Temporal Interpolation Is All You Need for Dynamic Neural Radiance Fields

Temporal interpolation often plays a crucial role to learn meaningful representations in dynamic scenes. In this paper, we propose a novel method to train spatiotemporal neural radiance fields of dynamic scenes based on temporal interpolation of feature vectors. Two feature interpolation methods are suggested depending on underlying representations, neural networks or grids. In the neural representation, we extract features from space-time inputs via multiple neural network modules and interpolate them based on time frames. The proposed multi-level feature interpolation network effectively captures features of both short-term and long-term time ranges. In the grid representation, space-time features are learned via four-dimensional hash grids, which remarkably reduces training time. The grid representation shows more than 100 times faster training speed than the previous neural-net-based methods while maintaining the rendering quality. Concatenating static and dynamic features and adding a simple smoothness term further improve the performance of our proposed models. Despite the simplicity of the model architectures, our method achieved state-of-the-art performance both in rendering quality for the neural representation and in training speed for the grid representation.Comment: CVPR 2023. Project page: https://sungheonpark.github.io/tempinterpner

Effects of Electroacupuncture on N-Methyl-D-aspartate Receptor-Related Signaling Pathway in the Spinal Cord of Normal Rats

This study examined the influence of the N-methyl-D-aspartate receptor (NMDAR) on the modulation of related spinal signaling after electroacupuncture (EA) treatment in normal rats. Bilateral 2 Hz EA stimulations (1-2-3.0 mA) were delivered at acupoints corresponding to Zusanli (ST36) and Sanyinjiao (SP6) in men for 30 min. Thermal sensitization was strongly inhibited by EA, but this analgesia was reduced by preintrathecal injection of the NMDAR antagonist, MK801. Phosphorylation of the NMDAR NR2B subunit, cAMP response element-binding protein (CREB), and especially phosphatidylinositol 3-kinase (PI3K) were significantly induced by EA. However, these marked phosphorylations were not observed in MK801-pretreated rats. EA analgesia was reduced by preintrathecal injection with the calcium chelators Quin2 and TMB8, similar to the results evident using MK801. Phosphorylation of PI3K and CREB induced by EA was also inhibited by TMB8. Calcium influx by NMDAR activation may play an important role in EA analgesia of normal rats through the modulation of the phosphorylation of spinal PI3K and CREB

Geriatric Medicine in South Korea: A Stagnant Reality amidst an Aging Population

In the face of an ever-increasing wave of an aging population, this paper provides an update on the current status of geriatric medicine in Korea, comparing it with global initiatives and suggesting future directions. Older adults require a multifaceted approach, addressing not only comorbidity management but also unmet complex medical needs, nutrition, and exercise to prevent functional decline. In this regard, the World Health Organization's Integrated Care for Older People guidelines underscore the importance of patient-centered primary care in preventing a decline in intrinsic capacity. Despite these societal needs and the ongoing aging process, the healthcare system in Korea has yet to show significant movement or a shift toward geriatric medicine, further complicated by the absence of a primary care system. We further explore global efforts in establishing age-integrative patient-centered medical systems in Singapore, Australia, Canada, the United Kingdom, and Japan. Additionally, we review the unmet needs and social issues that Korean society is currently facing, and local efforts by both government and a private tertiary hospital in Korea. In conclusion, considering the current situation, we propose that the framework of geriatric medicine should form the foundation of the future healthcare system

Neural correlates of tactile hardness intensity perception during active grasping

While tactile sensation plays an essential role in interactions with the surroundings, relatively little is known about the neural processes involved in the perception of tactile information. In particular, it remains unclear how different intensities of tactile hardness are represented in the human brain during object manipulation. This study aims to investigate neural responses to various levels of tactile hardness using functional magnetic resonance imaging while people grasp objects to perceive hardness intensity. We used four items with different hardness levels but otherwise identical in shape and texture. A total of Twenty-five healthy volunteers participated in this study. Before scanning, participants performed a behavioral task in which they received a pair of stimuli and they were to report the perceived difference of hardness between them. During scanning, without any visual information, they were randomly given one of the four objects and asked to grasp it. We found significant blood oxygen-level-dependent (BOLD) responses in the posterior insula in the right hemisphere (rpIns) and the right posterior lobe of the cerebellum (rpCerebellum), which parametrically tracked hardness intensity. These responses were supported by BOLD signal changes in the rpCerebellum and rpIns correlating with tactile hardness intensity. Multidimensional scaling analysis showed similar representations of hardness intensity among physical, perceptual, and neural information. Our findings demonstrate the engagement of the rpCerebellum and rpIns in perceiving tactile hardness intensity during active object manipulation

Combined Effects of Surface Morphology and Mechanical Straining Magnitudes on the Differentiation of Mesenchymal Stem Cells without Using Biochemical Reagents

Existing studies examining the control of mesenchymal stem cell (MSC) differentiation into desired cell types have used a variety of biochemical reagents such as growth factors despite possible side effects. Recently, the roles of biomimetic microphysical environments have drawn much attention in this field. We studied MSC differentiation and changes in gene expression in relation to osteoblast-like cell and smooth muscle-like cell type resulting from various microphysical environments, including differing magnitudes of tensile strain and substrate geometries for 8 days. In addition, we also investigated the residual effects of those selected microphysical environment factors on the differentiation by ceasing those factors for 3 days. The results of this study showed the effects of the strain magnitudes and surface geometries. However, the genes which are related to the same cell type showed different responses depending on the changes in strain magnitude and surface geometry. Also, different responses were observed three days after the straining was stopped. These data confirm that controlling microenvironments so that they mimic those in vivo contributes to the differentiation of MSCs into specific cell types. And duration of straining engagement was also found to play important roles along with surface geometry

Cell-free synthesis of functional phospholipase A1 from Serratia sp.

Additional file 1: Figure S1 Gas chromatography analysis of sesame oil incubated with cell-free synthesized PLA1

Anatomical Importance of Inner Ligamentum Flavum Parameters for Successful Endoscopic Lumbar Decompression Surgery

Objective Predicting the gross anatomy of the inner ligament flavum and surrounding interlaminar window is essential for sufficient neural decompression because endoscopic spine surgery is performed in a limited, narrow surgical corridor. This article aims to analyze the anatomical data of inner LF and interlaminar window on the 3D lumbar computed tomography (CT) for easy application to the endoscopic decompression surgery. Methods We measured nine parameters indicating the contour of inner LF and interlaminar window on 3D CT from 100 patients who were diagnosed with lumbar spinal stenosis or disc herniation. Inner LF angle, inner LF distance, inner LF volume, and inner foraminal ligament distance for inner LF contour; height, width, and lateral corner angle of interlaminar window contour were measured in five age groups consisted of twenty individuals from the 30s to the 70s. We then compared two age groups(ages 30–49 years, n=40; ages 60–79 years, n=40). Results In the old age group, the interlaminar window was changed to a smaller triangle shape representing decreased width and height and increased lateral corner angle. Inner LF volume, inner LF angle, inner LF distance were also reduced in the old age group. But these parameters have variations in levels with a significant difference. Uniportal endoscopic docking point has moved according to changed interlaminar window features more caudal and lateral direction. Inner LF angle could have used to decide the approach angle for endoscopic contralateral foraminotomy. Conclusion We found the changing features of these structures correlated with age and levels to help with endoscopic decompression surgery has a limited surgical corridor. The present study results may help the endoscopic surgeons decide the endoscopic docking site, the extent of bone drilling at the medial facet joint part, and the approach angle for contralateral lumbar foraminotomy

Ethanol Extract of Lepidium apetalum

The seeds of Lepidium apetalum Willdenow (called “Tinglizi” in China and “Jungryukza” in Korea) have been used to discharge phlegm and improve dropsy in Oriental medicine. The present study investigated the effects of ethanol extract of the seeds of Lepidium apetalum (ELA) on atrial dynamics and atrial natriuretic peptide (ANP) secretion in beating rabbit atria. ELA increased atrial stroke volume, pulse pressure, and cAMP efflux, concomitantly attenuating ANP secretion in a dose-dependent manner. ELA-induced increases in atrial stroke volume, pulse pressure, and cAMP levels and decrease in ANP secretion were not inhibited by pretreatment with staurosporine, a nonspecific protein kinase inhibitor, or diltiazem and verapamil, the L-type Ca2+ channel blockers, respectively. Helveticoside, a well-known digitalis-like cardiac glycosidic constituent of ELA, also increased atrial dynamics, including stroke volume and pulse pressure, without changing cAMP efflux and ANP secretion, and the effects of helveticoside were not inhibited by pretreatment with staurosporine, diltiazem, and verapamil. These results suggest that the ELA-induced positive inotropic activity in beating rabbit atria might, at least partly, be due to the digitalis-like activity of helveticoside rather than an increase in cAMP efflux

A Novel Technique of the Full Endoscopic Interlaminar Contralateral Approach for Symptomatic Extraforaminal Juxtafacet Cysts

Extraforaminal juxtafacet cyst is rare and present a surgical challenge due to its anatomical location. This study aimed to introduce the surgical technique of interlaminar contralateral endoscopic lumbar foraminotomy (ICELF) for extraforaminal juxtafacet cyst removal and reveal its approach-related benefits. The endoscope was docked on the ipsilateral spinolaminar junction and access the contralateral foraminal area through the contralateral sublaminar space created by the fine drilling. As the foraminal was enlarged by bony drilling, the endoscope was introduced deeper to the extraforaminal area without violation of the foraminal disc. Combined foraminal stenosis was also resolved while exploring the foraminal space. Subsequently, the extraforaminal cyst was safely and entirely removed while exposing the cyst-nerve root adhesion site with an endoscopic view looking up obliquely. Radiating pain in the right leg, back pain, leg hypesthesia, and ankle weakness improved. ICELF for the treatment of extraforaminal JFC can be an alternative surgical method to resolve symptomatic foraminal stenosis and the cyst simultaneously. The entire cyst contour and the site of cyst-nerve root adhesion can be detected without nerve root retraction, and meticulous dissection is possible without violating the cystic wall using the full endoscopic contralateral approach