Coupling Independent Operation in Wireless Power Transfer System without Ferrite Usage

The power transfer efficiency and output power of a wireless power transfer (WPT) system are mainly affected by magnetic coupling between the primary and secondary coils. This paper presents a constant-current series-series compensated WPT system. Based on the bifurcation criteria, kcri and Lcri, the splitting zero phase angle (ZPA) frequencies is adopted as the operating frequency. The proposed system remains fully compensated even under coupling variations, and without ferrite. The current and voltage gains at the operating frequency can be estimated through the primary current and voltage. A phase-locked loop circuit is used to track the corresponding ZPA frequency due to the coil positioning variations. Experimental results have shown that the 1-kW of output power with the satisfied efficiency of 96%.

Incidence of cardiovascular events in patients with atrial fibrillation anticoagulated with rivaroxaban after 2.5 years of follow-up: not all is stroke or bleeding

Introduction Atrial fibrillation (AF) is not a benign arrhythmia, but is associated with an increase in mortality, above all related to the risk of suffering thromboembolic events, mainly stroke. The use of oral anticoagulants (OAC) reduces this risk, but increases the risk of serious bleeding. The DOACs have been shown to be superior to the classic vitamin K antagonists (VKAs). It is not as well known whether AF is associated with an increase in other serious cardiac events. Purpose The objective of this analysis was to assess the incidence of stroke, major bleeding, total mortality and major adverse cardiac events [MACE, defined as cardiac mortality (including death for coronary events, progressive heart failure death and sudden cardiac death), coronary revascularization, myocardial infarction] in a contemporary series of patients with AF anticoagulated with rivaroxaban. Methods To do this, we have analyzed a series of 1,433 patients with AF, anticoagulated with rivaroxaban for at least the previous 6 months, consecutively included in the first half of year 2017 in 79 Spanish centers (EMIR study), and followed for 2.5 years. Results Mean age was 74.2±9.7 years, 44.5% being women. Prevalence of diabetes was 27.1%, chronic renal failure 16.1%, coronary heart disease 16.4% and heart failure 22.7%. 2MACE score was 1.8±1.4, CHA2DS2-VASc was 3.5±1.5 and HAS-BLED 1.6±1.0. 77.1% of patients received 20 mg/ day of rivaroxaban and 22.9% 15 mg/day. After a follow-up of 2.5 years, the annual rate (events/100 patients/year) of myocardial infarction was 0.16 (all non-STEMI), coronary revascularization 0.28, cardiac death 0.63 (sudden 0.16, heart failure 0.41, other 0.06), overall MACE 1.07 and overall mortality 2.73, while the incidence of stroke was 0.57 / 100 patients / year (ischemic 0.35, haemorrhagic 0.22) and major bleeding 1.04 (gastrointestinal 0.63, intracranial 0.28). Conclusion In a current series of patients with AF anticoagulated with rivaroxaban, the incidence of embolic and hemorrhagic complications and mortality are low, while the incidence of serious cardiac events is significant, being overall similar to that of stroke and major bleeding. Attention must be paid to the prevention and diagnosis of these problems. FUNDunding Acknowledgement Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): Bayer Hispania

SPINAL TUBERCULOSIS IN PEDIATRIC POPULATION

Background: There is a lack of reports on spinal tuberculosis in children. We report a retrospective analysis of 124 children with TB spine treated over 30 years. Materials and Methods: One hundred twenty-four patients were included in our study. Ninety-one children were treated conservatively, while 33 children were subjected to surgery for focal debridement (n=23), posterior interspinous wiring and cementation (n=4), and posterior instrumentation with rods and segmental wiring (n=14). Thus, some of the children in the current series belonged to conservative study patients. Results: All children attained healed status and showed neural recovery (n=18). The patients attained healed status at 12 months. Spontaneous intracorporal fusion occurred only in 8.06% of 124 children. Sagittal curves during growth showed three different patterns: Unchanged, decreased, and increased curves. The residual kyphosis was unavoidable in cases with growth plate damage. Kyphosis increased in cases with wedged monovertebra and fused wedged block vertebra, though it was different at a different level. Conclusion: The posterior instrumented stabilization alone could correct or prevent the progress of the kyphosis. However, for active tuberculosis, posterior instrumented stabilization combined with anterior radical surgery should be reserved only for advanced tuberculosis with instability, the rapid progress of kyphosis, and unacceptable pre-existing kyphosis. There is a new trend of prophylactic posterior instrumentation, even for early tuberculosis.

Iliosacral Bone Tumor Resection Using Cannulated Screw-Guided Gigli Saw - A Novel Technique

Background Adequate margins are technically difficult to achieve for malignant tumors involving the sacroiliac joint due to limited accessibility and viewing window. In order to address the technical difficulties faced in iliosacral tumor resection, we proposed a technique for precise osteotomy, which involved the use of canulated screws and Gigli saw (CSGS) that facilitated directional control, anteroposterior linkage of resection points and adequate surgical margins. The purpose of the current study was to evaluate whether CSGS technique facilitated sagittal osteotomy at sacral side, and were adequate surgical margins achieved? Also functional and oncological outcomes was determined along with the noteworthy complications. Methods From April 2018 to November 2019, we retrospectively reviewed 15 patients who underwent resections for primary tumors of pelvis or sacrum necessitating iliosacral joint removal using the proposed CSGS technique. Chondrosarcoma was the most common diagnosis. The osteotomy site within sacrum was at ipsilateral ventral sacral foramina in 8 cases, midline of sacrum in 5 cases, and contralateral ventral sacral foramina and sacral ala with 1 case each. The average intraoperative blood loss was 3640 mL (range, 1200 and 6000 mL) with a mean operation duration of 7.4 hours (range, 5 to 12 hours). The mean follow-up was 23.0 months (range, 18 and 39 months) for alive patients. Results Surgical margins were wide in 12 patients (80%), wide-contaminated in 1 patient (6.7%), and marginal in 2 patients (13.3%). R0 resection was achieved in 12 (80%) patients and R1 resection in 3 patients. There were three local recurrences (20%) occurred at a mean time of 11 months postoperatively. No local recurrence was observed at sacral osteotomy. The overall one-year and three-year survival rate was 86.7% and 72.7% respectively.Complications occurred in three patients. Conclusions The current study demonstrated that CSGS technique for tumor resection within the sacrum and pelvis was feasible and can achieve ideal resection accuracies. The use of CSGS was associated with high likelihood of negative margin resections in the current series. Intraoperative use of CSGS appeared to be technically straightforward and allowed achievement of planned surgical margins. It is worthwhile to consider the use of CSGS technique in resection of pelvic tumors with sacral invasion and iliosacral tumors, however further follow-up at mid to long-term is warranted to observe local recurrence rate.

Expression of STAT6 and Phosphorylated STAT6 in Primary Central Nervous System Lymphomas

The signal transducer and activator of transcription 6 (STAT6) is implicated in the pathogenesis of some lymphomas including primary central nervous system lymphomas (PCNSLs). The aim of this study was to investigate STAT6 expression and clinicopathologic features in 25 PCNSLs using immunohistochemistry with 2 different anti-STAT6 antibodies. One (YE361) recognizes the C-terminus domain of the STAT6 protein and the other (Y641) recognizes the phosphorylated form of the protein. The phosphorylated STAT6 form was not expressed in any of the cases studied whereas the YE361 STAT6 showed only cytoplasmic expression in 14 (56%) cases. This expression did not correlate with age, prognostic score, multiplicity, invasion of deep structures, response to treatment, disease recurrence, overall survival, or BCL6, BCL2, PD-L1, and CD8 expression. A STAT6 expression score showed a trend for correlating with clinical performance status. It also showed a positive correlation with MYC expression. Thus, the phosphorylated form of STAT6 was not found in the current series, while the YE361 STAT6 showed only cytoplasmic expression and was associated with expression of MYC.

Insular epilepsy surgery: lessons learned from institutional review and patient-level meta-analysis

OBJECTIVE Insular lobe epilepsy is a challenging condition to diagnose and treat. Due to anatomical intricacy and proximity to eloquent brain regions, resection of epileptic foci in that region can be associated with significant postoperative morbidity. The aim of this study was to review available evidence on postoperative outcomes following insular epilepsy surgery. METHODS A comprehensive literature search (PubMed/MEDLINE, Scopus, Cochrane) was conducted for studies investigating the postoperative outcomes for seizures originating in the insula. Seizure freedom at last follow-up (at least 12 months) comprised the primary endpoint. The authors also present their institutional experience with 8 patients (4 pediatric, 4 adult). RESULTS A total of 19 studies with 204 cases (90 pediatric, 114 adult) were identified. The median age at surgery was 23 years, and 48% were males. The median epilepsy duration was 8 years, and 17% of patients had undergone prior epilepsy surgery. Epilepsy was lesional in 67%. The most common approach was transsylvian (60%). The most commonly resected area was the anterior insular region (n = 42, 21%), whereas radical insulectomy was performed in 13% of cases (n = 27). The most common pathology was cortical dysplasia (n = 68, 51%), followed by low-grade neoplasm (n = 16, 12%). In the literature, seizure freedom was noted in 60% of pediatric and 69% of adult patients at a median follow-up of 29 months (75% and 50%, respectively, in the current series). A neurological deficit occurred in 43% of cases (10% permanent), with extremity paresis comprising the most common deficit (n = 35, 21%), followed by facial paresis (n = 32, 19%). Language deficits were more common in left-sided approaches (24% vs 2%, p < 0.001). Univariate analysis for seizure freedom revealed a significantly higher proportion of patients with lesional epilepsy among those with at least 12 months of follow-up (77% vs 59%, p = 0.032). CONCLUSIONS These findings may serve as a benchmark when tailoring decision-making for insular epilepsy, and may assist surgeons in their preoperative discussions with patients. Although seizure freedom rates are quite high with insular epilepsy treatment, the associated morbidity needs to be weighed against the potential for seizure freedom.

Making Space: Key Popular Women Writers Then and Now

Reclaiming lost or forgotten (Victorian) popular women writers and their works is still an important, ongoing aim of literary and gender studies. In this article, we take the Key Popular Women Writers series, published by Edward Everett Root Publishers and edited by Janine Hatter and Helena Ifill, as one example of a current series that continues and develops this feminist practice. By drawing upon the research, writing and publishing practice of current women academics, as well as related issues concerning literary value, canonicity and the popularity of the Victorian writers themselves, we showcase the methodological and pedagogical practice of finding motivation and inspiration beyond that which is established as the norm. Furthermore, through examining the current political, academic and publishing fields’ impact on researching and teaching (Victorian) popular fiction, we discuss breakthroughs, challenges and potential ways for the study of this area to move forward. Popular women’s writing continues to offer readers, students and academics, ways to challenge conventions, embrace the multi-faceted nature of our field and take our place on the landscape.

The last decade’s experience of management of central neurocytomas: Treatment strategies and new options

Background: The purpose of the presented work is to evaluate the last decade’s experience in surgical management of central neurocytoma (CN) and elucidate on the treatment strategies and new options. Methods: The current series consists of the remaining 125 patients (70 females and 55 males) operated on during the past decade from 2008 to 2018. Most tumors were resected through transcortical (n = 76, 61%), or transcallosal (n = 40, 32%) approaches. In 5 (4%) patients with predominantly posterior location of the tumor, non-dominant superior parietal lobule approach was utilized. Both approaches (transcortical + transcallosal) were used in 4 (3%) of cases. Seven consecutive patients with large CN underwent prophylactic intraventricular stenting to prevent hydrocephalus. Results: Gross total resection was achieved in 45 patients (36%), subtotal resection (STR) in 40 (32%) cases. After surgery, 63 (50%) patients had neurocognitive problems, including disorientation, attention deficit, global amnesia, short-term memory deficits, and perceptual motor and social cognition problems. A total of 26 patients (21%) had postoperative hemorrhage in the resection bed. Obstructive hydrocephalus was noted in 25 (20%) patients. The entrapment of the occipital and/or temporal horns was observed in seven cases. None of the seven patients with prophylactic intraventricular stents required shunting. Conclusion: Although high rates of gross total or STR can be expected, the mortality and morbidity remain significant even in the modern neurosurgical era. Prophylactic intraventricular stenting in patients with large posteriorly located tumors with hydrocephalus may prevent ventricular entrapment and shunting. The main risk factors for recurrence are presence of residual disease and Ki-67 index over 5%. Recurrent symptomatic tumors should be treated surgically, whereas asymptomatic progression can be managed with stereotactic radiosurgery. Both treatment modalities are associated with low risk of complications and high tumor control rates.

On subsonic near-wake flows of a space launcher configuration with various base geometries

Buffet/buffeting as load imposing mechanism on the base structures of space launcher has been of strong interest ever since it was found as partially responsible for the failed flight 157 of Ariane 5. Several studies suggested that the base region is most excited at Mach 0.8. A preceding study of the current series on base flow effects revealed a differing excitation in comparison to the other subsonic Mach number cases. It featured an especially pronounced excitation in the recirculation region. Thus, the current work attempts to answer the question why this case appears to be distinct. This is done by decreasing the relative nozzle length and focusing on the Reynolds stress distribution. The research question is approached by experiments in the ‘Vertical Test Section Cologne’ (VMK) on a base model with supersonic, over-expanded exhaust jet exposed to an ambient flow at Mach 0.8 and a Reynolds number of $$1.4\cdot 10^6$$ 1.4 · 10 6 . Data are acquired by means of particle image velocimetry (PIV) and high-speed schlieren imaging. The results reveal that a most unfavorable configuration appears to exist, which is if the mean shear layer reattachment takes place just on the tip of the nozzle. Graphic abstract

Characteristics and Electronic Band Alignment of a Transparent p-CuI/n-SiZnSnO Heterojunction Diode with a High Rectification Ratio

Transparent p-CuI/n-SiZnSnO (SZTO) heterojunction diodes are successfully fabricated by thermal evaporation of a (111) oriented p-CuI polycrystalline film on top of an amorphous n-SZTO film grown by the RF magnetron sputtering method. A nitrogen annealing process reduces ionized impurity scattering dominantly incurred by Cu vacancy and structural defects at the grain boundaries in the CuI film to result in improved diode performance; the current rectification ratio estimated at ±2 V is enhanced from ≈106 to ≈107. Various diode parameters, including ideality factor, reverse saturation current, offset current, series resistance, and parallel resistance, are estimated based on the Shockley diode equation. An energy band diagram exhibiting the type-II band alignment is proposed to explain the diode characteristics. The present p-CuI/n-SZTO diode can be a promising building block for constructing useful optoelectronic components such as a light-emitting diode and a UV photodetector.