Improving Neural Radiance Field using Near-Surface Sampling with Point Cloud Generation

Neural radiance field (NeRF) is an emerging view synthesis method that samples points in a three-dimensional (3D) space and estimates their existence and color probabilities. The disadvantage of NeRF is that it requires a long training time since it samples many 3D points. In addition, if one samples points from occluded regions or in the space where an object is unlikely to exist, the rendering quality of NeRF can be degraded. These issues can be solved by estimating the geometry of 3D scene. This paper proposes a near-surface sampling framework to improve the rendering quality of NeRF. To this end, the proposed method estimates the surface of a 3D object using depth images of the training set and sampling is performed around there only. To obtain depth information on a novel view, the paper proposes a 3D point cloud generation method and a simple refining method for projected depth from a point cloud. Experimental results show that the proposed near-surface sampling NeRF framework can significantly improve the rendering quality, compared to the original NeRF and a state-of-the-art depth-based NeRF method. In addition, one can significantly accelerate the training time of a NeRF model with the proposed near-surface sampling framework.Comment: 13 figures, 2 table

Arthroscopic Capsular Repair without Relaying Sutures: ‘Simple Sewing Technique’

We report a simple technique for repairing capsular tear, using only a hook-like, cannulated instrument and braided sutures without relaying steps. A No. 2 braided suture is passed through the lumen of the instrument. Under direct arthroscopic view, the tip of the instrument is passed through the side of the capsule that has previously been separated with the probe. One end of the suture is retrieved with a grasper through a separate portal. The tip is moved back without withdrawing through the skin, and reinserted into the other side of the capsule. Holding the end retrieved earlier, the other end of the suture is retrieved with a suture retriever. After complete removal of the instrument, the suture is tied through a cannula using the standard knot tying techniques. The same procedures are repeated for other required knots

Rotating Arm Internally Can Change the Arthroscopic Diagnosis of a Partial-thickness Tear of the Subscapularis

Background The aims of this study were (1) to examine the footprint of the subscapularis tendon using the traditional posterior portal and 30° arthroscope by simple internal rotation of the arm during surgery, and (2) to classify the pattern of a subscapularis partial-thickness tear. Methods This study analyzed a total of 231 patients with a partial-thickness subscapularis tear from 550 consecutive patients undergoing an arthroscopic operation who had a visualization of the subscapularis tendon footprint by internal rotation of the arm. First, the patients were classified into four categories according to the tear pattern: (1) stable lamination, (2) unstable lamination, (3) avulsion, and (4) laminated avulsion. Randomized arthroscopic videos were reviewed blindly by two independent orthopedic surgeons. The pattern of the tear of the subscapularis at the neutral position and after internal rotating the arm were assessed and compared with the treatment decision (level IV case series). Results Stable lamination, unstable lamination, avulsion, and laminated avulsion were observed in 9.1% (n=21), 20.8% (n=48), 41.1% (n=95), and 29.0% (n=67) of cases, respectively. In 145 out of 231 cases (62.8%), the decision was changed after inspecting the footprint after internal rotation of the arm, and the treatment method was changed in 116 (50.2%) cases. Conclusions In a subscapularis tendon partial-thickness tear, inspecting the footprint of the subscapularis tendon is essential to diagnosing and deciding on the appropriate treatment. In addition, simply internal rotating the arm during surgery when using the traditional posterior portal and 30° arthroscope can be a valuable method

ChIA-PET tool for comprehensive chromatin interaction analysis with paired-end tag sequencing

ChIA-PET Tool can be used to process long-range chromatin interaction data. Results are visualized on a user-friendly genome browser

Induction chemotherapy in head and neck squamous cell carcinoma of the paranasal sinus and nasal cavity: A role in organ preservation

Background/Aims: The role of induction chemotherapy (IC) for eyeball preservation has not been established in head and neck squamous cell carcinoma (HNSCC) of the paranasal sinus and nasal cavity (PNSNC). Periorbital involvement frequently leads to eyeball exenteration with a margin of safety. We evaluated the treatment outcomes, including survival and eyeball preservation, of patients who received IC for HNSCC of the PNSNC. Methods: We reviewed 21 patients diagnosed with HNSCC of the PNSNC who were treated with IC. We analyzed response, eyeball preservation rate, and overall survival. Results: Tumors were located in the paranasal sinus (n = 14) or nasal cavity (n = 7). Most patients had stage T4a (n = 10) or T4b (n = 7) disease. More than half of the patients received a chemotherapy regimen of docetaxel, fluorouracil, and cisplatin (n = 11). Thirteen patients (61.9%) achieved a partial response after IC and 15 patients (71.4%) achieved T down-staging. Among 17 patients with stage T4 disease, which confers a high risk of orbital exenteration, 14 (82.4%) achieved preservation of the involved eye. The 3-year overall survival (OS) rate of patients who achieved a partial response to IC was 84.6%. The 3-year OS rate of patients with stable disease or disease progression after IC was 25.0% (p = 0.038). Conclusions: IC could be considered for down-staging patients with advanced T-stage disease. It could also be a reasonable option for eyeball preservation in locally advanced HNSCC of the PNSNC.

Smaller pineal gland is associated with rapid eye movement sleep behavior disorder in Alzheimers disease

Background To investigate the association between pineal gland volume and symptoms of rapid eye movement (REM) sleep behavior disorder (RBD) in Alzheimers disease (AD) patients without any feature of dementia with Lewy bodies. Methods We enrolled 296 community-dwelling probable AD patients who did not meet the diagnostic criteria for possible or probable dementia with Lewy bodies. Among them, 93 were amyloid beta (Aβ) positive on 18F-florbetaben amyloid brain positron emission tomography. We measured RBD symptoms using the REM Sleep Behavior Disorder Screening Questionnaire (RBDSQ) and defined probable RBD (pRBD) as the RBDSQ of 5 or higher. We manually segmented pineal gland on 3T structural T1-weighted brain magnetic resonance imaging. Results The participants with pRBD had smaller pineal parenchyma volume (VPP) than those without pRBD (p <  0.001). The smaller the VPP, the more severe the RBD symptoms (p <  0.001). VPP was inversely associated with risk of prevalent pRBD (odds ratio = 0.909, 95% confidence interval [CI] = 0.878–0.942, p <  0.001). Area under the receiver operator characteristic curve for pRBD of VPP was 0.80 (95% CI = 0.750–0.844, p <  0.0001). These results were not changed when we analyzed the 93 participants with Aβ-positive AD separately. Conclusions In AD patients, reduced pineal gland volume may be associated with RBD.This study was supported by the grants from the Korean Health Technology R&D Project, Ministry of Health and Welfare, Republic of Korea (grant no.HI09C1379 [A092077]) and the Institute for Information & Communications Technology Promotion (IITP) grant funded by the Korea government (MSIT) (2018-2-00861, Intelligent SW Technology Development for Medical Data Analysis)

Insulin Fact Sheet in Type 1 and 2 Diabetes Mellitus and Trends of Antidiabetic Medication Use in Insulin Users with Type 2 Diabetes Mellitus: 2002 to 2019

Background This study investigated the trends of insulin use among Korean patients with type 1 diabetes mellitus (T1DM) and type 2 diabetes mellitus (T2DM). Changes in prescription of antidiabetic medications in T2DM patients taking insulin therapy were evaluated. Methods We analyzed data from the National Health Insurance Service database in Korea to evaluate the prevalence of insulin users and trends of insulin use in T1DM and T2DM patients from January 2002 to December 2019. We also investigated numbers and types of antidiabetic medications in insulin users with T2DM. Results The overall total number of insulin users increased from 2002 to 2019, reaching 348,254 for T2DM and 20,287 for T1DM in 2019 compared with 109,974 for T2DM and 34,972 for T1DM in 2002. The proportion of patients using basal analogs and short acting analogs have increased and those using human insulin, premixed insulin, or biphasic human insulin have decreased (rapid acting analogs: 71.85% and 24.12% in T1DM and T2DM, respectively, in 2019; basal analogs: 76.75% and 75.09% in T1DM and T2DM, respectively, in 2019). The use of other antidiabetic medication in addition to insulin increased for T2DM, especially in dual therapy, reaching up to 52.35% in 2019 compared with 16.72% in 2002. Conclusion The proportion of the patients using basal or rapid acting analogs increased among all insulin users in both T1DM and T2DM patients. Among patients with T2DM, the proportion of patients using antidiabetic medications in addition to insulin was significantly increased compared to those who used insulin alone

Arterial stiffness and its associations with left ventricular diastolic function according to heart failure types

Background Little is known about the characteristics of arterial stiffness in heart failure (HF). This study was performed to compare the degree of arterial stiffness and its association with left ventricular (LV) diastolic function among three groups: control subjects, patients with HF with reduced ejection fraction (HFrEF), and patients with HF with preserved ejection fraction (HFpEF). Methods A total of 83 patients with HFrEF, 68 patients with HFpEF, and 84 control subjects were analyzed. All HF patients had a history of hospitalization for HF treatment. Brachial-ankle pulse wave velocity (baPWV) measurement and transthoracic echocardiography were performed at the same day in a stable condition. Results The baPWV was significantly higher in patients with both HFrEF and HFpEF compared to control subjects (1,661 ± 390, 1,909 ± 466, and 1,477 ± 296cm/sec, respectively; P < 0.05 for each). After adjustment of age, baPWV values were similar between patients with HFrEF and HFpEF (P = 0.948). In the multiple linear regression analysis, baPWV was significantly associated with both septal e′ velocity (β = –0.360, P = 0.001) and E/e′ (β = 0.344, P = 0.001). However, baPWV was not associated with either of the diastolic indices in HFrEF group. The baPWV was associated only with septal e′ velocity (β = –0.429, P = 0.002) but not with E/e′ in the HFpEF group in the same multivariable analysis. Conclusions Although arterial stiffness was increased, its association with LV diastolic function was attenuated in HF patients compared to control subjects. The degree of arterial stiffening was similar between HFrEF and HFpEF.This study was supported by a research grant funded by the Korean Society of Hypertension (No. KSH-R-2020–01)