Haze-Suppressed Wideband Light Shutter from Near Ultraviolet to Infrared Rays Utilizing Electrophoretic Carbon Black Particles.

Carbon black (CB) particles that can absorb from near ultraviolet to infrared rays are well dispersed into an isotropic dielectric liquid and their optical properties can be kept even under exposure to sunlight over a long time. The shutter which controls the position of CB particles by electrophoretic force can be applied to switchable light shutters for windows in buildings and automobiles for the purpose of energy savings. Here, a wideband light shutter with three terminal electrodes is proposed, exhibiting excellent dark (transmittance ≈1.4%) and transparent state (transmittance >60%). The device operates at a low field intensity of about 1 V µm-1 to obtain transparent state and its wide temperature range operation from -50 to 120 °C is confirmed while conventional liquid crystal-based shutter cannot perform such levels due to a limited temperature range in the nematic phase. In addition, haze is minimized in a transparent state by adopting an insulation layer over electrodes and a solution is found to keep a transparent state without applying power. It is believed that the proposed broadband shutter with fast response time could open a new chapter in switchable windows owing to its low power consumption and working in a wide temperature range.

Relationships between common carotid artery blood flow and anesthesia, pneumoperitoneum, and head-down tilt position: a linear mixed-effect analysis.

This study investigated the effects of pneumoperitoneum and the head-down tilt position on common carotid artery (CCA) blood flow in surgical patients. METHODS: This prospective observational study included 20 patients who underwent gynecological surgery. CCA blood flow was measured using Doppler ultrasound at four-time points: awake in the supine position [T1], 3 min after anesthesia induction in the supine position [T2], 3 min after pneumoperitoneum in the supine position [T3], and 3 min after pneumoperitoneum in the head-down tilt position [T4]. Hemodynamic and respiratory parameters were also recorded at each time point. Linear mixed-effect analyses were performed to compare CCA blood flow across the time points and assess its relationship with hemodynamic parameters. RESULTS: Compared with T1, CCA blood flow decreased significantly at T2 (345.4 [288.0-392.9] vs. 293.1 [253.0-342.6], P = 0.048). CCA blood flow were also significantly lower at T3 and T4 compared with T1 (345.4 [288.0-392.9] vs. 283.6 [258.8-307.6] and 287.1 [242.1-321.4], P = 0.005 and 0.016, respectively). CCA blood flow at T3 and T4 did not significantly differ from that at T2. Changes in CCA blood flow were significantly associated with changes in cardiac index and stroke volume index (P = 0.011 and 0.024, respectively). CONCLUSION: CCA blood flow was significantly decreased by anesthesia induction. Inducing pneumoperitoneum, with or without the head-down tilt position, did not further decrease CCA blood flow if the cardiac index remained unchanged. The cardiac index and stroke volume index were significantly associated with CCA blood flow. CLINICAL TRIAL REGISTRATION: Clinicaltrials.gov (NCT04233177, January 18, 2020).

Effect of remifentanil on post-operative analgesic consumption in patients undergoing shoulder arthroplasty after interscalene brachial plexus block: a randomized controlled trial.

PURPOSE: Remifentanil is useful in balanced anesthesia; however, there is concern regarding opioid-induced hyperalgesia. The effect of remifentanil on rebound pain, characterized by hyperalgesia after peripheral nerve block has rarely been studied. This study evaluated whether intraoperative remifentanil infusion may increase postoperative analgesic requirement in patients receiving preoperative interscalene brachial plexus block (IBP). METHODS: Sixty-eight patients undergoing arthroscopic shoulder surgery under general anesthesia were randomly allocated to remifentanil (R) or control (C) group. Preoperative IBP with 0.5% ropivacaine 15 mL was performed in all patients. Intraoperative remifentanil was administered only in the R group. Postoperative pain was controlled using intravenous patient-controlled analgesia (IV-PCA) and rescue analgesics. The primary outcome was the dosage of fentanyl-nefopam IV-PCA infused over 24 h postoperatively. The secondary outcomes included the numeric rating scale (NRS) score recorded at 4-h intervals over 24 h, amount of rescue analgesics and total postoperative analgesics used over 24 h, occurrence of intraoperative hypotension, postoperative nausea and vomiting (PONV) and delirium. RESULTS: The dosage of fentanyl-nefopam IV-PCA was significantly less in C group than R group for postoperative 24 h. Fentanyl 101 [63-158] (median [interquartile range]) µg was used in the C group, while fentanyl 161 [103-285] µg was used in the R group (median difference 64 µg, 95% CI 10-121 µg, P = 0.02). Nefopam 8.1 [5.0-12.6] mg was used in the C group, while nefopam 12.9 [8.2-22.8] mg was used in the R group (median difference 5.1 mg, 95% CI 0.8-9.7 mg, P = 0.02). The total analgesic consumption: the sum of PCA consumption and administered rescue analgesic dose, converted to morphine milligram equivalents, was higher in the R group than C group (median difference 10.9 mg, 95% CI 3.0-19.0 mg, P = 0.01). The average NRS score, the incidence of PONV and delirium, were similar in both groups. The incidence of intraoperative hypotension was higher in R group than C group (47.1% vs. 20.6%, P = 0.005). CONCLUSIONS: Remifentanil administration during arthroscopic shoulder surgery in patients undergoing preoperative IBP increased postoperative analgesic consumption.

Optimal angle of needle insertion for spinal anesthesia in patients with spondylolisthesis: an ultrasonographic study.

BACKGROUND: Spondylolisthesis is a common degenerative spinal deformity. At the level of spondylolisthesis, the anatomy of the interlaminar space may differ from normal spine, in which case optimal angle of the needle insertion for spinal anesthesia may change. This study compared the optimal angle of needle insertion during spinal anesthesia in patients with and without lumbar spondylolisthesis using ultrasound. METHODS: We recruited 40 patients, 20 with and 20 without lumbar spondylolisthesis (group S and N, respectively). Ultrasonography was performed in the transverse midline and parasagittal oblique views at the spondylolisthesis level and the adjacent upper level. We measured the probe application angle with the longest interlaminar height of the ligamentum flavum-dura mater complex (LFD), depth from the skin to the LFD, depth from the skin to the anterior complex, and intrathecal space width. A positive angle represented a cephalad angulation. RESULTS: The optimal needle insertion angle in the transverse midline view at the spondylolisthesis level was (-) 2.7 ± 3.4° in group S and 0.8 ± 2.5° in group N (P [Formula: see text] 0.001). In the parasagittal oblique view, it was (-) 2.7 ± 4.5° in group S and 1.0 ± 3.2° in group N (P = 0.004). There were no between-group differences in the angles at the upper level, with all cephalad angles in both views. Other ultrasound image data were comparable between groups. CONCLUSION: In patients with spondylolisthesis, caudad angulation of the spinal needle can aid successful spinal puncture at spondylolisthesis level, both in the midline and paramedian approaches. TRIAL REGISTRATION: www.ClinicalTrials.gov ( NCT04426916 ); registered 11 June 2020.

Ultrasound-guided versus conventional lung recruitment manoeuvres in laparoscopic gynaecological surgery: A randomised controlled trial.

BACKGROUND: Pneumoperitoneum and steep Trendelenburg position promote the formation of pulmonary atelectasis during laparoscopic gynaecological surgery. OBJECTIVE: To determine whether lung ultrasound-guided alveolar recruitment manoeuvres could reduce peri-operative atelectasis compared with conventional recruitment manoeuvres during laparoscopic gynaecological surgery. DESIGN: Randomised controlled trial. SETTING: Tertiary hospital, Republic of Korea, from August 2018 to January 2019. PATIENTS: Adult patients scheduled for laparoscopic gynaecological surgery under general anaesthesia. INTERVENTION: Forty patients were randomised to receive either ultrasound-guided recruitment manoeuvres (manual inflation until no visibly collapsed area was seen with lung ultrasonography; intervention group) or conventional recruitment manoeuvres (single manual inflation with 30 cmH2O pressure; control group). Recruitment manoeuvres were performed 5 min after induction and at the end of surgery in both groups. All patients received volume-controlled ventilation with a tidal volume of 8 ml kg-1 and a positive end-expiratory pressure of 5 cmH2O. MAIN OUTCOME MEASURES: The primary outcome was the lung ultrasound score at the end of surgery; a higher score indicates worse lung aeration. RESULTS: Lung ultrasound scores at the end of surgery were significantly lower in the intervention group compared with control group (median [IQR], 7.5 [6.5 to 8.5] versus 9.5 [8.5 to 13.5]; difference, -2 [95% CI, -4.5 to -1]; P = 0.008). The intergroup difference persisted in the postanaesthesia care unit (7 [5 to 8.8] versus 10 [7.3 to 12.8]; difference, -3 [95% CI, -5.5 to -1.5]; P = 0.005). The incidence of atelectasis was lower in the intervention group compared with control group at the end of surgery (35 versus 80%; P = 0.010) but was comparable in the postanaesthesia care unit (40 versus 55%; P = 0.527). CONCLUSIONS: The use of ultrasound-guided recruitment manoeuvres improves peri-operative lung aeration; these effects may persist in the postanaesthesia care unit. However, the long-term effects of ultrasound-guided recruitment manoeuvres on clinical outcomes should be the subject of future trials. TRIAL REGISTRATION: ClinicalTrials.gov (NCT03607240).

Efficacy of intra-operative administration of iron isomaltoside for preventing postoperative anaemia after total knee arthroplasty: A randomised controlled trial.

BACKGROUND: Postoperative anaemia is common after total knee arthroplasty (TKA). Emerging evidence shows the beneficial effects of peri-operative iron supplementation in patients at risk of postoperative anaemia. OBJECTIVE: To evaluate the efficacy of intra-operative administration of iron isomaltoside for the prevention of postoperative anaemia in patients undergoing TKA. DESIGN: Randomised, controlled, double-blind, parallel-group study. SETTING: A tertiary care teaching hospital; between 29 March 2018 and 16 April 2019. PATIENTS: Eighty-nine patients scheduled for unilateral TKA were included. INTERVENTION: Iron isomaltoside or placebo were administered intravenously over 30 min during surgical wound closure. MAIN OUTCOME MEASURES: The primary outcome measure was the incidence of anaemia at 30 days after TKA: anaemia was defined as haemoglobin less than 12 g dl-1 for female and less than 13 g dl-1 for male. RESULTS: In total, 89 patients were included in the final analysis (44 in the treatment group; 45 in the control group). The administered dose of iron isomaltoside in the treatment group was 1136 ±â€Š225 mg. The incidence of anaemia at 30 days after TKA was significantly lower in the treatment group (34.1%, 15/44) than that in the control group (62.2%, 28/45): relative risk 0.55 (95% confidence interval, 0.34 to 0.88), P = 0.008. Haemoglobin concentration, serum ferritin concentrations, and transferrin saturation were also significantly higher in the treatment group at 30 days after TKA. CONCLUSION: The intra-operative administration of iron isomaltoside effectively prevents postoperative anaemia in patients undergoing TKA, and thus it can be included in patient blood management protocols for reducing postoperative anaemia in these population. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT03470649.

Ultrasound-Assisted Versus Landmark-Guided Spinal Anesthesia in Patients With Abnormal Spinal Anatomy: A Randomized Controlled Trial.

BACKGROUND: Spinal anesthesia using a surface landmark-guided technique can be challenging in patients with anatomical alterations of the lumbar spine; however, it is unclear whether using ultrasonography can decrease the technical difficulties in these populations. We assessed whether an ultrasound-assisted technique could reduce the number of needle passes required for block success compared with the landmark-guided technique in patients with abnormal spinal anatomy. METHODS: Forty-four patients with abnormal spinal anatomy including documented lumbar scoliosis and previous spinal surgery were randomized to receive either surface landmark-guided or preprocedural ultrasound-assisted spinal anesthesia. All spinal procedures were performed by 1 of 3 experienced anesthesiologists. The primary outcome was the number of needle passes required for successful dural puncture. Secondary outcomes included the success rate on the first pass, total procedure time, periprocedural pain scores, and the incidences of radicular pain, paresthesia, and bloody tap during the neuraxial procedure. Intergroup difference in the primary outcome was assessed for significance using Mann-Whitney U test. RESULTS: The median (interquartile range [IQR; range]) number of needle passes was significantly lower in the ultrasound group than in the landmark group (ultrasound 1.5 [1-3 {1-5}]; landmark 6 [2-9.3 {1-15}]; P < .001). First-pass success was achieved in 11 (50.0%) and 2 (9.1%) patients in the ultrasound and landmark groups, respectively (P = .007). The total procedure time, defined as the sum of the time for identifying landmarks and performing spinal anesthesia, did not differ significantly between the 2 groups (ultrasound 141 seconds [115-181 seconds {101-336 seconds}]; landmark 146 seconds [90-295 seconds {53-404 seconds}]; P = .888). The ultrasound group showed lower periprocedural pain scores compared with the landmark group (ultrasound 3.5 [1-5 {0-7}]; landmark 5.5 [3-8 {0-9}]; P = .012). The incidences of complications during the procedure showed no significant differences between the 2 groups. CONCLUSIONS: For anesthesiologists with experience in neuraxial ultrasonography, the use of ultrasound significantly reduces the technical difficulties of spinal anesthesia in patients with abnormal spinal anatomy compared with the landmark-guided technique. Our results can lead to practical suggestions that encourage the use of neuraxial ultrasonography for spinal anesthesia in such patients.

Influence of Employment on the Positive Mental Health of Individuals with Schizophrenia Living in the Community.

Lower levels in emotional well-being have been observed in individuals with schizophrenia but well-planned direct comparisons in positive mental health between employed and unemployed persons with schizophrenia are lacking. This study is among the first to test differences in positive mental health between employed and unemployed persons with schizophrenia living in the community. Participants were 101 unemployed individuals with schizophrenia living in the community and 67 employed ones. Socio-demographic data sheet and Mental Health Continuum-Short Form (MHC-SF) were used to collect the data. Results revealed that emotional and psychological well-being were lower in the unemployed group compared to the employed group, however, there was no significant difference in social well-being between the groups. Emotional and psychological well-being was correlated with employment status in individuals with schizophrenia living in the community.

Paper-like flexible optically isotropic liquid crystal film for tunable diffractive devices.

We have demonstrated a paper-like diffractive film in which nano-structured liquid crystal droplets are embedded in elastomeric monomer incorporated polymer matrix by polymerization induced phase-separation. The film with voltage-tunable phase grating exhibits an optically isotropic phase with high transparency and an effective chromatic diffraction for an incident white light with sub-millisecond switching time. In addition, the proposed diffractive film is exhibiting excellent chemical stability against organic and inorganic solvents. In this paper, the diffraction properties of test films depending on incident polarization direction, wavelength, and spatial dispersion are characterized. Easy processing and optically isotropic nature of the film imparts potential applications to flexible electro-optic devices that can be widely implemented in wearable photonics.

The effect of neck extension on success rate of blind intubation through Ambu® AuraGain™ laryngeal mask: a randomized clinical trial.

PURPOSE: Although the use of fibreoptic guidance is recommended for tracheal intubation through supraglottic airway devices, it can also be performed in a blind manner. Based on the previous finding that a fibreoptic view of the vocal cords was better in the extended neck position than in the neutral position, we hypothesized that neck extension can better facilitate blind intubation through the Ambu® AuraGain™ laryngeal mask than the neutral position. METHODS: Patients undergoing general anesthesia were randomly assigned to the extension group or the neutral group. After induction of anesthesia, the AuraGain™ was placed in the oropharynx, followed by blind intubation through the AuraGain™ in the assigned neck position within a maximum of two attempts. The primary outcome was successful blind intubation through the AuraGain™ in the first attempt. RESULTS: Of 168 adult patients screened, 124 patients were enrolled and 121 patients were included in the final analysis (extension group, n = 59; neutral group, n = 62). The incidence of successful blind intubation on the first attempt was significantly higher in the extension group than in the neutral group (68% vs. 47%, respectively; relative risk [RR], 1.45; 95% confidence interval [CI], 1.05 to 1.99; P = 0.02). The overall incidence of successful blind intubation was also significantly higher in the extension group than in the neutral group (71% vs 50%, respectively; RR, 1.42; 95% CI, 1.06 to 1.92; P = 0.02). The time required for successful blind intubation and the incidence of hoarseness, cough, or sore throat at 24 hr after extubation did not differ between groups. CONCLUSION: Neck extension can be used to facilitate blind intubation through the Ambu® AuraGain™ laryngeal mask. Considering the relatively high failure rate, blind intubation via the AuraGain™ should be used as an alternative, not as a first-line choice. TRIAL REGISTRATION: www.ClinicalTrials.gov (NCT03408431); registered 24 January 2018.

Safety margin for needle placement during lumbar plexus block: An anatomical study using magnetic resonance imaging.

PURPOSE: We aimed to provide anatomic characteristics of the lumbar plexus and a safety margin for needle placement during lumbar plexus block in adults. METHODS: Lumbar spine magnetic resonance images from 377 adults were reviewed. We determined the depth of the lumbar plexus from the needle insertion point for the modified traditional and Capdevila's approaches at the L4 and L5 levels. The relationship of age, height, and body weight with lumbar plexus depth, and the presence of the kidney on the transverse plane at the L4 level were assessed. RESULTS: The lumbar plexus was deeper at the L5 level than at the L4 level for both approaches (mean difference 3.2 mm [95% confidence interval (CI), 2.4 to 4.0] for the modified traditional approach; mean difference 4.4 mm [95% CI, 3.7 to 5.2] for Capdevila's approach). Eighty-six (22.8%) patients had an L4 transverse process shorter than 40 mm, which implies that the needle may not contact the L4 transverse process with the modified traditional approach. The mean (standard deviation) of safety margins for needle insertion, defined as the distance from the posterior aspect of the L4 transverse process to the anterior margin of the psoas muscle, were 45 (8) and 44 (6) mm, respectively for the modified traditional and Capdevila's approach (mean difference, 0.5 mm; 95% CI, -0.1 to 1.1]). The lumbar plexus depth for each approach at the L4 level was predicted using the following equations: Depth (mm) = 87.24 - 0.36 × height (cm) + 0.69 × weight (kg) for the modified traditional approach (r2 = 0.37) and Depth (mm) = 86.51 - 0.35 × height (cm) + 0.61 × weight (kg) for Capdevila's approach (r2 = 0.33). The kidney was observed at the L4 level in 60 (15.9%) patients, with higher incidence in patients over 70 yr and those shorter than 150 cm. CONCLUSION: The surface anatomic relations of the lumbar plexus found in this study may be useful for performing successful and safe lumbar plexus block.

RéSUMé: OBJECTIF: Nous avons cherché à fournir des données anatomiques du plexus lombaire et de la marge de sécurité pour le positionnement de l'aiguille au cours d'un bloc lombaire chez l'adulte. MéTHODES: Les images par résonance magnétique de la colonne vertébrale lombaire de 377 adultes ont été analysées. Nous avons déterminé la profondeur du plexus lombaire à partir du point d'insertion de l'aiguille pour les approches traditionnelle modifiée et de Capdevila aux niveaux L4 et L5. Les corrélations de l'âge, de la taille et du poids corporel avec la profondeur du plexus lombaire et la présence du rein sur le plan de l'apophyse transverse au niveau de L4 ont été évaluées. RéSULTATS: Le plexus lombaire était plus profond à l'étage L5 qu'à l'étage L4 pour les deux approches (différence moyenne : 3,2 mm [intervalle de confiance (IC) à 95 % : 2,4 à 4,0] pour l'approche traditionnelle modifiée; différence moyenne : 4,4 mm [IC à 95 % : 3,7 à 5,2] pour l'approche de Capdevila). Quatre-vingt-six patients (22,8 %) avaient l'apophyse transverse de L4 mesurant moins de 40 mm, ce qui implique que l'aiguille pourrait ne pas faire contact avec cette apophyse avec l'approche traditionnelle modifiée. Les marges de sécurité pour l'insertion de l'aiguille, définies comme étant la distance moyenne (écart-type) entre la face postérieure de l'apophyse transverse de L4 et la marge antérieure du muscle psoas, étaient de 45 (8) mm et 44 (6) mm pour, respectivement, l'approche traditionnelle modifiée et l'approche de Capdevila (différence des moyennes, 0,5 mm; IC à 95 % : −0,1 à 1,1). La profondeur du plexus lombaire pour chaque approche au niveau L4 a été prédite à l'aide des équations suivantes : Profondeur (mm) = 87,24 − 0,36 × taille (cm) + 0,69 × poids (kg) pour l'approche traditionnelle modifiée (r2 = 0,37) et Profondeur (mm) = 86,51 − 0,35 × taille (cm) + 0,61 × poids (kg) pour l'approche de Capdevila (r2 = 0,33). Le rein a été observé au niveau L4 chez 60 patients (15,9 %) avec une plus grande incidence chez les patients âgés de plus de 70 ans et chez ceux dont la taille était inférieure à 150 cm. CONCLUSION: Les rapports anatomiques de la surface du corps et du plexus lombaire identifiés dans cette étude peuvent contribuer à la réalisation d'un bloc lombaire efficace et sécuritaire.

Ultrasound-assisted vs. landmark-guided paramedian spinal anaesthesia in the elderly: A randomised controlled trial.

BACKGROUND: Neuraxial ultrasound might improve the efficacy of spinal anaesthesia but this has not been tested for the paramedian approach in the elderly. OBJECTIVE: The current study aims to assess whether the ultrasound-assisted paramedian technique can decrease the number of needle passes required for success compared with the landmark-guided paramedian technique in the elderly. DESIGN: Randomised controlled study. SETTING: Single-institution, tertiary-level hospital in Seoul, Republic of Korea from October 2017 to January 2018. PATIENTS: Eighty patients aged at least 60 years undergoing orthopaedic surgery. INTERVENTION: All received paramedian spinal anaesthesia by either the landmark-guided or preprocedural ultrasound-assisted technique. MAIN OUTCOME MEASURES: The number of needle passes required for successful dural puncture. RESULTS: The number of needle passes (median [interquartile range]) was significantly lower (1.0 [1.0 to 2.0] vs. 4.5 [2.0 to 7.0]) and the success rate at first pass significantly higher at 65.0 vs. 17.5% in the ultrasound compared with the landmark group (both P < 0.001). The ultrasound-assisted technique required a longer time for establishing landmarks (117.5 s [85.5 to 150.7 s] vs. 17.5 s [14.0 to 23.0 s]) and for total procedure (181.5 s [133.5 to 212.5 s] vs. 92.5 s [62.5 to 176.5 s]) but a shorter time for administering spinal anaesthesia (39.5 s [31.5 to 71.3 s] vs. 77.0 s [45.8 to 136.5 s]; all, P < 0.001) than the palpation-guided technique. The ultrasound group showed lower periprocedural pain scores (3 [2 to 4] vs. 4 [4 to 6]; P = 0.009) and discomfort scores (2 [0 to 3] vs. 5 [2 to 6]; P = 0.003) than the landmark group. CONCLUSION: Compared with the landmark-guided paramedian technique, the ultrasound-assisted paramedian technique decreases the number of needle manipulations and periprocedural pain and discomfort scores in the elderly. Our results suggest that neuraxial ultrasonography facilitates the performance of spinal anaesthesia in the elderly. TRIAL REGISTRATION: NCT03316352.

Contribution of self-compassion to positive mental health among Korean university students.

Although evidence suggests self-compassion can serve as an important predictor of positive mental health, few studies have examined the contribution of self-compassion to mental health. This study examined the relations between six components of self-compassion and three dimensions of positive mental health (Psychological, Emotional and Social Well-being) in young Korean adults. A sample of 689 Korean college students were administered the Self-Compassion Scale (SCS) and the Mental Health Continuum Short Form (MHC-SF) to evaluate self-compassion and positive mental health. A multiple indicators multiple causes (MIMIC) analysis revealed that Self-Kindness significantly predicted all dimensions of positive mental health. Additionally, Over-Identification significantly contributed to Emotional Well-being, Common Humanity to Social Well-being and Isolation to Psychological Well-being. These results suggest Self-Kindness is a key predictor of positive mental health and that specific components of self-compassion are strongly related to specific dimensions of mental health in Koreans.

Fast switching, high contrast and high resolution liquid crystal device for virtual reality display.

Virtual reality-head mounted displays require a display with high resolution over 2000 ppi, super-fast response time and high contrast ratio for realizing super image quality at near-eyes. Several liquid crystal devices utilizing fringe-field switching (FFS) mode, having response times less than of half of conventional FFS mode, were proposed for this purpose. However, its contrast ratio is still less than 2000:1 because of intrinsic electro-optic characteristics of homogenous alignment mode and also realizing high resolution like 2000 ppi has some difficulty because twist deformation of liquid crystals can easily affect liquid crystal orientation near pixels. In this paper, we propose a vertically aligned liquid crystal device in which bend deformation occurs in a confined area by an oblique electric field, exhibiting 4 times faster decay response time than that of conventional FFS mode, higher contrast ratio over 5000:1, and pixel pitch less than 4 µm. The proposed liquid crystal device has a strong potential to be the main display for high-resolution virtual reality over 2000 ppi.

Helical pitch-dependent electro-optics of optically high transparent nano-phase separated liquid crystals.

Feeble light leakage in a dark state of conventional optically isotropic liquid crystal (OILC) device has a strong impact on the contrast ratio of a liquid crystal (LC) device. In order to overcome such intrinsic problem, we proposed an OILC in which the LC directors inside droplets are twisted by introducing chirality. The light leakage is effectively suppressed by matching the refractive indices between LC and polymer matrix; consequently, we achieved a high contrast ratio, 1:1401. Interestingly, the on-state transmittance is enhanced by ~49% compared to conventional OILC. The response time was also improved and the hysteresis was suppressed to be negligible. The improved electro-optic performances of the proposed OILC device would give diverse applications in upcoming flexible display and various photonic devices.

Gamma knife radiosurgery for trigeminal schwannoma: a 20-year experience with long-term treatment outcome.

PURPOSE: This study evaluated the long-term tumor control rate (TCR) and symptomatic outcomes of patients treated with gamma knife radiosurgery (GKRS) for trigeminal schwannomas (TSs). METHODS: Thirty-two patients with TS who underwent GKRS between January 1994 and January 2013 with at least 2 years of follow-up were enrolled in the study. Clinical charts and surgical records were retrospectively reviewed to evaluate factors affecting TCR and symptomatic outcomes. The median patient age was 57.5 years (max = 81, interquartile range [IQR] = 51-67), and the median tumor volume was 3.55 cm3 (max = 25.2 cm3, IQR = 2.0-6.2 cm3). The median marginal and maximum doses were 13.0 Gy (max = 18.0 Gy, IQR = 12.5-15 Gy) and 23.8 Gy (max = 35 Gy, IQR = 21.7-25.0 Gy), respectively. RESULTS: At a median follow-up of 90.5 months (max = 281 months, IQR = 49-139.75 months), the actuarial 3-, 5-, and 10-year TCR were 93.8, 86.2, and 80.8%, respectively. Our data and multivariate analysis indicated that the target volume was the only significant factor determining TCR and that larger tumors (> 5 cm3) were more likely to progress (p = 0.011). Cystic tumors had a higher incidence of transient enlargement and temporary symptom change compared to those in solid tumors. An unfavorable outcome of symptoms was observed in five patients (15.6%). Complications were observed in two patients (6.25%), including hydrocephalus and radio-induced trigeminal neuropathy, respectively. CONCLUSIONS: GKRS can be a safe and effective treatment modality for TS with long-term follow-up, especially for small tumors. An extended period of follow-up observation is required to conclude the clinical response to GKRS.

Fast response and transparent optically isotropic liquid crystal diffraction grating.

We have demonstrated an electrically tunable less polarization sensitive and fast response nanostructured polymer dispersed liquid crystal (nano-PDLC) diffraction grating. Fabricated nano-PDLC is optically transparent in visible wavelength regime. The optical isotropic nature was increased by minimizing the liquid crystal droplet size below visible wavelength thereby eliminated scattering. Diffraction properties of in-plane switching (IPS) and fringe-field switching (FFS) cells were measured and compared with one another up to four orders. We have obtained a pore-type polymer network constructed by highly interlinked polymer beads at which the response time is improved by strong interaction of liquid crystal molecules with polymer beads at interface. The diffraction pattern obtained by transparent nano-PDLC film has several interesting properties such as less polarization dependence and fast response. This device can be used as transparent tunable diffractor along with other photonic application.

Comparison of Supraclavicular and Infraclavicular Brachial Plexus Block: A Systemic Review of Randomized Controlled Trials.

BACKGROUND: Supraclavicular (SC) and infraclavicular (IC) brachial plexus block (BPB) are commonly used for upper extremity surgery. Recent clinical studies have compared the effect of SC- and IC-BPB, but there have been controversies over spread of sensory blockade in each of the 4 peripheral nerve branches of brachial plexus. METHODS: This study included a systemic review, using the Medline and EMBASE database from their inceptions through March 2016. Randomized controlled trials (RCTs) comparing SC- and IC-BPB were included. The prespecified primary outcome was the incidences of incomplete sensory blockade in each of the 4 terminal nerve branches of brachial plexus. Secondary outcome included the incidence of successful blockade, performance time, onset of sensory block, duration of analgesia, and complication rates. RESULTS: Ten RCTs involving 676 patients were included. Pooled analyses showed the incidence of incomplete block at 30 minutes in radial nerve territory was significantly higher in IC-BPB, favoring SC-BPB (risk ratio 0.39; 95% confidence interval [0.17-0.88], P = .02, I = 0%). However, subgroup analysis according to the number of injections of IC-BPB showed that double or triple injections IC-BPB yielded no difference in the incomplete radial block. Furthermore, the incidence of incomplete ulnar block at 30 minutes was significantly lower in IC-BPB when using double or triple injection IC-BPB. There was no difference in the secondary outcomes between SC- and IC-BPB groups, with the exception of complication rates. The incidence of paresthesia/pain on local anesthetic injection, phrenic nerve palsy, and Horner syndrome was significantly higher in the SC group, favoring IC-BPB. CONCLUSIONS: This meta-analysis demonstrated that IC-BPB showed a significantly high incidence of incomplete radial nerve sensory block at 30 minutes, which may be avoided by double or triple injection. Furthermore, IC-BPB with multiple injection technique showed significantly lower incidence of incomplete ulnar block than SC-BPB. There were no differences in the incidence of successful blockade, block onset, and duration of analgesia between SC- and IC-BPB. Procedure-related paresthesia/pain and adjacent nerve-related complications were more frequent in SC-BPB. However, because of the small sample size, publication bias remains a concern when interpreting our results. Further studies with sufficient sample size and reporting large number of outcomes are required.

A Comparison Between the Conventional and the Laryngoscope-Assisted Lightwand Intubation Techniques in Patients With Cervical Immobilization: A Prospective Randomized Study.

BACKGROUND: Positioning of a lightwand in the midline of the oral cavity can be challenging in patients with cervical immobilization. Direct laryngoscopy may permit the lightwand tip to more easily access the glottic opening. We tested our hypothesis that a laryngoscope-assisted lightwand technique allows more successful endotracheal intubation than does a conventional lightwand approach. METHODS: A total of 162 patients requiring cervical immobilization during intubation for cervical spine surgery were allocated randomly to 2 groups. The conventional lightwand technique (group C, n = 80) or the laryngoscope-assisted lightwand technique (group L, n = 82) was used for endotracheal intubation. In the group L, a Macintosh laryngoscope was inserted into the oral cavity, advanced until the epiglottis tip was visible, but not used to lift the epiglottis tip. The lightwand tip was placed below the epiglottis under direct view of the epiglottis tip. The primary outcome (the initial intubation success rate) and secondary outcomes (intubation time, hemodynamic changes, and postoperative airway complications) were evaluated. RESULTS: The initial intubation success rate was significantly lower (75% vs 89%; relative risk [95% confidence interval]: 1.2 [1.0-1.4]; P = .034) in group C than group L. The intubation time (22 ± 13 vs 24 ± 12 seconds; mean difference [98.33% confidence interval]: 2.4 [-2.3 to 7.2]; P = .217) did not differ between groups. Postoperative sore throat score, incidences of hypertension and tachycardia, postoperative oral mucosal bleeding, and hoarseness also did not differ between groups. CONCLUSIONS: Laryngoscope-assisted lightwand intubation did not increase intubation time, and it increased first attempt intubation rates compared with traditional lightwand intubation in patients requiring cervical immobilization for cervical spine surgery.

The EC90 of remifentanil for blunting cardiovascular responses to head fixation for neurosurgery under total intravenous anesthesia with propofol and remifentanil based on bispectral index monitoring: estimation with the biased coin up-and-down sequential method.

BACKGROUND: Head fixation can induce hemodynamic instability. Remifentanil is commonly used with propofol for total intravenous anesthesia (TIVA) during neurosurgery. This study investigated the 90% effective concentration (EC90) of remifentanil for blunting of cardiovascular responses to head fixation during neurosurgery via bispectral index (BIS) monitoring. METHODS: Fifty patients undergoing neurosurgery requiring head fixation were enrolled. This study was performed using the biased coin up-and-down design sequential method (BCD). After tracheal intubation, the effect-site target concentration (Ce) of remifentanil was adjusted to achieve hemodynamic stability and reset to the level preoperatively assigned to each patient, according to the BCD method, approximately 10 min before head fixation. Baseline hemodynamic values were recorded before head fixation. An ineffective response was defined as a case with a > 20% increase in hemodynamic values from baseline. Otherwise, the response was determined to be effective. The EC90 of remifentanil was calculated as a modified isotonic estimator. RESULTS: Forty-three patients completed this study. The EC90 of remifentanil for blunting cardiovascular responses to head fixation was estimated to be 6.48 ng/mL (95% CI, 5.94-6.83 ng/mL). CONCLUSIONS: Adjustment of the Ce of remifentanil to approximately 6.5 ng/mL before head fixation could prevent noxious cardiovascular responses in 90% of neurosurgical ASA I-II patients aged 20 to 65 years old during propofol target-controlled infusion titrated to maintain BIS between 40 and 50. TRIAL REGISTRATION: ClinicalTrials.gov Identifier NCT01489137 , retrospectively registered 5 December 2011.