Wide-Field Super-Resolution Optical Fluctuation Imaging through Dynamic Near-Field Speckle Illumination.

Stochastic optical fluctuation imaging (SOFI) generates super-resolution fluorescence images by emphasizing the positions of fluorescent emitters via statistical analysis of their on-and-off blinking dynamics. In SOFI with speckle illumination (S-SOFI), the diffraction-limited grain size of the far-field speckles prevents independent blinking of closely located emitters, becoming a hurdle to realize the full super-resolution granted by SOFI processing. Here, we present a surface-sensitive super-resolution technique exploiting dynamic near-field speckle illumination to bring forth the full super-resolving power of SOFI without blinking fluorophores. With our near-field S-SOFI technique, up to 2.8- and 2.3-fold enhancements in lateral spatial resolution are demonstrated with computational and experimental fluorescent test targets labeled with conventional fluorophores, respectively. Fluorescent beads separated by 175 nm are also super-resolved by near-field speckles of 150 nm grain size, promising sub-100 nm resolution with speckle patterns of much smaller grain size.

Improved classification and localization approach to small bowel capsule endoscopy using convolutional neural network.

BACKGROUND: Although great advances in artificial intelligence for interpreting small bowel capsule endoscopy (SBCE) images have been made in recent years, its practical use is still limited. The aim of this study was to develop a more practical convolutional neural network (CNN) algorithm for the automatic detection of various small bowel lesions. METHODS: A total of 7556 images were collected for the training dataset from 526 SBCE videos. Abnormal images were classified into two categories: hemorrhagic lesions (red spot/angioectasia/active bleeding) and ulcerative lesions (erosion/ulcer/stricture). A CNN algorithm based on VGGNet was trained in two different ways: the combined model (hemorrhagic and ulcerative lesions trained separately) and the binary model (all abnormal images trained without discrimination). The detected lesions were visualized using a gradient class activation map (Grad-CAM). The two models were validated using 5,760 independent images taken at two other academic hospitals. RESULTS: Both the combined and binary models acquired high accuracy for lesion detection, and the difference between the two models was not significant (96.83% vs 96.62%, P = 0.122). However, the combined model showed higher sensitivity (97.61% vs 95.07%, P < 0.001) and higher accuracy for individual lesions from the hemorrhagic and ulcerative categories than the binary model. The combined model also revealed more accurate localization of the culprit area on images evaluated by the Grad-CAM. CONCLUSIONS: Diagnostic sensitivity and classification of small bowel lesions using a convolutional neural network are improved by the independent training for hemorrhagic and ulcerative lesions. Grad-CAM is highly effective in localizing the lesions.

Effect of Low-pressure Pulmonary Recruitment Maneuver on Postlaparoscopic Shoulder Pain: Randomized Controlled Trial.

STUDY OBJECTIVE: Postlaparoscopic shoulder pain (PLSP) is effectively reduced by a pulmonary recruitment maneuver (PRM). The goal of this study is to assess the efficacy of a PRM using maximal inspiratory pressure of 30 cm H2O, which is lower than previously studied pressure for reducing PLSP. DESIGN: Randomized controlled trial. SETTING: University hospital. PATIENTS: Eighty-four patients who were undergoing elective gynecologic laparoscopy. INTERVENTIONS: Patients were randomly assigned to the control (n = 42) or the PRM (n = 42) group. MEASUREMENTS AND MAIN RESULTS: The primary outcome was the intensity of the shoulder pain using the visual analog scale (VAS). The VAS score of shoulder pain (median [interquartile range]) was significantly lower in the PRM group than in the control group at 24 hours (0 [0-0] vs 1.5 [0-4.0], p <.001) and 48 hours (0 [0-0] vs 1.0 [0-2.0], p <.001) after surgery. Other variables, including surgical pain score and vital signs, were similar between the 2 groups. CONCLUSION: The PRM with 30 cm H2O can be a simple method to reduce PLSP. Therefore, it would be helpful to perform the PRM with 30 cm H2O routinely.

Full-field subwavelength imaging using a scattering superlens.

Light-matter interaction gives optical microscopes tremendous versatility compared with other imaging methods such as electron microscopes, scanning probe microscopes, or x-ray scattering where there are various limitations on sample preparation and where the methods are inapplicable to bioimaging with live cells. However, this comes at the expense of a limited resolution due to the diffraction limit. Here, we demonstrate a novel method utilizing elastic scattering from disordered nanoparticles to achieve subdiffraction limited imaging. The measured far-field speckle fields can be used to reconstruct the subwavelength details of the target by time reversal, which allows full-field dynamic super-resolution imaging. The fabrication of the scattering superlens is extremely simple and the method has no restrictions on the wavelength of light that is used.

Prospective comparative analysis of zero-heat-flux thermometer (SpotOn®) compared with tympanic thermometer and bladder thermometer in extremely aged patients undergoing lower extremity orthopedic surgery.

Thermoregulation is important for maintaining homeostasis in the body. It can be easily broken under anesthesia. An appropriate method for measuring core body temperature is needed, especially for elderly patients, because the efficiency of thermoregulation gradually decreases with age. Zero-heat-flux (ZHF) thermometry (SpotOn) is an alternative, noninvasive method for continuous temperature monitoring at the skin surface. The aim of this study was to examine the accuracy and feasibility of using the SpotOn sensor in lower extremity orthopedic surgery in elderly patients aged over 80 years by comparing a SpotOn sensor with 2 other reliable minimally invasive methods: a tympanic membrane thermometer and a bladder thermometer. This study enrolled 45 patients aged over 80 years who were scheduled to undergo lower extremity surgery. Body temperature was measured using a SpotOn sensor, a tympanic membrane thermometer and a bladder thermometer. Agreements between the SpotOn sensor and the other 2 methods were assessed using Bland and Altman plots for repeated measures adjusted for unequal numbers of measurements per patient. Compared with bladder temperature, bias and limits of agreement for SpotOn temperature were 0.07°C ± 0.58°C. Compared with tympanic membrane temperature, bias and limits of agreement for SpotOn temperature were -0.28°C ± 0.61°C. The 3M SpotOn sensor using the ZHF method for patients aged over 80 years undergoing lower extremity surgery showed feasible measurement value and sensitivity.

Allele-specific transactivation of matrix metalloproteinase 7 by FOXA2 and correlation with plasma levels in idiopathic pulmonary fibrosis.

Idiopathic pulmonary fibrosis (IPF) is a complex disease with poorly understood etiology. Previously, we reported upregulation of matrix metalloproteinase 7 (MMP7) in both lung and peripheral blood of IPF patients. Here we report evidence for genetic correlation of plasma levels and promoter polymorphisms (rs11568818 and rs11568819) of MMP7 in a well-characterized IPF cohort. Both the AA genotype of rs11568818 and the CT genotype of rs11568819 were found to be significantly associated with higher MMP7 plasma levels. These associations were observed only in IPF patients and not in healthy controls. The G-to-A transition of rs11568818 resulted in a novel binding site for the forkhead box A2 (FOXA2) transcription factor, a key regulator of embryonic lung development and proper function of the mature lung. In vitro, this transition led to increased sensitivity of the MMP7 promoter to FOXA2. In IPF lungs, FOXA2 was localized in the nucleus of epithelial cells that expressed MMP7 in the cytoplasm. These results suggest that increased sensitivity of the polymorphic MMP7 promoter to FOXA2 provides one of the genetic bases for the upregulation of MMP7 in IPF.

Active spectral filtering through turbid media.

We demonstrate controlled wavelength-dependent light focusing through turbid media using wavefront shaping. Due to the dispersion caused by multiple light scattering, light propagation through turbid media can be independently controlled between different wavelengths. Foci with various wavelengths can be generated by applying different optimized wavefronts to a highly scattering layer. Given the linearity of the transmission matrix, multiple foci with different wavelengths can also be simultaneously constructed.

An anesthetic experience of hereditary angioedema type I patient undertook total laparoscopic hysterectomy - A case report.

BACKGROUND: Hereditary angioedema (HAE) is an autosomal dominant disorder. The characteristic of HAE is recurrent angioedema episodes due to low C1 esterase inhibitor (C1-INH) level. HAE symptoms, especially those affecting oropharynx or larynx may develop respiratory distress syndrome due to impaired airway, which can be potentially fatal. CASE: We report a clinical case of a 57 year-old woman, with type I HAE, scheduled for total laparoscopic hysterectomy under general endotracheal anesthesia, which was done successfully without inducing airway edema. Danazol, which increases liver synthesis of C1-INH, was administered and fresh frozen plasma (FFP), which contained C1-INH, was transfused after induction. CONCLUSIONS: For HAE patients, the greatest concern is that general anesthesia can induces upper airway edema by direct mucosal irritation by the endotracheal tube. The perioperative management should include both prophylactic increase of C1-INH production and on-demand administration of C1-INH or FFP.

The Effect of Low-Dose Dexmedetomidine on Pain and Inflammation in Patients Undergoing Laparoscopic Hysterectomy.

Dexmedetomidine has sedative, sympatholytic, analgesic, and anti-inflammatory effects. We investigated the effects of intraoperative dexmedetomidine infusion without a loading dose in the prevention of pain and inflammation after laparoscopic hysterectomy. In this study, 100 patients undergoing laparoscopic hysterectomy under desflurane anesthesia were randomized to receive either 0.9% saline or dexmedetomidine (0.4 µg/kg/h) after induction to trocar removal. The primary endpoints were postoperative pain and inflammatory response presented by the level of tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), IL-10, and C-reactive protein (CRP). The secondary endpoints were hemodynamics during the anesthesia and surgery and postoperative nausea and vomiting. Postoperative pain was decreased in the dexmedetomidine group for every time point, and post-anesthesia care unit (PACU) rescue fentanyl doses were decreased in the dexmedetomidine group. The inflammatory response representing TNF-α, IL-6, IL-10, and CRP were similar across the two groups. Postoperative nausea and vomiting from PACU discharge to 24 h post-surgery were reduced in the dexmedetomidine group. During anesthesia and surgery, the patient's heart rate was maintained lower in the dexmedetomidine-receiving group. Dexmedetomidine of 0.4 µg/kg/h given as an intraoperative infusion significantly reduced postoperative pain but did not reduce the inflammatory responses in patients undergoing laparoscopic hysterectomy.

Effect of Adding Midazolam to Dual Prophylaxis for Preventing Postoperative Nausea and Vomiting.

Multimodal prophylaxis for postoperative nausea and vomiting (PONV) has been recommended, even in low-risk patients. Midazolam is known to have antiemetic properties. We researched the effects of adding midazolam to the dual prophylaxis of ondansetron and dexamethasone on PONV after gynecologic laparoscopy. In this prospective, randomized, double-blinded trial, 144 patients undergoing gynecological laparoscopic surgery under sevoflurane anesthesia were randomized to receive either normal saline (control group, n = 72) or midazolam 0.05 mg/kg (midazolam group, n = 72) intravenously at pre-induction. All patients were administered dexamethasone 4 mg at induction and ondansetron 4 mg at the completion of the laparoscopy, intravenously. The primary outcome was the incidence of complete response, which implied the absence of PONV without rescue antiemetic requirement until 24 h post-surgery. The complete response during the 24 h following laparoscopy was similar between the two groups: 41 patients (59%) in the control group and 48 patients (72%) in the midazolam group (p = 0.11). The incidence of nausea, severe nausea, retching/vomiting, and administration of rescue antiemetic was comparable between the two groups. The addition of 0.05 mg/kg midazolam at pre-induction to the dual prophylaxis had no additive preventive effect on PONV after gynecologic laparoscopy.

Nanoscale Focus Pinspot for High-Purity Quantum Emitters via Focused-Ion-Beam-Induced Luminescence Quenching.

Epitaxially grown quantum dots (QDs), especially embedded in photonic structures, play an essential role in various quantum photonic systems as on-demand single-photon sources. However, these QDs often suffer from adjacent unwanted emitters, which contribute to the background noise of the QD emission and fundamentally limit the single-photon purity. In this paper, a nanoscale focus pinspot (NFP) technique using focused-ion-beam-induced luminescence quenching enables us to improve single-photon purity from site-controlled QD as a proof-of-concept experiment. The optical quality of the QD emission is not degraded while the signal-to-noise ratio of the QD is improved. Moreover, the QD after the NFP technique reveals the single-photon nature at further elevated temperatures owing to the reduced background noise. As the NFP technique is nondestructive, it retains the apparent physical structures and photonic functions, thereby indicating its promising potential for applying diverse high-purity quantum emitters, particularly integrated in photonic devices and circuits.

The effect of preoperative intravenous lidocaine on postoperative pain following hysteroscopy: A randomized controlled trial.

BACKGROUND: The use of hysteroscopy for the diagnosis and treatment of uterine and endometrial abnormalities is often associated with postoperative pain. This randomized controlled trial aimed to assess the efficacy of preoperative intravenous (IV) lidocaine in reducing pain after hysteroscopy. METHODS: In total, 138 patients undergoing elective hysteroscopy at the CHA Bundang Medical Center, Seongnam, Korea were randomly assigned to a control group (n = 69) or a lidocaine group (n = 69), which received normal saline or IV lidocaine at 1.5 mg/kg, respectively. The primary outcome was the incidence of postoperative pain. RESULTS: The incidence of pain was significantly lower in the IV lidocaine group than in the control group at the post-anesthesia care unit (27.3% vs 68.2%, P < .001). The visual analog scale (0-10) score (median [interquartile range]) was lower in the IV lidocaine group than in the control group (0 [0-2]) vs 2 [0-4]), P < .001). The use of rescue analgesics and postoperative nausea and vomiting were similar between the 2 groups. This study demonstrated that administering 1.5 mg/kg of preoperative IV lidocaine can be a simple method to reduce incidence of pain after hysteroscopy. CONCLUSION: Preoperative bolus administration of 1.5 mg/kg of IV lidocaine may be used to decrease incidence of pain after hysteroscopy under general anesthesia.

Anesthetic Consideration for Peroral Endoscopic Myotomy.

A recent achalasia guideline suggests that peroral endoscopic myotomy (POEM) is a safe option for achalasia that is as effective as Heller myotomy. It is recommended that POEM should be performed under general anesthesia. The incidence of adverse events such as bleeding, perforation, and carbon dioxide insufflation-related complications was lower in POEM under endotracheal general anesthesia than in POEM under sedation. Subcutaneous emphysema, pneumothorax, pneumomediastinum, pneumoperitoneum, and accompanying hemodynamic instability can be caused by carbon dioxide insufflation. Treatment of possible physiological changes and adverse events during the POEM procedure from the point of view of anesthesiologists may give endoscopists a new perspective on improving patient safety. The territory of therapeutic endoscopy can be expanded through cooperation with other departments, including anesthesia services. Efforts to understand different perspectives will certainly help not only secure patient safety but also expand the area of treatment.

Postoperative infusion of a low dose of dexmedetomidine reduces intravenous consumption of sufentanil in patient-controlled analgesia.

BACKGROUND: Combining adjunctive medications with patient-controlled analgesia (PCA) has been used to minimize opioid related side-effects. The aim of this study was to evaluate whether postoperative infusion of a sub-sedative dose of dexmedetomidine can reduce opioid consumption and opioid related side-effects. METHODS: We selected 60 patients from 18 to 60 years old with an American Society of Anesthesiologists physical status of 1-2 who were scheduled for elective surgery. The types of surgery were limited to thoracoscopic wedge resection of the lung and pulmonary wedge resection under a mini-thoracotomy. Patients received PCA with sufentanil upon arrival in the recovery room, along with a separate continuous infusion of dexmedetomidine that was not mixed in the PCA but started at the same time. Patients were randomly allocated to two groups: dexmedetomidine 0.15 µg/kg/h was administered to patients in group D and normal saline was administered to patients in group C. The visual analogue scale (VAS) pain score, blood pressure, pulse rate, and respiratory rate were measured at each assessment. PCA related side-effects were evaluated. RESULTS: The VAS pain score was significantly lower in the dexmedetomidine group. Patients in the dexmedetomidine group required significantly less PCA at postoperative 1-4, 4-8, and 8-24 h time intervals. The incidence of nausea was significantly less in the dexmedetomidine group, and levels of sedation and hemodynamic variables except for blood pressure at postoperative 8 h were similar between the groups. CONCLUSIONS: In conclusion, a postoperatively administered sub-sedative dose of dexmedetomidine reduces PCA sufentanil consumption and decreases nausea.

Time-reversing a monochromatic subwavelength optical focus by optical phase conjugation of multiply-scattered light.

Due to its time-reversal nature, optical phase conjugation generates a monochromatic light wave which retraces its propagation paths. Here, we demonstrate the regeneration of a subwavelength optical focus by phase conjugation. Monochromatic light from a subwavelength source is scattered by random nanoparticles, and the scattered light is phase conjugated at the far-field region by coupling its wavefront into a single-mode optical reflector using a spatial light modulator. Then the conjugated beam retraces its propagation paths and forms a refocus on the source at the subwavelength scale. This is the first direct experimental realisation of subwavelength focusing beyond the diffraction limit with far-field time reversal in the optical domain.

Investigating carrier localization and transfer in InGaN/GaN quantum wells with V-pits using near-field scanning optical microscopy and correlation analysis.

The V-pits and potential fluctuations in InGaN/GaN multiple quantum wells (MQWs) are key factors for understanding the performance of InGaN/GaN-based light-emitting diodes (LEDs). However, photoluminescence (PL) measurements using conventional optical microscopy only provide ensemble information due to the spatial resolution limit, known as the diffraction barrier, which hinders the analysis of dislocations and potential fluctuations. Here, in order to investigate the influence of the V-pits and potential fluctuations on local optical properties, we performed nanoscopic luminescence mapping for standard and V-pit InGaN/GaN MQWs samples with different sized V-pits using near-field scanning optical microscopy (NSOM) with illumination mode (I-mode) at various laser excitation powers. From the nanoscopic PL mapping data, we could clearly observe luminescence features associated with dislocations and potential fluctuations in the InGaN/GaN MQWs. We also employed correlation analysis to quantitatively analyze the nanoscopic PL mapping data for the different MQWs samples. Based on the results of NSOM PL with I-mode and correlation analysis, we could demonstrate that carrier transfer in the MQWs sample with large sized V-pits is suppressed by deeper potential fluctuations and higher energy barriers compared to the standard sample.

Real-time monitoring and visualization of the multi-dimensional motion of an anisotropic nanoparticle.

As interest in anisotropic particles has increased in various research fields, methods of tracking such particles have become increasingly desirable. Here, we present a new and intuitive method to monitor the Brownian motion of a nanowire, which can construct and visualize multi-dimensional motion of a nanowire confined in an optical trap, using a dual particle tracking system. We measured the isolated angular fluctuations and translational motion of the nanowire in the optical trap, and determined its physical properties, such as stiffness and torque constants, depending on laser power and polarization direction. This has wide implications in nanoscience and nanotechnology with levitated anisotropic nanoparticles.

Scattering Optical Elements: Stand-Alone Optical Elements Exploiting Multiple Light Scattering.

Optical design and fabrication techniques are crucial for making optical elements. From conventional lenses to diffractive optical elements and to recent metasurfaces, various types of optical elements have been proposed to manipulate light where optical materials are fabricated into desired structures. Here, we propose a scattering optical element (SOE) that exploits multiple light scattering and wavefront shaping. Instead of fabricating optical materials, the SOE consists of a disordered medium and a photopolymer-based wavefront recorder, with shapes impinging on light on demand. With the proposed stand-alone SOEs, we experimentally demonstrate control of various properties of light, including intensity, polarization, spectral frequency, and near field. Due to the tremendous freedom brought about by disordered media, the proposed approach will provide unexplored routes to manipulate arbitrary optical fields in stand-alone optical elements.

Superresolution imaging with optical fluctuation using speckle patterns illumination.

Superresolution fluorescence microscopy possesses an important role for the study of processes in biological cells with subdiffraction resolution. Recently, superresolution methods employing the emission properties of fluorophores have rapidly evolved due to their technical simplicity and direct applicability to existing microscopes. However, the application of these methods has been limited to samples labeled with fluorophores that can exhibit intrinsic emission properties at a restricted timescale, especially stochastic blinking. Here, we present a superresolution method that can be performed using general fluorophores, regardless of this intrinsic property. Utilizing speckle patterns illumination, temporal emission fluctuation of fluorophores is induced and controlled, from which a superresolution image can be obtained exploiting its statistical property. Using this method, we demonstrate, theoretically and experimentally, the capability to produce subdiffraction resolution images. A spatial resolution of 500 nm, 300 nm and 140 nm with 0.4, 0.5 and 1.4 NA objective lenses respectively was achieved in various samples with an enhancement factor of 1.6 compared to conventional fluorescence microscopy.

Malposition of central venous catheter in the jugular venous arch via external jugular vein -a case report.

The central venous cannulation is commonly performed in the operating rooms and intensive care units for various purposes. Although the central venous catheter (CVC) is used in many ways, the malpositioning of the CVC is often associated with serious complications. We report a case of an unexpected malposition of a CVC in the jugular venous arch via external jugular vein.