An ongoing outbreak of pneumonia associated with a novel coronavirus was reported in Wuhan city, Hubei province, China. Affected patients were geographically linked with a local wet market as a ...potential source. No data on person-to-person or nosocomial transmission have been published to date.
In this study, we report the epidemiological, clinical, laboratory, radiological, and microbiological findings of five patients in a family cluster who presented with unexplained pneumonia after returning to Shenzhen, Guangdong province, China, after a visit to Wuhan, and an additional family member who did not travel to Wuhan. Phylogenetic analysis of genetic sequences from these patients were done.
From Jan 10, 2020, we enrolled a family of six patients who travelled to Wuhan from Shenzhen between Dec 29, 2019 and Jan 4, 2020. Of six family members who travelled to Wuhan, five were identified as infected with the novel coronavirus. Additionally, one family member, who did not travel to Wuhan, became infected with the virus after several days of contact with four of the family members. None of the family members had contacts with Wuhan markets or animals, although two had visited a Wuhan hospital. Five family members (aged 36–66 years) presented with fever, upper or lower respiratory tract symptoms, or diarrhoea, or a combination of these 3–6 days after exposure. They presented to our hospital (The University of Hong Kong-Shenzhen Hospital, Shenzhen) 6–10 days after symptom onset. They and one asymptomatic child (aged 10 years) had radiological ground-glass lung opacities. Older patients (aged >60 years) had more systemic symptoms, extensive radiological ground-glass lung changes, lymphopenia, thrombocytopenia, and increased C-reactive protein and lactate dehydrogenase levels. The nasopharyngeal or throat swabs of these six patients were negative for known respiratory microbes by point-of-care multiplex RT-PCR, but five patients (four adults and the child) were RT-PCR positive for genes encoding the internal RNA-dependent RNA polymerase and surface Spike protein of this novel coronavirus, which were confirmed by Sanger sequencing. Phylogenetic analysis of these five patients' RT-PCR amplicons and two full genomes by next-generation sequencing showed that this is a novel coronavirus, which is closest to the bat severe acute respiatory syndrome (SARS)-related coronaviruses found in Chinese horseshoe bats.
Our findings are consistent with person-to-person transmission of this novel coronavirus in hospital and family settings, and the reports of infected travellers in other geographical regions.
The Shaw Foundation Hong Kong, Michael Seak-Kan Tong, Respiratory Viral Research Foundation Limited, Hui Ming, Hui Hoy and Chow Sin Lan Charity Fund Limited, Marina Man-Wai Lee, the Hong Kong Hainan Commercial Association South China Microbiology Research Fund, Sanming Project of Medicine (Shenzhen), and High Level-Hospital Program (Guangdong Health Commission).
An approach for the synthesis of selenaheterocycles starting from aryl diazonium salts was developed. The one‐pot process and subsequent visible‐light‐mediated silver‐catalyzed cyclization enabled ...the synthesis of selenaheterocycles in the absence of a photocatalyst. The reactions were carried out under mild conditions without the use of toxic or sensitive reagents.
Task-related neural activity is widespread across populations of neurons during goal-directed behaviors. However, little is known about the synaptic reorganization and circuit mechanisms that lead to ...broad activity changes. Here we trained a subset of neurons in a spiking network with strong synaptic interactions to reproduce the activity of neurons in the motor cortex during a decision-making task. Task-related activity, resembling the neural data, emerged across the network, even in the untrained neurons. Analysis of trained networks showed that strong untrained synapses, which were independent of the task and determined the dynamical state of the network, mediated the spread of task-related activity. Optogenetic perturbations suggest that the motor cortex is strongly-coupled, supporting the applicability of the mechanism to cortical networks. Our results reveal a cortical mechanism that facilitates distributed representations of task-variables by spreading the activity from a subset of plastic neurons to the entire network through task-independent strong synapses.
A visible‐light‐promoted synthesis of quinoxalin‐2(1H)‐ones has been developed using 9‐mesityl‐10‐methylacridinium perchlorate as an organo‐photocatalyst. The atmosphere‐controlled method (Ar/air) ...enabled the selective synthesis of hydroxyl‐ and acyl‐containing quinoxalin‐2(1H)‐ones under mild reaction conditions without the use of any metal catalysts or toxic reagents. A fluorescent labelling experiment showed that hydroxyl‐containing quinoxalin‐2(1H)‐ones may have utility in various biological applications as potent fluorophores.
An efficient visible‐light‐induced α‐oxidation of N‐substituted tetrahydroisoquinolines to dihydroisoquinolones has been developed using eosin Y as an organo‐photocatalyst and oxygen as a green ...oxidant. The reactions were carried out under mild reaction conditions; the desired dihydroisoquinolones were obtained in up to 96% yield at room temperature under oxygen atmosphere. This transformation provides a convenient route to dihydroisoquinolones with a wide range of substrates.
Spiking activity of neurons engaged in learning and performing a task show complex spatiotemporal dynamics. While the output of recurrent network models can learn to perform various tasks, the ...possible range of recurrent dynamics that emerge after learning remains unknown. Here we show that modifying the recurrent connectivity with a recursive least squares algorithm provides sufficient flexibility for synaptic and spiking rate dynamics of spiking networks to produce a wide range of spatiotemporal activity. We apply the training method to learn arbitrary firing patterns, stabilize irregular spiking activity in a network of excitatory and inhibitory neurons respecting Dale's law, and reproduce the heterogeneous spiking rate patterns of cortical neurons engaged in motor planning and movement. We identify sufficient conditions for successful learning, characterize two types of learning errors, and assess the network capacity. Our findings show that synaptically-coupled recurrent spiking networks possess a vast computational capability that can support the diverse activity patterns in the brain.
The O2-producing Mn4CaO5 catalyst in photosystem II oxidizes two water molecules (substrate) to produce one O2 molecule. Considerable evidence supports the identification of one of the two substrate ...waters as the Mn4CaO5 cluster’s oxo bridge known as O5. The identity of the second substrate water molecule is less clear. In one set of models, the second substrate is the Mn-bound water molecule known as W2. In another set of models, the second substrate is the Ca2+-bound water molecule known as W3. In all of these models, a deprotonated form of the second substrate moves to a position next to O5 during the catalytic step immediately prior to O–O bond formation. In this study, FTIR difference spectroscopy was employed to identify the vibrational modes of hydrogen-bonded water molecules that are altered by the substitution of Sr2+ for Ca2+. Our data show that the substitution substantially altered the vibrational modes of only a single water molecule: the water molecule whose D-O–D bending mode is eliminated during the catalytic step immediately prior to O–O bond formation. These data are most consistent with the identification of the Ca2+-bound W3 as the second substrate involved in O–O bond formation.
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