Single Disc Research Articles

Filling of closed surfaces

Let [Formula: see text] denote a closed oriented surface of genus [Formula: see text]. A set of simple closed curves is called a filling of [Formula: see text] if its complement is a disjoint union of discs. The mapping class group [Formula: see text] of genus [Formula: see text] acts on the set of fillings of [Formula: see text]. The union of the curves in a filling forms a graph on the surface which is a so-called decorated fat graph. It is a fact that two fillings of [Formula: see text] are in the same [Formula: see text]-orbit if and only if the corresponding fat graphs are isomorphic. We prove that any filling of [Formula: see text] whose complement is a single disc (i.e. a so-called minimal filling) has either three or four closed curves and in each of these two cases, there is a unique such filling up to the action of [Formula: see text]. We provide a constructive proof to show that the minimum number of discs in the complement of a filling pair of [Formula: see text] is two. Finally, given positive integers [Formula: see text] and [Formula: see text] with [Formula: see text], we construct a filling pair of [Formula: see text] such that the complement is a union of [Formula: see text] topological discs.

Anterior Cervical Discectomy with or without Fusion in Non-traumatic Single level Cervical Disc Disorder: Study of 50 Cases

Objectives: The aim of this study is to compare patients undergoing single level anterior cervical discectomy without fusion (ACD) versus anterior cervical discectomy with fusion (ACDF).
 Methods: A retrospective analysis of 50 patients with degenerative cervical spondylosis of them 25 had undergone ACD without fusion and remaining 25 undergone ACDF at either C4-C5, C5- C6 level or at C6-C7 level.
 Results: The kinematic analysis included the range of motion, intervertebral angulations, anteroposterior translation and disc height assessed for the cervical functional spinal units at the operated level and adjacent levels. At the operated level of C4-C5, C5-C6 and C6-C7, the range of motion and the translation were minimal in the anterior cervical discectomy without fusion (ACD) group, but absent in the cervical discectomy with fusion (ACDF) group. The superior adjacent levels range of motion and the translation were greater in the ACDF group compared with the ACD group. But both groups had almost similar results in term of hospital stay, mean time for improvement and patient satisfaction.
 Conclusion: The clinical results of anterior cervical discectomy without fusion (ACD) and anterior cervical discectomy with fusion (ACDF) were comparable. In cervical discectomy without fusion, the elastic fibrous intradiscal scar at the operated level allows a small degree of mobility and the adjacent cervical levels are not overstressed. Fusion is not routinely required in single level cervical disc herniation until it is associated with instability, loss of cervical lordosis, hard disc, osteophytic bar and multi-segmental disease. So ACD is a better option in single level cervical disc disorder than ACDF.
 J Dhaka Medical College, Vol. 27, No.1, April, 2018, Page 29-35

Conversion of Single Optic Disc Photography into 3-Dimensional Image

Conversion of Single Optic Disc Photography into 3-Dimensional Image

Transcatheter closure of subaortic VSD with PDA device (single disc)

Transcatheter closure of subaortic VSD with PDA device (single disc)

Comparative Study on the Clinical Characteristics and Effects of Korean Medical Treatment between the Upper and Lower Lumbar Single Level Disc Herniation

Comparative Study on the Clinical Characteristics and Effects of Korean Medical Treatment between the Upper and Lower Lumbar Single Level Disc Herniation

The Effect of Fusion Added to Lumbar Discectomy in Patients with Modic Changes: A Retrospective Comparative Outcome Analysis Regarding Back Pain Control

Background Data: In 1988, Modic et al first described magnetic resonance (MR) degenerative changes in the lumbar vertebral bodies. changes in the intervertebral endplates, Modic Changes (MC) can also be incriminated in the production of such pain due to the mechanical failure and structural changes that can be detected the most in the region of the highly pain sensitive intervertebral endplates. There is still a controversy regarding the surgical treatment of the predominantly axial pain secondary to degenerative lumbar disc disease.Study Design: This is a retrospective cohort study.Purpose: To evaluate the effect of adding fusion to simple discectomy in treatment of patients of lumbar disc herniation that show evidence of MC on preoperative MR images regarding the control of postoperative back pain and functional outcome.Patients and Methods: This study included 44 patients who underwent surgical management of low back pain and/or sciatica due to lumbar intervertebral disc herniation with concomitant presence of Modic changes in the preoperative MR images. Patients were divided into two groups: Group A (Discectomy group), and Group B (Fusion group). Patients included had single level lumbar disc herniation with modic changes. Patients with radiographic evidence of instability and patients whose 1-year post-operative data were incomplete were excluded. Twenty five patients were males and 19 were females with a mean age of 43.48 years. Nineteen patients (43.2%) were allocated in Group A and 25 patients (56.8 %) in Group B. Clinical results and functional outcome were assessed based on changes in preoperative and postoperative Visual Analogue Scale (VAS) of low back pain and Oswestry Disability Index (ODI) scores of the functional disability.Results: Postoperative back pain improvement was statistically significant in both groups when comparing preoperative values of VAS using paired student-t test with P<0.001 for both groups. Comparison of post-operative back pain VAS for both groups using independent student-t test revealed a statistically non-significant difference with a P=0.239 (Mean VAS for group A=2.211 while mean VAS for Group B=1.48).Conclusion: Unless otherwise indicated, simple lumbar discectomy without fusion is a reasonable surgical option in treatment of patients with lumbar intervertebral disc herniation even in the presence of Modic changes in their pre-operative MRI. (2018ESJ167)

Off-label use of duct occluder devices to close hemodynamically significant perimembranous ventricular septal defects: A multicenter experience.

We sought to evaluate the feasibility, technical aspects, and outcome of transcatheter perimembranous ventricular septal defect (pmVSD) closure using duct occluder devices with a single retention disc. Use of duct occluder devices to close pmVSD seems a promising alternative therapy. However, limited data exist on this technique. From 2010 to 2016, 222 patients (female 47.7%) were identified from databases of five participating institutions in whom pmVSD closure was attempted using an Amplatzer Duct Occluder I or Lifetech duct occluder device. Patients ranged in age from 0.7 to 52 years (median, 7.0 years) and in weight from 4.0 to 70 kg (median, 18.0 kg). The mean size of the VSD was 6.8 ± 2.2 mm. A large defect (> 6 mm) was present in 137 patients (61.7%). Device closure was successful in 218 patients (98.2%). The 10/8 mm device was used in most patients (n = 85, 38.3%), and the vascular approach was from the femoral vein in 169 patients (76.1%). There were 18 early complications in 17/218 patients (7.8%). Three patients (1.4%) developed complete heart block (transient n = 2; requiring permanent pacing n = 1). Median follow-up was 6 months (6 months-6 years). A mild residual shunt was seen in 10 patients at 6 months follow-up. The immediate results of transcatheter pmVSD closure using a duct occluder device with a single retention disc are promising. It is an effective technique with a lower rate of complications than for other currently available devices.

Evaluation of Different Modalities of anterior Cervical Discectomy for Treatment of Single and Double Level Cervical Disc Herniation

Evaluation of Different Modalities of anterior Cervical Discectomy for Treatment of Single and Double Level Cervical Disc Herniation

Effect of 5% transdermal lidocaine patches on postoperative analgesia in dogs undergoing hemilaminectomy.

To investigate the effect of 5% lidocaine patches on postoperative analgesia in dogs undergoing hemilaminectomy. Client-owned dogs undergoing hemilaminectomy for a single acute intervertebral thoracolumbar disc extrusion were enrolled in this prospective, randomised, blinded clinical trial. Following methadone administration, anaesthesia was induced with propofol, and maintained with isoflurane in oxygen and fentanyl infusion, in both groups. After skin closure, two 1∙5cm wide 5% lidocaine patch strips were attached along both sides of the wound in dogs allocated to Group L. In Group C, the two lidocaine patch strips were applied but the transparent isolating liner was not removed. Postoperatively, all dogs received a non-steroidal anti-inflammatory drug, gabapentin and diazepam. Methadone was administered according to the short form of Glasgow Composite Pain Scale with pain assessed every 2hours for 48 hours by observers unaware of the treatment. Thirty-nine dogs completed the study. Demographic data, end-expiratory fraction of isoflurane, fentanyl consumption, anaesthesia and surgical times were similar between groups. The number of dogs requiring postoperative methadone and the number of doses of methadone administered were not different between groups. No macroscopic skin reaction was noticed once the patches were removed. In this setting, 5% lidocaine patches did not provide additional postoperative analgesia in dogs undergoing hemilaminectomy.

Factors Associated With Longer Postoperative Outpatient Follow-up Duration in Patients With Single Lumbar Disc Herniation: A Noncomplicated Patient Cohort Study.

ObjectiveMany reports have described the outcomes of surgical treatment of lumbar disc herniation (LDH). However, few reports have investigated the treatment period after lumbar disc surgery. If no complications occur, how long should an ordinary patient be treated? Which factors are associated with the outpatient follow-up period (OFP)? To answer these questions, we reviewed the medical records of patients who underwent lumbar disc surgery, calculated their average OFP, and sought to identify factors associated with the OFP. MethodsPatients who underwent surgical treatment of single-level LDH from July 2005 to December 2011 were enrolled in this study. Patients who had no pain or required no further treatment did not receive follow-up. Patients’ medical records were reviewed retrospectively. Cases of recurrent LDH, postoperative infections, instrumentation, cauda equina syndrome, postoperative hematoma, trauma-associated herniation, and spondylolisthesis were excluded. We reviewed the postoperative hospitalization period (PHP) and the OFP. Sex, age, operation year, surgical approach, the operating surgeon, disc level, and insurance type were investigated as associated factors. ResultsIn total, 611 patients underwent surgical treatment for single-level LDH by 4 surgeons. Their average age was 44.3 ± 15.1 years. There were 377 male and 234 female patients. The average PHP was 4.4 ± 3.2 days, the average OFP was 112.3 ± 198.6 days, and the 95% confidence interval for the OFP among the enrolled patients was between 96.5 and 128.1 days. ConclusionAlthough this is a single-institute report, most LDH patients showed an OFP of less than 4 months after surgical treatment. In this study, sex, age, and insurance type seemed to be related with the OFP.

Early presentation of traumatic cervical disc herniation with neurologic deficit and without an adjacent bone lesion

The purpose of this study was to explore clinical features and the operational opportunity of traumatic cervical disc herniation. Patients with cervical spine injury (413) were retrospectively reviewed. Six patients with neurological deficits were identified to have disc herniation without adjacent bone lesion. The diagnosis was confirmed by MRI. The Japanese Orthopedic Association (JOA) score was used to assess the severity of clinical symptoms. Different grading systems have been used in analyzing various stages of herniated cervical discs. All patients underwent anterior cervical decompression, insertion of autologous iliac crest graft, and fixation with cervical plate. The causes of injury were road traffic accidents in four patients and sport and domestic accidents in one patient each. There were five patients with single intervertebral disc herniation and one patient with double. Pre-operative JOA score was 14 for three patients, the remaining three patients scored 10, 6, and 3 respectively. At final follow-up, the score was 17 for four patients and 14 for two patients. Traumatic cervical disc herniation with neurologic deficit and without adjacent bone lesion is a rare condition. MRI is the golden examination to confirm diagnosis. Early recognition is essential for appropriate therapy and to minimize the extent of neurological deficit. The MRI is mandatory in diagnosing different types of traumatic herniated cervical disc. Discectomy and anterior cervical interbody fusion using autologous iliac crest graft are the treatment options.

Guided Wave-based System for Real-time Cure Monitoring of Composites using Piezoelectric Discs and Phase-shifted Fiber Bragg Gratings.

A real-time, in-process cure monitoring system employing a guided wave-based concept for carbon fiber reinforced polymer (CFRP) composites was developed. The system included a single piezoelectric disc that was bonded to the surface of the composite for excitation, and an embedded phase-shifted fiber Bragg grating (PS-FBG) for sensing. The PS-FBG almost simultaneously measured both quasi-static strain and the ultrasonic guided wave-based signals throughout the cure cycle. A traditional FBG was also used as a base for evaluating the high sensitivity of the PS-FBG sensor. Composite physical properties (degree of cure and glass transition temperature) were correlated to the amplitude and time of arrival of the guided wave-based measurements during the cure cycle. In addition, key state transitions (gelation and vitrification) were identified from the experimental data. The physical properties and state transitions were validated using cure process modeling software (e.g., RAVEN®). This system demonstrated the capability of using an embedded PS-FBG to sense a wide bandwidth of signals during cure. The distinct advantages of a fiber optic-based system include multiplexing of multiple gratings along a single optical fiber, small size compared to piezoelectric sensors, ability to embed or surface mount, utilization in harsh environments, electrically passive operation, and electromagnetic interference (EMI) immunity. The embedded PS-FBG fiber optic sensor can monitor the entire life-cycle of the composite structure from curing, post-cure/assembly, and in-service creating "smart structures".

Anterior Techniques in Managing Cervical Disc Disease.

Surgical treatment may be indicated for select patients with cervical disc disease, whether it is cervical disc herniation or spondylosis due to degenerative changes, acute cervical injury due to trauma, or other underlying cervical pathology. Currently, there are various surgical techniques, including anterior, posterior, or combined approaches, in addition to new interventions being utilized in practice. Ideally, the surgical approach should be selected in consideration of each patient’s clinical presentation, imaging findings, and overall medical comorbidities on an individual basis. But the unique advantages and disadvantages of each surgical technique often complicate the therapy choice in managing cervical disc diseases. Although anterior cervical discectomy and fusion (ACDF) is the most widely accepted procedure performed for both single and multi-level cervical disc diseases, there are multiple modifications to this technique. Surgeons have access to different types of plates, screws, and cages and can adopt newer advances in the field such as stand-alone and minimally invasive techniques when indicated. In short, no consensus exists in terms of a single approach that is preferred for all patients. This article aims to review the standard of care for management of cervical disc disease with a focus on the surgical techniques and, in particular, the anterior approach, exploring the various surgical options within this technique.

Integrated LAMP and immunoassay platform for diarrheal disease detection

The challenges of diagnosing infectious disease, especially in the developing world, and the shortcomings of available instrumentation have exposed the need for portable, easy-to-use diagnostic tools capable of detecting the wide range of causative microbes while operating in low resource settings. We present a centrifugal microfluidic platform that combines ultrasensitive immunoassay and isothermal amplification-based screening for the orthogonal detection of both protein and nucleic acid targets at the point-of-care. A disposable disc with automatic aliquoting inlets is paired with a non-contact heating system and precise rotary control system to yield an easy-to-use, field-deployable platform with versatile screening capabilities. The detection of three enterotoxins (cholera toxin, Staphylococcal enterotoxin B, and Shiga-like toxin 1) and three enteric bacteria (C. jejuni, E. coli, and S. typhimurium) were performed independently and shown to be highly sensitive (limit of detection = 1.35–5.50 ng/mL for immunoassays and 1–30 cells for isothermal amplification), highly exclusive in the presence of non-specific targets, and capable of handling a complex sample matrix like stool. The full panel of toxins and bacteria were reliably detected simultaneously on a single disc at clinically relevant sample concentrations in less than an hour. The ability of our technology to detect multiple analyte types in parallel at the point-of-care can serve a variety of needs, from routine patient care to outbreak triage, in a variety of settings to reduce disease impact and expedite effective treatment.

What the Milky Way bulge reveals about the initial metallicity gradients in the disc

AbstractWe examine the metallicity trends in the Milky Way (MW) bulge – using APOGEE DR13 data – and explore their origin by comparing two N-body models of isolated galaxies which develop a bar and a boxy/peanut (b/p) bulge. Both models have been proposed as scenarios for reconciling a disc origin of the MW bulge with a negative vertical metallicity gradient. The first is a superposition of co-spatial disc populations, different scaleheights and metallicities (with flat gradients) where the thick, metal-poor populations contribute significantly to the stellar mass budget in the inner galaxy. The second model is a single disc with an initial steep radial metallicity gradient which gets mapped by the bar into the b/p bulge in such a way that the vertical metallicity gradient of the MW bulge is reproduced – as shown already in previous works in the literature. As we show here, the latter model does not reproduce the positive longitudinal metallicity gradient of the inner disc, nor the metal-poor innermost regions seen in the data. The model with co-spatial thin and thick disc populations reproduces all the aforementioned trends. We therefore see that it is possible to reconcile a (primarily) disc origin for the MW bulge with the observed trends in metallicity by mapping the inner thin and thick discs of the MW into a b/p.

Carbon Iso-Dielectric Separation (CIDS) on Centrifugal Microfluidic Platforms

Centrifugal microfluidic platforms employ pseudo forces controlled by a spindle motor to automate bioanalytical assays on a single fluidic disc with no need for several syringe pumps [1]. Recently, we employed a portable cutter-plotter to fabricate microfluidic discs with active valves at point of need [2]. To address a healthcare issue of global interest, we developed a microfluidic disc to automate a sTREM-1 immunoassay for the detection of sepsis at late stages of the disease. To enable sepsis detection and monitoring at early stages, recently a gold iso-dielectric separation (GIDS) chip is develop that separates activated and non-activated leukocytes from blood serum [3]. However, the GIDS chip requires several syringe pumps and an off-chip manual step for sample preparation i.e., blood serum separation. As an alternative to GIDS, in this study we have developed 3D carbon IDS (CIDS) chips to reduce the cost of device fabrication. To prevent the need for the syringe pumps and external piping networks, we have integrated the CIDS on a microfluidic disc to automate the whole bioanalytical process from sample preparation to characterization of thousands of particles and cells. The main objective of developing the integrated microfluidic platform is the separation of activated and non-activated leukocytes for automated early sepsis detection at point of care (POC). However, as an early proof of the practicality of CIDS-on-disc, in this study we employed the hybrid centrifugal microfluidic system for separating various sizes of polystyrene microbeads as well as different bacteria. [1] M.M. Aeinehvand, F. Ibrahim, S.W. Harun, A. Kazemzadeh, H.A. Rothan, R. Yusof, M. Madou, Reversible thermo-pneumatic valves on centrifugal microfluidic platforms, Lab Chip. 15 (2015) 3358–3369. doi:10.1039/C5LC00634A. [2] M.M. Aeinehvand, P. Magaña, M.S. Aeinehvand, O. Aguilar, M.J. Madou, S.O. Martinez-Chapa, Ultra-rapid and low-cost fabrication of centrifugal microfluidic platforms with active mechanical valves, RSC Adv. 7 (2017) 55400–55407. doi:10.1039/C7RA11532F. [3] J.L. Prieto, H.-W. Su, H.W. Hou, M.P. Vera, B.D. Levy, R.M. Baron, J. Han, J. Voldman, Monitoring sepsis using electrical cell profiling, Lab Chip. 16 (2016) 4333–4340. doi:10.1039/C6LC00940A.

Effect of the gear local damage and profile error of the gear on the drivetrain dynamic response

The dynamic modeling of vibration of a drivetrain is used for increasing our information about vibration generating mechanisms, especially in the presence of some kind of gear faults. This paper describes a research work on the automotive driveline modeling, vibration analysis, and the effect of gear defects on the dynamic behavior of the system. Firstly, main drivetrain components including the engine, clutch, single stage spur gearbox and disc brake are modeled, respectively. The nonlinear dynamic model is simulated by a thirteen degrees of freedom (DOF) system and the nonlinear function is due to the dry friction path. Secondly, two types of defects are modeled and introduced into the spur gear system; local damage and profile error. Then, the nonlinear equations of motion are solved by the numerical Runge Kutta method and a comparative study of the dynamic behavior of the system in healthy and defected cases is discussed for each fault type. The influence of the defects on the vibration response is presented in the time and frequency domain. Finally, analysis of the two defects together is presented.

Percutaneous endoscopic discectomy: Gold standard technique for single level intervertebral disc prolapse

Introduction: DISC prolapse is a common problem seen in general population and 10% patients may require surgical intervention. Objective: To determine functional outcome of patients operated by percutaneous endoscopic discectomy. Methodology: Study Area: New Civil Hospital Surat. Sample Size: 40 Scores used: VAS and Oswestry Disability Index Results: Patients operated for Disc Herniation by percutaneous discectomy were followed up 1 month 3 months and 6 months postoperatively showing immediate pain relief, smaller incision size, almost no blood loss and earlier return to daily activities. Conclusion: Endoscopic discectomy is a newer technique which is practised now a days for PIVD and it shows better results than conventional discectomy in terms of post op pain the amount of blood loss, post op ambulation and anesthesia given. It can now be said that percutaneous endoscopic discectomy is the GOLD standard surgical technique for single level disc prolapse.

IPEG 2018The 27th Annual Congress for Endosurgery in ChildrenApril 11–14, 2018, Seattle, Washington

IPEG 2018The 27^th Annual Congress for Endosurgery in ChildrenApril 11–14, 2018, Seattle, Washington

Predictive value of Modic type II changes in the choice of surgical treatment of lumbar disc herniation

ObjectiveTo evaluate the predictive value of Modic typeII changes on nuclear magnetic resonance (NMR) prior to intervention by discectomy for lumbar disc herniation in patients with radicular symptoms. Material and methodRetrospective descriptive study of 190 patients (58.2% men and 41.8% women) with a mean age of 43.5 years, treated between December 2005 and January 2013.They were divided into group 1, single disc herniation (n=85), and group 2, with disc herniation and changes Modic typeII (n=80).Variables studied: weight, height, handedness, level of injury, previous neurological deficit, postoperative complications, persistent pain and need for posterior lumbar fusion, with a mean of 67 months (group 1: 68.1; group 2: 66.8). ResultsIn group 1 there were four hernia recurrences requiring revision surgery and six patients needed lumbar fusion. In group 2, four recurrences were also revised and eight cases requiring arthrodesis were observed.No statistically significant differences were found when comparing the occurrence of relapse (p=.903), the need for subsequent fusion (p=.572) or in the remaining variables. DiscussionThe data obtained and the characteristics of our study, we cannot say that Modic typeII changes were a predictive sign of the result of lumbar discectomy in our study population.