Hierarchical Materials from High Information Content Macromolecular Building Blocks: Construction, Dynamic Interventions, and Prediction.

Hierarchical materials that exhibit order over multiple length scales are ubiquitous in nature. Because hierarchy gives rise to unique properties and functions, many have sought inspiration from nature when designing and fabricating hierarchical matter. More and more, however, nature's own high-information content building blocks, proteins, peptides, and peptidomimetics, are being coopted to build hierarchy because the information that determines structure, function, and interfacial interactions can be readily encoded in these versatile macromolecules. Here, we take stock of recent progress in the rational design and characterization of hierarchical materials produced from high-information content blocks with a focus on stimuli-responsive and "smart" architectures. We also review advances in the use of computational simulations and data-driven predictions to shed light on how the side chain chemistry and conformational flexibility of macromolecular blocks drive the emergence of order and the acquisition of hierarchy and also on how ionic, solvent, and surface effects influence the outcomes of assembly. Continued progress in the above areas will ultimately usher in an era where an understanding of designed interactions, surface effects, and solution conditions can be harnessed to achieve predictive materials synthesis across scale and drive emergent phenomena in the self-assembly and reconfiguration of high-information content building blocks.

Structural Basis of the Mechanisms of Action and Immunity of Lactococcin A, a Class IId Bacteriocin.

Lactococcin A (LcnA), a class IId bacteriocin, induces membrane leakage and cell death by specifically binding to the membrane receptor-mannose phosphotransferase system (man-PTS), as is the case for pediocin-like (class IIa) bacteriocins. The cognate immunity protein of bacteriocins, which protects the producer cell from its own bacteriocin, recognizes and binds to the bacteriocin-man-PTS complex, consequently blocking membrane leakage. We previously deciphered the mode of action and immunity of class IIa bacteriocins. Here, we determined the structure of the ternary complex of LcnA, LciA (i.e., the immunity protein), and its receptor, i.e., the man-PTS of Lactococcus lactis (ll-man-PTS). An external loop on the membrane-located component IIC of ll-man-PTS was found to prevent specific binding of the N-terminal region of LcnA to the site recognized by pediocin-like bacteriocins. Thus, the N-terminal ß-sheet region of LcnA recognized an adjacent site on the extracellular side of ll-man-PTS, with the LcnA C-terminal hydrophobic helix penetrating into the membrane. The cytoplasmic cleft formed within the man-PTS Core and Vmotif domains induced by embedded LcnA from the periplasmic side is adopted by the appropriate angle between helices H3 and H4 of the N terminus of LciA. The flexible C terminus of LciA then blocks membrane leakage. To summarize, our findings reveal the molecular mechanisms of action and immunity of LcnA and LciA, laying a foundation for further design of class IId bacteriocins. IMPORTANCE Class IId (lactococcin-like) bacteriocins and class IIa (pediocin-like) bacteriocins share a few similarities: (i) both induce membrane leakage and cell death by specifically binding the mannose phosphotransferase system (man-PTS) on their target cells, and (ii) cognate immunity proteins recognize and bind to the bacteriocin-man-PTS complex to block membrane leakage. However, class IId bacteriocins lack the "pediocin box" motif, which is typical of class IIa bacteriocins, and basically target only lactococcal cells; in contrast, class IIa bacteriocins target diverse bacterial cells, but not lactococcal cells. We previously solved the structure of class IIa bacteriocin-receptor-immunity ternary complex from Lactobacillus sakei. Here, we determined the structure of the ternary complex of class IId bacteriocin LcnA, its cognate immunity protein LciA, and its receptor, the man-PTS of Lactococcus lactis. By comparing the interactions between man-PTS and class IIa and class IId bacteriocins, this study affords some clues to better understand the specificity of bacteriocins targeting the mannose phosphotransferase system.

Association of COVID-19 vaccination before conception with maternal thyroid function during early pregnancy: A single-center study in China.

Despite the high vaccination coverage, potential COVID-19 vaccine-induced adverse effects, especially in pregnant women, have not been fully characterized. We examined the association between COVID-19 vaccination before conception and maternal thyroid function during early pregnancy. We conducted a retrospective cohort study in Shanghai, China. A total of 6979 pregnant women were included. Vaccine administration was obtained from electronic vaccination records. Serum levels of thyroid hormone were measured by fluorescence and chemiluminescence immunoassays. Among the 6979 included pregnant women, 3470 (49.7%) received at least two doses of an inactivated vaccine. COVID-19 vaccination had a statistically significant association with both maternal serum levels of free thyroxine (FT4) and thyroid stimulating hormone (TSH). Compared with unvaccinated pregnant women, the mean FT4 levels were lower in pregnant women who had been vaccinated within 3 months before the date of conception by 0.27 pmol/L (ß = -0.27, 95% confidence interval [CI], -0.42, -0.12), and the mean TSH levels were higher by 0.08 mIU/L (ß = 0.08, 95% CI, 0.00, 0.15). However, when the interval from vaccination to conception was prolonged to more than 3 months, COVID-19 vaccination was not associated with serum FT4 or TSH levels. Moreover, we found that COVID-19 vaccination did not significantly associate with maternal hypothyroidism. Our study suggested that vaccination with inactivated COVID-19 vaccines before conception might result in a small change in maternal thyroid function, but this did not reach clinically significant levels.

No association of vaccination with inactivated COVID-19 vaccines before conception with pregnancy complications and adverse birth outcomes: A cohort study of 5457 Chinese pregnant women.

Data on the safety of inactivated COVID-19 vaccines in pregnant women is limited and monitoring pregnancy outcomes is required. We aimed to examine whether vaccination with inactivated COVID-19 vaccines before conception was associated with pregnancy complications or adverse birth outcomes. We conducted a birth cohort study in Shanghai, China. A total of 7000 healthy pregnant women were enrolled, of whom 5848 were followed up through delivery. Vaccine administration information was obtained from electronic vaccination records. Relative risks (RRs) of gestational diabetes mellitus (GDM), hypertensive disorders in pregnancy (HDP), intrahepatic cholestasis of pregnancy (ICP), preterm birth (PTB), low birth weight (LBW), and macrosomia associated with COVID-19 vaccination were estimated by multivariable-adjusted log-binomial analysis. After exclusion, 5457 participants were included in the final analysis, of whom 2668 (48.9%) received at least two doses of an inactivated vaccine before conception. Compared with unvaccinated women, there was no significant increase in the risks of GDM (RR = 0.80, 95% confidence interval [CI], 0.69, 0.93), HDP (RR = 0.88, 95% CI, 0.70, 1.11), or ICP (RR = 1.61, 95% CI, 0.95, 2.72) in vaccinated women. Similarly, vaccination was not significantly associated with any increased risks of PTB (RR = 0.84, 95% CI, 0.67, 1.04), LBW (RR = 0.85, 95% CI, 0.66, 1.11), or macrosomia (RR = 1.10, 95% CI, 0.86, 1.42). The observed associations remained in all sensitivity analyses. Our findings suggested that vaccination with inactivated COVID-19 vaccines was not significantly associated with an increased risk of pregnancy complications or adverse birth outcomes.

Real-infraredSR: real-world infrared image super-resolution via thermal imager.

Infrared image super-resolution technology aims to overcome the pixel size limitation of the infrared focal plane array for higher resolution images. Due to the real-world images with different resolutions having more complex degradation processes than mathematical calculation, most existing super-resolution methods using the synthetic data obtained by bicubic interpolation achieve unsatisfactory reconstruction performance in real-world scenes. To solve this, this paper innovatively proposes an infrared real-world dataset with different resolutions based on a refrigerated thermal detector and the infrared zoom lens, enabling the network to acquire more realistic details. We obtain images under different fields of view by adjusting the infrared zoom lens and then achieve the scale and luminance alignment of high and low-resolution (HR-LR) images. This dataset can be used for infrared image super-resolution, with an up-sampling scale of two. In order to learn complex features of infrared images efficiently, an asymmetric residual block structure is proposed to effectively reduce the number of parameters and improve the performance of the network. Finally, to solve the slight misalignment problem in the pre-processing stage, contextual loss and perceptual loss are introduced to improve the visual performance. Experiments show that our method achieves superior results both in reconstruction effect and practical value for single infrared image super-resolution in real scenarios.

Catalyst-free electrochemical trifluoromethylation of coumarins using CF3SO2NHNHBoc as the CF3 source.

An efficient electrochemical trifluoromethylation of coumarins using CF3SO2NHNHBoc as the source of the trifluoromethyl group was developed. Under catalyst-free and external oxidant-free electrolysis conditions, a range of 3-trifluoromethyl coumarins were obtained in moderate to good yields. The method could be easily scaled up with moderate efficiency.

VILO SLAM: Tightly Coupled Binocular Vision-Inertia SLAM Combined with LiDAR.

For the existing visual-inertial SLAM algorithm, when the robot is moving at a constant speed or purely rotating and encounters scenes with insufficient visual features, problems of low accuracy and poor robustness arise. Aiming to solve the problems of low accuracy and robustness of the visual inertial SLAM algorithm, a tightly coupled vision-IMU-2D lidar odometry (VILO) algorithm is proposed. Firstly, low-cost 2D lidar observations and visual-inertial observations are fused in a tightly coupled manner. Secondly, the low-cost 2D lidar odometry model is used to derive the Jacobian matrix of the lidar residual with respect to the state variable to be estimated, and the residual constraint equation of the vision-IMU-2D lidar is constructed. Thirdly, the nonlinear solution method is used to obtain the optimal robot pose, which solves the problem of how to fuse 2D lidar observations with visual-inertial information in a tightly coupled manner. The results show that the algorithm still has reliable pose-estimation accuracy and robustness in many special environments, and the position error and yaw angle error are greatly reduced. Our research improves the accuracy and robustness of the multi-sensor fusion SLAM algorithm.

The impact of fiscal transfer payments on energy conservation and emission reduction in China: Does the development stage matter?

Fiscal transfer payments (TRANS) are the institutional supplement of Chinese-style fiscal decentralization, which is of great significance to economic development. However, the relationship between TRANS and energy conservation and emission reduction (ECER) remains to be further discussed. Using panel data of 30 provinces in China from 2003 to 2020, this study empirically examines the impact of TRANS on energy-environmental performance (EEP) from the perspectives of influence mechanism, regional heterogeneity and nonlinearity. The results show that the influence of TRANS on ECER presents an obvious U-shaped relationship, and this influence has regional heterogeneity. At the same time, the investment-driven effect, infrastructure effect and industrial structure effect are important channels through which TRANS affect ECER. The partially linear functional coefficient models show that TRANS have different effects in different development stages. With the continuous improvement of economic level and urbanization level, the promotion effect of TRANS on ECER is more and more obvious. These results indicate that the government should increase fiscal investment in ECER, and pay attention to the development stage of different regions.

Red-diode-clad-pumped CW and mode-locked Er:ZBLAN fiber laser at 3.5†µm.

We report on a red-diode-clad-pumped continuous-wave (CW) and mode-locked Er:ZBLAN fiber laser at 3.5 µm for the first time. Numerical simulation shows that a heavily-doped Er:ZBLAN fiber is favorable for effective generation of 3.5 µm laser through 658 nm laser diode pumping. Using a 7.0 mol.% Er:ZBLAN fiber, CW output power of 203 mW was experimentally obtained at 3462 nm. By incorporating a home-made semiconductor saturable absorber mirror into the cavity, diode-pumped CW mode-locked 3.5 µm Er:ZBLAN fiber laser was first demonstrated with an average power of 19 mW, a pulse duration of 18.1 ps, and a repetition rate of 46 MHz. The research results show that red-diode-clad-pumping provides a simple and potential scheme for 3.5 µm CW and mode-locked Er:ZBLAN fiber laser.

2-MW peak-power pulses from a dispersion-managed fluoride fiber amplifier at 2.8 µm.

We report on a scheme of pulse amplification and simultaneous self-compression in fluoride fiber for generating a high-peak-power pulse at 2.8-µm wavelength. We find dispersion management plays a key role for the amplification and self-compression process. Through dispersion management with a Ge rod, pulse amplification and simultaneous pulse self-compression were realized in the small anomalous dispersion region. A 2-MW peak-power pulse was achieved through amplification and self-compression in Er:ZBLAN fiber, with pulse energy of 101 nJ and pulse duration of 49 fs. To the best of our knowledge, this is the highest peak power obtained from fluoride fiber at 2.8 µm, and will benefit a series of applications.

Functional characterization of Kid-Kis and MazF-MazE in Sf9 cells and Mythimna separata embryos.

Toxin-antitoxin (TA) systems are comprised of a toxin and its antidote antitoxin and are widely present in bacterial and in eukaryotic systems. However, no work regarding TA systems has been reported in insects. We characterized the Kid-Kis and MazF-MazE TA systems in Spodoptera frugiperda cells and Mythimna separata embryos and observed that the Kid and MazF toxins were highly toxic. In Sf9 cells transfected with Kid plasmid and MazF alone, the apoptosis rate was 24.37% and 29.47%, respectively. Whereas the toxicity of their cognate antitoxins were limited. Both apoptosis and necrosis were induced by the two toxins. Both the Kis and MazE antitoxins partly neutralized toxicity in a dose-dependent manner, with MazE accomplishing almost full neutralization at a 1:4 toxin:antitoxin ratio, the cell survival rate was 81% and 97%, respectively. Our results indicate that MazF-MazE is a good candidate module for application in insects, such as in developing new sterile insect technique (SIT).

Rational design of secondary operation for penetrating head injury: A case report.

Penetrating head injury is rare, and thus management of such injuries is non-standard. Early diagnosis and intraoperative comprehensive exploration are necessary considering the complexity and severity of the trauma. However, because of the lack of microsurgical techniques in local hospitals, the possible retained foreign bodies and other postoperative complications such as cerebrospinal fluid (CSF) leak usually require a rational design for a secondary operation to deal with. We present a case of a 15-year-old boy who was stabbed with a bamboo stick in his left eye. The chopsticks passed through the orbit roof and penetrated the skull base. In subsequent days, the patient sustained CSF leak and intracranial infection after an unsatisfied primary treatment in the local hospital and had to request a secondary operation in our department. Computed tomography including plain scan, three dimension reconstruction and computed tomographic angiography are used to determine the course and extent of head injury. A frontal craniotomy was performed. Three pieces of stick were found residual and removed with the comminuted orbit bone fragments. A pedicled temporalis muscle fascia graft was applied to repair the frontier skull base and a free temporalis muscle flap to seal the frontal sinus defect. Aggressive broad-spectrum antibiotics of vancomycin and meropenem were administrated for persistent fever after operation. CSF external drainage system continued for 12 days, and was removed 10 days after temperature returned to normal. The Glasgow coma scale score was improved to 15 at postoperative day 7 and the patient was discharged at day 22 uneventfully. We believe that appropriate preoperative surgical plan and thorough surgical exploration by microsurgery is essential for attaining a favorable outcome, especially in secondary operation. Good postoperative recovery depends on successfully management before and after operation for possible complications as well.

[The scalp localization system of neurosurgery based on augmented reality theory].

Neurosurgery navigation system, which is expensive and complicated to operate, has a low penetration rate, and is only found in some large medical institutions. In order to meet the needs of other small and medium-sized medical institutions for neurosurgical navigation systems, the scalp localization system of neurosurgery based on augmented reality (AR) theory was developed. AR technology is used to fuse virtual world images with real images. The system integrates computed tomography (CT) or magnetic resonance imaging (MRI) with the patient's head in real life to achieve the scalp positioning. This article focuses on the key points of Digital Imaging and Communications in Medicine (DICOM) standard, three-dimensional (3D) reconstruction, and AR image layer fusion in medical image visualization. This research shows that the system is suitable for a variety of mobile phones, can achieve two-dimensional (2D) image display, 3D rendering and clinical scalp positioning application, which has a certain significance for the auxiliary neurosurgical head surface positioning.

One-year outcome of patients with posttraumatic hydrocephalus treated by lumboperitoneal shunt: an observational study from China.

BACKGROUND: Lumboperitoneal shunt (LPS) attracts increasing number of research interest in the treatment of hydrocephalus due to minimal invasiveness. However, the outcome of LPS-treated posttraumatic hydrocephalus (PTH) is poorly learnt, remaining unknown to date. METHODS: We retrospectively analyzed adult patients with PTH treated by LPS in our department between May 2013 and Apr 2017. Baseline characteristics, preoperative clinical features, symptomatic and imageologic improvement, and postoperative complications were synchronously investigated. All patients were followed up to 1 year after LPS to determine the shunt outcome and quality of life. Furthermore, the Kaplan-Meier curve was drawn and binary logistic regression analysis was used to identify the possible predictive factors of shunt failure. RESULTS: Thirty-eight eligible patients were included in our study. Five days after LPS, chronic hydrocephalus scores (CHS; 10.26 ± 5.17 vs 5.21 ± 3.75; P < 0.001) and Evans index (0.36 ± 0.06 vs 0.28 ± 0.06; P < 0.001) were significantly improved with statistical difference. The overall incidence of complications was 50% (19 patients) while hydrocephalus-associated death or shunt failure was not observed immediately after LPS. According to the 1-year follow-up, most of the patients obtained good prognosis while 16 patients (42.1%) were failed, including 15 patients (39.5%) underwent shunt revision and one patient (2.6%) was dead ascribing to shunt malfunction. However, we failed to screen out any factors contributing to LPS failure. CONCLUSION: To sum up, we have, for the first time, demonstrated that LPS could be a potential option to treat PTH.

Socio-economic factors related with the subjective well-being of the rural elderly people living independently in China.

BACKGROUND: Many Chinese elderly increasingly face the serious problem of the "empty nest" phenomenon. The elderly living independently, also called empty-nest elderly, refers to elderly people living alone whose children left home. However few studies concerned about the subjective well-being (SWB) of the elderly living independently. METHODS: This study employs The Memorial University of Newfoundland Scale of Happiness (MUNSH) to explore the SWB of the elderly living independently in rural areas of Wenzhou, a relatively developed region in China. 536 sampled are randomly selected. RESULTS: The results indicate that participants obtained low scores in positive affect, positive experience, and the total SWB score, but high scores in negative affect and negative experience. Age, low education, poor health condition and little income were found to be negatively correlated with SWB. The SWB score of the elderly living with a spouse is higher than those who divorced or lost their spouse and the score of women is lower than that of men. In addition, the survey revealed that children's support has a positive influence on the SWB of the rural elderly living independently. CONCLUSIONS: The elderly living independently in rural Wenzhou, China have unfavorable SWB. Poor socio-economic statuses are negative impact factors. But the children's support can help to improve. Special attention is needed to those with lower socio-economic status and less children's support.

A comparative study of grain quality and physicochemical properties of premium japonica rice from three typical production regions.

Grain quality indicates rice commodity value. This research compared grain quality and physicochemical properties of premium japonica rice from three production regions, Yangtze River downstream of China (YRDCN), Northeast region of China (NECN) and Japan. Results showed that there were distinct quality and physicochemical characteristics variance among the three groups of japonica rice, while CVs of most quality parameters from low to high was Japan, YRDCN and NECN. YRDCN rice presented obvious lower apparent amylose content (AAC) and ratio of each chain-length sections of amylopectin, and showed higher protein contents especially glutelin and ratio in short and intermediate amylopectin molecules. Among three rice groups, YRDCN rice presented weaker appearance, whereas did not show inferior cooking and eating properties, which was primarily linked to lower AAC. Rice AAC and starch fine structure significantly correlated with pasting parameters, swelling power and solubility, while protein content had close relation with taste analyzer parameters. Results of this study indicated improvement direction for japonica rice of YRDCN, and also provided reference for consumers' rice purchasing selection in accordance with individual taste preference.

Pyroelectric-Accelerated Perovskite Photodetector for Picosecond Light Detection and Ranging.

Light detection and ranging (LiDAR) is indispensable in applications such as unmanned aerial vehicles, autonomous driving, and biomimetic robots. However, the precision and available distance of LiDAR are constrained by the speed and sensitivity of the photodetector, necessitating the use of expensive and energy-consuming avalanche diodes. To address these challenges, in this study, a pyroelectricity-based acceleration strategy with 2D-(graded 3D) perovskite heterojunction is proposed to achieve a record high speed (27.7 ns with an active area of 9 mm2, and 176 ps with an active area of 0.2 mm2) and high responsivity (0.65 A W-1) at zero bias. This success is attributed to the unique mechanism where the electrons from the pyroelectric effect at the Cl-rich 2D/3D interface directly recombine with excess holes during light-dark transitions, breaking speed limitations related to carrier mobility and capacitive effect. Furthermore, the introduced pyroelectric effect significantly enhances the photoresponse, resulting in a self-powered external quantum efficiency exceeding 100%. The study also demonstrates precise position detection at the centimeter level. In conclusion, this research presents a pioneering approach for developing high-speed photodiodes with exceptional sensitivity, mitigating energy and cost concerns in LiDAR applications.

Magnetodielectric Effect in a Triangular Dysprosium Single-Molecule Toroics.

Single-molecule toroics are molecular magnets with vortex distribution of magnetic moments. The coupling between magnetic and electric properties such as the magnetodielectric effect will provide potential applications for them. Herein, the observation of significant magnetodielectric effect in a triangular Dy3 crystal with toroidal magnetic moment and multiple magnetic relaxations is reported. The analysis of magnetic and electric properties implies that the magnetodielectric effect is closely related to the strong spin-lattice coupling, magnetic interactions of Dy3+ ions, as well as molecular packing models.

Assembly of short amphiphilic peptoids into nanohelices with controllable supramolecular chirality.

A long-standing challenge in bioinspired materials is to design and synthesize synthetic materials that mimic the sophisticated structures and functions of natural biomaterials, such as helical protein assemblies that are important in biological systems. Herein, we report the formation of a series of nanohelices from a type of well-developed protein-mimetics called peptoids. We demonstrate that nanohelix structures and supramolecular chirality can be well-controlled through the side-chain chemistry. Specifically, the ionic effects on peptoids from varying the polar side-chain groups result in the formation of either single helical fiber or hierarchically stacked helical bundles. We also demonstrate that the supramolecular chirality of assembled peptoid helices can be controlled by modifying assembling peptoids with a single chiral amino acid side chain. Computational simulations and theoretical modeling predict that minimizing exposure of hydrophobic domains within a twisted helical form presents the most thermodynamically favorable packing of these amphiphilic peptoids and suggests a key role for both polar and hydrophobic domains on nanohelix formation. Our findings establish a platform to design and synthesize chiral functional materials using sequence-defined synthetic polymers.

Miniature integrated spectrometers towards high-performance and cost-effective.

The conjugated mode of bound states in a continuum is integrated as a narrowband wavelength extraction unit. A low-cost and easy-to-prepare strategy, using solution-processable semiconductors, has been demonstrated to form a new platform for on-chip spectral analysis.