A Comparison of 2 Cage Sizes in Biportal Endoscopic Transforaminal Lumbar Interbody Fusion.

STUDY DESIGN: Retrospective study. OBJECTIVE: This study compared the fusion and subsidence rate and clinical outcomes when using different-sized static PEEK cages in BE-TLIF. SUMMARY OF BACKGROUND DATA: Biportal endoscopic techniques for transforaminal lumbar interbody fusion (BE-TLIF) have been shown to have similar clinical and fusion outcomes with faster clinical recovery in comparison to tubular surgery. Subsidence of the interbody, however, could be a complication. METHODS: Patients who underwent 1 or 2 level BE-TLIF for degenerative and isthmic spondylolisthesis between January 2019 and January 2022 were included. A 32×10 mm cage (group A) and a 40×15 mm cage (group B) were compared. The visual analog scale (VAS) for back and leg symptoms, and Oswestry disability index (ODI) were collected. Plain radiographs and computed tomography assessed fusion and subsidence at a minimum of 12 months. RESULTS: Of the 69 enrolled patients, 39 group A patients (51 levels) and 30 group B patients (32 levels) were compared. The operation time per level was 123 ± 15.8 and 138 ± 10.5 minutes per fusion level in groups A and B, respectively (P < 0.05). ODI improved from 64.8 ± 6.2 to 15.7 ± 7.1 in group A and from 65.3 ± 5.6 to 15.1 ± 6.3 in group B at the final follow-up (P < 0.05). VAS leg and back score improvement between the groups did not differ; however, the 3-month postoperative VAS back improvement was significantly higher in group B. The final fusion rate at the final follow-up did not significantly differ; however, the fusion ratio at 1 year was higher in group B (P < 0.05). Subsidence occurred in 5 cases (9.8%) in group A and none in group B (P < 0.05). CONCLUSION: BE-TLIF using a larger cage can be performed safely with similar patient-reported outcome measures with a faster fusion rate with less subsidence risk. LEVEL OF STUDY: III.

Agathobaculum butyriciproducens improves ageing-associated cognitive impairment in mice.

AIMS: The gut microbiota is increasingly recognised as a pivotal regulator of immune system homeostasis and brain health. Recent research has implicated the gut microbiota in age-related cognitive impairment and dementia. Agathobaculum butyriciproducens SR79 T (SR79), which was identified in the human gut, has been reported to be beneficial in addressing cognitive deficits and pathophysiologies in a mouse model of Alzheimer's disease. However, it remains unknown whether SR79 affects age-dependent cognitive impairment. MAIN METHOD: To explore the effects of SR79 on cognitive function during ageing, we administered SR79 to aged mice. Ageing-associated behavioural alterations were examined using the open field test (OFT), tail suspension test (TST), novel object recognition test (NORT), Y-maze alternation test (Y-maze), and Morris water maze test (MWM). We investigated the mechanisms of action in the gut and brain using molecular and histological analyses. KEY FINDINGS: Administration of SR79 improved age-related cognitive impairment without altering general locomotor activity or depressive behaviour in aged mice. Furthermore, SR79 increased mature dendritic spines in the pyramidal cells of layer III and phosphorylation of CaMKIIα in the cortex of aged mice. Age-related activation of astrocytes in the cortex of layers III-V of the aged brain was reduced following SR79 administration. Additionally, SR79 markedly increased IL-10 production and Foxp3 and Muc2 mRNA expression in the colons of aged mice. SIGNIFICANCE: These findings suggest that treatment with SR79 may be a beneficial microbial-based approach for enhancing cognitive function during ageing.

Early Assessment of Voice Problems in Post-Thyroidectomy Syndrome Using Cepstral Analysis.

Post-thyroidectomy syndrome (PTS), characterized by voice issues after thyroidectomy without recurrent laryngeal nerve injury, was investigated in this study. The Voice Fatigue Index (VFI) and cepstral analysis were employed for subjective and objective voice evaluation. Retrospective analysis involved 96 patients (37 males, 59 females) who underwent thyroidectomy without nerve injury from April 2018 to June 2022. Assessments pre- and post-thyroidectomy included the Voice Handicap Index (VHI) and VFI, along with auditory perceptual, acoustic (including cepstral), aerodynamic, and glottal vibration analyses. In females, although the GRBAS scale showed no significant change, both VHI and VFI increased post-thyroidectomy. Significant correlations were observed between the VHI and VFI in females. Acoustic analysis indicated a decrease in the cepstral peak prominence (CPP) of vowels (/a/) and sentences in females, with significant correlations between changes in the CPP/a/ and VHI/VFI. The maximum fundamental frequency (F0max) exhibited a significant decrease, correlating with the VHI and VFI changes. The VFI demonstrated effectiveness in subjective PTS voice evaluation, comparable to the VHI. The present study highlights the potential of cepstral analysis as an index reflecting subjective voice discomfort, suggesting its promise for a comprehensive PTS voice evaluation.

Exploring Nursing Research Culture in Clinical Practice: Qualitative Ethnographic Study.

BACKGROUND: Cultivating a positive research culture is considered the key to facilitating the utilization of research findings. In the realm of clinical nursing research, nurses conducting research may find the utilization of findings challenging due to the lack of a positive research culture. OBJECTIVE: This study aims to identify and describe the sociocultural context of nursing research in a clinical setting at a Korean tertiary hospital. METHODS: We included participant observation and ethnographic interviews with 6 registered nurses working in a medical-surgical unit in a Korean tertiary hospital who had experience conducting nursing research in clinical settings in this qualitative ethnographic study. The study was conducted from April 2022 to May 2022. Data analysis was conducted using Spradley's ethnographic approach, which includes domain analysis, taxonomic analysis, componential analysis, and theme analysis, and occurred concurrently with data collection. RESULTS: The overarching theme identified for nursing research culture in clinical practice was the development of a driving force for growth within the clinical environment. This theme encompasses (1) balancing positive and negative influences in the research process, (2) fostering transformational change for both nurses and patients, and (3) promoting complementary communication among nurses. CONCLUSIONS: Clinical research plays a vital role in nursing practice that requires a balance of supportive elements, such as patient-driven research questions and hospital research support, with practical challenges such as shift work and high work intensity. This study found that a positive clinical nursing research culture can serve as a unifying bridge, connecting researchers, patients, who serve as both the origin and ultimate beneficiaries of research, and hospitals that facilitate research endeavors. Future research should explore whether the themes derived from this study fully reflect a clinical nursing research culture comprising patients, nurses, and the hospital environment and determine what requirements are needed to establish such a nursing research culture.

Technical Feasibility and Early Clinical Outcome of Biportal Endoscopic Transforaminal Lumbar Interbody Fusion Using Larger Cage.

BACKGROUND: Transforaminal lumbar interbody fusion with biportal endoscopic guidance (BE-TLIF) has been previously reported with promising clinical results. However, complications such as delayed union or subsidence occurred as with open surgery. We assumed using larger cages would result in less occurrence of such complications. We aimed to analyze the clinical outcome and technical feasibility of BE-TLIF using larger cages, initially designed for oblique lumbar interbody fusion. METHODS: We enrolled cases that underwent single-level BE-TLIF between January 2021 and January 2022. Polyetheretherketone cages that were larger than the conventional size were used. Diagnoses were degenerative spondylolisthesis or isthmic spondylolisthesis. Visual analog scale scores of the back and leg and Oswestry Disability Index were collected perioperatively. Modified Macnab criteria were used to evaluate the patients at the final follow-up. Radiologic outcome of interbody fusion rate and perioperative complications were analyzed. RESULTS: A total of 35 cases were included in this study. The mean age was 67.5 ± 8.4 and consisted of 13 male patients, and the mean follow-up duration was 18.3 ± 3.7 months. The majority (32/35, 91.3%) of the index level was located within the lower lumbar region, L4-S1. Oswestry Disability Index scores improved from 65.4 ± 5.4 preoperatively to 15.4 ± 6.1 at the final follow-up (P < 0.001). Visual analog scale scores of the leg decreased from 7.9 ± 1.5 to 1.7 ± 1.5 at the final follow-up (P < 0.001). Per the modified Macnab criteria on the final follow-up, 94% of the patients reported good/excellent. Most (94.2%) of the patients showed fusion grade I and II at the 1-year follow-up. No patient showed subsidence or other postoperative complication. CONCLUSIONS: BE-TLIF using a larger cage was safely performed without risk of subsidence during the 1-year follow-up. A cage with a larger footprint may be advantageous in BE-TLIF in the aspect of interbody fusion and subsidence.

Isolation, Physicochemical Characterization, and Biological Properties of Inotodiol, the Potent Pharmaceutical Oxysterol from Chaga Mushroom.

Inotodiol, an oxysterol found only in Chaga mushroom, has received attention from the pharmaceutical industry due to its strong antioxidant and anti-allergic activities. However, the production of inotodiol is still challenging, and its fundamental properties have yet to be investigated. This study aims to develop an efficient method to produce high-purity inotodiol from Chaga mushroom. Then, pure inotodiol was used to assess its physicochemical properties and biological activities. By optimizing the solvent used for extraction and purification, a new method to produce inotodiol was developed with high purity (>97%) and purification yield (33.6%). Inotodiol exhibited a melting point (192.06 °C) much higher than lanosterol and cholesterol. However, the solubility of inotodiol in organic solvents was notably lower than those of the other two sterols. The difference in the hydroxyl group at C-22 of inotodiol has shown the distinctive physicochemical properties of inotodiol compared with cholesterol and lanosterol. Based on those findings, a nonionic surfactant-based delivery system for inotodiol was developed to improve its bioavailability. The inotodiol microemulsion prepared with 1-2% Tween-80 exhibited homogenous droplets with an acceptable diameter (354 to 217 nm) and encapsulation efficiency (85.6-86.9%). The pharmacokinetic analysis of inotodiol microemulsion in oral administration of 4.5 mg/kg exhibited AUC0-24h = 341.81 (ng·h/mL), and Cmax = 88.05 (ng/mL). Notably, when the dose increased from 4.5 to 8.0 mg/kg, the bioavailability of inotodiol decreased from 41.32% to 33.28%. In a mouse model of sepsis, the serum level of interleukin-6 significantly decreased, and the rectal temperature of mice was recovered in the inotodiol emulsion group, indicating that inotodiol microemulsion is an effective oral delivery method. These results could provide valuable information for applying inotodiol in functional food, cosmetic, and pharmaceutical industries.

Interactive effects of dietary supplementation between illite and probiotic on productive performance, intestinal microflora, and blood profiles of laying hens.

This study investigates the interactive effects of dietary illite and probiotic on productive performance, intestinal microflora, and blood profiles of laying hens. A total of 432 laying hens at 24 weeks old were allotted into six dietary groups. An experimental design was composed with a 3 (illite levels: 0, 0.3, and 0.6%) × 2 (probiotic levels: 0 and 0.2%). The probiotic based on Bacillus subtilis, Saccharomyces cerevisiae, and B. licheniformis was used. There were interactions between illite and probiotic on total microbes and salmonella of digesta. Higher egg production was observed in hens fed a diet supplemented with either 0.6% illite or 0.2% probiotic than in those fed a basal diet. The total microbes of the group fed a diet with 0.6% illite were lower than the groups fed diets with 0 and 0.3% illite. A lower number of Escherichia coli was observed in hens fed a diet with probiotic than those fed a basal diet. Higher immunoglobulin G concentration was observed in the group fed a diet supplemented with 0.6% illite than in those fed a basal diet. Our results suggest illite and probiotic can be used as feed additives for hens, separately or in combination to improve performance and intestinal microflora.

Increased Complement-Associated Inflammation in Cytomegalovirus-Positive Hypertensive Anterior Uveitis Patients Based on the Aqueous Humor Proteomics Analysis.

Herpetic anterior uveitis-associated ocular inflammation is commonly manifested with ocular hypertension and glaucoma. Relative to other viruses, cytomegalovirus (CMV) positive hypertensive anterior uveitis is associated with high recurrences of uveitis, as well as with uncontrolled intraocular pressure (IOP) and a subsequent higher requirement for future glaucoma surgery. To gain novel insights into the pathogenesis of ocular hypertension in these patients, we investigated the proteome changes of the aqueous humor (AH) derived from the CMV hypertensive anterior uveitis (CMV-HAU; n = 10) patients and non-glaucoma (cataract; n = 10) patients using liquid chromatography with tandem mass spectrometry. Among a total of 562 proteins identified, fifty and fifteen proteins were significantly elevated and decreased, respectively, in the AH of CMV-HAU patients compared to the control subjects by ≥2 fold. Gene ontology (GO) enrichment and network analyses of elevated proteins revealed that the enrichment of protein was involved in the complement activation, the humoral immune response mediated by the circulating immunoglobulins, proteolysis, and platelet degranulation. In the AH of CMV-HAU, GDF (growth/differentiation factor)-15, the inflammatory marker belonging to the TGF-ß superfamily proteins, was significantly increased, while vasorin, an anti-TGF-ß protein, levels were decreased. The trabecular meshwork cells infected with CMV exhibited a significantly increased expression of inflammatory markers. Collectively, these data indicate increased complement factor associated inflammation and humoral immunity in CMV-HAU associated ocular hypertension.

Static and Dynamic Biomaterial Engineering for Cell Modulation.

In the biological microenvironment, cells are surrounded by an extracellular matrix (ECM), with which they dynamically interact during various biological processes. Specifically, the physical and chemical properties of the ECM work cooperatively to influence the behavior and fate of cells directly and indirectly, which invokes various physiological responses in the body. Hence, efficient strategies to modulate cellular responses for a specific purpose have become important for various scientific fields such as biology, pharmacy, and medicine. Among many approaches, the utilization of biomaterials has been studied the most because they can be meticulously engineered to mimic cellular modulatory behavior. For such careful engineering, studies on physical modulation (e.g., ECM topography, stiffness, and wettability) and chemical manipulation (e.g., composition and soluble and surface biosignals) have been actively conducted. At present, the scope of research is being shifted from static (considering only the initial environment and the effects of each element) to biomimetic dynamic (including the concepts of time and gradient) modulation in both physical and chemical manipulations. This review provides an overall perspective on how the static and dynamic biomaterials are actively engineered to modulate targeted cellular responses while highlighting the importance and advance from static modulation to biomimetic dynamic modulation for biomedical applications.

Aseptic Meningitis Following Second Dose of an mRNA Coronavirus Disease 2019 Vaccine in a Healthy Male: Case Report and Literature Review.

Vaccines are one of the most important strategies against pandemics or epidemics involving infectious diseases. With the spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), there have been global efforts for rapid development of coronavirus disease 2019 (COVID-19) vaccine and vaccination is being performed globally on a massive scale. With rapid increase in vaccination, rare adverse events have been reported. Well-known neurological adverse events associated with COVID-19 vaccination include Guillain-Barré syndrome, myelitis, and encephalitis. However, COVID-19 vaccine-related aseptic meningitis has rarely been reported. A 32-year-old healthy man visited our hospital with a complaint of headache for 1 week. He had received the second dose of the BNT162b2 mRNA COVID-19 vaccine 2 weeks before the onset of headache. Since the initial cerebrospinal fluid (CSF) profile suggested viral meningitis, we started treatment with an antiviral agent. However, the symptoms and follow-up CSF profile on day 7 of hospitalization showed no improvement and SARS-CoV-2 IgG antibodies were detected in the CSF. We suspected aseptic meningitis associated with the vaccination and intravenous methylprednisolone (500 mg/day) was administered for 3 days. The symptoms improved and the patient was discharged on day 12 of hospitalization.

IL-6 and IL-10 Levels, Rather Than Viral Load and Neutralizing Antibody Titers, Determine the Fate of Patients With Severe Fever With Thrombocytopenia Syndrome Virus Infection in South Korea.

Severe fever with thrombocytopenia syndrome (SFTS) is a new tick-borne viral disease, and most SFTS virus (SFTSV) infections occur via bites from the tick Haemaphysalis longicornis; however, SFTSV transmission can also occur through close contact with an infected patient. SFTS is characterized by acute high fever, thrombocytopenia, leukopenia, elevated serum hepatic enzyme levels, gastrointestinal symptoms, and multiorgan failure and has a 16.2 to 30% mortality rate. In this study, we found that age, dyspnea rates, aspartate aminotransferase (AST), alanine aminotransferase (ALT), lactate dehydrogenase, multiorgan dysfunction score (MODS), viral load, IL-6 levels, and IL-10 levels were higher in patients with fatal disease than in patients with nonfatal disease during the initial clinical course of SFTS. In addition, we found that IL-6 and IL-10 levels, rather than viral load and neutralizing antibody titers, in patients with an SFTSV infection strongly correlated with outcomes (for severe disease with an ultimate outcome of recovery or death).

Cytokine profile and cytoskeletal changes after herpes simplex virus type 1 infection in human trabecular meshwork cells.

Uveitis caused by herpes simplex virus (HSV)-1 is characterized by increased intraocular pressure (IOP) in the presence of anterior chamber inflammation. Despite their clinical significance, the pathogenic changes associated with HSV-1 infection in trabecular meshwork (TM) cells, the key cell type regulating IOP, have not been completely elucidated. In this study, cytokine array analyses showed a significant stepwise increase in monocyte chemoattractant protein (MCP)-1 expression upon HSV-1 infection in TM cells (p < 0.05). HSV-1 infection led to downregulation of fibrogenic molecules (fibronectin, α-smooth muscle actin, connective tissue growth factor and TGF-ß1). Notably, HSV-1 infection caused a significant increase in actin stress fibres, with a twofold increase in active RhoA, which was enhanced by treatment with TGF-ß1 and inhibited by treatment with the Rho-kinase inhibitor, Y-27632. TM cells treated with MCP-1 exhibited a dose-dependent increase in actin stress fibres compared to untreated TM cells. Our study suggests that HSV-1 infection in TM cells increases cell contractile activity rather than fibrotic changes in the extracellular matrix (ECM) components. Taken together, these observations demonstrate the enhanced expression of MCP-1 and TM cell contractile activity upon HSV-1 infection and events with potential implications for the pathobiology of abrupt IOP elevation in HSV-1 anterior uveitis.

Corrigendum to "WS-5 Extract of Curcuma longa, Chaenomeles sinensis, and Zingiber officinale Contains Anti-AChE Compounds and Improves ß-Amyloid-Induced Memory Impairment in Mice".

[This corrects the article DOI: 10.1155/2019/5160293.].

Role of MCP-1 and IL-8 in viral anterior uveitis, and contractility and fibrogenic activity of trabecular meshwork cells.

The inflammatory chemokines, monocyte chemoattractant protein (MCP)-1 and IL-8, are produced by normal trabecular meshwork cells (TM) and elevated in the aqueous humor of primary open angle glaucoma (POAG) and hypertensive anterior uveitis associated with viral infection. However, their role in TM cells and aqueous humor outflow remains unclear. Here, we explored the possible involvement of MCP-1 and IL-8 in the physiology of TM cells in the context of aqueous outflow, and the viral anterior uveitis. We found that the stimulation of human TM cells with MCP-1 and IL-8 induced significant increase in the formation of actin stress fibers and focal adhesions, myosin light chain phosphorylation, and the contraction of TM cells. MCP-1 and IL-8 also demonstrated elevation of extracellular matrix proteins, and the migration of TM cells. When TM cells were infected with HSV-1 and CMV virus, there was a significant increase in cytoskeletal contraction and Rho-GTPase activation. Viral infection of TM cells revealed significantly increased expression of MCP-1 and IL-8. Taken together, these results indicate that MCP-1 and IL-8 induce TM cell contractibility, fibrogenic activity, and plasticity, which are presumed to increase resistance to aqueous outflow in viral anterior uveitis and POAG.

Prevalence of Dysphonia in Children with Adenotonsillar Problems and the Impact of Surgery on Voice.

OBJECTIVE/HYPOTHESIS: Adenotonsillar problems might affect the voices of patients with pediatric dysphonia, which is very common. This study aimed to evaluate the prevalence of dysphonia in patients with adenotonsillar problems and to demonstrate the impact of tonsillectomy and adenoidectomy (T & A) on their voice postoperatively. STUDY DESIGN: Single-institution retrospective study. METHODS: Subjects were recruited from those children admitted for the purpose of T & A, and all underwent the auditory-perceptual assessment by speech therapists preoperatively. If children demonstrated scores >2 in the G parameter, we performed subjective (pediatric voice handicap index [pVHI], severity, talkativeness scale) and objective (Multi-Dimensional Voice Program) voice analyses preoperatively and 1 and 3 months postoperatively. RESULTS: Among the 1,197 patients, 91 (7.6%) patients showed dysphonia with a score >2 in the G parameter preoperatively. The follow-up voice analysis was completed in 51 and 22 patients after 1 and 3 months, respectively. Although there were no significant differences in the amount of speech preoperatively and postoperatively, the average visual analog scale score for dysphonia severity was significantly decreased at postoperative 1 month and postoperative 3 months. The average total pVHI score, jitter, shimmer, noise-to-harmonic ratio, and soft phonation index were significantly decreased at 1 and 3 months postoperatively. Subjective scores given by parents did not correlate with the acoustic parameters; however, the postoperative subjective parameters were significantly correlated with objective parameters. CONCLUSIONS: Voice problems were significantly improved after T & A in the short term and long term. In those with pediatric dysphonia, decreased mouth breathing and compliance with vocal hygiene would be helpful for voice improvement. LEVEL OF EVIDENCE: 4 Laryngoscope, 131:2369-2375, 2021.

Synthesis of PEG-dendron for surface modification of pancreatic islets and suppression of the immune response.

Islet cell transplantation has been an effective method for the treatment of type 1 diabetes. The transplanted islets release insulin in response to changes in blood glucose levels. The clinical application of islet transplantation, however, has been hindered because of some critical problems including immune responses to grafted islets and side effects caused by overdosed immunosuppressive drugs. Herein, surface modification technology using poly(ethylene glycol) (PEG)-dendron was proposed to safeguard islets from the host immune system. PEG-dendron was synthesized by a divergent polymerization method and utilized to cover the islet antigen surface. Successful conjugation of PEG-dendron on the islet surface was achieved without affecting islet morphology, viability, and functionality at a concentration of 1.00%. Surface modification using PEG-dendron effectively prevented protein absorption and immune activation. Foremost, it improved the survival rate of islet grafts in vivo when combined with a low dose of immunosuppressive drugs. In conclusion, PEG-dendron is a potential candidate for the surface modification of pancreatic islets to mitigate immune responses after transplantation.

Comparison of Minimal Invasive Versus Biportal Endoscopic Transforaminal Lumbar Interbody Fusion for Single-level Lumbar Disease.

STUDY DESIGN: Retrospective study. OBJECTIVE: The authors aimed to compare the clinical outcomes of biportal endoscopic transforaminal lumbar interbody fusion (BE-TLIF) with those of minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) using a microscope. SUMMARY OF BACKGROUND DATA: Lumbar spinal fusion has been widely performed for various lumbar spinal pathologies. Minimally invasive transforaminal interbody fusion using a tubular retractor under a microscope is a method of achieving fusion while reducing soft tissue injury. Recently, several studies have reported minimally invasive techniques for lumbar discectomy, decompression, and interbody fusion using biportal endoscopic spinal surgery. MATERIALS AND METHODS: This retrospective study included 87 patients who underwent single-level TLIF for degenerative or isthmic spondylolisthesis between 2015 and 2018. Thirty-two and 55 patients underwent BE-TLIF (group A) and MI-TLIF (group B), respectively. Visual Analogue Scale scores of the back and leg and Oswestry Disability Index were collected perioperatively.Further, data regarding perioperative complications, including length of hospital stay, time to ambulation, and fusion rate, were collected. RESULTS: The Visual Analogue Scale score at 2 weeks and 2 months postoperatively was significantly lower in group A (P=0.001). All other clinical scores showed improvement with no significant difference between the 2 groups (P>0.05). The difference in the fusion rates between group A (93.7%) and group B (92.7%) were not significant (P=0.43). CONCLUSIONS: Because BE-TLIF yieldeds lesser early postoperative back pain than did MI-TLIF, it may allow early ambulation and a shorter hospitalization period. BE-TLIF may be a viable alternative to MI-TLIF in patients with degenerative or isthmic spondylolisthesis with superior clinical results in the early postoperative period.

Etch characteristics of magnetic tunnel junction materials using H2/NH3 reactive ion beam.

Magnetic tunneling junction (MTJ) materials such as CoFeB, Co, Pt, MgO, and the hard mask material such as W and TiN were etched with a reactive ion beam etching (RIBE) system using H2/NH3. By using gas mixtures of H2 and NH3, especially with the H2/NH3( 2:1) ratio, higher etch rates of MTJ related materials and higher etch selectivities over mask materials (>30) could be observed compared to those etching using pure H2( no etching) and NH3. In addition, no significant chemical and physical damages were observed on etched magnetic materials surfaces and, for CoPt and MTJ nanoscale patterns etched by the H2/NH3( 2:1) ion beam, highly anisotropic etch profiles >83° with no sidewall redeposition could be observed. The higher etch rates of magnetic materials such as CoFeB by the H2/NH3( 2:1) ion beam compared to those by H2 ion beam or NH3 ion beam are believed to be related to the formation of volatile metal hydrides (MH, M = Co, Fe, etc) through the reduction of M-NHx( x = 1 ∼ 3) formed in the CoFeB surface by the exposure to NH3 ion beam. It is believed that the H2/NH3 RIBE is a suitable technique in the etching of MTJ materials for the next generation nanoscale spin transfer torque magnetic random access memory (STT-MRAM) devices.

Learning Curve and Clinical Outcome of Biportal Endoscopic-Assisted Lumbar Interbody Fusion.

Interbody fusion is a common surgical technique for diseases of the lumbar spine. Biportal endoscopic-assisted lumbar interbody fusion (BE-LIF) is a novel minimally invasive technique that has a long learning curve, which can be a barrier for surgeons. Therefore, we analyzed the learning curve in terms of operative time and evaluated the outcomes of BE-LIF. A retrospective study of fifty-seven consecutive patients who underwent BE-LIF for degenerative lumbar disease by a single surgeon from January 2017 to December 2018 was performed. Fifty patients underwent a single-level procedure, and 7 underwent surgery at two levels. The mean follow-up period was 24 months (range, 14-38). Total operative time, postoperative drainage volume, time to ambulation, and complications were analyzed. Clinical outcome was measured using the Oswestry Disability Index (ODI), Visual Analog Scale (VAS) score for back and leg pain, and modified Macnab criteria. The learning curve was evaluated by a nonparametric regression locally weighted scatterplot smoothing curve. Cases before the stable point on the curve were designated as group A, and those after the stable point were designated group B. Operative time decreased as the number of cases increased. A stable point was noticed on the 400th day and the 34th case after the first BE-LIF was performed. All cases showed improved ODI and VAS scores at the final follow-up. Overall mean operative time was 171.74 ± 35.1 min. Mean operative time was significantly lower in group B (139.7 ± 11.6 min) compared to group A (193.4 ± 28.3 min). Time to ambulation was significantly lower in group B compared to group A. VAS and ODI scores did not differ between the two groups. BE-LIF is an effective minimally invasive technique for lumbar degenerative disease. In our case series, this technique required approximately 34 cases to reach an adequate performance level.

Safety Evaluation of Biportal Endoscopic Lumbar Discectomy: Assessment of Cervical Epidural Pressure During Surgery.

STUDY DESIGN: A prospective study. OBJECTIVE: To evaluate the change in cervical epidural pressure (CEP) during biportal endoscopic lumbar discectomy (BELD). SUMMARY OF BACKGROUND DATA: In percutaneous uniportal endoscopic lumbar discectomy, irrigation fluid (IF) introduced into the spinal canal during surgery can compress the thecal sac, and act as a potential risk for neurological complications by disturbing cerebrospinal fluid (CSF) circulation and increasing intracranial pressure. METHODS: Thirty consecutive patients, who underwent BELD, which was performed under automated pump system, an infusion pressure of 30 mmHg were enrolled. The change in CEP on C7-T1 level was measured. CEP was measured in each of the five phases of the procedure (1st phase-making surgical portals; 2nd phase-creating a workspace; 3rd phase-performing neural decompression and discectomy; 4th phase-factitious increase of pressure by clogging the outflow; 5th phase-dismission from fluid irrigation system). Neurological complications and independent risk factors were evaluated. RESULTS: In the final 27 patients, changes in CEP during surgery were similar. The baseline CEP was 14.8 ±â€Š2.8 mmHg, and the mean CEP in the 3rd phase 18.8 ±â€Š5.1 mmHg was not significantly higher. In the 4th phase, however, the CEPs rose with linear correlation as the pressure increased. In the 5th phase, the elevated CEP returned to baseline in 2.5 ±â€Š5.6 minutes. No patient had neurological complications. No statistically significant risk factors were observed. CONCLUSION: In BELD, which is performed to allow continuous lavage with infusion pressure set to 30 mmHg, CEP does not increase beyond the physiological range. Therefore, BELD may be considered as a potentially safe technique. LEVEL OF EVIDENCE: 4.