A versatile apparatus for simultaneous trapping of multiple species of ultracold atoms and ions to enable studies of low energy collisions and cold chemistry.

We describe an apparatus where many species of ultracold atoms can be simultaneously trapped and overlapped with many species of ions in a Paul trap. Several design innovations are made to increase the versatility of the apparatus while keeping the size and cost reasonable. We demonstrate the operation of a three-dimensional (3D) magneto-optical trap (MOT) of 7Li using a single external cavity diode laser. The 7Li MOT is loaded from an atomic beam, with atoms slowed using a Zeeman slower designed to work simultaneously for Li and Sr. The operation of a 3D MOT of 133Cs, loaded from a 2D MOT, is demonstrated, and provisions for MOTs of Rb and K in the same vacuum manifold exist. We demonstrate the trapping of 7Li+ and 133Cs+ at different settings of the Paul trap and their detection using an integrated time-of-flight mass spectrometer. We present results on low energy neutral-neutral collisions (133Cs-133Cs, 7Li-7Li, and 133Cs-7Li collisions) and charge-neutral collisions (133Cs+-133Cs and 7Li+-7Li collisions). We show evidence of sympathetic cooling of 7Li+ (133Cs+) due to collisions with the ultracold 7Li (133Cs).

Recent Developments in Metallic Degradable Micromotors for Biomedical and Environmental Remediation Applications.

Synthetic micromotor has gained substantial attention in biomedicine and environmental remediation. Metal-based degradable micromotor composed of magnesium (Mg), zinc (Zn), and iron (Fe) have promise due to their nontoxic fuel-free propulsion, favorable biocompatibility, and safe excretion of degradation products Recent advances in degradable metallic micromotor have shown their fast movement in complex biological media, efficient cargo delivery and favorable biocompatibility. A noteworthy number of degradable metal-based micromotors employ bubble propulsion, utilizing water as fuel to generate hydrogen bubbles. This novel feature has projected degradable metallic micromotors for active in vivo drug delivery applications. In addition, understanding the degradation mechanism of these micromotors is also a key parameter for their design and performance. Its propulsion efficiency and life span govern the overall performance of a degradable metallic micromotor. Here we review the design and recent advancements of metallic degradable micromotors. Furthermore, we describe the controlled degradation, efficient in vivo drug delivery, and built-in acid neutralization capabilities of degradable micromotors with versatile biomedical applications. Moreover, we discuss micromotors' efficacy in detecting and destroying environmental pollutants. Finally, we address the limitations and future research directions of degradable metallic micromotors.

Recent Developments in Engineered Magnesium Scaffolds for Bone Tissue Engineering.

Significant attention has been drawn in recent years to develop porous scaffolds for tissue engineering. In general, porous scaffolds are used for non-load bearing applications. However, various metallic scaffolds have been investigated extensively for hard tissue repair due to their favorable mechanical and biological properties. Stainless steel (316L) and titanium (Ti) alloys are the most commonly used material for metallic scaffolds. Although stainless steel and Ti alloys are employed as scaffold materials, it might result in complications such as stress shielding, local irritation, interference with radiography, etc. related to the permanent implants. To address the above-mentioned complications, degradable metallic scaffolds have emerged as a next generation material. Among the all metallic degradable scaffold materials, magnesium (Mg) based material has gained significant attention owing to its advantageous mechanical properties and excellent biocompatibility in a physiological environment. Therefore, Mg based materials can be projected as load bearing degradable scaffolds, which can provide structural support toward the defected hard tissue during the healing period. Moreover, advanced manufacturing techniques such as solvent cast 3D printing, negative salt pattern molding, laser perforation, and surface modifications can make Mg based scaffolds promising for hard tissue repair. In this article, we focus on the advanced fabrication techniques which can tune the porosity of the degradable Mg based scaffold favorably and improve its biocompatibility.

N-Heterocyclic carbene catalyzed desymmetrization of diols: access to enantioenriched oxindoles having a C3-quaternary stereocenter.

Herein, we describe an effective strategy for enantioselective synthesis of oxindoles having a C3-quaternary stereocenter via N-heterocyclic carbene (NHC) catalyzed desymmetrization of diols. The process is based on the catalytic asymmetric transfer acylation of primary alcohols using readily available aldehydes as an acylation agent. The reaction enables easy access to diversely functionalized C3-quaternary oxindoles with excellent enantioselectivity. The synthetic potential of the process is further demonstrated via the preparation of the key intermediate for (-)-esermethole and (-)-physostigmine.

Synergistic Effects of Cerium and Hot Forging on Biodegradation, Antibacterial Properties, and In Vivo Biocompatibility of Microalloyed Mg-Zr-Sr Alloys.

Biodegradable magnesium (Mg)-based alloys are potential candidates for orthopedic applications. In the present study, we have discussed the effect of cerium (Ce) addition and hot forging on mechanical properties, in vitro-in vivo corrosion, antibacterial activity, and cytocompatibility of microalloyed Mg-0.2Zr-0.1Sr-xCe (x = 0 [MZS], 0.5 wt % [MZS-Ce]) alloys. Addition of 0.5 wt % Ce to forged MZS alloys leads to strengthening of the basal texture as well as formation of a higher fraction of dynamic recrystallized (DRX) grains. Hot forging and addition of cerium to the MZS alloy improve both the yield strength and ultimate tensile strength of the forged MZS-Ce alloy by 1.39 and 1.21 times, respectively, compared to those of the forged MZS alloy. The potentiodynamic polarization test in Hank's solution indicates that the corrosion resistance of the forged MZS alloy improves with addition of 0.5 wt % Ce. Uniform distribution of Mg12Ce precipitates, a higher DRX fraction, strengthened texture, and formation of a compact CeO2 passive layer result in 1.68 times reduction in the immersion corrosion rate of the forged MZS-Ce alloy compared to that of the forged MZS alloy. Addition of Ce to the MZS alloy shows excellent antibacterial activity. The forged MZS-Ce alloy exhibited the highest antibacterial efficacy (76.73%). All the alloys show favorable cytocompatibility and alkaline phosphatase (ALP) activity with MC3T3-E1 cells. The improved corrosion resistance of the forged MZS-Ce alloy (95%) leads to higher cell viability compared to that of the forged MZS alloy (85%). In vivo biodegradation and the ability to generate new bones were analyzed by implanting cylindrical samples in the rabbit femur. Histological analysis showed no adverse effects around the implants. Gradual degradation of the implants and higher new bone formation around the forged MZS-Ce sample were confirmed by micro-CT analysis. Bone regeneration around the implants (58.21%) was validated by flurochrome labeling. After 60 days, the forged MZS-Ce alloy showed controlled corrosion and better bone-implant integration, presenting it as a potential candidate for internal fracture fixation materials.

Stable 671-nm external cavity diode laser with output power exceeding 150†mW suitable for laser cooling of lithium atoms.

We report the design and performance of a Littrow-type 671-nm external cavity diode laser (ECDL) that delivers output power greater than 150 mW and features enhanced passive stability. The main body of the ECDL is constructed using titanium to minimize temperature related frequency drifts. The laser diode is mounted in a cylindrical mount that allows vertical adjustments while maintaining thermal contact with the temperature stabilized baseplate. The wavelength tuning is achieved by horizontal displacement of the diffraction grating about an optimal pivot point. The compact design increases the robustness and passive stability of the ECDL and the stiff but lightweight diffraction grating-arm reduces the susceptibility to low-frequency mechanical vibrations. The linewidth of the ECDL is ∼360 kHz. We use the 671-nm ECDL, without any additional power amplification, for laser cooling and trapping of lithium atoms in a magneto-optical trap. This simple, low-cost ECDL design using off-the-shelf laser diodes without anti-reflection coating can also be adapted to other wavelengths.

Early loss of endogenous NAD+ following rotenone treatment leads to mitochondrial dysfunction and Sarm1 induction that is ameliorated by PARP inhibition.

Sarm1 is an evolutionary conserved innate immune adaptor protein that has emerged as a primary regulator of programmed axonal degeneration over the past decade. In vitro structural insights have revealed that although Sarm1 induces energy depletion by breaking down nicotinamide adenine dinucleotide+ (NAD+ ), it is also allosterically inhibited by NAD+ . However, how NAD+ levels modulate the activation of intracellular Sarm1 has not been elucidated so far. This study focuses on understanding the events leading to Sarm1 activation in both neuronal and non-neuronal cells using the mitochondrial complex I inhibitor rotenone. Here, we report the regulation of rotenone-induced cell death by loss of NAD+ that may act as a 'biological trigger' of Sarm1 activation. Our study revealed that early loss of endogenous NAD+ levels arising due to PARP1 hyperactivation preceded Sarm1 induction following rotenone treatment. Interestingly, replenishing NAD+ levels by the PARP inhibitor, PJ34 restored mitochondrial complex I activity and also prevented subsequent Sarm1 activation in rotenone-treated cells. These cellular data were further validated in Drosophila melanogaster where a significant reduction in rotenone-mediated loss of locomotor abilities, and reduced dSarm expression was observed in the flies following PARP inhibition. Taken together, these observations not only uncover a novel regulation of Sarm1 induction by endogenous NAD+ levels but also point towards an important understanding on how PARP inhibitors could be repurposed in the treatment of mitochondrial complex I deficiency disorders.

Nanoparticles for super-resolution microscopy: intracellular delivery and molecular targeting.

Following an overview of the approaches and techniques used to acheive super-resolution microscopy, this review presents the advantages supplied by nanoparticle based probes for these applications. The various clases of nanoparticles that have been developed toward these goals are then critically described and these discussions are illustrated with a variety of examples from the recent literature.

Hyperfine coupling constants of the cesium 7D5/2 state measured up to the octupole term.

We report the measurement of hyperfine splitting (HFS) in the 7D5/2 state of 133Cs using high-resolution Doppler-free two-photon spectroscopy enabled by precise frequency scans using an acousto-optic modulator (AOM). All six hyperfine levels are resolved in our spectra. We determine the hyperfine coupling constants A = -1.70867(62) MHz and B = 0.050(14) MHz which represent an over 20-times improvement in the precision of both A and B. Moreover, our measurement is sufficiently precise to put bounds on the value of the magnetic octupole coupling constant C = 0.4(1.4) kHz for the 7D5/2 state. We additionally report the measurement of the ac Stark shift [-46 ± 4 Hz/(W/cm2)], collisional shift, and pressure broadening which are important for optical frequency standards based on the 6S1/2 → 7D5/2 two-photon transition.

In Vitro Degradation and In Vivo Biocompatibility of Strontium-Doped Magnesium Phosphate-Reinforced Magnesium Composites.

Magnesium is projected for use as a degradable orthopedic biomaterial. However, its fast degradation in physiological media is considered as a significant challenge for its successful clinical applications. Bioactive reinforcements containing Mg-based composites constitute one of the promising approaches for developing degradable metallic implants because of their adjustable mechanical behaviors, corrosion resistance, and biological response. Strontium is a trace element known for its role in enhancing osteoblast activity. In this study, bioactive SrO-doped magnesium phosphate (MgP)-reinforced Mg composites containing 1, 3, and 5 wt % MgP were developed through the casting route. The influence of the SrO-doped MgP reinforcement on degradation behaviors of the composites along with its cell-material interactions and in vivo biocompatibility was investigated. The wt % and distribution of MgP particles significantly improved the mechanical properties of the composite. HBSS immersion study indicated the least corrosion rate (0.56 ± 0.038 mmpy) for the Mg-3MgP composite. The higher corrosion resistance of Mg-3MgP leads to a controlled release of Sr-containing bioactive reinforcement, which eventually enhanced the cytotoxicity as measured using MG-63 cell-material interactions. The in vivo biocompatibility of the composite was evaluated using the rabbit femur defect model. Micro-computed tomography (µ-CT) and histological analysis supported the fact that Mg-3MgP maintained its structural integrity and enhanced osteogenesis (50.36 ± 2.03%) after 2 months of implantation. The results indicated that the Mg-MgP composite could be used as a degradable internal fracture fixation device material.

Neural sampling machine with stochastic synapse allows brain-like learning and inference.

Many real-world mission-critical applications require continual online learning from noisy data and real-time decision making with a defined confidence level. Brain-inspired probabilistic models of neural network can explicitly handle the uncertainty in data and allow adaptive learning on the fly. However, their implementation in a compact, low-power hardware remains a challenge. In this work, we introduce a novel hardware fabric that can implement a new class of stochastic neural network called Neural Sampling Machine (NSM) by exploiting the stochasticity in the synaptic connections for approximate Bayesian inference. We experimentally demonstrate an in silico hybrid stochastic synapse by pairing a ferroelectric field-effect transistor (FeFET)-based analog weight cell with a two-terminal stochastic selector element. We show that the stochastic switching characteristic of the selector between the insulator and the metallic states resembles the multiplicative synaptic noise of the NSM. We perform network-level simulations to highlight the salient features offered by the stochastic NSM such as performing autonomous weight normalization for continual online learning and Bayesian inferencing. We show that the stochastic NSM can not only perform highly accurate image classification with 98.25% accuracy on standard MNIST dataset, but also estimate the uncertainty in prediction (measured in terms of the entropy of prediction) when the digits of the MNIST dataset are rotated. Building such a probabilistic hardware platform that can support neuroscience inspired models can enhance the learning and inference capability of the current artificial intelligence (AI).

Identification and characterization of novel microRNAs in disease-resistant and disease-susceptible Penaeus monodon.

MicroRNAs (miRNAs), known as a translational regulator, are evolutionary conserved, small, and noncoding RNA. They have played a vital role in disease biology through the host-virus-miRNA-interaction. In this study, novel miRNAs of naturally occurring, virus-free disease-resistant and disease-susceptible Penaeus monodon were identified and characterized. In disease-susceptible samples, 45 homologous mature miRNAs and 28 homologous precursor miRNAs were identified. In disease-resistant samples, 52 homologous mature miRNAs and 87 homologous precursor miRNAs were identified. In disease-susceptible samples, 33 novel mature miRNAs and 33 novel precursor miRNAs were identified. In disease-resistant samples, 523 novel mature miRNAs and 141 novel precursor miRNAs were identified. Differential expression study revealed the up-regulated and down-regulated miRNAs in disease-resistant and disease-susceptible P. monodon. Gene ontology pathway of known and novel miRNAs revealed that P. monodon miRNAs might have a potential and specific role in signal transduction, cell-to-cell signaling, innate immune response and defense response to different pathogens.

Exploring the Thermal Signature of Guilt, Shame, and Remorse.

The recent study of complex emotions using visual storyboards by Bhushan et al. (2020) endorses that same scenario can induce guilt/remorse or guilt/shame in people based on valence. These findings were based on behavioral data and did not consider body physiology. The present study aimed to explore the difference in the thermal signature of scenarios that elicit guilt in some and shame/remorse in others. Using storyboard depicting 13 scenarios, we analyzed the thermal changes on the forehead, eyes (left and right separately), cheek (left and right separately), nose tip, and mouth regions of the face with the objective of exploring the thermal signature of guilt, shame, and remorse. Data were collected from 31 participants using a thermal camera in a laboratory setting. We found a difference of 0.5°C or above change in temperature on the forehead, left and right cheeks, and mouth regions during guilt experience compared to shame and remorse experiences. The temperature of the right and left cheeks was high for guilt as compared to remorse for two scenarios inducing guilt/remorse, and the difference was statistically significant. For one of the scenarios inducing guilt/shame, thermal change in the right eye region was higher for shame as compared to guilt. The findings are discussed in light of the distribution of blood vessels on the face.

Understanding the Switching Mechanisms of the Antiferromagnet/Ferromagnet Heterojunction.

Electric-field-driven spintronic devices are considered promising candidates for beyond CMOS logic and memory applications thanks to their potential for ultralow energy switching and nonvolatility. In this work, we have developed a comprehensive modeling framework to understand the fundamental physics of the switching mechanisms of the antiferromagnet/ferromagnet heterojunction by taking BiFeO3/CoFe heterojunctions as an example. The models are calibrated with experimental results and demonstrate that the switching of the ferromagnet in the antiferromagnet/ferromagnet heterojunction is caused by the rotation of the Neel vector in the antiferromagnet and is not driven by the unidirectional exchange bias at the interface as was previously speculated. Additionally, we demonstrate that the fundamental limit of the switching time of the ferromagnet is in the subnanosecond regime. The geometric dependence and the thermal stability of the antiferromagnet/ferromagnet heterojunction are also explored. Our simulation results provide the critical metrics for designing magnetoelectric devices.

Picking up a Fight: Fine Tuning Mitochondrial Innate Immune Defenses Against RNA Viruses.

As the world faces the challenge of the COVID-19 pandemic, it has become an urgent need of the hour to understand how our immune system sense and respond to RNA viruses that are often life-threatening. While most vaccine strategies for these viruses are developed around a programmed antibody response, relatively less attention is paid to our innate immune defenses that can determine the outcome of a viral infection via the production of antiviral cytokines like Type I Interferons. However, it is becoming increasingly evident that the "cytokine storm" induced by aberrant activation of the innate immune response against a viral pathogen may sometimes offer replicative advantage to the virus thus promoting disease pathogenesis. Thus, it is important to fine tune the responses of the innate immune network that can be achieved via a deeper insight into the candidate molecules involved. Several pattern recognition receptors (PRRs) like the Toll like receptors (TLRs), NOD-like receptors (NLRs), and the retinoic acid inducible gene-I (RIG-I) like receptors (RLRs) recognize cytosolic RNA viruses and mount an antiviral immune response. RLRs recognize invasive viral RNA produced during infection and mediate the induction of Type I Interferons via the mitochondrial antiviral signaling (MAVS) molecule. It is an intriguing fact that the mitochondrion, one of the cell's most vital organelle, has evolved to be a central hub in this antiviral defense. However, cytokine responses and interferon signaling via MAVS signalosome at the mitochondria must be tightly regulated to prevent overactivation of the immune responses. This review focuses on our current understanding of the innate immune sensing of the host mitochondria by the RLR-MAVS signalosome and its specificity against some of the emerging/re-emerging RNA viruses like Ebola, Zika, Influenza A virus (IAV), and severe acute respiratory syndrome-coronavirus (SARS-CoV) that may expand our understanding for novel pharmaceutical development.

Supervised Learning in All FeFET-Based Spiking Neural Network: Opportunities and Challenges.

The two possible pathways toward artificial intelligence (AI)-(i) neuroscience-oriented neuromorphic computing [like spiking neural network (SNN)] and (ii) computer science driven machine learning (like deep learning) differ widely in their fundamental formalism and coding schemes (Pei et al., 2019). Deviating from traditional deep learning approach of relying on neuronal models with static nonlinearities, SNNs attempt to capture brain-like features like computation using spikes. This holds the promise of improving the energy efficiency of the computing platforms. In order to achieve a much higher areal and energy efficiency compared to today's hardware implementation of SNN, we need to go beyond the traditional route of relying on CMOS-based digital or mixed-signal neuronal circuits and segregation of computation and memory under the von Neumann architecture. Recently, ferroelectric field-effect transistors (FeFETs) are being explored as a promising alternative for building neuromorphic hardware by utilizing their non-volatile nature and rich polarization switching dynamics. In this work, we propose an all FeFET-based SNN hardware that allows low-power spike-based information processing and co-localized memory and computing (a.k.a. in-memory computing). We experimentally demonstrate the essential neuronal and synaptic dynamics in a 28 nm high-K metal gate FeFET technology. Furthermore, drawing inspiration from the traditional machine learning approach of optimizing a cost function to adjust the synaptic weights, we implement a surrogate gradient (SG) learning algorithm on our SNN platform that allows us to perform supervised learning on MNIST dataset. As such, we provide a pathway toward building energy-efficient neuromorphic hardware that can support traditional machine learning algorithms. Finally, we undertake synergistic device-algorithm co-design by accounting for the impacts of device-level variation (stochasticity) and limited bit precision of on-chip synaptic weights (available analog states) on the classification accuracy.

Data on optimization of microprojectile bombardment parameters in development of salinity tolerant transgenic lines.

This data deals with the optimization of microprojectile bombardment particles for efficient genetic transformation in an indica rice involving AmSOD gene for development of salinity tolerant transgenic lines [1]. In this study, various parameters such as effect of genotypes, helium pressure, osmoticum, explants, flight distance, particle size, particle volume, vacuum, carrier DNA and stopping screen properties have been evaluated to determine their role in transformation of indica rice involving AmSOD gene for development of salinity tolerant Pusa Basmati 1 rice variety. To perform the transformation process, plasmid vector pCAMBIA 1305.2 was used, which harbours GUS Plus™ gene, intron from the castor bean catalase gene, pBR322 ori, kanamycin resistant gene and Xho I site. The transformants have been confirmed using slot blot, polymerase chain reaction and Southern hybridization techniques.

Recent Developments in Magnesium Metal-Matrix Composites for Biomedical Applications: A Review.

Recently, there is a growing interest in developing magnesium (Mg) based degradable biomaterial. Although corrosion is a concern for Mg, other physical properties, such as low density and Young's modulus, combined with good biocompatibility, lead to significant research and development in this area. To address the issues of corrosion and low yield strength of pure Mg, several approaches have been adopted, such as, composite preparation with suitable bioactive reinforcements, alloying, or surface modifications. This review specifically focuses on recent developments in Mg-based metal matrix composites (MMCs) for biomedical applications. Much effort has gone into finding suitable bioactive, bioresorbable reinforcements and processing techniques that can improve upon existing materials. In summary, this review provides a comprehensive overview of existing Mg-based composite preparation and their mechanical and corrosion properties and biological responses and future perspectives on the development of Mg-based composite biomaterials.

Development and characterization of white spot disease linked microsatellite DNA markers in Penaeus monodon, and their application to determine the population diversity, cluster and structure.

Pathogens that are introduced suddenly to natural populations can potentially cause quick changes to the genetics and diversity of the host. In the past three decades, white spot syndrome virus (WSSV) has caused damaging epizootics in Penaeus monodon populations. In this study, we developed WSSV resistance- or susceptibility-linked microsatellite DNA markers, and their effectiveness was validated experimentally. WSSV-resistant marker linked retroelements and genes that may have an important role in WSSV-resistance phenomena were partially identified. Allelic data of 1,694 samples from nine distinct geographic locations in India were revealed that populations from Digha and Kochi were highly dispersed, and also showed higher genetic diversity, higher population diversity, and lower prevalence of disease resistance. A very high level of gene flow was observed within all populations and a very high level of genetic variation was present within populations. Two genetically admixture population clusters were estimated in nature. WSSV-resistance has a significant link with genetic diversity, population cluster and population diversity. Microsatellite marker analysis characterized genetic divergence, diversity and structure among wild populations.