Arginine-Rich Cell-Penetrating Peptides Induce Lipid Rearrangements for Their Active Translocation across Laterally Heterogeneous Membranes.

Arginine-rich cell-penetrating peptides (CPPs) have emerged as valuable tools for the intracellular delivery of bioactive molecules, but their membrane perturbation during cell penetration is not fully understood. Here, nona-arginine (R9)-mediated membrane reorganization that facilitates the translocation of peptides across laterally heterogeneous membranes is directly visualized. The electrostatic binding of cationic R9 to anionic phosphatidylserine (PS)-enriched domains on a freestanding lipid bilayer induces lateral lipid rearrangements; in particular, in real-time it is observed that R9 fluidizes PS-rich liquid-ordered (Lo) domains into liquid-disordered (Ld) domains, resulting in the membrane permeabilization. The experiments with giant unilamellar vesicles (GUVs) confirm the preferential translocation of R9 through Ld domains without pore formation, even when Lo domains are more negatively charged. Indeed, whenever R9 comes into contact with negatively charged Lo domains, it dissolves the Lo domains first, promoting translocation across phase-separated membranes. Collectively, the findings imply that arginine-rich CPPs modulate lateral membrane heterogeneity, including membrane fluidization, as one of the fundamental processes for their effective cell penetration across densely packed lipid bilayers.

Novel approach of ultrasound-guided lateral recess block for a patient with lateral recess stenosis: A case report.

BACKGROUND: Ultrasound guide technology, which can provide real-time visualization of the needle tip and tissues and avoid many adverse events, is widely used in minimally invasive therapy. However, the studies on ultrasound-guided Lateral recess block (LRB) are limited, this is probably because there is no recognized standard method for ultrasound scanning. This study aimed to evaluate the effect of ultrasound-guided LRB in patients with lateral recess stenosis (LRS). CASE SUMMARY: A 65-year-old patient complained of low back pain accompanied occasionally by pain and numbness in the left lower limb. Physical examination showed tenderness on the spinous process and paraspinal muscles from L1 to S1, extensor hallucis longus and tibialis anterior weakness (muscle strength: 4-), and a positive straight leg raising test in the left lower limb (60°). Magnetic resonance imaging showed L4-L5 disc degeneration with left LRS and nerve root entrapment. Subsequently, the patient was diagnosed with LRS. This patient was treated with a novel ultrasound-guided LRB approach. The patient's symptoms significantly improved without any complications at 1 wk postoperatively and at the 3-month follow-up. CONCLUSION: This is the first report on the LRS treatment with ultrasound-guided LRB from the contralateral spinous process along the inner side of the articular process by out-plane technique. Further studies are expected to investigate the efficacy and safety of ultrasound-guided LRB for patients with LRS.

Real-time single-molecule visualization using DNA curtains reveals the molecular mechanisms underlying DNA repair pathways.

The demand for direct observation of biomolecular interactions provides new insights into the molecular mechanisms underlying many biological processes. Single-molecule imaging techniques enable real-time visualization of individual biomolecules, providing direct observations of protein machines. Various single-molecule imaging techniques have been developed and have contributed to breakthroughs in biological research. One such technique is the DNA curtain, a novel, high-throughput, single-molecule platform that integrates lipid fluidity, nano-fabrication, microfluidics, and fluorescence imaging. Many DNA metabolic reactions, such as replication, transcription, and chromatin dynamics, have been studied using DNA curtains. In particular, the DNA curtain platform has been intensively applied in investigating the molecular details of DNA repair processes. This article reviews DNA curtain techniques and their applications for imaging DNA repair proteins.

Evaluation of Augmented Reality Surgical Navigation in Percutaneous Endoscopic Lumbar Discectomy: Clinical Study.

BACKGROUND: The puncture procedure in percutaneous endoscopic lumbar discectomy (PELD) is non-visual, and the learning curve for PELD is steep. METHODS: An augmented reality surgical navigation (ARSN) system was designed and utilized in PELD. The system possesses three core functionalities: augmented reality (AR) radiograph overlay, AR puncture needle real-time tracking, and AR navigation. We conducted a prospective randomized controlled trial to evaluate its feasibility and effectiveness. A total of 20 patients with lumbar disc herniation treated with PELD were analyzed. Of these, 10 patients were treated with the guidance of ARSN (ARSN group). The remaining 10 patients were treated using C-arm fluoroscopy guidance (control group). RESULTS: The AR radiographs and AR puncture needle were successfully superimposed on the intraoperative videos. The anteroposterior and lateral AR tracking distance errors were 1.55 ± 0.17 mm and 1.78 ± 0.21 mm. The ARSN group exhibited a significant reduction in both the number of puncture attempts (2.0 ± 0.4 vs. 6.9 ± 0.5, p = 0.000) and the number of fluoroscopies (10.6 ± 0.9 vs. 18.5 ± 1.6, p = 0.000) compared with the control group. Complications were not observed in either group. CONCLUSIONS: The results indicate that the clinical application of the ARSN system in PELD is effective and feasible.

Augmented Reality Surgical Navigation in Minimally Invasive Spine Surgery: A Preclinical Study.

BACKGROUND: In minimally invasive spine surgery (MISS), where the surgeon cannot directly see the patient's internal anatomical structure, the implementation of augmented reality (AR) technology may solve this problem. METHODS: We combined AR, artificial intelligence, and optical tracking to enhance the augmented reality minimally invasive spine surgery (AR-MISS) system. The system has three functions: AR radiograph superimposition, AR real-time puncture needle tracking, and AR intraoperative navigation. The three functions of the system were evaluated through beagle animal experiments. RESULTS: The AR radiographs were successfully superimposed on the real intraoperative videos. The anteroposterior (AP) and lateral errors of superimposed AR radiographs were 0.74 ± 0.21 mm and 1.13 ± 0.40 mm, respectively. The puncture needles could be tracked by the AR-MISS system in real time. The AP and lateral errors of the real-time AR needle tracking were 1.26 ± 0.20 mm and 1.22 ± 0.25 mm, respectively. With the help of AR radiographs and AR puncture needles, the puncture procedure could be guided visually by the system in real-time. The anteroposterior and lateral errors of AR-guided puncture were 2.47 ± 0.86 mm and 2.85 ± 1.17 mm, respectively. CONCLUSIONS: The results indicate that the AR-MISS system is accurate and applicable.

Designing a Low-Cost System to Monitor the Structural Behavior of Street Lighting Poles in Smart Cities.

The structural collapse of a street lighting pole represents an aspect that is often underestimated and unpredictable, but of relevant importance for the safety of people and things. These events are complex to evaluate since several sources of damage are involved. In addition, traditional inspection methods are ineffective, do not correctly quantify the residual life of poles, and are inefficient, requiring enormous costs associated with the vastness of elements to be investigated. An advantageous alternative is to adopt a distributed type of Structural Health Monitoring (SHM) technique based on the Internet of Things (IoT). This paper proposes the design of a low-cost system, which is also easy to integrate in current infrastructures, for monitoring the structural behavior of street lighting poles in Smart Cities. At the same time, this device collects previous structural information and offers some secondary functionalities related to its application, such as meteorological information. Furthermore, this paper intends to lay the foundations for the development of a method that is able to avoid the collapse of the poles. Specifically, the implementation phase is described in the aspects concerning low-cost devices and sensors for data acquisition and transmission and the strategies of information technologies (ITs), such as Cloud/Edge approaches, for storing, processing and presenting the achieved measurements. Finally, an experimental evaluation of the metrological performance of the sensing features of this system is reported. The main results highlight that the employment of low-cost equipment and open-source software has a double implication. On one hand, they entail advantages such as limited costs and flexibility to accommodate the specific necessities of the interested user. On the other hand, the used sensors require an indispensable metrological evaluation of their performance due to encountered issues relating to calibration, reliability and uncertainty.

Single-molecule fluorescence imaging techniques reveal molecular mechanisms underlying deoxyribonucleic acid damage repair.

Advances in single-molecule techniques have uncovered numerous biological secrets that cannot be disclosed by traditional methods. Among a variety of single-molecule methods, single-molecule fluorescence imaging techniques enable real-time visualization of biomolecular interactions and have allowed the accumulation of convincing evidence. These techniques have been broadly utilized for studying DNA metabolic events such as replication, transcription, and DNA repair, which are fundamental biological reactions. In particular, DNA repair has received much attention because it maintains genomic integrity and is associated with diverse human diseases. In this review, we introduce representative single-molecule fluorescence imaging techniques and survey how each technique has been employed for investigating the detailed mechanisms underlying DNA repair pathways. In addition, we briefly show how live-cell imaging at the single-molecule level contributes to understanding DNA repair processes inside cells.

Using real-time visualization system for data-driven decision support to achieve lung protective strategy: a retrospective observational study.

BACKGROUND: Although lung protective strategy and adjunctive intervention are associated with improved survival in patients with acute respiratory distress syndrome (ARDS), the implementation of effective therapies remains low. This study aimed to evaluate whether the use of business intelligence (BI) for real-time data visualization is associated with an improvement in lung protective strategy and adjunctive therapy. METHODS: A retrospective observational cohort study was conducted on patients with ARDS admitted between September 2020 and June 2021 at two intensive care units (ICUs) of a tertiary referral hospital in Taiwan. BI was imported for data visualization and integration to assist in clinical decision in one of the ICUs. The primary outcomes were the implementation of low tidal volume ventilation (defined as tidal volume/predicted body weight ≤ 8 mL/kg) within 24 h from ARDS onset. The secondary outcomes included ICU and hospital mortality rates. RESULTS: Among the 1201 patients admitted to the ICUs during the study period, 148 (12.3%) fulfilled the ARDS criteria, with 86 patients in the BI-assisted group and 62 patients in the standard-of-care (SOC) group. Disease severity was similar between the two groups. The application of low tidal volume ventilation strategy was significantly improved in the BI-assisted group compared with that in the SOC group (79.1% vs. 61.3%, p = 0.018). Despite their ARDS and disease severity, the BI-assisted group tended to achieve low tidal volume ventilation. The ICU and hospital mortality were lower in the BI-assisted group. CONCLUSIONS: The use of real-time visualization system for data-driven decision support was associated with significantly improved compliance to low tidal volume ventilation strategy, which enhanced the outcomes of patients with ARDS in the ICU.

A water-soluble fluorescent probe for real-time visualization of γ-glutamyl transpeptidase activity in living cells.

γ-glutamyl transpeptidase (GGT) is a kind of cell-surface enzyme that is overexpressed in many cancer cells. It is of great significance to develop an ideal tool for the diagnosis of GGT-rich cancer cells. Here, we reported a simple-structured but effective imaging probe for the detection of GGT activity. In the presence of GGT, the γ-glutamyl linkage could be cleaved specifically to produce amino-substituted product, resulting in significant fluorescence enhancement at 578 nm. Moreover, we successfully employed the probe to monitor GGT activity in HepG2 cells. We envisaged that such a simple but effective imaging tool could improve the practical applications for bioimaging.

In Situ Visualization on Surface Oxidative Corrosion with Free Radicals: Black Phosphorus Nanoflake as an Example.

Free radicals exert a significant impact on the fate of redox-active substances and play a crucial role in the surface corrosion of solid in environment. Dynamic visualization on the response of the surface to the free radicals at nanoscale is essential to explore the mechanism. Environmental transmission electron microscopy will be a powerful tool for dynamic changes of the interface redox process of solid surface with electron beams induced free radicals, to simulate the redox process of a solid in the environment. Black phosphorus (BP), an environment-sensitive material, is selected as an example to visualize the degradation pathways with environmental transmission electron microscopy. The distribution of the corrosion initiation points, formation and growth of corrosion areas, and the eventual splintering and disappearance of BP nanoflakes are recorded vividly. In situ results are substantiated by the ex situ experiments and density functional theory (DFT) calculations. Results show that degradation originates at the edges and defect structures when the humidity reaches high enough. The microscopic structural oxidative etching of solid surface with radicals in natural light is simulated with radicals produced by electron beam irradiation on suspending medium O2 and H2O for the first time. This method will offer unprecedented details and valuable insights into the mechanism involved in the oxidative etching with natural light.

Ultra-Stable Freestanding Lipid Membrane Array: Direct Visualization of Dynamic Membrane Remodeling with Cholesterol Transport and Enzymatic Reactions.

Cell membranes actively change their local compositions, serving essential biological processes such as cellular signaling and endocytosis. Although membrane dynamics is vital in the cellular functions, the complexity of natural membranes has made its fundamental understanding and systematic assessment difficult. Here, a powerful artificial membrane system is developed for real-time visualization of the spatiotemporal dynamics of membrane remodeling. Through well-defined air/oil/water interfaces on grid holes, tens of planar lipid bilayer membranes are easily created, and their reproducibility, controllability, and generality are highlighted. The freestanding membranes are large but also highly stable, facilitating direct long-term monitoring of dynamic membrane reconstitution caused by external stimuli. As an example to demonstrate the superiority of this membrane system, the effect of cholesterol trafficking, which significantly affects biophysical properties of cell membranes, is investigated at different membrane compositions. Cholesterol transport into and out of the membranes at different rates causes anomalous lipid arrangements through cholesterol-mediated phase transitions and decomposition, which have never been witnessed before. Furthermore, enzyme-induced membrane dynamics is successfully shown in this platform; sphingomyelinases locally generate asymmetry between two membrane leaflets. This technique is broadly applicable for exploring the membrane heterogeneity under various membrane-based reactions, providing valuable insight into the membrane dynamics.

Anonymous Real-Time Analytics Monitoring Solution for Decision Making Supported by Sentiment Analysis.

Currently, social networks present information of great relevance to various government agencies and different types of companies, which need knowledge insights for their business strategies. From this point of view, an important technique for data analysis is to create and maintain an environment for collecting data and transforming them into intelligence information to enable analysts to observe the evolution of a given topic, elaborate the analysis hypothesis, identify botnets, and generate data to aid in the decision-making process. Focusing on collecting, analyzing, and supporting decision-making, this paper proposes an architecture designed to monitor and perform anonymous real-time searches in tweets to generate information allowing sentiment analysis on a given subject. Therefore, a technological structure and its implementation are defined, followed by processes for data collection and analysis. The results obtained indicate that the proposed solution provides a high capacity to collect, process, search, analyze, and view a large number of tweets in several languages, in real-time, with sentiment analysis capabilities, at a low cost of implementation and operation.

Modular DNA-Incorporated Aggregation-Induced Emission Probe for Sensitive Detection and Imaging of DNA Methyltransferase.

DNA adenine methylation (Dam) MTase serves a very important epigenetic process that transfers a methyl group on an adenine residue including N6-methyladenosine (m6A). A variety of evidence have demonstrated that m6A methylation plays a significant role in modulating genes in human disease and development. Hence, a modular DNA-incorporated AIEgen probe (TPE-Py-DNA) was specifically developed for detection and imaging of Dam MTase. TPE-Py-DNA consisted of two modules: a "turn-on" fluorescent AIEgen (TPE-Py) and a DNA sequence (Alk-DNA) involved in specific recognition of the targeted strand. The TPE-Py-DNA probe was dispersed and almost nonfluorescent in an aqueous environment. On the contrary, the TPE-Py-DNA molecule was digested based on the target-recycling strategy in assistance with exonuclease III (Exo III) when Dam MTase was presented, finally releasing aggregated AIEgens to produce a remarkably increased fluorescence signal. Therefore, the detection limit toward Dam MTase was as low as 3.1 × 10-5 U mL-1, and the fluorescent signal could be used to detect Dam MTase activities in real samples and screen its inhibitors. More importantly, the Dam MTase expression was visualized in E. coli cells via CLMS imaging and confirmed in E. coli cell-bearing tissues. In this vein, our results demonstrated that the TPE-Py-DNA probe is a potent tool for the Dam MTase detection and imaging as well as offers an efficient biosensing platform for further investigation of disease pathway and carcinogenesis.

Real-Time Visualization of Ureters Using Indocyanine Green During Laparoscopic Surgeries: Can We Make Surgery Safer?

Background. Intraoperative ureteral injury is rare, but a grave complication during laparoscopic surgery. Several methods for intraoperative localization of ureters are described with their own pitfalls. Intraoperative localization using near-infrared (NIR) fluorescence with indocyanine green (ICG) is an easier and assured method during laparoscopic pelvic surgeries. Method. From September 2017 to December 2017, patients undergoing laparoscopic pelvic surgeries were administered cystoscopic-guided intraureteral ICG immediately preoperatively with tip of a 6-Fr ureteral catheter. The fluorescence of ureters was visualized in the NIR mode of the camera system, localizing the ureters precisely and in real time. Results. This technique was used to visualize ureters in 30 surgeries. Median age of the patients was 46.7 years with median body mass index of 23.2 kg/m2. Mean duration between administration of dye and insertion of trocar was 10 minutes. Mean duration for insertion of cystoscopically guided intraureteral ICG was 7 minutes. Ureteral fluorescence was visualized in all cases with some variation in intensity of the brightness perceived depending on surrounding fat. Duration of the lengthiest surgery was 240 minutes, and fluorescence was appreciated till the end. There were no intraoperative or postoperative complications attributed to ICG administration. In 10 patients (33%), there was difficulty in identifying the ureters on conventional white light mode, in which ICG localization was extremely helpful. Conclusion. ICG-stained ureteral visualization under NIR light is a safe and feasible method that provides real-time ureteral demarcation. This easily replicable, sensitive, and specific method of ureteral visualization can make complex laparoscopic pelvic surgeries safer.

Gadofosveset-enhanced MRI as simple surrogate parameter for real-time evaluation of the initial tumour vessel infarction by retargeted tissue factor tTF-NGR.

Truncated tissue factor (tTF)-NGR consists of the extracellular domain of the human TF and the binding motif NGR. tTF-NGR activates blood coagulation within the tumour vasculature following binding to CD13, and is overexpressed in the endothelial cells of tumour vessels, resulting in tumour vessel infarction and subsequent retardation/regression of tumour growth. The aim of the present study was to investigate gadofosveset-based real-time dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in evaluating the initial therapeutic effects of the anti-vascular tTF-NGR approach. DCE-MRI (3.0 T) was performed in human U87-glioblastoma tumour-bearing nude mice. During a dynamic T1w GE-sequence, a gadolinium-based blood pool contrast agent (gadofosveset) was injected via a tail vein catheter. Following the maximum contrast intensity inside the tumour being obtained, tTF-NGR was injected (controls received NaCl) and the contrast behaviour of the tumour was monitored by ROI analysis. The slope difference of signal intensities between controls and the tTF-NGR group was investigated, as well as the differences between the average area under the curve (AUC) of the two groups. The association between intensity, group (control vs. tTF-NGR group) and time was analysed by fitting a linear mixed model. Following the injection of tTF-NGR, the signal intensity inside the tumours exhibited a statistically significantly stronger average slope decrease compared with the signal intensity of the tumours in the NaCl group. Furthermore, the initial average AUC values of mice treated with tTF-NGR were 5.7% lower than the average AUC of the control animals (P<0.05). Gadofosveset-enhanced MRI enables the visualization of the initial tumour response to anti-vascular treatment in real-time. Considering the clinical application of tTF-NGR, this method may provide a simple alternative parameter for monitoring the tumour response to vascular disrupting agents and certain vascular targeting agents in humans.

Real-Time Analysis of the Heart Rate Variability During Incremental Exercise for the Detection of the Ventilatory Threshold.

BACKGROUND: It has never been possible to immediately evaluate heart rate variability (HRV) during exercise. We aimed to visualize the real-time changes in the power spectrum of HRV during exercise and to investigate its relationship to the ventilatory threshold (VT). METHODS AND RESULTS: Thirty healthy subjects (29.1±5.7 years of age) and 35 consecutive patients (59.0±13.2 years of age) with myocardial infarctions underwent cardiopulmonary exercise tests with an RAMP protocol ergometer. The HRV was continuously assessed with power spectral analyses using the maximum entropy method and projected on a screen without delay. During exercise, a significant decrease in the high frequency (HF) was followed by a drastic shift in the power spectrum of the HRV with a periodic augmentation in the low frequency/HF (L/H) and steady low HF. When the HRV threshold (HRVT) was defined as conversion from a predominant high frequency (HF) to a predominant low frequency/HF (L/H), the VO2 at the HRVT (HRVT-VO2) was substantially correlated with the VO2 at the lactate threshold and VT) in the healthy subjects (r=0.853 and 0.921, respectively). The mean difference between each threshold (0.65 mL/kg per minute for lactate threshold and HRVT, 0.53 mL/kg per minute for VT and HRVT) was nonsignificant (P>0.05). Furthermore, the HRVT-VO2 was also correlated with the VT-VO2 in these myocardial infarction patients (r=0.867), and the mean difference was -0.72 mL/kg per minute and was nonsignificant (P>0.05). CONCLUSIONS: A HRV analysis with our method enabled real-time visualization of the changes in the power spectrum during exercise. This can provide additional information for detecting the VT.

Demons registration for in vivo and deformable laser scanning confocal endomicroscopy.

A critical effect found in noninvasive in vivo endomicroscopic imaging modalities is image distortions due to sporadic movement exhibited by living organisms. In three-dimensional confocal imaging, this effect results in a dataset that is tilted across deeper slices. Apart from that, the sequential flow of the imaging-processing pipeline restricts real-time adjustments due to the unavailability of information obtainable only from subsequent stages. To solve these problems, we propose an approach to render Demons-registered datasets as they are being captured, focusing on the coupling between registration and visualization. To improve the acquisition process, we also propose a real-time visual analytics tool, which complements the imaging pipeline and the Demons registration pipeline with useful visual indicators to provide real-time feedback for immediate adjustments. We highlight the problem of deformation within the visualization pipeline for object-ordered and image-ordered rendering. Visualizations of critical information including registration forces and partial renderings of the captured data are also presented in the analytics system. We demonstrate the advantages of the algorithmic design through experimental results with both synthetically deformed datasets and actual in vivo, time-lapse tissue datasets expressing natural deformations. Remarkably, this algorithm design is for embedded implementation in intelligent biomedical imaging instrumentation with customizable circuitry.

Investigation of the influence of fluid dynamics on thrombus growth at the interface between a connector and tube.

Thrombus formation at the interface between connectors and tubes is a potential risk factor for complications. We investigated time-dependent relationships between formation of thrombus and hemodynamic factors at the interface between connectors and tubes using optical coherence tomography (OCT) under pulsatile flow. A swept-source OCT with the center wavelength of 1330 nm was employed. The sequential process of thrombus formation at the interface of connectors and tubes in the inlet and outlet was investigated. Connectors with and without tapers were tested using identical 50-ml air-contactless circuits. Fresh human blood from healthy volunteers was circulated under pulsatile flow. Thrombus initially formed at the interface between the connector tip and the tube. Geometries of thrombus growth were different between the 2 connectors, and between the inlet and the outlet. Growth of thrombus was observed at the interface between the connectors and tubes over time in 60 min circulation, except at the outlet part of connector without tapers. At the connector without tapers outlet, thrombus propagation length from the connector edge toward the flow downstream was comparable at 10 and 60 min (0.55 ± 0.35 vs. 0.51 ± 0.32 mm, p = 0.83). Analysis using particle image velocimetry showed the presence of a flow reattachment point 1.5 mm downstream from the connector edge. These results suggest that the flow reattachment point inhibits downstream thrombus growth. We quantitatively demonstrated sequential thrombus process at the interface between the connectors and tubes under pulsatile flow of human blood using OCT.

A Nondestructive Method for Measuring Protein Distribution in Frozen Drug Substance.

We describe a noninvasive method developed to make in situ measurements of protein concentration in frozen drug substance. This technique is based on fluorescence from artificially labeled protein and a charge-coupled device camera. Data collected using this method in laboratory small-scale experiments are in good agreement with traditional ice core method. The technique allows real-time visualization of freezing process and provides rich local details of ice crystal growth and morphology for the whole freezing process from beginning to the last point to freeze, and the whole freezing process can be described in 2- and 3-dimensional heat maps with appropriate software. In combining with other existing methods, this method can provide evaluation and optimization of formulation, cooling rate, and cryoconcentration distribution and impacts of combined stresses during freezing. The ability to understand and to control the protein concentration profile in the frozen state offers the potential to improve stability of protein in long-term frozen storage.