Genetically encoded dopamine sensors based on green fluorescent protein (GFP) enable high-resolution imaging of dopamine dynamics in behaving animals. However, these GFP-based variants cannot be ...readily combined with commonly used optical sensors and actuators, due to spectral overlap. We therefore engineered red-shifted variants of dopamine sensors called RdLight1, based on mApple. RdLight1 can be combined with GFP-based sensors with minimal interference and shows high photostability, permitting prolonged continuous imaging. We demonstrate the utility of RdLight1 for receptor-specific pharmacological analysis in cell culture, simultaneous assessment of dopamine release and cell-type-specific neuronal activity and simultaneous subsecond monitoring of multiple neurotransmitters in freely behaving rats. Dual-color photometry revealed that dopamine release in the nucleus accumbens evoked by reward-predictive cues is accompanied by a rapid suppression of glutamate release. By enabling multiplexed imaging of dopamine with other circuit components in vivo, RdLight1 opens avenues for understanding many aspects of dopamine biology.
African swine fever virus (ASFV) is a large double-stranded DNA virus with an icosahedral multilayered structure. ASFV causes a lethal swine hemorrhagic disease and is currently responsible for ...widespread damage to the pork industry in Asia. Neither vaccines nor antivirals are available and the molecular characterization of the ASFV particle is outstanding. Here, we describe the cryogenic electron microscopy (cryo-EM) structure of the icosahedral capsid of ASFV at 4.6-Å. The ASFV particle consists of 8,280 copies of the major capsid protein p72, 60 copies of the penton protein, and at least 8,340 minor capsid proteins, of which there might be 3 different types. Like other nucleocytoplasmic large DNA viruses, the minor capsid proteins form a hexagonal network below the outer capsid shell, functioning as stabilizers by “gluing” neighboring capsomers together. Our findings provide a comprehensive molecular model of the ASFV capsid architecture that will contribute to the future development of countermeasures, including vaccines.
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•Cryo-EM structure of the icosahedrally averaged ASFV capsid described at 4.6-Å•ASFV capsid comprises 8,280 major capsid protein p72 and 60 penton protein copies•At least three different minor proteins stabilize capsid by gluing neighboring capsomers•ASFV differs from other NCLDVs in multilayered structure and icosahedral morphology
African swine fever virus (ASFV) is a large DNA virus that causes a lethal swine hemorrhagic disease and is currently responsible for widespread outbreaks in domestic pigs. Liu et al. describe the cryo-EM structure of ASFV capsid at 4.6-Å, which reveals several critical proteins and structural elements.
Serotonin plays a central role in cognition and is the target of most pharmaceuticals for psychiatric disorders. Existing drugs have limited efficacy; creation of improved versions will require ...better understanding of serotonergic circuitry, which has been hampered by our inability to monitor serotonin release and transport with high spatial and temporal resolution. We developed and applied a binding-pocket redesign strategy, guided by machine learning, to create a high-performance, soluble, fluorescent serotonin sensor (iSeroSnFR), enabling optical detection of millisecond-scale serotonin transients. We demonstrate that iSeroSnFR can be used to detect serotonin release in freely behaving mice during fear conditioning, social interaction, and sleep/wake transitions. We also developed a robust assay of serotonin transporter function and modulation by drugs. We expect that both machine-learning-guided binding-pocket redesign and iSeroSnFR will have broad utility for the development of other sensors and in vitro and in vivo serotonin detection, respectively.
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•Developed a machine learning approach for rapid binding-pocket redesign•Engineered a high dynamic range, sensitive, selective sensor for 5-HT: iSeroSnFR•Demonstrated the use of iSeroSnFR for fiber photometry in awake behaving mice•Developed a clinically relevant assay using iSeroSnFR for 5-HT transporter function
Machine-learning-guided binding-pocket redesign enables engineering of genetically encoded sensor for serotonin that detects serotonin release in freely behaving mice and is used for the development of an assay for serotonin transporter function and modulation by drugs.
Compared to higher-precision data formats, lower-precision data formats result in higher performance for computational intensive applications on FPGAs because of their lower resource cost, reduced ...memory bandwidth requirements, and higher circuit frequency. On the other hand, scientific computations usually demand highly accurate solutions. This paper seeks to utilize lower-precision data formats whenever possible for higher performance without losing the accuracy of higher-precision data formats by using mixed-precision algorithms and architectures. First, we analyze the floating-point performance of different data formats on FPGAs. Second, we introduce mixed-precision iterative refinement algorithms for linear solvers and give error analysis. Finally, we propose an innovative architecture for a mixed-precision direct solver for reconfigurable computing. Our results show that our mixed-precision algorithm and architecture significantly improve the performance of linear solvers on FPGAs.
The recent outbreak of mpox epidemic, caused by monkeypox virus (MPXV), poses a new threat to global public health. Here, we initially assessed the preexisting antibody level to the MPXV B6 protein ...in vaccinia vaccinees born before the end of the immunization program and then identified two monoclonal antibodies (MAbs), hMB621 and hMB668, targeting distinct epitopes on B6, from one vaccinee. Binding assays demonstrate that both MAbs exhibit broad binding abilities to B6 and its orthologs in vaccinia (VACV), variola (VARV) and cowpox viruses (CPXV). Neutralizing assays reveal that the two MAbs showed potent neutralization against VACV. Animal experiments using a BALB/c female mouse model indicate that the two MAbs showed effective protection against VACV via intraperitoneal injection. Additionally, we determined the complex structure of B6 and hMB668, revealing the structural feature of B6 and the epitope of hMB668. Collectively, our study provides two promising antibody candidates for the treatment of orthopoxvirus infections, including mpox.
Applying the B3LYP calculations, the reactivity and sensitivity of a graphyne-like BN sheet (BN-yne) were explored toward NO2 gas. The NO2 molecule preferentially adsorbs via its both oxygen atoms ...simultaneously on two B atoms of both –BN– linkage and hexagonal ring with adsorption energy of −12.5) kcal/mol. The NO2 gas increases the electrical conductance of BN-yne sheet by stabilizing the LUMO level. The electrical conductance of NO2/BN-yne complex is predicted to be much higher than that of the pristine BN-yne nanosheet. We showed that the NO2 gas interacts faster and stronger than the SO2, NH3, CO2, O2, H2O, and N2 gases with the BN-yne sheet, quickly occupying the adsorption sites. Therefore, we conclude that the BN-yne sheet may be promising selective sensor for NO2 gas in the presence of these gases. The recovery time for NO2 desorption from the surface of BN-yne is predicted to be 0.14 ms at room temperature, indicating a short time.
This technical note is concerned with the problem of controlling plants over communication channels, where the plant is subject to two types of unstructured uncertainty: additive uncertainty and ...stable coprime factor uncertainty. Necessary lower bounds on the rate of transmission (or channel capacity) C , for robust stabilization, are computed explicitly. In particular, it is shown that the lower bound in the additive uncertainty case corresponds to a fixed point of a particular function. In the stable coprime factor uncertainty case, the derivation relies on linear fractional transformation concepts. The results are important in determining the minimum channel capacity needed in order to stabilize plants subject to unstructured uncertainty over communication channels. For instance, the bounds obtained can be used to analyze the effect of uncertainty on the channel capacity. An illustrative example is provided.
Multiple SARS-CoV-2 Omicron sub-variants, such as BA.2, BA.2.12.1, BA.4, and BA.5, emerge one after another. BA.5 has become the dominant strain worldwide. Additionally, BA.2.75 is significantly ...increasing in some countries. Exploring their receptor binding and interspecies transmission risk is urgently needed. Herein, we examine the binding capacities of human and other 28 animal ACE2 orthologs covering nine orders towards S proteins of these sub-variants. The binding affinities between hACE2 and these sub-variants remain in the range as that of previous variants of concerns (VOCs) or interests (VOIs). Notably, R493Q reverse mutation enhances the bindings towards ACE2s from humans and many animals closely related to human life, suggesting an increased risk of cross-species transmission. Structures of S/hACE2 or RBD/hACE2 complexes for these sub-variants and BA.2 S binding to ACE2 of mouse, rat or golden hamster are determined to reveal the molecular basis for receptor binding and broader interspecies recognition.
A parafoil delivery system has usually been used in the fields of military and civilian airdrop supply and aircraft recovery in recent years. However, since the altitude of the unpowered parafoil is ...monotonically decreasing, it is limited by the initial flight altitude. Thus, combining the multiple constraints, such as the ground obstacle avoidance and flight time, it puts forward a more stringent standard for the real-time performance of trajectory planning of the parafoil delivery system. Thus, to enhance the real-time performance, we propose a new parafoil trajectory planning method based on an improved twin delayed deep deterministic policy gradient. In this method, by pre-evaluating the value of the action, a scale of noise will be dynamically selected for improving the globality and randomness, especially for the actions with a low value. Furthermore, not like the traditional numerical computation algorithm, by building the planning model in advance, the deep reinforcement learning method does not recalculate the optimal flight trajectory of the system when the parafoil delivery system is launched at different initial positions. In this condition, the trajectory planning method of deep reinforcement learning has greatly improved in real-time performance. Finally, several groups of simulation data show that the trajectory planning theory in this paper is feasible and correct. Compared with the traditional twin delayed deep deterministic policy gradient and deep deterministic policy gradient, the landing accuracy and success rate of the proposed method are improved greatly.
Doxorubicin (Dox) is a potent anticancer agent that is widely used in the treatment of a variety of cancers, but its usage is limited by cumulative dose-dependent cardiotoxicity mainly due to ...oxidative damage. Ataxia telangiectasia mutated (ATM) kinase is thought to play a role in mediating the actions of oxidative stress. Here, we show that ATM in cardiac fibroblasts is essential for Dox-induced cardiotoxicity.
ATM knockout mice showed attenuated Dox-induced cardiotoxic effects (e.g. cardiac dysfunction, apoptosis, and mortality). As ATM was expressed and activated predominantly in cardiac fibroblasts, fibroblast-specific Atm-deleted mice (Atm(fl/fl);Postn-Cre) were generated to address cell type-specific effects, which showed that the fibroblast is the key lineage mediating Dox-induced cardiotoxicity through ATM. Mechanistically, ATM activated the Fas ligand, which subsequently regulated apoptosis in cardiomyocytes at later stages. Therapeutically, a potent and selective inhibitor of ATM, KU55933, when administered systemically was able to prevent Dox-induced cardiotoxicity.
ATM-regulated effects within cardiac fibroblasts are pivotal in Dox-induced cardiotoxicity, and antagonism of ATM and its functions may have potential therapeutic implications.
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