The widespread popularity of smart meters enables an immense amount of fine-grained electricity consumption data to be collected. Meanwhile, the deregulation of the power industry, particularly on the delivery side, has continuously been moving forward worldwide. How to employ massive smart meter data to promote and enhance the efficiency and sustainability of the power grid is a pressing issue. To date, substantial works have been conducted on smart meter data analytics. To provide a comprehensive overview of the current research and to identify challenges for future research, this paper conducts an application-oriented review of smart meter data analytics. Following the three stages of analytics, namely, descriptive, predictive and prescriptive analytics, we identify the key application areas as load analysis, load forecasting, and load management. We also review the techniques and methodologies adopted or developed to address each application. In addition, we also discuss some research trends, such as big data issues, novel machine learning technologies, new business models, the transition of energy systems, and data privacy and security.

: Tail disc percutaneous needle puncture is a simple method for inducing disc degeneration and the rate of degeneration is positively related to the depth of needle puncture. This model still has some limitations that should be taken into consideration when results of disc regeneration research in this model are interpreted and extrapolated to human.

Object The authors evaluated different surgical methods used to treat thoracic ossification of the ligamentum flavum (OLF). Methods Data obtained in 40 patients who underwent posterior decompression for thoracic myelopathy caused by thoracic OLF were studied retrospectively. There were 32 men and eight women. All patients underwent posterior decompression in which laminoplasty was performed or laminectomy combined with lateral fusion. Every surgical specimen was stained with H & E, and scanning electron microscopy was performed in 20 cases. The mean follow-up period was 28 months. Postoperative outcomes were evaluated using a recovery scale based on the Japanese Orthopaedic Association classification. There were a total of 168 ossified segments in this series, 77.4% of which were located in the lower thoracic spine. Marginal osteophyte formation was found in 36 patients; in 32 of the 36 patients, these marginal osteophytes were located at the intervertebral space either higher or lower than the ossified segment. Scanning electron microscopy showed elastic fiber breakdown, proliferation of collagenous fibers, calcification, and OLF in the same microscopy region. Laminoplasty was performed in four patients. In three cases surgery resulted in unchanged or worse outcome (increased kyphotic deformity in two), and in one it resulted in good outcome. Laminectomy combined with lateral fusion was performed in 36 patients, in 30 cases of which it resulted in a good or fair outcome, and increased kyphotic deformity in only one. Of these 36 laminectomy-treated patients, an en bloc laminectomy-treated procedure was performed in 16 patients; in 11 of the 12 patients with lateral or diffuse-type lesions the surgery resulted in a good or fair outcome. En bloc laminectomy, however, seems ineffective in the treatment of patients with thickened, nodular-type thoracic OLF, as the procedure resulted in worse outcome in two of the four patients. The authors have thus developed a new modality of laminectomy that they have termed “separating laminectomy,” which they performed in 16 patients with thickened, nodular-type OLF; in 13 cases it resulted in a good or fair outcome, and in only one case did it result in a worse outcome. Conclusions The pathogenesis of thoracic OLF is mainly due to the localized mechanical stress on the ligament. Laminectomy combined with lateral fusion is the treatment of choice for thoracic OLF; furthermore, in terms of the configuration of the ossified lesion, en bloc laminectomy is suitable for the treatment of lateral-type and diffuse-type OLF, and the separating laminectomy is suitable for the thickened, nodular-type OLF.

The microenvironment of the intervertebral disc (IVD) is characterized by matrix acidity, hypoxia, hyperosmolarity and limited nutrition, which are major obstacles to stem cell-based regeneration. Our recent work showed that nucleus pulposus mesenchymal stem cells (NPMSCs) had advantages over traditional sources of cell therapy under IVD-like hypoxic and hyperosmotic conditions. Here, we examined the viability, proliferation and matrix metabolism of NPMSCs compared with adipose tissue-derived mesenchymal stem cells (ADMSCs) under IVD-like acidic conditions in vitro. ADMSCs and NPMSCs from Sprague-Dawley rats were cultured at four different pH levels representing the standard condition (pH 7.4) and the normal, mildly degenerated and severely degenerated IVD (pH 7.1, 6.8 and 6.5, respectively). Cell viability was examined by annexin-V-fluorescein isothiocyanate/propidium iodide staining. Cell proliferation was measured using a cell counting kit cell proliferation assay. The expression of aggrecan, collagen-I, collagen-II, matrix metalloproteinase-2 (MMP-2), a disintegrin and metalloproteinase with thrombospondin motifs-4 (ADAMTS4) and the tissue inhibitor of metalloproteinase-3 (TIMP-3) was measured at mRNA and protein levels by RT-PCR and Western blotting. In both cell types, acidic pH inhibited cell viability and proliferation, downregulated the expression of aggrecan, collagen-I, collagen-II and TIMP-3, and upregulated the expression of MMP-2 and ADAMTS4. Compared with ADMSCs, NPMSCs were significantly less inhibited in viability and proliferation; they expressed significantly higher levels of aggrecan and collagen-II, and lower levels of MMP-2 and ADAMTS4. Thus, an acidic environment is a major obstacle for IVD regeneration by ADMSCs or NPMSCs. NPMSCs appeared less sensitive to inhibition by acidic pH and might be promising candidates for cell-based IVD regeneration.

When the volume of PBS injected into the rat tail-disc exceeded a threshold, it rapidly exhibited degenerative changes according to radiographic, biochemical, and histologic analysis. The degenerative changes were dose-dependent and increased as the dose increased.