High-Efficiency Flicker-Free LED Driver with Soft-Switching Feature.

A novel interleaved DC-DC buck converter is proposed to drive high-brightness light-emitting diodes (LEDs). The circuit configuration mainly consists of two buck converters, which are connected in parallel and use interleaved operation. Through interleaved operation, the power capability of the converter is doubled. Traditionally, two individual inductors are used in the two buck converters. The difference between conventional parallel-operated buck converters using two energy storage inductors and the proposed circuit is that the proposed circuit uses two small inductors and a coupled inductor that replace the two inductors of the buck converters. In this way, both buck converters can be designed to operate in discontinuous-current mode (DCM), even if the magnetizing inductance of the coupled inductor is large. Therefore, the freewheeling diodes can achieve zero-current switching off (ZCS). Applying the principle of conservation of magnetic flux, the magnetizing current is converted between the two windings of the coupled inductor. Because nearly constant magnetizing current continuously flows into the output, the output voltage ripple can be effectively reduced without the use of large-value electrolytic capacitors. In addition, each winding current can drop from positive to negative, and this reverse current can discharge the parasitic capacitor of the active switch to zero volts. In this way, the active switches can operate at zero-voltage switching on (ZVS), leading to low switching losses. A 180 W prototype LED driver was built and tested. Our experimental results show satisfactory performance.

Repeated subarachnoid administrations of allogeneic human umbilical cord mesenchymal stem cells for spinal cord injury: a phase 1/2 pilot study.

BACKGROUND AIMS: Stem cell transplantation is a potential treatment for intractable spinal cord injury (SCI), and allogeneic human umbilical cord mesenchymal stem cells (hUC-MSCs) are a promising candidate because of the advantages of immune privilege, paracrine effect, immunomodulatory function, convenient collection procedure and little ethical concern, and there is an urgent need to develop a safe and effective protocol regarding their clinical application. METHODS: A prospective, single-center, single-arm study in which subjects received four subarachnoid transplantations of hUC-MSCs (1 × 106 cells/kg) monthly and were seen in follow-up four times (1, 3, 6 and 12 months after final administration) was conducted. At each scheduled time point, safety and efficacy indicators were collected and analyzed accordingly. Adverse events (AEs) were used as a safety indicator. American Spinal Injury Association (ASIA) and SCI Functional Rating Scale of the International Association of Neurorestoratology (IANR-SCIFRS) total scores at the fourth follow-up were determined as primary efficacy outcomes, whereas these two indicators at the remaining time points as well as scores of pinprick, light touch, motor and sphincter, muscle spasticity and spasm, autonomic system, bladder and bowel functions, residual urine volume (RUV) and magnetic resonance imaging (MRI) were secondary efficacy outcomes. Subgroup analysis of primary efficacy indicators was also performed. RESULTS: Safety and efficacy assessments were performed on 102 and 41 subjects, respectively. Mild AEs involving fever (14.1%), headache (4.2%), transient increase in muscle tension (1.6%) and dizziness (1.3%) were observed following hUC-MSC transplantation and resolved thoroughly after conservative treatments. There was no serious AE. ASIA and IANR-SCIFRS total scores revealed statistical increases when compared with the baselines at different time points during the study, mainly reflected in the improvement of pinprick, light touch, motor and sphincter scores. Moreover, subjects showed a continuous and remarkable decrease in muscle spasticity. Regarding muscle spasm, autonomic system, bladder and bowel functions, RUV and MRI, data/imaging at final follow-up showed significant improvements compared with those at first collection. Subgroup analysis found that hUC-MSC transplantation improved neurological functions regardless of injury characteristics, including level, severity and chronicity. CONCLUSIONS: The authors' present protocol demonstrates that intrathecal administration of' allogeneic hUC-MSCs at a dose of 106 cells/kg once a month for 4 months is safe and effective and leads to significant improvement in neurological dysfunction and recovery of quality of life.

LncRNA SPRY4­IT1 promotes progression of osteosarcoma by regulating ZEB1 and ZEB2 expression through sponging of miR­101 activity.

Long non­coding (lnc)RNA sprouty receptor tyrosine kinase signalling antagonist 4­intronic transcript 1 (SPRY4­IT1) has been demonstrated to serve a critical role in the tumorigenesis of osteosarcoma (OS); however, the specific underlying mechanism remains unclear. The aim of the present study was to examine the interactions between SPRY4­IT1 and its downstream effectors, to determine if any of the interactions contributed to SPRY4­IT1­mediated proliferation, migration and invasion in cancer cells. A signalling cascade which involved SPRY4­IT1, miR­101 and zinc finger E­box­binding homeoboxes (ZEBs) was examined in the present study. Intracellular SPRY4­IT1 and miR­101 expression levels were altered through transfection to assess their effect on proliferation, cell cycle progression, survival, migration and invasion. A dual­luciferase assay was utilized to determine the association between SPRY4­IT1/miR­101 and ZEBs/miR­101 and nude mouse xenograft experiments were performed to determine the effect of SPRY4­IT1 in vivo. The results indicated that the SPRY4­IT1 levels were negatively associated with miR­101 expression levels in OS cells, an association which was not observed in the normal osteoblast cells. SPRY4­IT1 knockdown or miR­101 overexpression reduced proliferation, cell cycle progression, survival, migration and invasion of MG­63 and U2OS cells. SPRY4­IT1 knockdown was accompanied by increased expression of miR­101 and E­cadherin levels, as well as decreased expression levels of ZEB1/2 and other epithelial­mesenchymal transition­associated proteins. Simultaneous knockdown of SPRY4­IT1 and inhibition of miR­101 partially reversed the anti­tumour effects of SPRY4­IT1 inhibition in vitro. Consistent with these findings, short hairpin RNA targeting SPRY4­IT1 also hindered xenograft tumour growth and altered the levels of miR­101, ZEB1/2 and E­cadherin in vivo. Dual­luciferase reporter assays demonstrated that SPRY4­IT1 may have regulated the expression of ZEB1 and ZEB2 by sponging miR­101. In conclusion, SPRY4­IT1 inhibition increased miR­101 levels, resulting in downregulation of ZEB1/2 expression and thus exerting anti­tumour effects in OS.

Surgery vs conservative treatment for type II and III odontoid fractures in a geriatric population: A meta-analysis.

BACKGROUND: It is unclear whether surgery or conservative treatment is more suitable for elderly patients with type II and type III odontoid fractures. We performed this meta-analysis to compare the efficacy of surgical and conservative treatments for type II and type III odontoid fractures. METHODS: A literature search was performed in PubMed, Embase, Web of Science, and Cochrane Library in January 2017. Only articles comparing surgery with conservative treatment in elderly patients with type II and type III odontoid fractures were selected. After 2 authors independently assessed the retrieved studies, 18 articles were included in this meta-analysis, and the primary endpoints were the nonunion rate and mortality rate. The secondary outcomes were patient satisfaction, complications, and the length of the hospital stay. The quality of the included studies was evaluated using the modified Newcastle-Ottawa scale. Sensitivity analyses were performed for high-quality studies, and the publication bias was evaluated using a funnel plot. RESULTS: Lower nonunion (odds ratio [OR]: 0.27, 95% confidence interval [CI]: 0.18-0.40, P < .05) and mortality rates (OR: 0.52, 95% CI: 0.34-0.79, P < .05) confirmed the superiority of surgery in treating type II and type III fractures. The secondary outcomes differed. Patients in the surgery group felt more satisfied with the outcome (OR: 3.44, 95% CI: 1.19-9.95, P < .05), and the complications were similar in the 2 groups (OR: 1.14, 95% CI: 0.78-1.68, P = .5), whereas patients in conservative groups spent less time in the hospital (OR: 5.10, 95% CI: 2.73-7.47, P < .05). The results of the subgroup analyses and sensitivity analysis were similar to the original outcomes, and no obvious publication bias was observed in the funnel plot. CONCLUSION: Most elderly (younger than 70 years) patients with type II or type III odontoid fractures should be considered candidates for surgical treatment, due to the higher union rate and lower mortality rate, while statistically significant differences were not observed in the population with an advanced age (older than 70 years). Therefore, the selection of the therapeutic approach for elderly patients with odontoid fractures requires further exploration. Simultaneously, based on our meta-analysis, a posterior arthrodesis treatment was significantly superior to the anterior odontoid screw treatment.

Curcumol induces apoptosis in SPC-A-1 human lung adenocarcinoma cells and displays anti-neoplastic effects in tumor bearing mice.

Curcumol is a sesquiterpene originally isolated from curcuma rhizomes, a component of herbal remedies commonly used in oriental medicine. Its beneficial pharmacological activities have attract significant interest recently. In this study, anti-cancer activity of curcumol was examined with both in vitro and in vivo models. It was found that curcumol exhibited time- and concentration-dependent anti-proliferative effects in SPC-A-1 human lung adenocarcinoma cells with cell cycle arrest in the G0/G1 phase while apoptosis-induction was also confirmed with flow cytometry and morphological analyses. Interestingly, curcumol did not display growth inhibition in MRC-5 human embryonic lung fibroblasts, suggesting the anti-proliferative effects of curcumol were specific to cancer cells. Anti-neoplastic effects of curcumol were also confirmed in tumor bearing mice. Curcumol (60 mg/kg daily) significantly reduced tumor size without causing notable toxicity. In conclusion, curcumol appears a favorable anti-cancer candidate for further development.

[Analysis of posterior lumbar interbody fusion (PLIF) in treating lumbar degenerative disease in elderly patients].

OBJECTIVE: To explore the clinical effects of PLIF surgery for elderly patients with lumbar degenerative disease. METHODS: From March 2010 to May 2013, 28 patients with lumbar degenerative disease, aged more than 80 years were treated with PLIF surgery. There were 10 males and 18 females, aged from 80 to 93 years old with an average of (85.44±3.66) years. Course of disease was from 3 to 20 years. The operation time, intra-operative blood loss, operation complications were recorded and JOA scores and Macnab criteria were used to evaluate the clinical outcomes. RESULTS: All patients were followed up from 12 to 40 months with an average of 26.5 months. The average operation time was (150.00±26.42) min and the average intra-operative blood loss was (373.33±99.88) ml. The pre-operative JOA score was 12.30±2.43, and the corresponding postoperative JOA score at the final follow-up was 24.81±2.09 which was much higher than the preoperative one (P<0.01). According to the modified Macnab criteria to evaluate at the final follow-up, 16 patients got an excellent result, 10 good, 2 fair. In the weeks postoperatively, injuries of nerve root happened in 3 cases, superficial wound infection with delayed healing in 3 cases, and tear of the dural sac accompanied with cerebrospinal fluid leakage in 1 case. After long term follow-up, adjacent segment degeneration and the corresponding spinal canal stenosis occurred in 1 case at 34 months after operation. All cases got successful fusion without any displacement of internal fixation and pseudoarthrosis formation. CONCLUSION: With proper cases, fully preoperative preparation, perfect intra-operative manipulation and active treatment after operation, even advanced ages older than 80 years with lumbar degenerative disease could get satisfactory outcomes after PLIF surgery.

Cell-wall-deficient bacteria: a major etiological factor for psoriasis?

BACKGROUND: Psoriasis is a common inflammatory skin disease, yet knowledge of the factors that may induce, trigger, or exacerbate psoriasis is not fully delineated. Recent advances have improved our understanding of the link between psoriasis and cell-wall-deficient bacteria (CWDB) infections. In the present study we assessed the prevalence of CWDB infection in patients with psoriasis. METHODS: The carriage rate of CWDB in the tonsil or pharynx of psoriasis patients, chronic tonsillitis patients and controls were investigated using hypertonic medium. Psoriasis patients with CWDB were randomly assigned to two groups and respectively treated with antibiotics or systemic therapy without antibiotic. Human peripheral blood mononuclear cells (PBMC) from psoriasis patients, chronic tonsillitis patients and control subjects were stimulated with bacteria antigens and extra-cellular levels of interferon-gamma (IFN-gamma) and interleukin (IL)-10 were measured in the supernatants using the ELISA technique, in vitro. Meanwhile, the proliferation ability of PBMC to respond to bacteria antigens was detected by MTT assay. RESULTS: CWDB were isolated from 74.2% of psoriasis patients, 23.5% of chronic tonsillitis patients and only 6.3% of controls. Antibiotic therapy was appropriate for approximately 80% of psoriasis patients with CWDB infection, and in only 8.9% psoriasis patients CWDB infection was detected after antibiotic therapy. Meanwhile, our study showed that CWDB and wide-type bacteria did remarkably enhance the production of IFN-gamma, in vitro, and PBMC proliferation. CONCLUSION: CWDB infection may be a virtual triggering factor in psoriasis by regulating T-cell activation.

[Comparative study of vertebral body stress distribution following insertion of artificial lumbar intervertebral disc].

OBJECTIVE: To study vertebral body stress distribution of normal disc, post-Diskectomy and artificial disk respectively by 3-D finite element methods, and to explore artificial intervertebral disk insertion impact on stress distribution of vertebral body. METHODS: Models of normal disk, post-Diskectomy, artificial disk and L(4 - 5) motion segment were established by using finite element software MSC. MARK, then vertebral body stress was analyzed through model of L(4 - 5) motion segment respectively. RESULTS: The vertebral body's stress was the smallest after insertion of artificial intervertebral disk (AID), and its stress distributed equally. But the stress under post-discectomy was bigger than the normal disc's in all the motion state. On the other hand, the stress distribution state of the post-discectomy changed while the spine were in different motion state, during the spine flexion, the stress in the anterior of vertebral body was the biggest; While extension, in the posterior and in right flexion state, the biggest stress was in the right. While vertical compression and rotation, the stress distributed equally. CONCLUSION: The results illustrate that the vertebral body's stress is the smallest after insertion of AID in 3 groups of all motion state, and its stress distributes equally. But the level of vertebral body stress increases after discectomy comparing with the normal group. In generally, it is much more reasonable that the disc is reconstructed with AID because of the biomechanical effect on vertebral body made by AID insertion.