Scanning Area Research Articles

Oriented AFM Scanning on a Large Sample with Cooperative Rotating Stage and Auxiliary Optical Microscopy

Atomic force microscope (AFM) is a powerful tool capable of constructing accurate 3-D surface profiles at a nanometer resolution. However, the scanning area of the AFM is limited by the piezo-scanner. Hence, this will restrict the AFM from scanning those applications to large samples. Moreover, some features (e.g., strip shape) orientation relative to the AFM scanning direction is necessary to be considered. To address these issues, the AFM system combined with a rotation stage and a long-range stage is constructed. Besides, an automatic method to move the oriented scan region into the AFM workspace is provided through the assistance of an optical microscope (OM). Finally, the result shows that the AFM scanning on large samples is achievable.

Workflow and performance of intraoperative CT, cone-beam CT, and robotic cone-beam CT for spinal navigation in 503 consecutive patients.

A direct comparison of intraoperative CT (iCT), cone-beam CT (CBCT), and robotic cone-beam CT (rCBCT) has been necessary to identify the ideal imaging solution for each individual user's need. Herein, the authors sought to analyze workflow, handling, and performance of iCT, CBCT, and rCBCT imaging for navigated pedicle screw instrumentation across the entire spine performed within the same surgical environment by the same group of surgeons. Between 2014 and 2018, 503 consecutive patients received 2673 navigated pedicle screws using iCT (n = 1219), CBCT (n = 646), or rCBCT (n = 808) imaging during the first 24 months after the acquisition of each modality. Clinical and demographic data, workflow, handling, and screw assessment and accuracy were analyzed. Intraoperative CT showed image quality and workflow advantages for cervicothoracic cases, obese patients, and long-segment instrumentation, whereas CBCT and rCBCT offered independent handling, around-the-clock availability, and the option of performing 2D fluoroscopy. All modalities permitted reliable intraoperative screw assessment. Navigated screw revision was possible with each modality and yielded final accuracy rates > 92% in all groups (iCT 96.2% vs CBCT 92.3%, p < 0.001) without a difference in the accuracy of cervical pedicle screw placement or the rate of secondary screw revision surgeries. Continuous training and an individual setup of iCT, CBCT, and rCBCT has been shown to permit safe and precise navigated posterior instrumentation across the entire spine with reliable screw assessment and the option of immediate revision. The perceived higher image quality and larger scan area of iCT should be weighed against the around-the-clock availability of CBCT and rCBCT technology with the option of single-handed robotic image acquisition.

CT evaluated sarcopenia signals: Shorter survival for small cell lung cancer patients.

Sarcopenia is an independent risk factor for morbidity and mortality in patients suffering from small cell lung cancer (SCLC), however, a universal indicator of sarcopenia usable in clinical practice is still missing. A novel indicator for describing the severity of cancer could be helpful in tailoring the anti-tumor therapy. The aim of this study was to evaluate the computed tomography (CT) scans of total muscle area and radiation attenuation in patients suffering from small cell lung cancer. We used staging CT scans performed at the time of diagnosis to measure total muscle area (TMA) and average psoas density (PD) at level of the 3rd lumbar vertebra. TMA and PD were statistically evaluated in association with overall survival and disease staging. We used Mann-Whitney test and Spearman´s correlation coefficient for statistical testing and p-value under 0.05 was considered statistically significant. Retrospectively we examined 47 patients suffering from SCLC (mean age 65.05+/-7.3 years, BMI 23.97+/-4.4 kg/m2, BSA 1.77+/-0.2 m2, 30-day mortality was 4.3 % with 10 months median survival). As sarcopenia was pointed TMA under 55 and 39 cm2/m2 for men and women respectively. The sarcopenic patients had significantly shorter median survival (7 vs. 11 months, p=0.05). We observed a significant relationship between survival and performance status (Spearman´s correlation, R=-0.39, p=0.05). The patients were divided into two groups according to the extensive (ED, n=34) or limited (LD, n=13) form of the disease. We observed significant difference in PD (42.49+/-6.1 vs. 47.67+/-4.5 HU, p=0.006) between ED vs. LD groups.

GaN-Based Resonant-Cavity Light-Emitting Diodes Grown on Si.

GaN-on-Si resonant-cavity light-emitting diodes (RCLEDs) have been successfully fabricated through wafer bonding and Si substrate removal. By combining the chemical mechanical polishing technique, we obtained a roughness of about 0.24 nm for a scan area of 5 μm × 5 μm. The double-sided dielectric distributed Bragg reflectors could form a high-quality optical resonant cavity, and the cavity modes exhibited a linewidth of 1 nm at the peak wavelength of around 405 nm, corresponding to a quality factor of 405. High data transmission in free space with an opening in the eye diagram was exhibited at 150 Mbps, which is limited by the detection system. These results showed that GaN-based RCLEDs grown on Si are promising as a low-cost emitter for visible light communications in future.

Choroidal caverns in pachychoroid neovasculopathy

Background. Choroid plays an important role in the pathogenesis of retinal pathology. Choroidal cavern, a recently identifi ed fi nding of optical coherent tomography (OCT), has been described in some degenerative and atrophic forms of retinal pathology. In the literature, there are only a few studies of choroidal cavers in pachychoroid neovasculopathy, newly described form of age related macular degeneration.The aim: to perform a detailed analysis of choroidal structure on OCT scans of patients with pachychoroid neovasculopathy and to reveal the frequency of choroidal caverns identifi cation.Material and methods. The data of 30 patients (30 eyes) aged 64.4 ± 5.6 years with pachychoroid neovascularization were retrospectively analyzed. The patients underwent spectral OCT and OCT-angiography (OCTA) using a Spectralis device (Heidelberg Engineering, Germany). The protocol was “Posterior Pole”, consisting of 61 scans. To assess the structure of the choroid, an enhanced image depth (EDI) module was used. OCT angiography was performed with a scan area of 6 × 6 mm. These methods were compared to identify choroidal caverns.Results. On OCT subretinal type 1 neovascularization was revealed as a fl at detachment of the pigment epithelium and visualization of blood flow on OCTA in the lesion as angled vessels (21 eyes) or a seafan (9 eyes). On OCT-EDI scans, there was diffuse or local choroidal thickening of choroid with an increase in the vessels of the Haller’s layer and thinning of the choriocapillaries. Choroidal caverns appeared on OCT and en-face OCT as areas with low optical density, round or irregular, located in different layers of the chorioid, without hyperrefl ective boundaries. A typical sign of choroidal cavern is the tail of hypertransmission after the cavern toward the sclera. Choroidal caverns were found in 4 of 30 eyes (13.3 %) and were located both near the choroidal neovascularization lesion and beyond this area.Conclusion. The prevalence of choroidal cavities, a new choroidal biomarker, in pachychoroid neovasculopathy was 13.3 %. Identification of these changes is possible with the use of modern diagnostic techniques (OCT-EDI, OCTA and en-face OCT) that allow visualization the state of the choroid. The prognostic signifi cance of choroidal cavities requires further study.

Organ-Preserving Surgery in Urethral Cancer (a Clinical Case)

Background. Despite low incidence, malignant urethral neoplasms are among the most aggressive tumours. Prevalence of muscle-invasive and metastatic cancer at diagnosis, as well as a high relapse rate compel adherence to the most radical treatment. At the same time, the high incidence of urethral tumours in elderly and senile patients and high postoperative complication rates warrant the development of organ-preserving treatment.Aim. A case description to verify the organ-preserving treatment applicability in urethral cancer.Materials and methods. We report the treatment experience in a senile patient with concomitant chronic kidney disease at the Volgograd Regional Clinical Oncology Dispensary’s Oncourology Unit. Accounting for the age, concomitant pathology and tumour histology factors, a minimally invasive organ-preserving surgical intervention was performed as laparoscopic urethral resection with ureterocystoneostomy.Results and discussion. Renal function was assessed in postoperative period with dynamic nephroscintigraphy and blood creatinine monitoring. Control cysto-, ureteroscopy and contrast-enhanced CT scanning in areas of interest were performed to rule out relapse and progression.Conclusion. No report of disease relapse or progression at follow-up indicates the oncological safety of organ-preserving surgery in this patient category. Th is approach also gains support from immediate and long-term outcomes of the patient’s improved renal function and sustained good quality of life.

Oil as an Enabler for Efficient Materials Removal in Three-Dimensional Scanning Probe Microscopy Applications

The ever-increasing complexity of semiconductor devices requires innovative three-dimensional materials characterization techniques for confined volumes. Multiple atomic force microscopy (AFM)-based methodologies, using a slice-and-measure approach have been proposed to meet this demand. They consist of scanning AFM probes that erode locally the sample’s material at a relatively high load while sensing with the secondary AFM channel, thus accessing in-depth information compared to the standard surface-limited analysis. Nonetheless, the rapid tip apex wear caused by the high forces involved, and the debris accumulation at the tip apex and inside/around the scan area, have been identified as major limitations to the accuracy and repeatability of the existing tomographic AFM sensing methods. Here we explore the use of oil as a suitable medium to overcome some of the issues such as the scan debris accumulation and the removal variability when working in air. We show how the use of oil preserves the tomographic operation while improving the efficiency in material removal for large depth sensing at a reduced debris accumulation. This is reported by comparing the results between air and oil environments, where the removal rate, depth accuracy, and tip-contamination are benchmarked. Finally, we provide the first demonstration of electrical AFM sensing using scanning spreading resistance microscopy (SSRM) in oil.

Lung Ultrasound in COVID-19 and Post-COVID-19 Patients, an Evidence-Based Approach.

ObjectivesWorldwide, lung ultrasound (LUS) was utilized to assess coronavirus disease 2019 (COVID‐19) patients. Often, imaging protocols were however defined arbitrarily and not following an evidence‐based approach. Moreover, extensive studies on LUS in post‐COVID‐19 patients are currently lacking. This study analyses the impact of different LUS imaging protocols on the evaluation of COVID‐19 and post‐COVID‐19 LUS data.MethodsLUS data from 220 patients were collected, 100 COVID‐19 positive and 120 post‐COVID‐19. A validated and standardized imaging protocol based on 14 scanning areas and a 4‐level scoring system was implemented. We utilized this dataset to compare the capability of 5 imaging protocols, respectively based on 4, 8, 10, 12, and 14 scanning areas, to intercept the most important LUS findings. This to evaluate the optimal trade‐off between a time‐efficient imaging protocol and an accurate LUS examination. We also performed a longitudinal study, aimed at investigating how to eventually simplify the protocol during follow‐up. Additionally, we present results on the agreement between AI models and LUS experts with respect to LUS data evaluation.ResultsA 12‐areas protocol emerges as the optimal trade‐off, for both COVID‐19 and post‐COVID‐19 patients. For what concerns follow‐up studies, it appears not to be possible to reduce the number of scanning areas. Finally, COVID‐19 and post‐COVID‐19 LUS data seem to show differences capable to confuse AI models that were not trained on post‐COVID‐19 data, supporting the hypothesis of the existence of LUS patterns specific to post‐COVID‐19 patients.ConclusionsA 12‐areas acquisition protocol is recommended for both COVID‐19 and post‐COVID‐19 patients, also during follow‐up.

Radial peripapillary capillary network microvascular changes in Alzheimer's disease, mild cognitive impairment, and cognitively healthy controls

AbstractBackgroundThe retinal and optic nerve head microvasculature may represent a non‐invasive, inexpensive biomarker for Alzheimer’s disease (AD) and mild cognitive impairment (MCI). In this study, we characterize microvascular changes at the optic nerve head (radial peripapillary capillary network) using optical coherence tomography angiography (OCTA).MethodOptic nerve head‐centered OCTA images were obtained from 66 eyes of 36 patients with AD, 119 eyes of 63 patients with MCI, and 513 eyes of 265 cognitively healthy controls in a cross‐sectional study (NCT03233646) using Zeiss Cirrus HD‐5000 OCTA. Exclusion criteria included diabetes, uncontrolled hypertension, glaucoma, non‐AD dementia, and other optic nerve pathology. Two metrics of vessel perfusion were calculated in a 2.5mm‐wide annulus centered on the optic nerve head using Zeiss AngioPlex (Version 11.0.0.29946) – capillary perfusion density (CPD) and capillary flux index (CFI). CPD represents the percentage of perfused capillaries in a unit scan area; CFI is a unitless ratio of perfused capillaries in a unit scan area weighted by intensity of flow signal. Retinal nerve fiber layer (RNFL) thickness was measured using a peripapillary optic disc cube scan. Groups were compared using multivariable generalized estimating equations, controlling for age and sex as covariates.ResultAverage CPD was significantly greater in AD vs controls (0.446 ± 0.015 vs 0.439 ± 0.017, p = 0.001) and in MCI vs controls (0.443 ± 0.020 vs 0.439 ± 0.017, p = 0.007) but not AD vs MCI (p = 0.69). CFI and average RNFL thickness did not significantly differ among groups (all p &gt; 0.05). Among all groups, average CPD differed significantly (p = 0.001), as did CPD in the nasal and inferior peripapillary quadrants (p &lt; 0.001 and p = 0.001, respectively).ConclusionPeripapillary CPD is increased in eyes of patients with AD or MCI compared to cognitively healthy controls, despite similar RNFL thickness between these groups. This finding represents a novel biomarker and contrasts with macular microvascular changes, which show decreased vessel and perfusion density in AD and MCI compared to controls. Integration of optic nerve head OCTA in models using retinal imaging to diagnose AD and MCI may improve specificity; further investigation is necessary.

Extreme-resolution synchrotron X-Ray fluorescence mapping of ore samples

In order to maximise profit and sustainability of a mining operation, knowledge of the chemistry, mineralogy, texture, and structure of the ore is essential. Continuous advancements in analytical techniques enable studying these features with increasing detail. Synchrotron radiation X-ray fluorescence is unparalleled in its simultaneously high spatial resolution and detection range. Yet, its application in ore geology research and the mining industry is still in its infancy. This study investigated opportunities of extreme-resolution synchrotron X-ray fluorescence mapping of ore samples. Analysis was performed at the NanoMAX beamline at the MAX IV synchrotron facility in Lund, Sweden. The samples investigated are from the Liikavaara Östra Cu-(W-Au) deposit, northern Sweden. Analysis covered areas of several hundreds of μm2 in grains of molybdenite, pyrite, and native Bi. Key results included successful mapping of the lattice-bound distribution of Re, Se, and W in molybdenite at 200 nm spot/step size and detection of nanometre inclusions of Au in native Bi at 50 nm spot/step size. Challenges were encountered concerning data acquisition and processing. In order to achieve satisfactory resolution of both light and heavy elements and to limit mapping artefacts, repeated scans of the same area with varied experimental parameters and very thin (quasi-2d) samples are required. For complex geological samples, the software used for analysing spectral data (PyMCA) requires a considerable degree of human examination, which may be a source of error. Overall, synchrotron X-ray fluorescence mapping has a strong analytical potential for ore geology research, in analysing and imaging trace elements that would constitute potential by-products in mining operations. Detailed knowledge of how trace elements occur in the ores will inform the development of appropriate metal extraction programs thus ensuring that a larger part of the ore may then be utilized.

Structural, Morphological, Topographical Characterization of Titanium Dioxide Nanotubes Metal Substrates for Solar Cell Application

High demand on energy conversion in DSSC, requires development of well-organized TiO2 nanotube structures because of their large surface area-to-volume ratio, superior lifetime and provision of optimal pathways for electron percolation. In this work multi-layered Titanium dioxide nanotubes (MTNTs) have been fabricated by an electrochemical anodization technique. MTNTs were annealed at 350‚°C, 450‚°C, 550‚°C and 650‚°C. The structural and morphological properties of the MTNTs have been evaluated by XRD, Confocal Raman Microscopy (CRM) through Large Area Scan (LAS), Depth Profiling (DP) and SEM analysis. SEM-EDX has been employed for element elucidation of TNTs. SEM analysis has revealed the change in surface with increase in annealing temperature. Moreover SEM analysis has revealed the presence of porous and MTNTs for the samples annealed at 350‚°C and 650‚°C with modal pore size of 35.56 nm and 31.05 nm respectively. EDX analysis has revealed that the fabricated MTNTs consist of Ti and O atoms. CRM has confirmed the presence of Anatase phase TiO2 with Raman vibration modes at 142.37 cm-1, 199.04 cm-1, 394.67 cm-1, 516.16 cm-1 and 639.29 cm-1with the Rutile phase TiO2 with Raman vibration modes at 445.26 cm-1 and 612.07 cm-1. The XRD analysis has revealed that the MTNTs consist of multiphase Anatase and Rutile phase depending on the annealing temperature. AFM has confirmed the existence of porous nano-tubular structure for all samples.

Variability of redundant scan coverages along the Z-axis and dose implications for common computed tomography examinations

BackgroundScan length optimization is a method of optimization which ensures that, imaging is performed to cover just the area of interest without unnecessarily exposing structures that would not add value to answer a given clinical question. PurposeThis study assessed the variability and degree of redundant scan coverages along the z-axis of CT examinations of common indications and the associated radiation dose implications in CT facilities in Ghana for optimization measures to be recommended. MethodsOn reconstructed acquired CT images, the study measured extra distances covered above and below anatomical targets for common indications with calibrated calipers across 25 CT facilities. The National Cancer Institute Dosimetry System for CT (NCICT) (Monte Carlo-based-software) was used to simulate the scanning situations and organ dose implications for scans with and without the inclusion of the redundant scan areas. ResultsA total of 1,640 patients’ CT data sets were used in this study. The results demonstrated that CT imaging utilized varying scan lengths (16.45±21.0–45.99±4.3 cm), and 70.6% of the scans exceeded their pre-defined anatomic boundaries by a mean range of 2.86±1.07–5.81±1.66 cm, thereby resulting in extra patient radiation dose. Hence, scanning without the redundant coverages could generate a dose length product (DLP) reduction of 17.5%, 18.8%, 15.5% and 9.0% without degrading image quality for brain lesion, lung lesion, pulmonary embolism and abdominopelvic lesion CT imaging, respectively, whilst ensuring organ dose reduction of0.8%–79.1%. ConclusionThe study strongly recommends that radiographers should avoid the inclusion of redundant areas in CT examinations to reduce organ doses.

Complete Visualization of T Follicular Helper Cells in Germinal Centers by Light Sheet Fluorescence Microscopy.

Long-lasting immunity depends on generation of antibody forming cells in germinal centers (GCs). Conventional methods such as immunohistology and intravital live imaging have been used extensively to investigate the location of cellular assemblies within tissues as well as their dynamic motility and cellular interactions. Two photon laser scanning microscopy (TPLSM) intravital imaging allows scanning of large areas within tissues and reveals multiple immune cell niches. Nonetheless, this type of imaging is limited by the depth of penetration and cannot capture effectively all of the GC niches within lymphoid organs. Here we describe a method to visualize antigen-specific T and B cells in multiple microanatomical locations and niches at the level of a whole organ. This large-scale imaging approach can greatly increase our understanding of the spatial distribution of immune cells and help obtain detailed 3D maps of their locations and quantities.

Combined wide-field optical coherence tomography angiography density map for high myopic glaucoma detection

The present study aimed to evaluate the diagnostic ability of wide-field optical coherence tomography angiography (OCTA) density map for detection of glaucomatous damage in high myopic (HM) eyes and to further compare the diagnostic ability of OCTA with that of conventional imaging approaches including red-free photography and swept-source OCT (SS-OCT) wide-field maps. A total of 77 healthy HM eyes and 72 HM eyes with open angle glaucoma (OAG) participated in this retrospective observational study. Patients underwent a comprehensive ocular examination, including wide-field SS-OCT scan and peripapillary area and macular OCTA scans. An integrated OCTA density map thereafter was merged by vascular landmark-guided superimposition of peripapillary and macular superficial vascular density maps onto the red-free photography (resulting in the OCTA-PanoMap). Glaucoma specialists then determined the presence of glaucomatous damage in HM eyes by reading the OCTA-PanoMap and compared its sensitivity and specificity with those of conventional images. Sensitivity and specificity of OCTA-PanoMap for HM-OAG diagnosis was 94.4% and 96.1%, respectively. Compared with other imaging methods, the sensitivity of OCTA-PanoMap was significantly higher than that of red-free photography (P = 0.022) and comparable to that of wide-field SS-OCT maps. Specificity of OCTA-PanoMap was significantly higher than those of other conventional imaging methods (except for wide-field thickness map). The OCTA-PanoMap showed good diagnostic ability for discrimination of HM-OAG eyes from healthy HM eyes. As a complementary method of an alternative imaging modality, OCTA-PanoMap can be a useful tool for detection of HM-OAG.

Identification of Appendicitis Using Ultrasound with the Aid of Machine Learning.

Background: Diagnosing pediatric appendicitis by ultrasonography (US) is difficult because US requires significant training and skill. We evaluated whether artificial intelligence (AI) can augment US. Materials and Methods: Among 70 abdominal ultrasound videos containing 85-347 images each, 50 were used to train the AI neural network. Each video was categorized based on the detection percentage and percent accuracy: most (>50%), partial (10-50%), and none (<10%). Test 1 involved verification of appendix detection by AI using the remaining 20 videos. Test 2 involved the evaluation of the effect of AI utilization on pediatricians. Results: From 50 videos, 6914 images were used to train the AI network. In test 1, 3 pediatric surgeons judged 10 (50.0%), 4 (20.0%), and 6 (30.0%) videos as "most," "partial," and "none," respectively, regarding the detection percentage; 7 (35.0%), 7 (35.0%), and 6 (30.0%) videos were judged, respectively, concerning the percent accuracy. Five (83.3%) of six test videos with a scan area depth of 8 cm were judged as "none" for both detection and accuracy. In test 2, six videos were also judged as "none" for both categories, showing a negative effect on the participants (5 pediatric residents and 5 pediatric intensive-emergency fellows), but the other categories showed little negative effect. Conclusions: Appendicitis in a shallow US scan area can be easily identified with AI support. Even with the detection of a partial appendicitis shadow, AI is still helpful. However, if AI does not detect appendicitis at all, examiners may be negatively affected.

Divergent abiotic spectral pathways unravel pathogen stress signals across species

Plant pathogens pose increasing threats to global food security, causing yield losses that exceed 30% in food-deficit regions. Xylella fastidiosa (Xf) represents the major transboundary plant pest and one of the world’s most damaging pathogens in terms of socioeconomic impact. Spectral screening methods are critical to detect non-visual symptoms of early infection and prevent spread. However, the subtle pathogen-induced physiological alterations that are spectrally detectable are entangled with the dynamics of abiotic stresses. Here, using airborne spectroscopy and thermal scanning of areas covering more than one million trees of different species, infections and water stress levels, we reveal the existence of divergent pathogen- and host-specific spectral pathways that can disentangle biotic-induced symptoms. We demonstrate that uncoupling this biotic–abiotic spectral dynamics diminishes the uncertainty in the Xf detection to below 6% across different hosts. Assessing these deviating pathways against another harmful vascular pathogen that produces analogous symptoms, Verticillium dahliae, the divergent routes remained pathogen- and host-specific, revealing detection accuracies exceeding 92% across pathosystems. These urgently needed hyperspectral methods advance early detection of devastating pathogens to reduce the billions in crop losses worldwide.

The multilayer distributed intelligence system model foremergency area scanning

Emergency situations have a huge impact on various important areas of human life. Every year there are many situations, the elimination of which requires a lot of financial and human resources. Therefore, the ability to reduce the impact of the consequences and increase the speed of their elimination is extremely important. In this article, a multi-level model of a system was proposed that provides support for performing operational tasks in emergency situations in open areas. The most important elements, areas of their responsibility, and interconnection were identified and described in architectural style. The idea of the work is to design asystem that should use Swarm intelligence under the hood to provide continuous support in emergency situations. The system consists of 4 main parts: Cloud, Swarm, Swarm operator, and Swarm Node. The Cloud (Swarm Wamb) is the main decision-maker that provides ETL data pipelines and operates under strategicallytasks. In accordance with the idea, Swarm womb should be a cloud service-like system with the ability to scale over the world. The Swarm is a combined set of multiple Swarm Nodes and only one Swarm Operator. The main task of the Swarm is to provide support in local operational tasks where SN is responsible for the execution and SOis for control. Rescue and search operation after any natural disaster is a target to show the system’s purpose. In practice, the cloud system (Swarm Wamb) receives requests to perform an operation, calculates resources effort first, anddelegates a task to the Swarm. When the swarm reaches the location, it starts executing. Operator with nodes tries to find survivors and collect as much important information as they can. Video, images, recognized objects are continuously sending to the Cloud for additional analysis in real-time. Any information in an emergency situation can help save more humans lives and reduce risks. In this article, the multilayer distributed intelligence system architecture for emergency area scanning was designed and described. The set of terminology was proposed as well. This architecture covers different levels of tactical and operational tasks.

Impact of Muscle Mass on Survival in Patients with Sepsis: A Systematic Review and Meta-Analysis

Introduction: The aim of this study is to investigate the association between loss of muscle mass and prognosis of sepsis. Methods: Six databases, including PubMed, Embase, Cochrane Library, Web of Science, Scopus, and Ovid, were searched by the deadline of August 18, 2020. A meta-analysis was conducted on the collected data by means of a random-effects model. The quality of each included article was assessed according to the Newcastle-Ottawa Scale. Results: Out of 1,819 references, 6 articles and 1 conference abstract were included. Sepsis patients with a loss of muscle mass or sarcopenia had higher mortality (risk ratio [RR]: 1.94, 95% confidence intervals [CI]: 1.59–2.37; I-squared = 18.7%, p < 0.001). The RR of mortality within 30 days (RR: 2.31, 95% CI: 1.78–2.99, p < 0.001) was higher than that of mortality over 30 days. Loss of psoas muscle mass, as evaluated by CT, showed the highest RR of sepsis mortality. In addition, based on data on overall survival retrieved from 4 trials, the pooled hazard ratio (HR) for patients with a loss of muscle mass or sarcopenia was 3.04. Subgroup analysis showed that survival time was the main source of heterogeneity for the overall HR. Furthermore, the scanning areas of muscle mass in survival patients were 0.33 cm²/m² higher than those measured in deceased patients. Conclusion: A loss of muscle mass, as evaluated by CT scan, was associated with a poor outcome in sepsis.

Multimodal and Multiview Wound Monitoring with Mobile Devices

Along with geometric and color indicators, thermography is another valuable source of information for wound monitoring. The interaction of geometry with thermography can provide predictive indicators of wound evolution; however, existing processes are focused on the use of high-cost devices with a static configuration, which restricts the scanning of large surfaces. In this study, we propose the use of commercial devices, such as mobile devices and portable thermography, to integrate information from different wavelengths onto the surface of a 3D model. A handheld acquisition is proposed in which color images are used to create a 3D model by using Structure from Motion (SfM), and thermography is incorporated into the 3D surface through a pose estimation refinement based on optimizing the temperature correlation between multiple views. Thermal and color 3D models were successfully created for six patients with multiple views from a low-cost commercial device. The results show the successful application of the proposed methodology where thermal mapping on 3D models is not limited in the scanning area and can provide consistent information between multiple thermal camera views. Further work will focus on studying the quantitative metrics obtained by the multi-view 3D models created with the proposed methodology.

Selective powder feeding system in additive manufacturing using laser-induced forward transfer technique

In this study, we demonstrate a powder feeding system without a recoater for powder bed fusion-type additive manufacturing. The powder bed fusion system disposes a large quantity of powder, which is filled in the building container. To solve this problem, we developed a selective powder feeding system using laser-induced forward transfer technology. Our system comprised a donor film, laser component, and receiver substrate. The donor film was continuously moved from roll to roll, and the polymer powder was supplied on the lower side of the film with a rotating roller. The powder was transferred from the film surface to the receiver substrate, 3D object building area, by the irradiation of the laser beam with a wavelength of 532 nm. The laser beam was scanned over the scan area on the donor film. By continuously moving the donor film and receiver substrate, the powder layer was stacked on the receiver substrate. From the single-layer stacking experiment, we investigated that the gap between the donor film and receiver substrate strongly depended on the spreading of the powder. Moreover, by stacking 60 times, we acquired the rectangular-shaped powder block with a height of 10 mm. These results pave the way for developing an economical powder bed fusion system with reduced powder waste. • Additive manufacturing system with selective powder feeding was developed. • This system selectively feeds the powder to a 3D model or powder bed without contact by using LIFT technologies. • This selective powder feeder achieves a more economical AM strategy without exposing the powder to high temperatures. • Our results pave the way for developing an economical powder bed fusion system with reduced powder waste.