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Abstract: We report the detection of bright aurora spanning Mars' nightside during the space weather event occurring in September 2017. The phenomenon was similar to diffuse aurora detected previously at Mars, but 25 times brighter and detectable over the entire visible nightside. The observations were made with the Imaging UltraViolet Spectrograph, a remote sensing instrument on the Mars Atmosphere and Volatile EvolutioN spacecraft orbiting Mars. Images show that the emission was brightest around the limb of the planet, with a fairly uniform faint glow against the disk itself. Spectra identified four molecular emissions associated with aurora, and limb scans show the emission originated from an altitude of ~60 km in the atmosphere. Both are consistent with very high energy particle precipitation. The auroral brightening peaked around 13 September, when the flux of solar energetic electrons and protons both peaked. During the declining phase of the event, faint but statistically significant auroral emissions briefly appeared against the disk of the planet in the form of narrow wisps and small patches. These features are approximately aligned with predicted open field lines in the region of strong crustal magnetic fields in Mars' southern hemisphere. [ABSTRACT FROM AUTHOR]

The title salt, C3H6N3S2 (+)·Cl(-)·H2O, crystallized with two organic cations, two chloride anions and two water mol-ecules in the asymmetric unit. The methyl C atoms deviate from their respective bound ring planes by 0.081 and 0.002 Å. In the crystal, the components are connected via N-H⋯O, N-H⋯Cl and O-H⋯Cl hydrogen bonds, forming sheets lying parallel to (100). The sheets are linked into bilayers by O-H⋯Cl hydrogen bonds involving the chloride ions and water mol-ecules. Within the bilayers there are π-π inter-actions [inter-centroid distances = 3.4654 (4) and 3.4789 (4) Å] involving inversion-related cations.

In the title hydrated mol-ecular salt, 2C5H8N3O(+)·SO4 (2-)·H2O, the components are linked by N-H⋯Os and Ow-H⋯Os (s = sulphate, w = water) hydrogen bonds, generating a layer by a+b+c and 2a-b translations. The cations are arranged nearly in parallel and show displaced π-π stacking centroid-centroid distance = 4.661 (2) Å between adjacent layers.

The asymmetric unit of the title compound, [K3(C4H2N3O4)3(H2O)2] n , contains two potassium cations (one in general position, one located on a twofold rotation axis), one and a half oxonate anions (the other half generated by twofold symmetry) and one water mol-ecule. As a result of the twofold symmetry, one H atom of the symmetric anion is statistically occupied. Both potassium cations are surrounded by eight oxygen atoms in the form of distorted polyhedra. Adjacent cations are inter-connected by oxygen bridges, generating layers parallel to (100). The aromatic ring system of the oxonate anions link these layers into a network structure. The crystal packing is stabilized by N-H⋯O, O-H⋯O and O-H⋯N hydrogen bonds, three of which are bifurcated. In addition, inter-molecular π-π stacking inter-actions exist between neighboring aromatic rings with a centroid-centroid distance of 3.241 (2) Å.

In the crystal structure of the title organic-inorganic hybrid material, (C10H22N2)[ZnCl4], the tetrachloridozincate anions and 1-cyclohexylpiperazine-1,4-diium dications are interconnected via N-H...Cl and C-H...Cl hydrogen bonds to form layers parallel to the (001) plane. The cyclohexyl groups from adjacent chains interdigitate, thus building the three-dimensional structure. The piperazinium and cyclohexyl rings exhibit regular spatial chair conformations. The title salt was also characterized by FT-IR and Raman spectroscopic analyses.

In the title compound, [Mg(C3H3N2)4(H2O)2]Cl2, the Mg(II) cation lies on a crystallographic inversion centre and is coordinated by two water mol-ecules and four N-atom donors from monodentate imidazole ligands, giving a slightly distorted octa-hedral stereochemistry. In the crystal, water O-H⋯Cl and imidazole N-H⋯Cl hydrogen bonds give rise to a three-dimensional structure.

In the title compound, C5H9N4 (+)·NO3 (-), the organic cations and the nitrate anions have both crystallographically imposed mirror symmetry and are linked via N-H⋯O hydrogen bonds, forming infinite chains running along the c-axis direction. The values of the N-O bond lengths [1.2256 (19)-1.2642 (18) Å] and O-N-O angles [118.39 (16)-121.64 (15)°] indicate that the nitrate anion exhibits a slightly distorted C3h geometry. The N atom of the NH2 group has sp (2) character.

In the title molecular salt, C6H10N2 (2+)·2ClO4 (-), the Cl-O bond lengths [anion 1: 1.369 (3)-1.415 (3); anion 2: 1.420 (2)-1.441 (2) Å] and the O-Cl-O angles [anion 1: 105.4 (2)-111.8 (4); anion 2: 107.8 (1)-110.3 (1)°] indicate a slight distortion of the perchlorate anions from regular tetra-hedral symmetry. In the crystal, the components are linked into columns along the a-axis direction via N-H⋯O and C-H⋯O hydrogen bonds, with stacks of the organic mol-ecules being surrounded by stacks of perchlorate anions.

In the title mol-ecular salt, C6H10N2 (2+)·NO3 (-)·Cl(-), the complete cation is generated by a crystallographic mirror plane. The complete nitrate ion is also generated by reflection, with the N atom and one O atom lying on the mirror plane; the chloride ion also lies on the reflection plane. In the crystal, the components are linked by N-H⋯Cl and N-H⋯(N,O) hydrogen bonds, forming (001) layers with the benzene rings projecting into the inter-layer regions. The layers are linked by weak C-H⋯O hydrogen bonds, generating a three-dimensional network.

The asymmetric unit of the title salt, C(6)H(9)ClN(2) (2+)·2H(2)PO(4) (-), contains two dihydrogenphosphate anions and one 2-chloro-benzene-1,4-diaminium dication. The H(2)PO(4) (-) anions are inter-connected through strong O-H⋯O hydrogen bonds to form two-dimensional infinite layers parallel to (001). The organic entities are anchored to the inorganic layers through N-H⋯O hydrogen bonds, and through weak C-Cl⋯O halogen bonds [3.159 (2) Å, 140.48 (7)°]. No π-π stacking inter-actions between neighboring aromatic rings or C-H⋯π inter-actions towards them are observed. Minor disorder is observed for the Cl atom and one hy-droxy group [minor-component occupancy = 3.29 (9)%].

In the crystal structure of the title molecular salt, 3C2H5N4(+)·HPO4(2-)·H2PO4(-)·3H2O, the phosphate-based framework is built upon layers parallel to (010) made up from the H2PO4(-) and HPO4(2-) anions and water mol-ecules, which are inter-connected through O-H⋯O hydrogen bonds. The organic cations are located between the phosphate-water layers and are connected to them via N-H⋯O hydrogen bonds. The bond-length features are consistent with an imino resonance form for the exocyclic amino group, as is commonly found for a C-N single bond involving sp(2)-hybridized C and N atoms.

The structure of the title compound, C(6)H(18)N(3)·HPO(4)·H(2)PO(4), is characterized by two kinds of inorganic chains running along the a-axis direction. The first one is composed of HPO(4) (2-) anions, while the second one is built up by H(2)PO(4) (-) anions. Both types of chains are held together by O-H⋯O hydrogen bonds. The organic cations are attached to these chains through N-H⋯O and C-H⋯O hydrogen bonds. The piperazin-1,4-diium ring adopts a chair conformation.

The asymmetric unit of the title compound, 2C(10)H(18)N(+)·HPO(4) (2-)·1.5C(4)H(4)O(4), contains two adamantan-1-aminium cations, one hydrogen phosphate anion, and one and a half mol-ecules of fumaric acid, one of which exhibits crystallographic inversion symmetry. Each HPO(4) (2-) anion is hydrogen bonded, via all of its O atoms, to four NH(3) (+) groups of the adamantan-1-aminium cations, forming chains along [100]. These chains are, in turn, inter-connected via a set of O-H⋯O hydrogen bonds involving the fumaric acid solvent mol-ecules, forming layers parallel to (001). Weak C-H⋯O inter-actions lead to a consolidation of the three-dimensional set-up.

In the title hydrated salt, C(8)H(11)N(2)O(+)·NO(3) (-)·H(2)O, the N-C bond distances [1.349 (2) and 1.413 (2) Å] along with the sum of the angles (359.88°) around the acetamide N atom clearly indicate that the heteroatom has an sp(2) character. The ammonium group is involved in a total of three N-H⋯O hydrogen bonds, two of these are with a water mol-ecule, which forms two O-H⋯O hydrogen bonds. All these hydrogen bonds link the ionic units and the water mol-ecule into infinite planar layers parallel to (100). The remaining two N-H⋯O inter-actions in which the ammoniun group is involved link these layers into an infinite three-dimensional network.

In the title compound, {(C(5)H(14)N(2))[Cd(2)Cl(6)]·H(2)O}(n), the asymmetric unit contains one piperazinediium cation, one [Cd(2)Cl(6)](2-) anion and a water mol-ecule. The coordination geometries of the two Cd(2+) cations are distorted octa-hedral. Adjacent Cd(II) atoms are inter-connected alternately by paired chloride bridges, generating polymeric chains parallel to [010]. Neighbouring chains are connected by O-H⋯Cl hydrogen bonds involving the water mol-ecules, forming layers at z = n/2. The crystal packing is further stabilized by inter-molecular N-H⋯Cl and N-H⋯O hydrogen bonds, one of which is bifurcated.

In the title compound, C(5)H(8)N(3)O(+)·ClO(4) (-)·C(5)H(7)N(3)O·H(2)O, each perchlorate anion is paired with a protonated cationic 2-amino-6-methyl-pyrimidin-4(1H)-one and another non-protonated entity of the same organic pyrimidinone. The crystal structure is stabilized by N-H⋯O(org), N-H⋯O(water), N-H⋯O(ClO4), O-H⋯O(ClO4), N-H⋯N and C-H⋯O(ClO4) hydrogen bonds between the anions, organic entities and water mol-ecules. Inter-molecular π-π stacking inter-actions between neighbouring organic rings are observed with a face-to-face distance of 3.776 (2) Å, and O-H⋯O hydrogen bonds link the perchlorate anions and the water mol-ecules into chains along the b-axis direction. The perchlorate anion and the inter-stitial water mol-ecule are disordered over two mutually incompatible positions with a common occupancy ratio of 0.678 (16):0.322 (16).

The asymmetric unit of the title compound, (C(7)H(7)N(2)S)(2)[ZnCl(4)], contains a network of 2-amino-benzothia-zolium cations and tetra-hedral [ZnCl(4)](2-) anions. The crystal packing is influenced by cation-to-anion N-H⋯Cl and C-H⋯Cl hydrogen bonds. The [ZnCl(4)](2-) anions have a distorded tetra-hedral geometry. Inter-molecular π-π stacking inter-actions are present between neighboring benzene rings, thia-zole and benzene rings and neighboring thia-zole rings [centroid-centroid distances = 3.711 (2), 3.554 (1), 3.536 (2) and 3.572 (1) Å].

A new noncentrosymmetric organic-inorganic hybrid material, (C(8)H(12)N)(2)[ZnCl(4)], has been synthesized as single crystals at room temperature and characterized by X-ray diffraction and solid-state NMR spectroscopy. Its novel structure consists of two 4-methylbenzylammonium cations and one [ZnCl(4)](2-) anion connected by N-H···Cl and C-H···Cl hydrogen bonds, two of which are three-centre interactions. The Zn(II) metal centre has a slightly distorted tetrahedral coordination geometry. Results from (13)C CP-MAS NMR spectroscopy are in good agreement with the X-ray structure. Density functional theory calculations allow the assignment of the carbon peaks to the independent crystallographic sites., (© 2011 International Union of Crystallography)

In the title compound, (C(12)H(20)N(2))[ZnCl(4)]·H(2)O, the two piperazine N atoms are protonated and the [ZnCl(4)](2-) anions adopt a slightly distorted tetra-hedral configuration. In the crystal, O-H⋯Cl hydrogen bonds link the tetra-chloridozincate anions and the water mol-ecules into corrugated inorganic chains parallel to [010]. The crystal structure is stabilized by N-H⋯Cl, N-H⋯O and O-H⋯Cl hydrogen bonds, with the N-H hydrogen bond originating from one of the two N atoms being trifurcated.

The asymmetric unit of the title compound, (C(5)H(6)ClN(2))(2)[ZnCl(4)], contains two 2-amino-5-chloro-pyridinium cations and one [ZnCl(4)](2-) dianion which are held together by N-H⋯Cl and C-H⋯Cl hydrogen bonds. The [ZnCl(4)](2-) anions have a distorted tetra-hedral geometry. Weak inter-molecular π-π stacking inter-actions exist between neighbouring aromatic rings of the cations with a centroid-centroid distance of 3.712 (7) Å.

In the crystal structure of the title salt, C(8)H(12)NO(+)·Cl(-), the methoxy group of the cation is co-planar with the phenylene moiety with an r.m.s. deviation from the mean plane of only 0.005 Å. The ammonium N atom deviates from this plane by 1.403 (1) Å. In the crystal, the (4-meth-oxy-phen-yl)methan-aminium cations and chloride anions are linked by N-H⋯Cl and C-H⋯O hydrogen bonds, resulting in an open framework architecture with hydrogen-bonded ammonium groups and chloride anions located in layers parallel to (011), separated by more hydrophobic layers with interdigitating anisole groups.

In the title compound, (C(4)H(12)N(2))[CdCl(4)]·H(2)O, the [CdCl(4)](2-) anions adopt a slightly distorted tetra-hedral configuration. In the crystal, O-H⋯Cl hydrogen bonds link the anions and water mol-ecules into corrugated inorganic chains along the b axis which are inter-connected via piperazinediiumN-H⋯O and N-H⋯Cl inter-actions into a three-dimensional framework structure.

In the title compound, (C(7)H(11)N(2))(2)[ZnCl(4)], [ZnCl(4)](2-) anions and 4-(dimethyl-amino)-pyridinium cations are held together by various inter-molecular inter-actions including Coulombic attraction, hydrogen bonding and π-π stacking inter-actions. Three Cl atoms of the [ZnCl(4)](2-) tetra-hedron act as acceptors in N-H⋯Cl hydrogen bonds. The hydrogen bonds, both of which are bifurcated, lead to the formation of a three-dimensional network. Within the network, inter-molecular π-π stacking inter-actions with a centroid-centroid distance of 3.5911 (7) Å arrange the 4-(dimethyl-amino)-pyridinium cations into anti-parallel dimers.

In the crystal structure of the title compound, C(12)H(12)N(+)·H(2)PO(4) (-), the dihydrogen phosphate anions and the 2-phenyl-anilinium cations are associated via O-H⋯O and N-H⋯O hydrogen bonds so as to build inorganic layers around the x = 1/2 plane. The organic entities are anchored between these layers through C-H⋯O hydrogen bonds, forming a three-dimensional infinite network. The dihedral angle between the aromatic rings is 44.7 (4)°.

In the title compound, [CdCl(2)(C(5)H(7)N(3)O)(2)], the Cd(II) atom is six-coordinated by two heterocyclic N atoms [Cd-N = 2.261 (2) and 2.286 (2) Å] and two O atoms [Cd-O = 2.624 (2) and 2.692 (2) Å] from two bidentate chelate 2-amino-6-methyl-pyrimidin-4(1H)-one ligands and two chloride ions [Cd-Cl = 2.4674 (6) and 2.4893 (7) Å]. The crystal packing is characterized by an open-framework architecture with the crystal packing stabilized by inter-molecular N-H⋯Cl and N-H⋯O hydrogen bonds.

In the title compound, [Cu(ClO(4))(2)(C(12)H(8)N(2))(H(2)O)(2)], the Cu(II) atom is coordinated in a square-planar fashion by the two N atoms of a chelating 1,10-phenanthroline ligand and by two water mol-ecules trans to the N atoms. The coordination sphere of the metal atom is augmented by O atoms of two weakly bonded perchlorate anions, thus yielding a strongly distorted CuN(2)O(4) octa-hedral environment. The crystal packing is stabilized by O-H⋯O hydrogen bonds between the water mol-ecules and the perchlorate anions. In addition, the organic mol-ecules are associated by π-π stacking inter-actions between symmetry-equivalent anti-parallel non-nitro-gen aromatic rings, with inter-planar distances of 3.543 (2) Å.

In the title compound, [ZnCl(HPO(4))](C(5)H(8)NO), polymeric inorganic layers constructed from ZnO(3)Cl and PO(4) tetra-hedra are linked by O atoms: O-H⋯O hydrogen bonds occur within the layers. The organic cations occupy the interlayer regions and interact with the layers by way of N-H⋯O, N-H⋯Cl, and C-H⋯Cl hydrogen bonds.

The asymmetric unit of the title compound, (C(11)H(18)N(2))(2)[CdCl(6)]·2H(2)O, consists of one 1-benzyl-piperazine-1,4-diium dication, one water mol-ecule and one-half of a [CdCl(6)](4-) anion, located on an inversion centre. The crystal packing is governed by an extensive three-dimensional network of inter-molecular O-H⋯Cl, C-H⋯Cl, N-H⋯O and N-H⋯Cl hydrogen bonds, two of them bifurcated.

In the title compound, C(11)H(18)N(2) (2+)·2ClO(4) (-)·H(2)O, one perchlor-ate anion is disordered over two orientations in a 0.66 (3):0.34 (3) ratio. Inter-molecular O-H⋯O, N-H⋯O and C-H⋯O hydrogen bonds link the cations, anions and water mol-ecules into ribbons extending along [100].

The title compound, (C(8)H(12)NO)(C(16)H(18)NO(2))[ZnCl(4)]·H(2)O, was obtained as a by-product of the Zn(2+) and HCl catalyzed condensation of (2-meth-oxy-phen-yl)methanamine in water. Both cations feature an intra-molecular N-H⋯O hydrogen bond. In the crystal, the components are linked by an extensive three-dimensional network of N-H⋯O, O-H⋯Cl and N-H⋯Cl hydrogen bonds (three of them bifurcated). Weak C-H⋯O intera-ctions also occur.

In the title compound, [Cd(NO(3))(2)(C(5)H(7)N(3)O)(2)], the Cd(II) atom is eight-coordinated by two amine N atoms and two O atoms from two zwitterionic, biodentate 2-amino-6-methyl-pyrimidin-1-ium-4-olate ligands and by four O atoms from two nitrate groups. Intra-molecular N-H⋯O hydrogen bonds occur. The crystal packing is stabilized by inter-molecular N-H⋯O and C-H⋯O hydrogen bonds, two of which are bifurcated, between the nitrate anions and the organic groups.

In the crystal structure of the title compound, C(9)H(22)N(2) (2+)·2H(2)PO(4) (-)·H(2)O, the H(2)PO(4) (-) anions are hydrogen bonded to each other, forming a ribbon parallel to the b axis. The water mol-ecules connect these ribbons via O-H⋯O hydrogen bonds. The organic cations are attached to the dihydrogen phosphate anions and water mol-ecules through N-H⋯O and C-H⋯O hydrogen bonds, forming an infinite three-dimensional network.

In the title compound, (C(7)H(18)N(2)O)[ZnCl(4)], the Zn(II) ion is coordinated by four Cl atoms in a close to tetra-hedral geometry. The crystal packing exhibits C-H⋯Cl, N-H⋯Cl and N-H⋯O hydrogen bonds.

The title compound, C(6)H(10)N(2) (2+)·2Cl(-), contains a network of 4-(ammonio-meth-yl)pyridinium cations and chloride anions which are inter-connected by N-H⋯Cl hydrogen bonds. The crystal packing is also influenced by inter-molecular π-π stacking inter-actions between identical anti-parallel organic cations with a face-to-face distance of ca 3.52 Å.

The title compound, C(12)H(19)N(2) (+)·Cl(-)·H(2)O, contains a network of 4-(2,3-dimethyl-phen-yl)piperazin-1-ium cations, water mol-ecules and chloride anions. The crystal packing is influenced by O-H⋯Cl, N-H⋯Cl, N-H⋯O, C-H⋯O and C-H⋯Cl hydrogen bonds, resulting in structure with an open-framework architecture.

In the crystal structure of the title compound, (C(10)H(15)ClN(2))[ZnCl(4)]·H(2)O, the Zn atom is coordinated by four Cl atoms in a tetrahedral geometry. The water mol-ecules and the 1-(4-chloro-phen-yl)piperazine-1,4-diium cations inter-act with the [ZnCl(4)](2-) anions through O-H⋯Cl, N-H⋯Cl, N-H⋯O and C-H⋯Cl hydrogen bonds (five simple and one bifurcated). Inter-molecular π-π stacking inter-actions are present between adjacent aromatic rings of 1-(4-chloro-phenyl)-piperazine-1,4-diium cations (the centroid-centroid distance is 3.453 Å).

The growing interest in forward osmosis (FO) for water reclamation and desalination over the past two decades stems from its potential for lower energy consumption. Despite its promise, FO faces significant challenges, such as the lack of an appropriate draw solute, concentration polarization, membrane fouling, and reverse solute flux (RSF). Recent trends in research have focused on combining various technologies with FO to address these challenges. Notably, the integration of electrochemical technologies with FO offers new possibilities. This review covers FO combined with electrochemical cells (FO‐ECs), categorizing them based on their working principles and applications in improving FO. The review discusses different FO‐EC configurations, including (1) electrodialysis‐combined FO for RSF, (2) electro‐FO for water flux enhancement, and (3) electrochemical oxidation‐combined FO and FO with electro‐conductive membranes for self‐cleaning and fouling mitigation. Additionally, it covers (4) reusable electro‐responsive draw solutes, (5) electrochemical osmosis systems for metal removal and energy production, and (6) osmotic microbial fuel cells for energy recovery and other benefits. The review also assesses the practical applicability and potential for achieving carbon neutrality of the FO‐ECs. It concludes with a forward‐looking perspective, outlining future research directions to optimize and expand the use of electrochemical‐enhanced FO technologies. [ABSTRACT FROM AUTHOR]

The African Light Source (AfLS) project is now almost eight years old. This article assesses the history, current context and future of the project. There is by now considerable momentum in building the user community, including deep training, facilitating access to current facilities, growing the scientific output, scientific networks and growing the local laboratory-scale research infrastructure. The Conceptual Design Report for the AfLS is in its final editing stages. This document specifies the socio-economic and scientific rationales and the technical aspects amongst others. The AfLS is supported by many national and Pan-African scientific professional bodies and voluntary associates across many scientific disciplines, and there are stakeholders throughout the continent and beyond. The current roadmap phases have expanded to include national and Pan-African level conversations with policy makers through new Strategic Task Force groups. The document summarizes this progress and discusses the future of the project. [ABSTRACT FROM AUTHOR]

Discrete aurora are sporadic emissions of light originating in Mars upper atmosphere. We report nadir imaging observations from MAVEN's Imaging UltraViolet Spectrograph which identify the conditions which trigger electron precipitation causing these events. Prior studies have shown that discrete aurora events in the strong crustal magnetic field region in the southern hemisphere are the brightest and most repeatable compared to events occurring outside the region. Our new data set offers a more complete and accurate characterization of aurora in this area. The region of strongest crustal fields is composed of two distinct magnetic regions, with magnetic fields in opposite directions; discrete aurora events trigger in one region after dusk and in the other before dawn. Magnetic reconnection in these two adjacent regions with the draped interplanetary field may open the crustal fields in these regions during opposing local times. Particle precipitation can then cause discrete aurora at the observed times and locations. Plain Language Summary: Mars has a surprising variety of types of aurora, all different from Earth's "northern lights." Mars lacks the familiar high‐latitude aurora because it no longer has the same kind of global magnetic field Earth does. This study examines "discrete aurora" events that occur in region in Mars southern hemisphere that has retained some of the ancient magnetic field. It takes the form of long arcades of magnetic loops that resemble a set of arches. As Mars rotates, these arcades are carried around the planet as the solar wind and its imbedded magnetic field are carried past the planet. We show that when conditions are favorable, the magnetic field locked in the solar wind can interact and "reconnect" with Mars magnetic loops, allowing energetic particles to spiral down the field lines into the atmosphere to cause discrete aurora. Key Points: New data confirm that Mars discrete aurora events occur most frequently near strong crustal fields and vary with local timeAuroral events in adjacent regions with opposite magnetic polarity occur before or after midnight depending on local magnetic field directionMagnetic reconnection between crustal fields and the draped interplanetary field appears to control regional and local time behavior [ABSTRACT FROM AUTHOR]

Although circular RNAs (circRNAs) are involved in cell proliferation, differentiation, apoptosis, and invasion, the underlying regulatory mechanisms of circRNAs in thyroid cancer have not been fully elucidated. This article aimed to study the role of circRNA regulated by N6‐methyladenosine modification in papillary thyroid cancer (PTC). Quantitative real‐time PCR, western blotting, and immunohistochemistry were used to investigate the expressions of circRNA nuclear receptor‐interacting protein 1 (circNRIP1) in PTC tissues and adjacent noncancerous thyroid tissues. In vitro and in vivo assays were carried out to assess the effects of circNRIP1 on PTC glycolysis and growth. The N6‐methyladenosine mechanisms of circNRIP1 were evaluated by methylated RNA immunoprecipitation sequencing, luciferase reporter gene, and RNA stability assays. Results showed that circNRIP1 levels were significantly upregulated in PTC tissues. Furthermore, elevated circNRIP1 levels in PTC patients were correlated with high tumor lymph node metastasis stage and larger tumor sizes. Functionally, circNRIP1 significantly promoted glycolysis, PTC cell proliferation in vitro, and tumorigenesis in vivo. Mechanistically, circNRIP1 acted as a sponge for microRNA (miR)‐541‐5p and miR‐3064‐5p and jointly upregulated pyruvate kinase M2 (PKM2) expression. Knockdown of m6A demethylase α‐ketoglutarate‐dependent dioxygenase alkB homolog 5 (ALKBH5) significantly enhanced circNRIP1 m6A modification and upregulated its expression. These results show that ALKBH5 knockdown upregulates circNRIP1, thus promoting glycolysis in PTC cells. Therefore, circNRIP1 can be a prognostic biomarker and therapeutic target for PTC by acting as a sponge for oncogenic miR‐541‐5p and miR‐3064‐5p to upregulate PKM2 expression. [ABSTRACT FROM AUTHOR]

The Martian proton aurora is a distinct aurora phenomenon resulting from the direct deposition of solar wind energy into Mars' dayside atmosphere. What solar wind parameters influence the aurora activity in the short term is yet unknown, as are the associated repercussions in the Martian atmospheric ion loss. Here we present observational evidence of synchronized proton aurora brightening and atmospheric ion loss intensifying on Mars, controlled by solar wind dynamic pressure, using observations by the Mars Atmosphere and Volatile Evolution spacecraft. The solar wind dynamic pressure possibly has a saturation effect on brightening proton aurora. Significant erosion of the Martian ionosphere during periods of high dynamic pressure indicates at least five‐to‐tenfold increase in atmospheric ion loss. An empirical relationship between ion escape rate and auroral emission enhancement is established, providing a new proxy of Mars' atmospheric ion loss with optical imaging that may be used remotely and with greater flexibility. Plain Language Summary: Ion loss during solar events early in Mars history may have been the major cause to the long‐term evolution of the Mars atmosphere. Restricted by observation data, the relationship between ion loss and solar wind is still in debate. We have shown observational evidence for synchronized dayside proton aurora brightening and atmospheric ion loss intensifying on Mars, controlled by solar wind dynamic pressure using comprehensive observations by the NASA's MAVEN spacecraft. A power law model between ion escape rate and proton auroral emission enhancement is established for the first time, providing a new proxy of Mars' atmospheric loss with optical imaging that may be used remotely and with greater flexibility. The results presented in this study shed light on the direct control of dynamic pressure on interactions of the solar wind with Mars and other objects in solar system (e.g., Venus and Titan), and presumably stellar wind with exoplanets. Key Points: Synchronized proton aurora brightening and atmospheric ion loss intensifying on Mars, both controlled by solar wind dynamic pressureThe solar wind dynamic pressure possibly has a saturation effect on brightening proton auroraAn empirical power law model between ion escape rate and proton auroral emission enhancement is established [ABSTRACT FROM AUTHOR]

We present the first measurements of Mars discrete aurora in the extreme ultraviolet (<110 nm) and the first synoptic aurora images in the far ultraviolet (110–180 nm). Auroral emission is detected in >75% of nightside images, with patterns shifting visibly over 15–20 min. Aurora is observed most frequently in regions of open magnetic topology (where crustal magnetic fields are very weak and/or vertical), with the brightest aurora where crustal fields are strongest. We present the first disk‐averaged spectrum of discrete aurora, with several O, C, and CO features as expected for electron impact primarily on CO2. We categorize discrete auroral morphology into three types: crustal field aurora, non‐crustal field patchy aurora, and a new type we call "sinuous" aurora, an elongated serpentine structure that stretches thousands of kilometers into the nightside from near midnight in the northern hemisphere. These observations point to a highly dynamic environment in Mars' magnetotail. Plain Language Summary: In this study, we present near‐global images of localized aurora on Mars and the first measurements of these aurora at very short ultraviolet wavelengths (<110 nm). They are caused by energetic electrons from the solar wind smashing into Mars' upper atmosphere. We find auroras in >75% of images, with their patterns shifting visibly over 15–20 min. They are observed most frequently in regions where magnetic fields are very weak or both strong and vertical, with the brightest aurora where magnetic fields are strongest. We present the first disk‐averaged spectrum of these auroras, showing features expected for electrons striking CO2 (the most abundant gas in Mars' atmosphere). We categorize discrete auroral patterns into three types: those near strong vertical crustal magnetic field, patchy aurora near very weak crustal fields, and a new type we call "sinuous," an elongated serpentine structure that stretches thousands of kilometers into the nightside from near midnight in the northern hemisphere. These observations point to a highly dynamic environment in Mars' nightside space environment. Key Points: We present the first disk measurements of Mars discrete aurora in the EUV end FUV, with the oxygen feature at 130.4 nm being the brightestAuroras are detected in ∼75% of nightside images and are more likely where crustal fields are either very weak or both strong and verticalAn elongated, sinuous discrete aurora is discovered, extending far into the nightside. It may be related to the magnetotail current sheet [ABSTRACT FROM AUTHOR]

Discrete aurorae have been observed at magnetized planets such as Earth and Jupiter, triggered by accelerated electrons. Similar aurorae have also been observed at Mars with only localized strong crustal magnetisms. However, our understanding of this phenomenon at Mars is still limited. In particular, direct and quantitative comparisons of the auroral and its source electron events are lacking as these two types of observations are usually made at different times and/or locations. In this study, we establish empirical criteria to select electron events ("auroral electrons") that could trigger detectable auroral emissions with Mars Atmosphere and Volatile EvolutioN measurements, thereby enabling a direct statistical comparison. We find auroral electrons share similar statistical characteristics to those previously reported for discrete auroral events. This study bridges the gap between electron observations and auroral detections and enables collaborations across different Mars missions, as well as comparative planetary studies of discrete aurora. Plain Language Summary: Aurorae have been observed in the polar regions at magnetized planets such as Earth and Jupiter, triggered by accelerated electrons. Similarly, localized auroral emissions have also been reported at Mars with no global dipole field but localized strong crustal magnetisms. However, our understanding of aurorae at Mars is still very limited in terms of their characteristics and the source electrons. In particular, direct and quantitative comparisons of the auroral and electron events are lacking as these two types of observations are usually made at different times and/or locations because of the limitation of single‐spacecraft observations. This study establishes empirical criteria to select auroral electrons and statistically compare these two types of observations. This study bridges the gap between the electron observations and auroral detections and enables collaborations across different Mars missions, as well as studies of auroral phenomena at different planets. Key Points: We establish empirical criteria to select electron events that could trigger detectable auroral observationsWe find similar statistical behaviors in selected electron events as discrete auroral events and explore the cause of statistical trendsThis study bridges the gap of these two types of observations and motivates collaborations across different Mars missions [ABSTRACT FROM AUTHOR]

Secondarily aquatic tetrapods have many unique morphologic adaptations for life underwater compared with their terrestrial counterparts. A key innovation during the land‐to‐water transition was feeding. Pinnipeds, a clade of air‐breathing marine carnivorans that include seals, sea lions, and walruses, have evolved multiple strategies for aquatic feeding (e.g., biting, suction feeding). Numerous studies have examined the pinniped skull and dental specializations for underwater feeding. However, data on the pinniped craniofacial musculoskeletal system and its role in aquatic feeding are rare. Therefore, the objectives of this study were to conduct a comparative analysis of pinniped craniofacial musculature and examine the function of the craniofacial musculature in facilitating different aquatic feeding strategies. We performed anatomic dissections of 35 specimens across six pinniped species. We describe 32 pinniped craniofacial muscles—including facial expression, mastication, tongue, hyoid, and soft palate muscles. Pinnipeds broadly conform to mammalian patterns of craniofacial muscle morphology. Pinnipeds also exhibit unique musculoskeletal morphologies—in muscle position, attachments, and size—that likely represent adaptations for different aquatic feeding strategies. Suction feeding specialists (bearded and northern elephant seals) have a significantly larger masseter than biters. Further, northern elephant seals have large and unique tongue and hyoid muscle morphologies compared with other pinniped species. These morphologic changes likely help generate and withstand suction pressures necessary for drawing water and prey into the mouth. In contrast, biting taxa (California sea lions, harbor, ringed, and Weddell seals) do not exhibit consistent craniofacial musculoskeletal adaptations that differentiate them from suction feeders. Generally, we discover that all pinnipeds have well‐developed and robust craniofacial musculature. Pinniped head musculature plays an important role in facilitating different aquatic feeding strategies. Together with behavioral and kinematic studies, our data suggest that pinnipeds' robust facial morphology allows animals to switch feeding strategies depending on the environmental context—a critical skill in a heterogeneous and rapidly changing underwater habitat. [ABSTRACT FROM AUTHOR]

Whistler mode waves have been proposed as a crucial mechanism in determining the velocity‐space distribution of electrons on the dayside crustal magnetic fields of Mars. A superthermal electron transport model has been unable to reproduce the observed pitch angle distributions on a crustal field line. The two key differences are that the observed pitch angle distributions are much more isotropic and the observed high energy pitch angle distributions have a flux peak at perpendicular pitch angles. We solve the bounce‐averaged quasi‐linear diffusion equation to calculate the steady‐state pitch angle distribution of electrons along a crustal field line when in resonance with whistler mode waves. We perform two simulations, changing the background ionosphere, which affects what energies are in resonance with the whistler mode wave. The wave parameters are chosen based on previous observations of whistlers at Mars. Our results reconcile both qualitative differences between the previous data‐model comparisons. Plain Language Summary: An understanding of how electrons move through space environments is important for a multitude of reasons. It tells us where electrons will transfer their energy to the neutral atmosphere and it can indirectly inform us of where the magnetic field lines are connected to (the planet or solar wind). If the physical processes that control electron transport are unknown, then incorrect assumptions may be made. At Mars, our satellite observations and numerical simulations have not agreed, indicating that we do not include all the relevant physics in our models. Whistler mode waves are extremely low frequency radio waves that interact with electrons and can change the direction they are moving and increase their velocity. In this study, we simulate the effect of whistler mode waves on electrons at Mars. We find that our simulation results agree quite well with the data and reconciles the two key qualitative differences between previous data‐model comparisons. Key Points: We have solved the bounce‐averaged quasi‐linear diffusion equation along a Mars crustal field line to study wave‐particle interactionsSteady‐state due to photoelectron resonance with whistler mode waves was reached on the order of minutesBoth previous data‐model discrepancies are resolved: a high energy perpendicular flux peak and increased isotropy [ABSTRACT FROM AUTHOR]

Objective: The aim of this study was to investigate whether subclinical hypothyroidism could increase the risk of postoperative complications in patients undergoing primary total knee arthroplasty (TKA). Methods: A prospective case‐control study of 796 patients undergoing primary TKA between January 2015 and January 2020 was performed. A total of 700 patients (87.9%) were female and the average age of included patients was 65.0 years, with a standard deviation of 5.6. The participants who had subclinical hypothyroidism were referred to as the case group, while those without abnormal thyrotropin (TSH) were included in the control group (matched for age and gender). The fasting plasma levels of TSH were tested in the morning in all patients. The diagnosis of subclinical hypothyroidism was completed by a senior endocrinologist based on laboratory tests; namely, a serum TSH ≥ 5 mu/L and normal free thyroxine (FT4). Subclinical hypothyroidism was further described as mild (TSH < 10 mu/L) or severe (TSH ≥ 10 mu/L). The incidence of 90‐day postoperative complications was compared between two cohorts. Logistic regression analysis was used for the risk factors of 90‐day postoperative complications following TKA. Results: A total of 398 patients had a diagnosis of subclinical hypothyroidism. Among them, 275 cases (69.1%) were described as mild (79 patients [19.8%] with low FT4 and 196 patients [49.2%] with normal FT4 in the repeated test) and 123 cases (30.9%) as severe subclinical hypothyroidism. Of the 196 patients (49.2%) with mild subclinical hypothyroidism and normal FT4, 63 patients (15.8%) had symptoms before surgery. Patients were followed up for an average duration of 25.4 months (6 to 43 months). A total of 265 patients (66.6%) received preoperative treatment for subclinical hypothyroidism, with an average therapy time of 9.2 months. There were 162 patients (40.7%) with positive autoantibodies to thyroid peroxidase (anti‐TPO). There were no statistically significant differences in baseline data between cohorts (all P > 0.05). As for the cumulative 90‐day outcomes, subclinical hypothyroidism increased the incidences of both medical and surgical complications following primary TKA compared to those without this condition (11.6% vs 7.2%, OR = 1.55, 95% confidence interval [CI] = 1.47–1.62, P < 0.05). Subclinical hypothyroidism caused patients to suffer increased total incidence of readmission within the first 90 days after discharge when compared to those without this condition (20.61% vs 14.15%, OR = 1.45, 95% CI = 1.41–1.49, P < 0.001). Controlling for preoperative and intraoperative variables, the patients with TSH ≥ 10 mu/L and positive anti‐TPO and those without corrected subclinical hypothyroid and thyroid hormone supplementation were more likely to experience postoperative complications within 90 days of TKA. Conclusion: Subclinical hypothyroidism might increase the risk of postoperative complications within 90 days of TKA, especially for the patients with TSH ≥ 10 mu/L and positive anti‐TPO and those without corrected subclinical hypothyroid and thyroid hormone supplementation. [ABSTRACT FROM AUTHOR]

Lysophosphatidic acid receptor 5 (LPAR5) is involved in mediating thyroid cancer progression, but the underlying mechanism needs to be further revealed. In this study, we confirmed that LPAR5 is upregulated in papillary thyroid carcinoma (PTC), especially in BRAF‐like PTC, by analyzing The Cancer Genome Atlas (TCGA) database and performing immunohistochemistry assay in human thyroid cancer tissues. LPAR5‐specific antagonist TC LPA5 4 treatment inhibited CGTH‐W3, TPC‐1, B‐CPAP, and BHT‐101 cell proliferation, CGTH‐W3 and TPC‐1 cell migration significantly. In vivo, TC LPA5 4 treatment could delay CGTH‐W3 xenograft growth in nude mice. We also found that LPAR5‐specific antagonist TC LPA5 4, PI3K inhibitor wortmannin, or mTOR inhibitor rapamycin pretreatment abrogated phosphorylation of Akt and p70S6K1 stimulated by LPA in CGTH‐W3 and TPC‐1 cells. Stimulating CGTH‐W3 cells transfected with pEGFPC1‐Grp1‐PH fusion protein with LPA resulted in the generation of phosphatidylinositol (3,4,5)‐triphosphate, which indicates that PI3K was activated by LPA directly. The p110β‐siRNA instead of p110α‐siRNA transfection abrogated the increase of levels of phosphorylated Akt and S6K1 stimulated by LPA. Furthermore, immunoprecipitation assay confirmed an interaction between LPAR5 and p110β. Overall, we provide new insights that the downregulation of LPAR5 decreased the proliferation and migration phenotype via the PI3K/Akt pathway. Inhibition of LPAR5 or the PI3K/Akt signal may be a novel therapeutic strategy for treating thyroid cancer. [ABSTRACT FROM AUTHOR]

From February to March 2019, the Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft repeatedly observed aurora near periapsis over Mars' southern strong crustal fields. During these orbits, the Solar Wind Electron Analyzer observed accelerated electrons at similar locations to where the auroras were observed, resembling the inverted‐V structure observed near Earth's auroral region. In this study, we present a case study of such an acceleration event, where we estimate a field‐aligned electrostatic potential drop of ∼440 V. We determine the field‐aligned current from the observed magnetic perturbation reaches 1.1 μA/m2, agreeing reasonably well with the estimated net electron current carried by acceleration electrons with a maximum of 2.5 μA/m2. Similar to Earth, the potential drop develops when the ambient plasma cannot sustain the imposed field‐aligned current. We also estimate the potential layer to be located above 750‐ to 850‐km altitude and the associated electric field to be ∼0.6 V/m. Key Points: We estimate a field‐aligned potential drop of 440 V during an inverted‐V electron acceleration event concurring with auroral observationsThe current density estimated from the observed magnetic perturbation reaches 1.1 μA/m2, agreeing with estimated net electron currentSimilar to Earth, this potential drop develops when the ambient plasma is unable to support the necessary field‐aligned current [ABSTRACT FROM AUTHOR]

Objective: Chronic pain is a prevalent condition which has a significant effect on the lives of those it impacts. High‐frequency 10 kHz spinal cord stimulation (10 kHz SCS) has been shown to provide paresthesia‐free pain relief for a wide variety of pain indications. This article summarizes the current and emerging data as they relate to the clinical use of the therapy in various pain syndromes. Methods: A literature search was conducted using the PubMed electronic database using keywords related to 10 kHz SCS. The database was queried from 2013 to May 2019. Articles reporting clinical studies that included human subjects permanently treated with 10 kHz SCS (Senza® system) were included in the review. Recent and relevant conference proceedings known to the authors were also included. Results: The selected literature demonstrated significant evidence for the efficacy of 10 kHz SCS in treating chronic back and leg pain (CBLP), including a randomized, controlled trial as well as prospective and retrospective studies. One‐year follow‐up responder rates (pain relief ≥50%) ranged from 60% to 80%. Other studies and case series showed promising outcomes in specific conditions, including nonsurgical refractory back pain, neuropathic limb pain, complex regional pain syndrome, chronic widespread pain, chronic pelvic pain, and intractable headache. Subgroup analyses also pointed toward the potential of 10 kHz SCS being successful when low‐frequency SCS has failed. The vast majority of these studies reported improved quality of life (QOL) metrics and/or reduced opioid consumption. Conclusions: Level I evidence already exists for the efficacy of 10 kHz SCS in treating CBLP, supported by real‐world clinical experience. Other studies demonstrate the potential of the therapy across a range of chronic pain etiologies, although larger confirmatory studies are recommended. Overall, the literature suggests that the therapy is associated with improved QOL as well as reduced opioid consumption. [ABSTRACT FROM AUTHOR]