Water-Enhanced Direct Air Capture of Carbon Dioxide in Metal-Organic Frameworks.

We have developed two series of amine-functionalized zirconium (Zr) metal-organic framework-808 (MOF-808), which were produced by postsynthetic modifications to have either amino acids coordinated to Zr ions (MOF-808-AAs) or polyamines covalently bound to the chloro-functionalized structure (MOF-808-PAs). These MOF variants were comprehensively characterized by liquid-state 1H nuclear magnetic resonance (NMR) measurements and potentiometric acid-base titration to determine the amounts of amines, energy-dispersive X-ray spectroscopy to assess the extent of covalent substitution by polyamines, powder X-ray diffraction analysis to verify the maintenance of the MOF crystallinity and structure after postsynthetic modifications, nitrogen sorption isotherm measurements to confirm retention of the porosity, and water sorption isotherm measurements to find the water uptake in the pores of each member of the series. Evaluation and testing of these compounds in direct air capture (DAC) of CO2 showed improved CO2 capture performance for the functionalized forms, especially under humid conditions: In dry conditions, the l-lysine- and tris(3-aminopropyl)amine-functionalized variants, termed as MOF-808-Lys and MOF-808-TAPA, exhibited the highest CO2 uptakes at 400 ppm, measuring 0.612 and 0.498 mmol g-1, and further capacity enhancement was achieved by introducing 50% relative humidity, resulting in remarkable uptakes of 1.205 and 0.872 mmol g-1 corresponding to 97 and 75% increase compared to the dry uptakes, respectively. The mechanism underlying the enhanced uptake efficiency was revealed by 13C solid-state NMR and temperature-programmed desorption measurements, indicating the formation of bicarbonate species, and therefore a stoichiometry of 1:1 CO2 to each amine site.

Improving Voice Outcomes After Thyroid Surgery - Review of Safety Parameters for Using Energy-Based Devices Near the Recurrent Laryngeal Nerve.

Technological advances in thyroid surgery have rapidly increased in recent decades. Specifically, recently developed energy-based devices (EBDs) enable simultaneous dissection and sealing tissue. EBDs have many advantages in thyroid surgery, such as reduced blood loss, lower rate of post-operative hypocalcemia, and shorter operation time. However, the rate of recurrent laryngeal nerve (RLN) injury during EBD use has shown statistically inconsistent. EBDs generate high temperature that can cause iatrogenic thermal injury to the RLN by direct or indirect thermal spread. This article reviews relevant medical literatures of conventional electrocauteries and different mechanisms of current EBDs, and compares two safety parameters: safe distance and cooling time. In general, conventional electrocautery generates higher temperature and wider thermal spread range, but when applying EBDs near the RLN adequate activation distance and cooling time are still required to avoid inadvertent thermal injury. To improve voice outcomes in the quality-of-life era, surgeons should observe safety parameters and follow the standard procedures when using EBDs near the RLN in thyroid surgery.

New Developments in Anterior Laryngeal Recording Technique During Neuromonitored Thyroid and Parathyroid Surgery.

A recurrent laryngeal nerve (RLN) injury resulting in vocal fold paralysis and dysphonia remains a major source of morbidity after thyroid and parathyroid surgeries. Intraoperative neural monitoring (IONM) is increasingly accepted as an adjunct to the standard practice of visual RLN identification. Endotracheal tube (ET) surface recording electrode systems are now widely used for IONM; however, the major limitation of the clinical use of ET-based surface electrodes is the need to maintain constant contact between the electrodes and vocal folds during surgery to obtain a high-quality recording. An ET that is malpositioned during intubation or displaced during surgical manipulation can cause a false decrease or loss of electromyography (EMG) signal. Since it may be difficult to distinguish from an EMG change caused by a true RLN injury, a false loss or decrease in EMG signal may contribute to inappropriate surgical decision making. Therefore, researchers have investigated alternative electrode systems that circumvent common causes of poor accuracy in ET-based neuromonitoring. Recent experimental and clinical studies have confirmed the hypothesis that needle or adhesive surface recording electrodes attached to the thyroid cartilage (transcartilage and percutaneous recording) or attached to the overlying neck skin (transcutaneous recording) can provide functionality similar to that of ET-based electrodes, and these recording methods enable access to the EMG response of the vocalis muscle that originates from the inner surface of the thyroid cartilage. Studies also indicate that, during surgical manipulation of the trachea, transcartilage, percutaneous, and transcutaneous anterior laryngeal (AL) recording electrodes could be more stable than ET-based surface electrodes and could be equally accurate in depicting RLN stress during IONM. These findings show that these AL electrodes have potential applications in future designs of recording electrodes and support the use of IONM as a high-quality quantitative tool in thyroid and parathyroid surgery. This article reviews the major recent developments of newly emerging transcartilage, percutaneous, and transcutaneous AL recording techniques used in IONM and evaluates their contribution to improved voice outcomes in modern thyroid surgery.

Laryngeal Neural Monitoring during Pediatric Thyroid Cancer Surgery-Is Transcartilage Recording a Preferable Method?

The use of transcartilage (TC) intraoperative neuromonitoring (IONM) in a pediatric population has not been reported. This study evaluated the feasibility and the benefit of using TC-IONM for thyroid cancer surgery in a pediatric population. This retrospective single-center study enrolled 33 pediatric patients who had received an IONM-assisted thyroidectomy. Demographic characteristics, standardized IONM laryngeal examinations and stimulation information (L1-V1-R1-R2-V2-L2) were compared between endotracheal tube (ET) and TC methods. In the 15 cancer patients (30 nerves), TC-IONM provided significant higher electromyography (EMG) amplitude (p < 0.001), signal stability (lower V1/V2 signal correlation, r = 0.955 vs. r = 0.484, p = 0.004), signal quality (higher ratio of V1 or V2 amplitude <500 µV, 0.0% vs. 43.8%, p = 0.005) and lower R1-R2p change (7.1% vs. 37.5%, p = 0.049) compared to ET-IONM. In the 18 benign patients (28 nerves), TC-IONM provided significantly higher EMG amplitude (p < 0.001), signal stability (r = 0.945 vs. r = 0.746, p = 0.0324) and non-significant higher signal quality and R1-R2p change. This report is the first to discuss the use of TC-IONM in pediatric thyroid surgery. In contrast with ET-IONM, TC-IONM had superior amplitude, stability and quality of EMG signals, which greatly facilitates the meticulous recurrent laryngeal nerve dissection in pediatric thyroidectomies. The TC-IONM method can be considered a feasible, effective and preferable method of monitored thyroidectomy in pediatric thyroid cancer.

Training Courses in Laryngeal Nerve Monitoring in Thyroid and Parathyroid Surgery- The INMSG Consensus Statement.

Intraoperative neural monitoring (IONM) is now an integral aspect of thyroid surgery in many centers. Interest in IONM and the number of institutions that perform monitored thyroidectomies have increased throughout the world in recent years. For surgeons considering the introduction of IONM in their practice, specific training in IONM devices and procedures can substantially shorten the learning curve. The International Neural Monitoring Study Group (INMSG) has been at the forefront of IONM technology and procedural adoption since the introduction of neural monitoring in thyroid and parathyroid surgery. The purpose of this document is to define the INMSG consensus on essential elements of IONM training courses. Specifically, this document describes the minimum training required for teaching practical application of IONM and consensus views on key issues that must be addressed for the safe and reliable introduction of IONM in surgical practice. The intent of this publication is to provide societies, course directors, teaching institutions, and national organizations with a practical reference for developing IONM training programs. With these guidelines, IONM will be implemented optimally, to the ultimate benefit of the thyroid and parathyroid surgical patients.

Comparison of Surgical Complications Rates Between LigaSure Small Jaw and Clamp-and-Tie Hemostatic Technique in 1,000 Neuro-Monitored Thyroidectomies.

Over the past decade, the use of neuromonitoring in thyroid surgery has become well established and is increasing accepted across the world. In addition, new developments in energy devices have significantly improved efficacy in achieving hemostasis in thyroid surgery. Few studies focused on the complication rates in energy device-assisted sutureless neuro-monitored thyroidectomy. This study investigates a novel LigaSure Small Jaw (LSJ) technique for sutureless thyroidectomy and compares the surgical complication rates between LSJ and conventional clamp-and-tie technique in one thousand consecutive neuro-monitored thyroidectomy patients. Five hundred patients received sutureless thyroidectomy performed with LSJ (Group L), and 500 patients received surgery performed with conventional clamp-and-tie technique (Group C). Complication rates of postoperative hematoma, hypocalcemia and recurrent laryngeal nerve (RLN) palsy were compared between groups. The overall complication rates of hematoma, hypocalcemia (temporary/ permanent), and RLN (temporary/ permanent) palsy were 0.9%, 24.9% (24.6%/0.3%), and 1.7% (1.5%/0.2%), respectively. Group L and Group C significantly differed in postoperative hematoma rate (0.0% vs. 1.8%, respectively; p = 0.0026) and in postoperative hypocalcemia rate (20.1% vs. 30.0%, respectively; p = 0.0032). The incidence of RLN palsy did not significantly differ between Group L and Group C (1.38% vs. 2.08%; p = 0.2652). The overall surgical complication rates are low in neuro-monitored thyroidectomy. The LSJ is feasible for performing completely sutureless thyroidectomy and obtains superior outcomes of postoperative hematoma and hypocalcemia in comparison with clamp-and-tie hemostatic technique. The novel LSJ technique using double or overlapped sealing is useful for sutureless thyroidectomy. However, surgeons must carefully observe the tissue contraction that may reduce the LSJ-RLN distance and increase the risk of thermal injury during the LSJ activation.

ß spectrin-dependent and domain specific mechanisms for Na+ channel clustering.

Previously, we showed that a hierarchy of spectrin cytoskeletal proteins maintains nodal Na+ channels (Liu et al., 2020). Here, using mice lacking ß1, ß4, or ß1/ß4 spectrins, we show this hierarchy does not function at axon initial segments (AIS). Although ß1 spectrin, together with AnkyrinR (AnkR), compensates for loss of nodal ß4 spectrin, it cannot compensate at AIS. We show AnkR lacks the domain necessary for AIS localization. Whereas loss of ß4 spectrin causes motor impairment and disrupts AIS, loss of ß1 spectrin has no discernable effect on central nervous system structure or function. However, mice lacking both neuronal ß1 and ß4 spectrin show exacerbated nervous system dysfunction compared to mice lacking ß1 or ß4 spectrin alone, including profound disruption of AIS Na+ channel clustering, progressive loss of nodal Na+ channels, and seizures. These results further define the important role of AIS and nodal spectrins for nervous system function.

Nodal ß spectrins are required to maintain Na+ channel clustering and axon integrity.

Clustered ion channels at nodes of Ranvier are critical for fast action potential propagation in myelinated axons. Axon-glia interactions converge on ankyrin and spectrin cytoskeletal proteins to cluster nodal Na+ channels during development. However, how nodal ion channel clusters are maintained is poorly understood. Here, we generated mice lacking nodal spectrins in peripheral sensory neurons to uncouple their nodal functions from their axon initial segment functions. We demonstrate a hierarchy of nodal spectrins, where ß4 spectrin is the primary spectrin and ß1 spectrin can substitute; each is sufficient for proper node organization. Remarkably, mice lacking nodal ß spectrins have normal nodal Na+ channel clustering during development, but progressively lose Na+ channels with increasing age. Loss of nodal spectrins is accompanied by an axon injury response and axon deformation. Thus, nodal spectrins are required to maintain nodal Na+ channel clusters and the structural integrity of axons.

NuMA1 promotes axon initial segment assembly through inhibition of endocytosis.

Axon initial segments (AISs) initiate action potentials and regulate the trafficking of vesicles between somatodendritic and axonal compartments. However, the mechanisms controlling AIS assembly remain poorly defined. We performed differential proteomics and found nuclear mitotic apparatus protein 1 (NuMA1) is downregulated in AIS-deficient neonatal mouse brains and neurons. NuMA1 is transiently located at the AIS during development where it interacts with the scaffolding protein 4.1B and the dynein regulator lissencephaly 1 (Lis1). Silencing NuMA1 or protein 4.1B by shRNA disrupts AIS assembly, but not maintenance. Silencing Lis1 or overexpressing NuMA1 during AIS assembly increased the density of AIS proteins, including ankyrinG and neurofascin-186 (NF186). NuMA1 inhibits the endocytosis of AIS NF186 by impeding Lis1's interaction with doublecortin, a potent facilitator of NF186 endocytosis. Our results indicate the transient expression and AIS localization of NuMA1 stabilizes the developing AIS by inhibiting endocytosis and removal of AIS proteins.

Axonal Spectrins: Nanoscale Organization, Functional Domains and Spectrinopathies.

Spectrin cytoskeletons are found in all metazoan cells, and their physical interactions between actin and ankyrins establish a meshwork that provides cellular structural integrity. With advanced super-resolution microscopy, the intricate spatial organization and associated functional properties of these cytoskeletons can now be analyzed with unprecedented clarity. Long neuronal processes like peripheral sensory and motor axons may be subject to intense mechanical forces including bending, stretching, and torsion. The spectrin-based cytoskeleton is essential to protect axons against these mechanical stresses. Additionally, spectrins are critical for the assembly and maintenance of axonal excitable domains including the axon initial segment and the nodes of Ranvier (NoR). These sites facilitate rapid and efficient action potential initiation and propagation in the nervous system. Recent studies revealed that pathogenic spectrin variants and diseases that protealyze and breakdown spectrins are associated with congenital neurological disorders and nervous system injury. Here, we review recent studies of spectrins in the nervous system and focus on their functions in axonal health and disease.

Erratum: USP11 regulates PML stability to control Notch-induced malignancy in brain tumours.

This corrects the article DOI: 10.1038/ncomms4214.

K33-Linked Polyubiquitination of Coronin 7 by Cul3-KLHL20 Ubiquitin E3 Ligase Regulates Protein Trafficking.

Ubiquitin chains are formed as structurally distinct polymers via different linkages, and several chain types including K33-linkage remain uncharacterized. Here, we describe a role for K33-polyubiquitination in protein trafficking. We show that the Cullin 3 (Cul3) substrate adaptor KLHL20 is localized to the trans-Golgi network (TGN) and is important for post-Golgi trafficking by promoting the biogenesis of TGN-derived transport carriers. The Cul3-KLHL20 ubiquitin E3 ligase catalyzes a nondegradable, K33-linked polyubiquitination on coronin 7 (Crn7), which facilitates Crn7 targeting to TGN through a ubiquitin-dependent interaction with Eps15. Blockage of K33-chain formation, Crn7 ubiquitination, or disruption of Crn7-Eps15 interaction impairs TGN-pool F-actin assembly, a process essential for generating transport carriers. Enforced targeting of Crn7 to TGN bypasses the requirement of K33-ubiquitination for TGN-pool F-actin assembly and post-Golgi trafficking. Our study reveals a role of KLHL20-mediated K33-ubiquitination of Crn7 in post-Golgi transport and identifies a cellular recognition mechanism for this ubiquitin chain type.

USP11 regulates PML stability to control Notch-induced malignancy in brain tumours.

The promyelocytic leukaemia (PML) protein controls multiple tumour suppressive functions and is downregulated in diverse types of human cancers through incompletely characterized post-translational mechanisms. Here we identify USP11 as a PML regulator by RNAi screening. USP11 deubiquitinates and stabilizes PML, thereby counteracting the functions of PML ubiquitin ligases RNF4 and the KLHL20-Cul3 (Cullin 3)-Roc1 complex. We find that USP11 is transcriptionally repressed through a Notch/Hey1-dependent mechanism, leading to PML destabilization. In human glioma, Hey1 upregulation correlates with USP11 and PML downregulation and with high-grade malignancy. The Notch/Hey1-induced downregulation of USP11 and PML not only confers multiple malignant characteristics of aggressive glioma, including proliferation, invasiveness and tumour growth in an orthotopic mouse model, but also potentiates self-renewal, tumour-forming capacity and therapeutic resistance of patient-derived glioma-initiating cells. Our study uncovers a PML degradation mechanism through Notch/Hey1-induced repression of the PML deubiquitinase USP11 and suggests an important role for this pathway in brain tumour pathogenesis.