Search

Our previously discovered monomeric aptamer for SARS-CoV-2 (MSA52) possesses a universal affinity for COVID-19 spike protein variants but is ultimately limited by its ability to bind only one subunit of the spike protein. The symmetrical shape of the homotrimeric SARS-CoV-2 spike protein presents the opportunity to create a matching homotrimeric molecular recognition element that is perfectly complementary to its structural scaffold, causing enhanced binding affinity. Here, we describe a branched homotrimeric aptamer with three-fold rotational symmetry, named TMSA52, that not only possesses excellent binding affinity but is also capable of binding several SARS-CoV-2 spike protein variants with picomolar affinity, as well as pseudotyped lentiviruses expressing SARS-CoV-2 spike protein variants with femtomolar affinity. Using Pd-Ir nanocubes as nanozymes in an enzyme-linked aptamer binding assay (ELABA), TMSA52 was capable of sensitively detecting diverse pseudotyped lentiviruses in pooled human saliva with a limit of detection as low as 6.3 × 10

Objectives This study aims to investigate what factors correlate with osteopathic medical students’ preparedness to provide care for the LGBTQ+ community through a multi-institutional survey. Context This is one of the few formal research projects to assess the impact of LGBTQ+ medical education on osteopathic students’ comfort level with caring for the community. Methods This study was approved by the IRB at Western University of Health Sciences, Pomona, CA on 11/19/2020. An 18-question survey was created regarding the exposure to the LGBTQ+ population and healthcare education before and after attending osteopathic medical schools. The anonymous survey was electronically distributed at Western University of Health Sciences College of Osteopathic Medicine Pacific and Pacific Northwest, Idaho College of Osteopathic Medicine, Touro University, Philadelphia College of Osteopathic Medicine, Rocky Vista University College of Osteopathic Medicine, and Michigan State University College of Osteopathic Medicine between 1/6/21 and 5/8/21. The survey information was statistically analyzed via SAS University edition. Results The survey had 441 responses: 63% were female, 34% were male, and 3% selected other gender identities. From 441 responses to the survey, 378 responses were analyzed using a logistics regression model to comprehensively model a binary-dependent variable for the students’ preparedness. Students knowing the meaning of the acronym LGBTQ+ (p =0.04) and actively engaging in extracurricular activities for the LGBTQ+ population (p =0.01) showed the strongest correlation based on the logistic regression analysis. Additionally, Chi-square results identified 6 independent variables associated with students’ preparedness to care for the LGBTQ+ population: being a second year or a third year osteopathic medical student (p Conclusions Our study indicates that medical students’ educational exposure through college and medical school is a more correlating influencing factor for their preparedness to care for the LGBTQ+ population in comparison with student’s gender, hometown size, or socioeconomic, geographical, and religious background. Future studies to objectively identify medical students’ preparedness and experience with LGBTQ+ patients, as well as studying effective curricula for filling in knowledge gaps, will be necessary.

We report a simple and rapid saliva‐based SARS‐CoV‐2 antigen test that utilizes a newly developed dimeric DNA aptamer, denoted as DSA1N5, that specifically recognizes the spike proteins of the wildtype virus and its Alpha and Delta variants with dissociation constants of 120, 290 and 480 pM, respectively, and binds pseudotyped lentiviruses expressing the wildtype and alpha trimeric spike proteins with affinity constants of 2.1 pM and 2.3 pM, respectively. To develop a highly sensitive test, DSA1N5 was immobilized onto gold electrodes to produce an electrochemical impedance sensor, which was capable of detecting 1000 viral particles per mL in 1:1 diluted saliva in under 10 min without any further sample processing. Evaluation of 36 positive and 37 negative patient saliva samples produced a clinical sensitivity of 80.5 % and specificity of 100 % and the sensor could detect the wildtype virus as well as the Alpha and Delta variants in the patient samples, which is the first reported rapid test that can detect any emerging variant of SARS‐CoV‐2., Rapid and simple: an electrochemical sensor, based on a high‐affinity dimeric DNA aptamer for the SARS‐CoV‐2 spike protein was developed to detect the wildtype and Alpha and Delta variant in unprocessed saliva samples in 10 minutes, providing a detection limit of 1000 copies mL−1, clinical sensitivity of 80.5 % and specificity of 100 %.

We report on a unique DNA aptamer, denoted MSA52, that displays universally high affinity for the spike proteins of wildtype SARS-CoV-2 as well as the Alpha, Beta, Gamma, Epsilon, Kappa, Delta and Omicron variants. Using an aptamer pool produced from round 13 of selection against the S1 domain of the wildtype spike protein, we carried out one-round SELEX experiments using five different trimeric spike proteins from variants, followed by high-throughput sequencing and sequence alignment analysis of aptamers that formed complexes with all proteins. A previously unidentified aptamer, MSA52, showed K

SummaryThe conserved hemagglutinin stalk domain is an attractive target for broadly effective antibody-based therapeutics and next generation universal influenza vaccines. Protection provided by hemagglutinin stalk binding antibodies is principally mediated through activation of immune effector cells. Titers of stalk-binding antibodies are highly variable on an individual level, and tend to increase with age as a result of increasing exposures to influenza virus. In our study, we show that stalk-binding antibodies cooperate with neuraminidase inhibitors to protect against influenza virus infection in an Fc-dependent manner. These data suggest that the effectiveness of neuraminidase inhibitors is likely influenced by an individual’s titers of stalk-binding antibodies, and that neuraminidase inhibitors may enhance the effectiveness of future stalk-binding monoclonal antibody-based treatments.

UV light, more specifically UV-C light at a wavelength of 254 nm, is often used to disinfect surfaces, air, and liquids. In early 2020, at the cusp of the COVID-19 pandemic, UV light was identified as an efficient means of eliminating coronaviruses; however, the variability in published sensitivity data is evidence of the need for experimental rigor to accurately quantify the effectiveness of this technique. In the current study, reliable and reproducible UV techniques have been adopted, including accurate measurement of light intensity, consideration of fluid UV absorbance, and confirmation of uniform dose delivery, including dose verification using an established biological target (T1UV bacteriophage) and a resistant recombinant virus (baculovirus). The experimental results establish the UV sensitivity of SARS-CoV-2, HCoV-229E, HCoV-OC43, and mouse hepatitis virus (MHV) and highlight the potential for surrogate viruses for disinfection studies. All four coronaviruses were found to be easily inactivated by 254 nm irradiation, with UV sensitivities of 1.7, 1.8, 1.7, and 1.2 mJ/cm2/log10 reduction for SARS-CoV-2, HCoV-229E, HCoV-OC43, and MHV, respectively. Similar UV sensitivities for these species demonstrate the capacity for HCoV-OC43, HCoV-229E, and MHV to be considered surrogates for SARS-CoV-2 in UV-inactivation studies, greatly reducing hazards and simplifying procedures for future experimental studies. IMPORTANCE Disinfection of SARS-CoV-2 is of particular importance due to the global COVID-19 pandemic. UV-C irradiation is a compelling disinfection technique because it can be applied to surfaces, air, and water and is commonly used in drinking water and wastewater treatment facilities. UV inactivation depends on the dose received by an organism, regardless of the intensity of the light source or the optical properties of the medium in which it is suspended. The 254 nm irradiation sensitivity was accurately determined using benchmark methodology and a collimated beam apparatus for four coronaviruses (SARS-CoV-2, HCoV-229E, HCoV-OC43, and MHV), a surrogate indicator organism (T1UV), and a resistant recombinant virus (baculovirus vector). Considering the light distribution across the sample surface, the attenuation of light intensity with fluid depth, the optical absorbance of the fluid, and the sample uniformity due to mixing enable accurate measurement of the fundamental inactivation kinetics and UV sensitivity.

The induction of broadly neutralizing antibodies (bNAbs) that target the hemagglutinin stalk domain is a promising strategy for the development of "universal" influenza virus vaccines. bNAbs can be boosted in adults by sequential exposure to heterosubtypic viruses through natural infection or vaccination. However, little is known about if or how bNAbs are induced by vaccination in more immunologically naive children. Here, we describe the impact of repeated seasonal influenza vaccination and vaccine type on induction of bNAbs against group 1 influenza viruses in a pediatric cohort enrolled in randomized controlled trials of seasonal influenza vaccination. Repeated seasonal vaccination results in significant boosting of a durable bNAb response. Boosting of serological bNAb titers is comparable within inactivated and live attenuated (LAIV) vaccinees and declines with age. These data provide insights into vaccine-elicited bNAb induction in children, which have important implications for the design of universal influenza vaccine modalities in this critical population.

SummaryThe emerging SARS-CoV-2 variants of concern (VOC) increasingly threaten the effectiveness of current first-generation COVID-19 vaccines that are administered intramuscularly and are designed to only target the spike protein. There is thus a pressing need to develop next-generation vaccine strategies to provide more broad and long-lasting protection. By using adenoviral vectors (Ad) of human and chimpanzee origin, we developed Ad-vectored trivalent COVID-19 vaccines expressing Spike-1, Nucleocapsid and RdRp antigens and evaluated them following single-dose intramuscular or intranasal immunization in murine models. We show that respiratory mucosal immunization, particularly with chimpanzee Ad-vectored vaccine, is superior to intramuscular immunization in induction of the three-arm immunity, consisting of local and systemic antibody responses, mucosal tissue-resident memory T cells, and mucosal trained innate immunity. We further show that single-dose intranasal immunization provides robust protection against not only the ancestral strain of SARS-CoV-2, but also two emerging VOC, B.1.1.7 and B.1.351. Our findings indicate that single-dose respiratory mucosal delivery of an Ad-vectored multivalent vaccine represents an effective next-generation COVID-19 vaccine strategy against current and future VOC. This strategy has great potential to be used not only to boost first-generation vaccine-induced immunity but also to expand the breadth of protective T cell immunity at the respiratory mucosa.

The emerging SARS-CoV-2 variants of concern (VOCs) threaten the effectiveness of current COVID-19 vaccines administered intramuscularly and designed to only target the spike protein. There is a pressing need to develop next-generation vaccine strategies for broader and long-lasting protection. Using adenoviral vectors (Ad) of human and chimpanzee origin, we evaluated Ad-vectored trivalent COVID-19 vaccines expressing spike-1, nucleocapsid, and RdRp antigens in murine models. We show that single-dose intranasal immunization, particularly with chimpanzee Ad-vectored vaccine, is superior to intramuscular immunization in induction of the tripartite protective immunity consisting of local and systemic antibody responses, mucosal tissue-resident memory T cells and mucosal trained innate immunity. We further show that intranasal immunization provides protection against both the ancestral SARS-CoV-2 and two VOC, B.1.1.7 and B.1.351. Our findings indicate that respiratory mucosal delivery of Ad-vectored multivalent vaccine represents an effective next-generation COVID-19 vaccine strategy to induce all-around mucosal immunity against current and future VOC.

We performed in vitro selection experiments to identify DNA aptamers for the S1 subunit of the SARS-CoV-2 spike protein (S1 protein). Using a pool of pre-structured random DNA sequences, we obtained over 100 candidate aptamers after 13 cycles of enrichment under progressively more stringent selection pressure. The top 10 sequences all exhibited strong binding to the S1 protein. Two aptamers, named MSA1 (Kd = 1.8 nM) and MSA5 (Kd = 2.7 nM), were assessed for binding to the heat-treated S1 protein, untreated S1 protein spiked into 50% human saliva and the trimeric spike protein of both the wildtype and the B.1.1.7 variant, demonstrating comparable affinities in all cases. MSA1 and MSA5 also recognized the pseudotyped lentivirus of SARS-CoV-2 with respective Kd values of 22.7 pM and 11.8 pM. Secondary structure prediction and sequence truncation experiments revealed that both MSA1 and MSA5 adopted a hairpin structure, which was the motif pre-designed into the original library. A colorimetric sandwich assay was developed using MSA1 as both the recognition element and detection element, which was capable of detecting the pseudotyped lentivirus in 50% saliva with a limit of detection of 400 fM, confirming the potential of these aptamers as diagnostic tools for COVID-19 detection.

In this work, we investigate the use of the guard bands of a linear frequency modulated (LFM) radar waveform for communications. For illustration, quaternary phase-shift keying (QPSK) is used. The effect of the LFM waveform on the symbol error rate (SER) is investigated. Conversely, the effect of injecting the QPSK RF carriers on the radar’s probability of detection (P D ) is also investigated. To reduce the interference on each other, a spectral distance metric is introduced and its effect on SER and P D is evaluated. To mitigate the obvious effect or large radar power compared to communications, radar mainlobe notch filtering, parameter estimation and subtraction are used in the communications receiver. In terms of the radar’s P D , the effect of low-power communications due to the use of the guard bands turns out to be minimal.

The conserved hemagglutinin stalk domain is an attractive target for broadly effective antibody-based therapeutics and next-generation universal influenza vaccines. Protection provided by hemagglutinin stalk-binding antibodies is principally mediated through activation of immune effector cells. Titers of stalk-binding antibodies are highly variable on an individual level and tend to increase with age as a result of increasing exposures to influenza virus. In our study, we show that stalk-binding antibodies cooperate with neuraminidase inhibitors to protect against influenza virus infection in an Fc-dependent manner. These data suggest that the effectiveness of neuraminidase inhibitors is likely influenced by an individual's titers of stalk-binding antibodies and that neuraminidase inhibitors may enhance the effectiveness of future stalk-binding monoclonal antibody-based treatments.

Coronavirus Disease 2019 (COVID-19) is a global pandemic caused by the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). While detection of SARS-CoV-2 by polymerase chain reaction with reverse transcription (RT-PCR) is currently used to diagnose acute COVID-19 infection, serological assays are needed to study the humoral immune response to SARS-CoV-2. Anti-SARS-CoV-2 immunoglobulin (Ig)G/A/M antibodies against spike (S) protein and its receptor-binding domain (RBD) were characterized in recovered subjects who were RT-PCR-positive (n = 153) and RT-PCR-negative (n = 55) using an enzyme-linked immunosorbent assay (ELISA). These antibodies were also further assessed for their ability to neutralize live SARS-CoV-2 virus. Anti-SARS-CoV-2 antibodies were detected in 90.9% of resolved subjects up to 180 days post-symptom onset. Anti-S protein and anti-RBD IgG titers correlated (r= 0.5157 and r= 0.6010, respectively) with viral neutralization. Of the RT-PCR-positive subjects, 22 (14.3%) did not have anti-SARS-CoV-2 antibodies, and of those, 17 had RT-PCR cycle threshold (Ct) values &gt, 27. These high Ct values raise the possibility that these indeterminate results are from individuals who were not infected or had mild infection that failed to elicit an antibody response. This study highlights the importance of serological surveys to determine population-level immunity based on infection numbers as determined by RT-PCR.

IgA is the second most abundant antibody present in circulation and is enriched at mucosal surfaces. As such, IgA plays a key role in protection against a variety of mucosal pathogens, including viruses. In addition to neutralizing viruses directly, IgA can also stimulate Fc-dependent effector functions via engagement of Fc alpha receptors (FcαRI) expressed on the surface of certain immune effector cells. Neutrophils are the most abundant leukocyte, express FcαRI, and are often the first to respond to sites of injury and infection. Here, we describe a novel function for IgA:virus immune complexes (ICs) during viral infections. We show that IgA:virus ICs potentiate NETosis – the programmed cell death pathway through which neutrophils release neutrophil extracellular traps (NETs). Mechanistically, IgA:virus ICs potentiated a suicidal NETosis pathway via engagement of FcαRI on neutrophils through a toll-like receptor (TLR)-independent, NADPH oxidase complex-dependent pathway. NETs also were capable of trapping and inactivating viruses, consistent with an antiviral function.

Coronavirus Disease 2019 (COVID-19) is a global pandemic caused by the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). While detection of SARS-CoV-2 by polymerase chain reaction with reverse transcription (RT-PCR) is currently used to diagnose acute COVID-19 infection, serological assays are needed to study the humoral immune response to SARS-CoV-2. SARS-CoV-2 IgG/A/M antibodies against SARS-CoV-2 spike (S) protein and its receptor-binding domain (RBD) were characterized using an enzyme-linked immunosorbent assay (ELISA) and assessed for their ability to neutralize live SARS-CoV-2 virus in recovered subjects who were RT-PCR-positive (n=153), RT-PCR-negative (n=55), and control samples collected pre-COVID-19 (n=520). Anti-SARS-CoV-2 antibodies were detected in 90.9% of resolved subjects up to 180 days post-symptom onset. Anti-S protein and anti-RBD IgG titers correlated (r= 0.5157 and r = 0.6010, respectively) with viral neutralization. Of the RT-PCR-positive subjects, 22 (14.3%) did not have anti-SARS-CoV-2 antibodies; and of those, 17 had RT-PCR cycle threshold (Ct) values >27, raising the possibility that these indeterminate results are from individuals who were not infected, or had mild infection that failed to elicit an antibody response. This study highlights the importance of serological surveys to determine population-level immunity based on infection numbers as determined by RT-PCR.

A rehabilitation audit was performed comparing admission and discharge values of FIM and Barthel Index (self report) of the last 6 years. The results indicate substantial changes in FIM and BI thus justifying the rehabilitation process. Performing an audit of the used instruments we found a small group of patients (between 6% (post surgery patients) and 26.4% (rheumatological patients)) for whom no overall improvement could be indicated. These patients differ significantly from the other patients in reaching higher values on admission thus indicating a possible ceiling effect in FIM and in BI.

During embryonic development, undifferentiated progenitor cells balance the generation of additional progenitor cells with differentiation. Within the developing limb, cartilage cells differentiate from mesodermal progenitors in an ordered process that results in the specification of the correct number of appropriately sized skeletal elements. The internal process by which these cells maintain an undifferentiated state while preserving their capacity to differentiate is unknown. Here, we report that the arginine methyltransferase PRMT5 has a critical role in maintaining progenitor cells. Mouse embryonic buds lacking PRMT5 have severely truncated bones with wispy digits lacking joints. This novel phenotype is caused by widespread cell death that includes mesodermal progenitor cells that have begun to precociously differentiate into cartilage cells. We propose that PRMT5 maintains progenitor cells through its regulation of Bmp4. Intriguingly, adult and embryonic stem cells also require PRMT5 for maintaining pluripotency, suggesting that similar mechanisms may regulate lineage-restricted progenitor cells during organogenesis.

Anglo-American law instructs jurors that defendants' emotions might constitute mitigating circumstances in murder/manslaughter cases. The present study examined which aspects of defendants' emotions mock jurors take into consideration when determining their murder/manslaughter verdicts. Four factors found to be predictive of perceptions of emotional intensity in previous research were shown to be predictive of murder/manslaughter convictions. These factors included whether the defendant had a history of violence with the victim, the particular emotion experienced, whether the defendant dwelt upon the feelings associated with his or her emotion, and whether the defendant intended the actions associated with his or her emotion. These findings are compared with two approaches that the law has taken to evaluate defendants' emotions: objective standards and subjective standards. Ramifications of these findings for jury instructions as well as for the law's conception of emotion are discussed.

Mock-juries' deliberations of murder/manslaughter verdicts were videotaped and analysed. It was found that jurors' deliberations incorporated their theories of emotion and of the relationship between emotion and reason. Although there was agreement among jurors that emotions can overwhelm persons' rational faculties, there was disagreement between jurors voting for murder and for manslaughter as to the relationship of emotion and reason. Jurors voting for murder suggested emotion and reason are interdependent and that persons can simultaneously act from emotion as well as reason, whereas jurors voting for manslaughter suggested the two are independent and that they cannot operate simultaneously. The import of jurors' folk concepts of emotion and reason to the legal system, as well as to our understanding of emotions themselves, is discussed.

Management decisions and market reactions to those decisions do not occur in isolation. Despite this fact, little or no research has examined two events when they occur in a sequence, even when theory suggests that those two events convey opposite signals. We examine firms that do a stock-based acquisition then announce an open-market repurchase program. These two actions, according to the signaling theory, signal conflicting valuation errors. This paper is the first to examine a sequence of events that convey seemingly conflicting signals. Among other results, we find that repurchasers who had previously made a stock-based acquisition have a less positive market reaction than do otherwise comparable repurchasers with no previous acquisition. These results indicate that the market reactions to events are tempered by previous information-releasing events.

Analyst forecast information is collected for firms following their IPOs and is used in an examination of subsequent seasoned equity offerings (SEOs). Consistent with information asymmetry arguments, the analysis indicates that a larger percentage of firms conducting SEOs within three years of the IPO are covered by financial analysts than those without SEOs, and that analyst coverage is a significant predictor of subsequent SEOs. In addition, the results indicate that long-term earnings growth forecasts are larger for firms with subsequent SEOs, but growth forecasts decline significantly following the SEOs. Further, SEO abnormal returns exhibit a significant negative relationship with earnings growth forecasts. These results are consistent with “windows of opportunity” arguments since they suggest that SEOs are “timed” to coincide with the peak of earnings growth expectations, but that market participants compensate by reacting more negatively to offerings by firms with high growth forecasts.

We examine wealth effects, for banks and insurers, of bank rights to sell and underwrite annuities. The stock-price reactions to four court and regulatory decisions are consistent with expectations of bank gains at insurers’ expense. Cross-sectionally, smaller, riskier insurers with higher distribution costs and substantial annuity business sustain larger wealth losses. Larger, riskier bank-holding companies with fee-based and consumer business gain most, consistent with the extension of federal safety-net guarantees as a source of gains. Banking stock-price reactions to the Supreme Court’s decision are opposite other findings, possibly reflecting unfulfilled expectations of a broader mandate for expanded bank rights.

Corporate governance and managerial behavior, both in terms of entrenchment and financial leverage, have been individually shown to directly affect firm performance and to indirectly affect it through influence on other determinants of performance. Employing an empirical model that captures documented interactions among the explanatory variables, we examine the importance of these integrated factors in an investment decision by focusing on the determinants of bank bidding activity for failed thrift institutions. While the endogenous relationships based on previous research appear tractable, their overall addition to the explanatory power of the bidding model based on traditional auction variables is very limited. These results suggest questions that should be further examined regarding how much managerial variables as defined by previous studies actually affect firm investment decisions once their endogeneity and unique linkages are formally recognized.

Defendants' emotions at the time of their crimes may potentially serve as mitigating circumstances in murder/manslaughter cases. The present study examined whether differences between two forms of instructions given juries in such cases affected mock-juries' murder/manslaughter distinctions. Jurors' reasons for their verdicts and definitions of murder and manslaughter were also compared. In addition, three factors found to be predictive of murder/manslaughter distinctions in previous research were evaluated. It was found that, though instruction forms affected jurors' stated reasons for their verdicts and their definitions of murder and manslaughter, they did not significantly affect murder/manslaughter distinctions. Defendants were most likely to be convicted of murder if they had a history of violence with the victim and dwelt upon their emotions. We suggest jurors likely construe instructions given them to fit their a priori understandings of murder, manslaughter, and the potentially mitigating role of defendants' emotions.