RESUMO
Asteroids with diameters less than about 5 km have complex histories because they are small enough for radiative torques (that is, YORP, short for the Yarkovsky-O'Keefe-Radzievskii-Paddack effect)1 to be a notable factor in their evolution2. (152830) Dinkinesh is a small asteroid orbiting the Sun near the inner edge of the main asteroid belt with a heliocentric semimajor axis of 2.19 AU; its S-type spectrum3,4 is typical of bodies in this part of the main belt5. Here we report observations by the Lucy spacecraft6,7 as it passed within 431 km of Dinkinesh. Lucy revealed Dinkinesh, which has an effective diameter of only 720 m, to be unexpectedly complex. Of particular note is the presence of a prominent longitudinal trough overlain by a substantial equatorial ridge and the discovery of the first confirmed contact binary satellite, now named (152830) Dinkinesh I Selam. Selam consists of two near-equal-sized lobes with diameters of 210 m and 230 m. It orbits Dinkinesh at a distance of 3.1 km with an orbital period of about 52.7 h and is tidally locked. The dynamical state, angular momentum and geomorphologic observations of the system lead us to infer that the ridge and trough of Dinkinesh are probably the result of mass failure resulting from spin-up by YORP followed by the partial reaccretion of the shed material. Selam probably accreted from material shed by this event.
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The Harderian gland (HG) is an orbital structure whose proteinaceous secretions pass through the nasolacrimal duct to the vomeronasal organ (VNO). Though these three structures occur in many tetrapod vertebrates, the garter snake (Thamnophis sirtalis) is one of the few vertebrates in which the passage of the proteinaceous secretions have been experimentally shown. Secreted proteins from the HG may function as transporters for chemical signals to the VNO epithelium. To investigate the proteins being produced by the HG of the garter snake, cDNA libraries were constructed from HG mRNA, and several individual cDNAs were analyzed by sequencing, RT-qPCR, and PCR on genomic DNA. Two of the three cDNAs that were characterized are abundantly expressed only in the Harderian gland and contain putative signal sequences for secretion, which makes them candidates for transporter proteins secreted from the HG. One is a member of the large lipocalin family of proteins, based on its similarity to other members of that protein family. Many lipocalins are binding/carrier proteins for a variety of ligands. The other is a family of proteins, with five members identified so far, all of unknown structure and function and present in the garter snake genome but not in other squamate genomes.
Assuntos
Colubridae/genética , DNA Complementar/genética , Glândula de Harder/metabolismo , Animais , DNA Complementar/isolamento & purificação , Genoma , Ducto Nasolacrimal/metabolismo , Órgão Vomeronasal/metabolismoRESUMO
The discovery of water vapour and ice particles erupting from Saturn's moon Enceladus fuelled speculation that an internal ocean was the source. Alternatively, the source might be ice warmed, melted or crushed by tectonic motions. Sodium chloride (that is, salt) is expected to be present in a long-lived ocean in contact with a rocky core. Here we report a ground-based spectroscopic search for atomic sodium near Enceladus that places an upper limit on the mixing ratio in the vapour plumes orders of magnitude below the expected ocean salinity. The low sodium content of escaping vapour, together with the small fraction of salt-bearing particles, argues against a situation in which a near-surface geyser is fuelled by a salty ocean through cracks in the crust. The lack of observable sodium in the vapour is consistent with a wide variety of alternative eruption sources, including a deep ocean, a freshwater reservoir, or ice. The existing data may be insufficient to distinguish between these hypotheses.
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Gases/química , Lua , Sódio/análise , Exobiologia , Planetas , Análise EspectralRESUMO
The small bodies in the Solar System are thought to have been highly affected by collisions and erosion. In the asteroid belt, direct evidence of the effects of large collisions can be seen in the existence of separate families of asteroids--a family consists of many asteroids with similar orbits and, frequently, similar surface properties, with each family being the remnant of a single catastrophic impact. In the region beyond Neptune, in contrast, no collisionally created families have hitherto been found. The third largest known Kuiper belt object, 2003 EL61, however, is thought to have experienced a giant impact that created its multiple satellite system, stripped away much of an overlying ice mantle, and left it with a rapid rotation. Here we report the discovery of a family of Kuiper belt objects with surface properties and orbits that are nearly identical to those of 2003 EL61. This family appears to be fragments of the ejected ice mantle of 2003 EL61.
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Jupiter's moon Europa has a subsurface ocean, the chemistry of which is largely unknown. Carbon dioxide (CO2) has previously been detected on the surface of Europa, but it was not possible to determine whether it originated from subsurface ocean chemistry, was delivered by impacts, or was produced on the surface by radiation processing of impact-delivered material. We mapped the distribution of CO2 on Europa using observations obtained with the James Webb Space Telescope (JWST). We found a concentration of CO2 within Tara Regio, a recently resurfaced terrain. This indicates that the CO2 is derived from an internal carbon source. We propose that the CO2 formed in the internal ocean, although we cannot rule out formation on the surface through radiolytic conversion of ocean-derived organics or carbonates.
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The large Kuiper Belt object Eris is tidally locked to its small companion Dysnomia. Recently obtained bounds on the mass of Dysnomia demonstrate that Eris must be unexpectedly dissipative for it to have despun over the age of the solar system. Here, we show that Eris must have differentiated into an ice shell and rocky core to explain the dissipation. We further demonstrate that Eris's ice shell must be convecting to be sufficiently dissipative, which distinguishes it from Pluto's conductive shell. The difference is likely due to Eris's apparent depletion in volatiles compared with Pluto, perhaps as the result of a more energetic impact.
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Therapeutic antibodies represent the most significant modality in biologics, with around 150 approved drugs on the market. In addition to specific target binding mediated by the variable fragments (Fvs) of the heavy and light chains, antibodies possess effector functions through binding of the constant region (Fc) to Fcγ receptors (FcγR), which allow immune cells to attack and kill target cells using a variety of mechanisms. However, for some applications, including T-cell-engaging bispecifics, this effector function is typically undesired. Mutations within the lower hinge and the second constant domain (CH2) of IgG1 that comprise the FcγR binding interface reduce or eliminate effector function ("Fc silencing") while retaining binding to the neonatal Fc receptor (FcRn), important for normal antibody pharmacokinetics (PKs). Comprehensive profiling of biophysical developability properties would benefit the choice of constant region variants for development. Here, we produce a large panel of representative mutations previously described in the literature and in many cases in clinical or approved molecules, generate select combinations thereof, and characterize their binding and biophysical properties. We find that some commonly used CH2 mutations, including D265A and P331S, are effective in reducing binding to FcγR but significantly reduce stability, promoting aggregation, particularly under acidic conditions commonly employed in manufacturing. We highlight mutation sets that are particularly effective for eliminating Fc effector function with the retention of WT-like stability, including L234A, L235A, and S267K (LALA-S267K), L234A, L235E, and S267K (LALE-S267K), L234A, L235A, and P329A (LALA-P329A), and L234A, L235E, and P329G (LALE-P329G).
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Bispecific antibodies continue to represent a growth area for antibody therapeutics, with roughly a third of molecules in clinical development being T-cell engagers that use an anti-CD3 binding arm. CD3 antibodies possessing cross-reactivity with cynomolgus monkey typically recognize a highly electronegative linear epitope at the extreme N-terminus of CD3 epsilon (CD3ε). Such antibodies have high isoelectric points and display problematic polyreactivity (correlated with poor pharmacokinetics for monospecific antibodies). Using insights from the crystal structure of anti-Hu/Cy CD3 antibody ADI-26906 in complex with CD3ε and antibody engineering using a yeast-based platform, we have derived high-affinity CD3 antibody variants with very low polyreactivity and significantly improved biophysical developability. Comparison of these variants with CD3 antibodies in the clinic (as part of bi- or multi-specifics) shows that affinity for CD3 is correlated with polyreactivity. Our engineered CD3 antibodies break this correlation, forming a broad affinity range with no to low polyreactivity. Such antibodies will enable bispecifics with improved pharmacokinetic and safety profiles and suggest engineering solutions that will benefit the large and growing sector of T-cell engagers.
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Anticorpos Biespecíficos , Animais , Macaca fascicularis , Linfócitos T , Complexo CD3 , Muromonab-CD3RESUMO
The ROSINA (Rosetta Orbiter Spectrometer for Ion and Neutral Analysis) instrument aboard the Rosetta mission revolutionized our understanding of cometary material composition. One of Rosetta's key findings is the complexity of the composition of comet 67P/Churyumov-Gerasimenko. Here, we used ROSINA data to analyze dust particles that were volatilized during a dust event in September 2016 and report the detection of large organosulfur species and an increase in the abundances of sulfurous species previously detected in the coma. Our data support the presence of complex sulfur-bearing organics on the surface of the comet. In addition, we conducted laboratory simulations that show that this material may have formed from chemical reactions that were initiated by the irradiation of mixed ices containing H2S. Our findings highlight the importance of sulfur chemistry in cometary and precometary materials and the possibility of characterizing organosulfur materials in other comets and small icy bodies using the James Webb Space Telescope.
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Ganymede is the only satellite in the solar system known to have an intrinsic magnetic field. Interactions between this field and the Jovian magnetosphere are expected to funnel most of the associated impinging charged particles, which radiolytically alter surface chemistry across the Jupiter system, to Ganymede's polar regions. Using observations obtained with JWST as part of the Early Release Science program exploring the Jupiter system, we report the discovery of hydrogen peroxide, a radiolysis product of water ice, specifically constrained to the high latitudes. This detection directly implies radiolytic modification of the polar caps by precipitation of Jovian charged particles along partially open field lines within Ganymede's magnetosphere. Stark contrasts between the spatial distribution of this polar hydrogen peroxide, those of Ganymede's other radiolytic oxidants, and that of hydrogen peroxide on neighboring Europa have important implications for understanding water-ice radiolysis throughout the solar system.
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Multiple studies of vaccinated and convalescent cohorts have demonstrated that serum neutralizing antibody (nAb) titers correlate with protection against coronavirus disease 2019 (COVID-19). However, the induction of multiple layers of immunity after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) exposure has complicated the establishment of nAbs as a mechanistic correlate of protection (CoP) and hindered the definition of a protective nAb threshold. Here, we show that a half-life-extended monoclonal antibody (adintrevimab) provides about 50% protection against symptomatic COVID-19 in SARS-CoV-2-naïve adults at serum nAb titers on the order of 1:30. Vaccine modeling results support a similar 50% protective nAb threshold, suggesting that low titers of serum nAbs protect in both passive antibody prophylaxis and vaccination settings. Extrapolation of adintrevimab pharmacokinetic data suggests that protection against susceptible variants could be maintained for about 3 years. The results provide a benchmark for the selection of next-generation vaccine candidates and support the use of broad, long-acting monoclonal antibodies as alternatives or supplements to vaccination in high-risk populations.
Assuntos
COVID-19 , Adulto , Humanos , SARS-CoV-2 , Anticorpos Neutralizantes , Anticorpos Antivirais , Vacinação , Anticorpos Monoclonais/uso terapêuticoRESUMO
Previous research on workplace conflict has focused on disagreements about work tasks, processes, and personal relationships. However, conflicts often involve matters of right and wrong; yet, ethical conflict is notably absent from the literature. Informed by moral convictions theory, we introduce the construct of ethical conflict, create and validate a measure of it, and explore its unique effects on workplace outcomes. Ultimately, we find that ethical conflict is a double-edged sword: It is negatively associated with team dynamics (i.e., decreased satisfaction with group, group viability, group cohesion, group psychological safety; increased negative emotions; and perceived goal difficulty) as well as group performance on a non-ethics-related task, but positively related to moral cognition (i.e., moral awareness and moral identity accessibility) and elaboration of information and perspectives during group ethical decision making. Overall, our studies provide a conceptual and empirical foundation for the future research on ethical conflict. (PsycInfo Database Record (c) 2022 APA, all rights reserved).
Assuntos
Formação de Conceito , Princípios Morais , Tomada de Decisões , Humanos , Motivação , Local de TrabalhoRESUMO
Voltage-sensitive dye activity within the thin, unfoliated turtle cerebellar cortex (Cb) was recorded in vitro during eighth cranial nerve (nVIII) stimulation. Short latency responses were localized to the middle of the lateral edges of both ipsilateral and contralateral Cb [vestibulocerebellum (vCb)]. Even with a severed contralateral Cb peduncle, stimulation of the nVIII ipsilateral to the intact peduncle evoked contralateral vCb responses with a mean latency of only 0.25 ms after the ipsilateral responses, even though the distance between them was â¼ 5 mm. We investigated whether a rapidly conducting commissure exists between each vCb by stimulating one of them directly. Responses in both vCb spread sagittally, but, surprisingly, there was no sequential activation along a transverse Cb beam between them. In contrast, stimulation medial to either vCb evoked transverse beams that required â¼ 20 ms to cross the Cb. Therefore, the rapid commissural connection between each vCb is not mediated by slowly conducting parallel fibers. Also, the vCb was not strongly activated by climbing fiber stimulation, suggesting that inputs to vCb involve distinct cerebellar circuits. Responses between the two vCb remained following knife cuts through the rostral and caudal Cb along the midline, through both peduncles, and even shallow midline cuts to the middle Cb through its white matter and granule cell layer. Commissural responses were still observed only with a narrow transverse bridge between each vCb or in thick transverse Cb slices. Horseradish peroxidase transport from one vCb labeled transverse axons traveling within the Purkinje cell layer that were larger than parallel fibers and lacked varicosities. In sagittal sections, cross-section profiles of myelinated axons were observed around Purkinje cells midway between the rostral and caudal Cb. This novel pathway for transverse communication between lateral edges of turtle Cb suggests that afferents may directly conduct vestibular information rapidly across the Cb to coordinate vestibulomotor reflex behaviors.
Assuntos
Cerebelo/anatomia & histologia , Cerebelo/fisiologia , Transmissão Sináptica/fisiologia , Tartarugas/fisiologia , Vestíbulo do Labirinto/anatomia & histologia , Vestíbulo do Labirinto/fisiologia , Animais , Vias Neurais/anatomia & histologia , Vias Neurais/fisiologiaRESUMO
The recurrent zoonotic spillover of coronaviruses (CoVs) into the human population underscores the need for broadly active countermeasures. We employed a directed evolution approach to engineer three severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibodies for enhanced neutralization breadth and potency. One of the affinity-matured variants, ADG-2, displays strong binding activity to a large panel of sarbecovirus receptor binding domains and neutralizes representative epidemic sarbecoviruses with high potency. Structural and biochemical studies demonstrate that ADG-2 employs a distinct angle of approach to recognize a highly conserved epitope that overlaps the receptor binding site. In immunocompetent mouse models of SARS and COVID-19, prophylactic administration of ADG-2 provided complete protection against respiratory burden, viral replication in the lungs, and lung pathology. Altogether, ADG-2 represents a promising broad-spectrum therapeutic candidate against clade 1 sarbecoviruses.
Assuntos
Anticorpos Monoclonais/imunologia , Anticorpos Antivirais/imunologia , Betacoronavirus/imunologia , Anticorpos Amplamente Neutralizantes/imunologia , SARS-CoV-2/imunologia , Glicoproteína da Espícula de Coronavírus/imunologia , Enzima de Conversão de Angiotensina 2/metabolismo , Animais , Anticorpos Monoclonais/genética , Anticorpos Monoclonais/metabolismo , Anticorpos Antivirais/genética , Anticorpos Antivirais/metabolismo , Afinidade de Anticorpos , Sítios de Ligação , Sítios de Ligação de Anticorpos , Anticorpos Amplamente Neutralizantes/genética , Anticorpos Amplamente Neutralizantes/metabolismo , COVID-19/prevenção & controle , COVID-19/terapia , Técnicas de Visualização da Superfície Celular , Evolução Molecular Direcionada , Epitopos/imunologia , Humanos , Imunização Passiva , Fragmentos Fc das Imunoglobulinas/imunologia , Camundongos Endogâmicos BALB C , Domínios Proteicos , Engenharia de Proteínas , Receptores de Coronavírus/metabolismo , Coronavírus Relacionado à Síndrome Respiratória Aguda Grave/imunologia , Síndrome Respiratória Aguda Grave/imunologia , Síndrome Respiratória Aguda Grave/prevenção & controle , Síndrome Respiratória Aguda Grave/terapia , Glicoproteína da Espícula de Coronavírus/metabolismo , Soroterapia para COVID-19RESUMO
Here we describe an industry-wide collaboration aimed at assessing the binding properties of a comprehensive panel of monoclonal antibodies (mAbs) against programmed cell death protein 1 (PD-1), an important checkpoint protein in cancer immunotherapy and validated therapeutic target, with well over thirty unique mAbs either in clinical development or market-approved in the United States, the European Union or China. The binding kinetics of the PD-1/mAb interactions were measured by surface plasmon resonance (SPR) using a Carterra LSA instrument and the results were compared to data collected on a Biacore 8K. The effect of chip type on the SPR-derived binding rate constants and affinities were explored and the results compared with solution affinities from Meso Scale Discovery (MSD) and Kinetic Exclusion Assay (KinExA) experiments. When using flat chip types, the LSA and 8K platforms yielded near-identical kinetic rate and affinity constants that matched solution phase values more closely than those produced on 3D-hydrogels. Of the anti-PD-1 mAbs tested, which included a portion of those known to be in clinical development or approved, the affinities spanned from single digit picomolar to nearly 425 nM, challenging the dynamic range of our methods. The LSA instrument was also used to perform epitope binning and ligand competition studies which revealed over ten unique competitive binding profiles within this group of mAbs.
Assuntos
Anticorpos Monoclonais/farmacologia , Técnicas Biossensoriais/métodos , Receptor de Morte Celular Programada 1/imunologia , China , Desenvolvimento de Medicamentos , Epitopos/imunologia , União Europeia , Ensaios de Triagem em Larga Escala , Humanos , Receptor de Morte Celular Programada 1/química , Ligação Proteica , Ressonância de Plasmônio de Superfície , Estados UnidosRESUMO
The recurrent zoonotic spillover of coronaviruses (CoVs) into the human population underscores the need for broadly active countermeasures. Here, we employed a directed evolution approach to engineer three SARS-CoV-2 antibodies for enhanced neutralization breadth and potency. One of the affinity-matured variants, ADG-2, displays strong binding activity to a large panel of sarbecovirus receptor binding domains (RBDs) and neutralizes representative epidemic sarbecoviruses with remarkable potency. Structural and biochemical studies demonstrate that ADG-2 employs a unique angle of approach to recognize a highly conserved epitope overlapping the receptor binding site. In murine models of SARS-CoV and SARS-CoV-2 infection, passive transfer of ADG-2 provided complete protection against respiratory burden, viral replication in the lungs, and lung pathology. Altogether, ADG-2 represents a promising broad-spectrum therapeutic candidate for the treatment and prevention of SARS-CoV-2 and future emerging SARS-like CoVs.
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In a field study, the authors investigated the relationship between socialized charismatic leadership and values congruence between leaders and followers. Socialized charismatic leadership theory holds that charismatic leaders convey a values-based message and bring about values congruence between themselves and their followers. Yet, other research suggests that individuals' values are stable and closely linked to occupational membership and that employees' values are therefore likely to be quite difficult to change. Results of this study suggest that occupations are indeed associated with multiple types of employee values. The results also demonstrate that, for 3 of the 4 values studied, socialized charismatic leadership is associated with values congruence between the specific values leaders say they transmit to their followers and the values their followers say they use in work. The findings shed additional light on the values alignment process. Implications for research and practice are discussed.
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Logro , Liderança , Valores Sociais , Socialização , Adulto , Coleta de Dados , Feminino , Setor de Assistência à Saúde , Humanos , Masculino , Pessoa de Meia-Idade , Motivação , Objetivos Organizacionais , Identificação SocialRESUMO
The potential habitability of Europa's subsurface ocean depends on its chemical composition, which may be reflected in that of Europa's geologically young surface. Investigations using Galileo Near-Infrared Mapping Spectrometer data led to the prevailing view that Europa's endogenous units are rich in sulfate salts. However, recent ground-based infrared observations have suggested that, while regions experiencing sulfur radiolysis may contain sulfate salts, Europa's more pristine endogenous material may reflect a chloride-dominated composition. Chlorides have no identifying spectral features at infrared wavelengths, but develop distinct visible-wavelength absorptions under irradiation, like that experienced on the surface of Europa. Using spectra obtained with the Hubble Space Telescope, we present the detection of a 450-nm absorption indicative of irradiated sodium chloride on the surface. The feature correlates with geologically disrupted chaos terrain, suggesting an interior source. The presence of endogenous sodium chloride on the surface of Europa has important implications for our understanding of its subsurface chemistry.
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Salicylanilides were found as selective inhibitors of interleukin-12p40 production in stimulated dendritic cells. The conversion of one of these bioactive salicylanilides into a comparably bioactive, chemically labeled derivative was achieved using a facile and systematic functional group derivatization strategy. This resulted in a tool reagent that was then employed in an affinity chromatography approach that resulted in the identification of the protein 14-3-3zeta as having selective affinity for the chromatography matrix that was derivatized with a salicylanilide that inhibited IL-12p40 production.
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Proteínas 14-3-3/química , Marcadores de Afinidade/química , Subunidade p40 da Interleucina-12/antagonistas & inibidores , Salicilanilidas/química , Animais , Linhagem Celular , Cromatografia de Afinidade , Células Dendríticas , Subunidade p40 da Interleucina-12/biossíntese , Camundongos , RatosRESUMO
Interleukin (IL)-12p40, a subunit component of both IL-12 and IL-23, is being widely studied for its role in inflammatory disease. As part of an effort to profile cellular signaling pathways across different cell types, we report salicylanilide inhibitors of IL-12p40 production in stimulated dendritic cells. Based on a hypothesis that a desirable therapeutic profile is one that could block IL-12p40 but not IL-6 production, we engaged in directed analoging. This resulted in salicylanilides with similar IL-12p40 related potency but enhanced selectivity relative to IL-6 production.