L-Hexoses are key components of many biologically relevant natural products and pharmaceuticals. As rare sugars, L-hexoses are not readily obtained from natural sources. Access to L-hexose building blocks from commercially available and inexpensive D-sugars is highly desirable from the viewpoints of organic synthesis and drug discovery. As demonstrated by the convenient preparation of L-glucosyl, L-galactosyl, and L-mannosyl fluorides from readily available β-D-C-glucosyl, β-D-C-mannosyl, and β-D-C-galactosyl derivatives, we describe a novel and efficient approach to the demanding L-glycosyl fluorides. The transformation features the installation of anomeric hydroxymethyl group under mild conditions and head-to-tail inversion of sugar rings through radical decarboxylative fluorination of uronic acids. The power of this protocol is highlighted by the first assembly of a pentasaccharide repeating unit of Pseudomonas ATCC 31554 extracellular polysaccharide (S-88). This synthesis relies on the efficient extension of sugar chain at the sterically hindered hydroxy group and the facile introduction of L-mannosyl unit using L-mannosyl fluoride as glycosylating agent. The methods developed in this work would provide new tools to the arsenal of synthesis of L-sugar building blocks and of assembly of glycans containing L-sugar moieties.
Background: Food-induced immediate response of the esophagus (FIRE) is a new phenomenon that has been described in eosinophilic esophagitis (EoE) patients. It is suspected when unpleasant symptoms occur suddenly on contact of the triggering food with the esophageal surface and recur with repeated exposures. It can often be mistaken for pollen-food allergy syndrome (PFAS) and solid food dysphagia. Data on FIRE is limited to one survey study and case reports, and there are no screening studies conducted on either adults or children with EoE. In this study, we aimed to screen children aged ≥7 years old with EoE for FIRE. Methods: Demographic data were collected from medical records. A questionnaire about FIRE was applied to all participants. Skin prick tests (SPTs) were done on suspected patients to identify the triggering foods. FIRE is defined as suitable clinical symptoms with suspected food allergen exposure. Results: Seventy-eight patients (74.4% male, median age: 13.5 years) were included. Unpleasant and recurrent symptoms distinct from dysphagia with specific foods were reported in %16.7 of the patients, all of whom had concomitant allergic rhinitis (AR). The symptoms described by almost all patients were oropharyngeal itching and tingling (PFAS: 15.3%) excluding only one patient reporting retrosternal narrowing and pressure after specific food consumption (FIRE: 1.2%). Conclusions: Although definitive conclusions regarding the true prevalence of FIRE cannot be made, it does not seem to be common as PFAS. However, it deserves questioning particularly in the presence of concurrent AR and/or PFAS in children with EoE.
Root traits and functioning: from individual plants to ecosystemsFine roots, the most distal portions of the root system, are responsible for the uptake of water and nutrients by plants, represent the main type of plant tissue contributing to soil organic matter accrual, and are key drivers of mineral weathering and soil microbial dynamics (Bardgett et al. 2014). Despite the overwhelming importance of fine root traits for plant and plant community functioning and biogeochemical cycles, basic information about their ecology is lacking, particularly compared to the wealth of information developed for leaves and stems. Testing hypotheses on how root traits underlie these ecosystem processes has been particularly hampered due to (1) a paucity of systematically collected data and (2) the complexity of the relationships between root traits and root, plant and ecosystem functioning. Nonetheless, the development of the field of root ecology in the last two decades has been outstanding, in particular in the compilation of belowground trait datasets (Iversen et al. 2017), methodological root ecological handbooks (Freschet et al. 2021b), novel conceptual frameworks to describe root trait diversity (Bergmann et al. 2020), its connection with belowground plant and community function (Bardgett et al. 2014, Freschet et al. 2021a), species’ distributions (Laughlin et al. 2021), and scaling up traits from the individual root to the ecosystem level (McCormack et al. 2017). The papers that feature in this Special Issue on Root traits and functioning: from individual plants to ecosystems cover different climate regions, taxonomic and spatial scales, and a diversity of traits (Table 1) and form perfect examples of this upward moment of the belowground component in plant ecology.
Laser- based PVI has been around for many years and this modality of ablation is to provide a continuous circular overlapping lesions around the PVs' ostia. In order to ensure the continuity of the lesion, a camera is embedded in the system as to guide the placement of sequential applications with the target to make an adequate overlapping of two contiguous lesions as to reduce the likelihood of gaps. The first version of the system required the operator to manually rotate the catheter as to create a continuous arc of lesion around the PV's ostium. This approach is time-consuming, with a substantial overall time for each PV. The evolvement of the technique has been recently offered, with a novel semi-automated VGLA as to improve ablation efficiency by using a motorized system which moves the laser arc continuously in order to reduce the application time and, hopefully, minimize the creation of gaps.
An exoskeleton robot is a sample of a wearable robot. One of the most critical challenges in developing wearable robots is the application of the interactive force between human and robot. Force sensors need to be placed on the robot. Consideration in using these sensors needs to be given to factors such as cost, noise, and weight. One way that can be used to help with the operation of the exoskeleton is to support the sensors with observers. This study will estimate the interactive force applied to a human arm model and the exoskeleton robot. The Sliding Mode Control (SMC) method will be employed to design a chattering-free robust fixed-time controller and observer, for estimating the states of the human arm and exoskeleton robot. Utilising this information from state observers, the interactive force is estimated. The state observer and the controller work together in real-time (online estimation). The Lyapunov theory is used to show the fixed-time stability analysis of the controller and the observer. Numerical simulation with three scenarios demonstrates the performance of the proposed design.
INTRODUCTIONThe frequency of pediatric head and neck neoplasms ranges from approximately 2-15% of all pediatric cancers1. Skull base and calvarial neoplasms, including temporal bone and orbital masses are a subset of head and neck neoplasms occupying a number of neoplastic processes and categorically encompass several imaging patterns: singular dominant mass lesions with or without metastatic disease (e.g., rhabdomyosarcoma (RMS), chordoma), singular or multifocal metastatic disease (e.g., neuroblastoma), and multifocal disease due to systemic malignancy (e.g., leukemia, lymphoma, histiocytosis, etc.).While pathologies certainly vary between pediatric and adult patients, there remains significant overlap. As such, imaging protocols for skull base and calvarial neoplasms are similar in their general construct. However, optimized pediatric-specific protocols remain a must, as a retrofitted adult head and neck protocol is often ill equipped to offer quality, efficient and safe imaging (e.g., limiting radiation exposure) of the size-variable infant and pediatric patient. Moreover, sedation or general anesthesia is often required in the pediatric population in order to minimize motion artifact. Thus, optimization of imaging acquisition time is a very important technical consideration because it may decrease the necessity and duration of sedation/anesthesia and their potential risks in this vulnerable population. Standardized protocols for anatomic sub sites of the head and neck offer significant benefit in individual patient follow up on a local scale, and, on a broader scale, allow for collaborative understanding of imaging pathologies and innovative or benchmarked standardized treatment response assessment across institutions.In an effort to standardize protocols, this article offers minimum, pediatric specific anatomy-based initial and follow up imaging guidelines for pediatric malignancies of the orbits, calvarium, skull base and temporal bone. This manuscript was funded in part by the National Clinical Trials Network Operations Center Grant U10CA180886. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.
Can We Trust the Force?Frank Pelosi, Jr., MD, FHRS, FACCAssociate Professor of MedicineDepartment of Internal MedicineCardiac Electrophysiology SectionUniversity of Michigan Medical SchoolAnn Arbor, MichiganCorresponding Author:Frank Pelosi, Jr, MD, FACC, FHRS1500 East Medical Center DriveAnn Arbor MI. [email protected] words: contact force, radiofrequency ablationWord count: 1165 excluding referencesInvited manuscript for JCE-22-0822.R2
Wolf spiders are typically the most common group of arthropod predators on both lake and marine shorelines, because of the high prey availability in these habitats. However, shores are also harsh environments due to flooding and, in proximity to marine waters, to toxic salinity levels. Here, we describe the spider community, prey availabilities and spider diets between shoreline sites with different salinities, albeit with comparatively small differences (5 vs. 7‰). Despite the small environmental differences, spider communities between low and higher saline sites showed an almost complete species turnover. At the same time, differences in prey availability or spider gut contents did not match changes in spider species composition but rather changed with habitat characteristics within region, where spiders collected at sites with thick wrack beds had a different diet than sites with little wrack. These data suggest that shifts in spider communities are due to habitat characteristics rather than prey availabilities, and the most likely candidate restricting species in high salinity would be saline sensitivity. At the same time, species absences from low-saline habitats remain unresolved.
Coronavirus disease 2019 (COVID-19) can cause various complications. Pneumothorax secondary to COVID-19 is relatively uncommon and bilateral pneumothorax is even more so. In patients with poor general health to undergo surgery for pneumothorax, internal treatments are essential to relieving refractory pneumothorax.
Intussusception is a surgical emergency. If not immediately treated, it can lead to bowel wall perforation. In 2.2-15% of cases, they have pathologic lead points such as Intestinal duplication. This case report presents a rare tubular ileal duplication as a necrotic Ileoileal intussusception in a 4-year-old girl.
Machine learning methods can be used as robust techniques to provide invaluable information for analyzing biological samples in pharmaceutical industries, such as predicting the concentration of viral particles of interest in biological samples. Here, we utilized both convolutional neural networks and random forests to predict the concentration of the samples containing measles, mumps, rubella, and varicella-zoster viruses (ProQuad®) based on Raman and absorption spectroscopy. We prepared Raman and absorption spectra datasets with known concentration values, then used the Raman and absorption signals individually and together to train RFs and CNNs. We demonstrated that both RFs and CNNs can make predictions with R2 values as high as 95%. We proposed two different networks to jointly use the Raman and absorption spectra, where our results demonstrated that concatenating the Raman and absorption data increases the prediction accuracy compared to using either Raman or absorption spectrum alone. Additionally, we further verified the advantage of using joint Raman-absorption with principal component analysis (PCA). Furthermore, our method can be extended to characterize properties other than concentration, such as the type of viral particles.
Laryngeal venous malformations rarely but do cause airway obstruction resulting in life-threatening events. The perioperative airway management for the patients with them have not been well established. We suggest a strategy for laryngeal venous malformations management in the patients who undergo surgery in addition to planning for airway management.
We report two cases of previously healthy young men with COVID-19 infection who developed acute ischemic stroke due to large vessel occlusion followed by secondary events concerning for a further thromboembolic event. We hypothesize that the hypercoagulable state related to COVID-19 exacerbated the underlying hereditary thrombophilia due to MTHFR-gene mutation.