rats subjected to abdominal adhesion lesions operation at the cecum and abdominal wall were randomly divided into six groups as follows: (a) EAN: EA non-channel acupoints; (b) EA: EA ST36 after abdominal lesions; (c) VGX/EA: vagotomy (VGX) after abdominal lesions, then EA ST36; (d) VGX/EAN: VGX after abdominal lesions, then EAN; (e) α-BGT/EA: intraperitoneal injection of α-bungarotoxin (α-BGT, an antagonist of α7 subunit of cholinergic nicotinic receptor) before EA ST36, and (f) α-BGT/EAN group: α-BGT injection before EAN. Seven days after abdominal surgical lesions, the levels of tumor necrosis factor-α (TNF-α) and vascular endothelial growth factor (VEGF) in the adhesive tissue were evaluated, macroscopic observation and histopathologic evaluation of adhesion formation and assessment of angiogenesis by immunohistochemical staining of platelet endothelial cell adhesion molecule-1 (CD31) were performed. RESULTS: EA ST36 reduced TNF-α and VEGF levels in adhesive tissue homogenates 7 d after surgery, whereas vagotomy or intraperitoneal injection of α-BGT before EA ST36 reversed its suppressive effects. EA at non-channel acupoints with or without vagotomy or intraperitoneal injection of α-BGT before EA had no suppressive effects on TNF-α and VEGF levels. EA ST36 alleviated the adhesion formation, with both of macroscopic and histopathologic adhesion scores significantly lower than those of the EAN group (1.56 ± 0.29 versus 3.00 ± 0.82, 1.35 ± 0.4 versus 3.91 ± 0.8, respectively, both P < 0.05). Compared with the EAN group, EA ST36 significantly decreased angiogenesis evidenced by reduced CD31 positive microvessel density in adhesive tissue. CONCLUSIONS: EA ST36 might reduce the postoperative local inflammatory response, attenuate the angiogenesis, and alleviate the adhesion formation partly via activating the cholinergic anti-inflammatory mechanism.

Low osteotomy cut of Dega procedure for older children with developmental dysplasia of the hip.

The effect on acetabular management in developmental dysplasia of the hip (DDH) patients aged 7 or older with modified low Dega osteotomy procedure was evaluated. Patients between 7 and 14 years old were managed with modified low Dega osteotomy and open reduction and concomitant procedures to evaluate whether low level osteotomy improved the clinical and radiologic outcomes after treatment. Clinical status was assessed using the modified McKay's criteria; radiologic evaluations were assessed for the modified Severin classification, the mean acetabular index (AI), Sharp angle and center-edge (CE) angle. And occurrence of triradiate cartilage injury and complications was recorded. Forty-two DDH patients (57 hips) between 7 and 14 years old were managed with modified low Dega osteotomy. The results demonstrated the latest follow-up 43 hips (75.4%) were rated excellent and 10 hips (17.5%) rated good according to the modified McKay criteria and 41 hips (71.9%) were rated excellent and 11 hips (19.3%) rated good according to Modified Severin classification, respectively. The mean Hip Score improved from 69.53 ±â€…7.14 before the operation to 93.17 ±â€…8.43 at the final follow-up. The mean AI changed from 31.9° to 20.2°, mean Sharp angle decreased from 59.3° to 38.8° and mean CE angle increased from -10.9° to 35.2°, preoperatively and at latest follow-up, respectively. The modified low Dega osteotomy combined with open reduction and concomitant procedures were found to be adequate in improving instant and sustained clinical and radiographic outcomes for the late detected pediatric walking DDH patients.

A Stackable Triboelectric Nanogenerator for Wave-Driven Marine Buoys.

Marine distributed devices are essential infrastructure for exploring and utilizing the ocean. As the most common carrier of these devices, floating and submerged buoys are subject to a bottleneck of power supply. Recent progress in nanogenerators could convert the high-entropy marine kinetic energy (e.g., wave) robustly, which may form an in-situ power solution to marine distributed devices. This study is devoted to develop a stackable triboelectric nanogenerator (S-TENG), while each layer of it is made into multiple channels carrying PTFE balls in between Aluminum electrodes. In the experiments based on forced motion, the peak power density of the S-TENG reaches 49 W/m3, about 29% promotion from our previous benchmark. The S-TENG has also become less vulnerable to directional variation of the excitation, making its integration on various platforms more flexible in real conditions. In practice, the S-TENG has demonstrated its capability of powering LEDs as well as various sensors measuring salinity, temperature and acidity, which means the S-TENG could self-power many compact marine buoys.

A preliminary comparative study of percutaneous CT-guided cryoablation with surgical resection for osteoid osteoma.

BACKGROUND: The traditional treatment for osteoid osteoma is the nidus' surgical resection, which was difficult to eradicate with more invasive and complications because of osteosclerosis surrounding the nidus. This study aimed to analyze the efficacy and safety of percutaneous CT-guided cryoablation of osteoid osteoma at different sites (especially refractory sites such as the spine). METHODS: Fifteen patients with osteoid osteoma who underwent cryoablation at our institution were analyzed retrospectively on their imaging data and clinical visual analog scale (VAS) pain scores before and after the procedure. Fifty-three patients underwent surgical resection during the period were also included in this study as a control group. Treatment efficacy was assessed primarily by comparing the differences in VAS scores at different time points in each group of patients by paired-sample t-test. Differences in length of hospital stay and complications between the two groups were also compared. RESULTS: The technical success rate was 100% in both the cryoablation and surgical resection group. Cryoablation had a significantly shorter hospitalization time than surgery (p = 0.001). Clinically, the post-operative VAS scores were all significantly improved compared to the pre-operative period, and the clinical cure was achieved in both groups. Surgical operations had more complications than cryoablation, although there was no significant difference. In the group of cryoablation, only one patient had mild numbness of the left lower extremity, which relieved itself; two patients had mild post-operative pain. No patients in the cryoablation group experienced recurrence during the follow-up period. In the surgery group, three of the patients experienced massive bleeding (>500 ml), and two underwent transfusion therapy. Only one patient in the surgical resection group experienced a recurrence at 29 months postoperatively and underwent a second resection. All patients had local scars on the skin after surgical resection. CONCLUSION: Cryoablation is a minimally invasive, safe, and effective treatment strategy for osteoid osteoma, and is fully comparable to surgical resection.

Biomechanical analysis between Orthofix® external fixator and different K-wire configurations for pediatric supracondylar humerus fractures.

BACKGROUND: Closed reduction and percutaneous fixation are considered as the optional treatments for displaced supracondylar humerus fractures. However, there was no published report about the biomechanical analysis in Orthofix® external fixator. In this study, we developed a model of supracondylar humerus fractures and compared the biomechanical analysis of external fixator and different K-wires configurations in order to evaluate the stability of external fixator in supracondylar humerus fractures. METHODS: We developed an anatomic humerus model by third-generation synthetic composite, and 60 synthetic humeris were osteotomized to simulate the humeral transverse supracondylar fracture. Those fractures were reduced and fixed by external fixator or K-wires, and then biomechanical analysis was performed in extension, varus, valgus, and internal and external rotation loading. A paired-sample t test was used to evaluate the distance at the fracture site between the external fixator and K-wire configurations. RESULTS: During all direction loading, there was a significant statistical difference between external fixator and K-wires (P < 0.001 for all pairwise comparisons). In extension and internal rotation loading, the external fixator and three crossed K-wires had no comparable stiffness values (P = 0.572; P = 0.795), and both were significantly greater than two crossed and lateral K-wires (P < 0.05). In external rotation loading, there was no significance between the external fixator and K-wire configurations except two lateral K-wires (P > 0.05). In valgus loading, the stability of the external fixator was less than that of three crossed K-wires (P = 0.001) but was not significantly different with those of two crossed or three lateral K-wires (P = 0.126; P = 0.564). In varus loading, the stability of the external fixator was larger than those of two and three lateral K-wires (P = 0.000; P = 007). CONCLUSIONS: External fixator could provide enough stability for pediatric supracondylar humerus fractures without the injury of the ulnar nerve. Besides, it could enhance the rotational stiffness of the construct in rotation loading to avoid the complication of cubitus varus.

Treatment of rabbit growth plate injuries with oriented ECM scaffold and autologous BMSCs.

Tissue-engineered technology has provided a promising method for the repair of growth plate injuries using biocompatible and biodegradable scaffolds and appropriate cells. The aim of this study was to fabricate oriented ECM scaffolds to imitate the material and structure of a natural growth plate and to investigate whether BMSCs in a scaffold could prevent the formation of bone bridges in an injured growth plate. We developed a natural, acellular and oriented scaffold derived from a growth plate. The oriented scaffold was fabricated using new freeze-drying technology and by cross-linking the microfilaments in the growth plate. From histological examination, the scaffold contained most of the ECM components including GAG and collagen II without cell DNA fragments, and SEM revealed that oriented scaffold had a uniform aperture in the transverse plane and columnar structure in length plane. Cytotoxicity testing with MTT showed no cytotoxic effect of the scaffold extracts on BMSCs. Autogenous BMSCs in oriented scaffolds promoted the regeneration of neogenetic growth plate when repairing an injured growth plate and prevent the formation of bone bridges to reduce the angular deformity and length discrepancy in the proximal tibia in rabbits. The well-characterized ECM-derived oriented growth plate scaffold shows potential for the repair of injured growth plates in young rabbits.

Lateral shelf acetabuloplasty for severe Legg-Calvé-Perthes disease in patients older than 8 years: A mean eleven-year follow-up.

The natural history of Legg-Calvé-Perthes disease (LCPD) in children older than 8 years is usually poor without treatment. The treatment goal is to prevent deformity and incongruity of the hip by achieving a stable spherical femoral head in a deep, congruent, sharp-edged acetabulum, with a good range of hip movement at skeletal maturity. Lateral shelf acetabuloplasty in LCPD can increase the coverage of the femoral head, benefiting the remodeling of the femoral head and acetabulum. The aim of this study was to evaluate the efficacy of lateral shelf acetabuloplasty for severe LCPD in patients older than 8 years.We evaluated 51 patients with severe LCPD who underwent shelf acetabuloplasty between 1994 and 2005. Clinical and radiological examinations were evaluated preoperatively and over a mean follow-up of 132.35 months (range 102-183 months). According to the Catterall classification, the LCPD was classified as grade II in 11 (21.6%) patients, grade III in 15 (29.4%), and grade IV in 25 (49.0%). According to the Herring classification, there were 12 (23.5%) patients in grade B, 24 (47.1%) in grade B/C, and 15 (29.4%) in grade C. The mean ages at the onset of signs and at surgery were 103.39 months and 110.78 months, respectively.By the end of follow-up, all patients had a normal passive range of hip movement without pain. The mean Iowa hip score was improved from 69.5 ±â€Š7.28 to 91.6 ±â€Š5.14 (P < 0.001). According to the Stulberg classification, 11 (21.6%) hips were classified as grade 1, 19 (37.3%) hips as grade 2, 14 (27.5%) hips as grade 3, and 7 (13.7%) hips as grade 4. The CE angle, Sharp angle, medial joint space ratio, epiphysis height ratio, and percentage of acetabular coverage were significantly improved by shelf acetabuloplasty (P < 0.001).We recommend shelf acetabuloplasty for severe LCPD in patients older than 8 years. The procedure yields a favorable clinical outcome and Stulberg outcome for the hip. Shelf acetabuloplasty can improve femoral head coverage and reduce subluxation of the hip, with a benefit to the biological remodeling of the femoral head within the acetabulum.

The Periosteal Autografts Transplantation for Cartilage Defects of the Hip in Older Children With Developmental Dysplasia as an Adjunctive Procedure.

Cartilage lesions are at a high prevalence in dysplastic hips and may relate to arthritic changes and hip joint dysfunction. To date, the effectiveness of repair of articular cartilage defects in the dysplastic hips has not yet been thoroughly evaluated. Here we retrospectively reviewed the effects of acetabuloplasty procedures with/without concomitant autologous tibial periosteal transplantation (ATPT) for articular cartilage defects of the hip in older children with developmental dysplasia of the hip (DDH).Older DDH children with focal cartilage defects of the acetabular or femoral cartilage or both in the hip joint were treated by acetabuloplasty procedures with (Group I) or without (Group II) concomitant ATPT to evaluate the improvements in range of motion (ROM), pain relief of hip, walking tolerability (WL), radiologic evaluations, and outcomes in the long-term follow-up.More satisfactory functional outcome is readily achieved among patients treated with combined acetabuloplasty and ATPT, evidenced by marked pain relief and improved ROM and WL. The latest favorable radiologic evaluation was 70.6% in Group I and 60.0% in Group II, respectively. More hips exhibited congruency between the femoral head and the shell, with less deformity of femoral head and acetabulum or narrowed joint space in Group I. Few major complications were recorded in Group I.Application of periosteal autograft for repair of cartilage defects within the hip joint might be an effective adjunctive treatment for acetabuloplasty in preventing stiffness, reducing pain, and improving ROM and outcomes in hip rehabilitation in the long-term follow-up in older children with DDH.