Hydrogen-Bonded Organic Cocrystal-Encapsulated Perovskite Nanocrystals as Coreactant-Free Electrochemiluminescent Luminophore for the Detection of Uranium.

Lead halide perovskite nanocrystals with excellent photophysical properties are promising electrochemiluminescence (ECL) candidates, but their poor stability greatly restricts ECL applications. Herein, hydrogen-bonded cocrystal-encapsulated CsPbBr3 perovskite nanocrystals (PeNCs@NHS-M) were synthesized by using PeNCs as nuclei for inducing the crystallization of melamine (M) and N-hydroxysuccinimide (NHS). The as-synthesized composite exhibits multiplicative ECL efficiencies (up to 24-fold that of PeNCs) without exogenous coreactants and with excellent stability in the aqueous phase. The enhanced stability can be attributed to the well-designed heterostructure of the PeNCs@NHS-M composite, which benefits from both moiety passivation and protection of the peripheral cocrystal matrix. Moreover, the heterostructure with covalent linkage facilitates charge transfer between PeNCs and NHS-M cocrystals, realizing effective ECL emission. Meanwhile, the NHS and M components act as coreactants for PeNCs, shortening the electron-transport distance and resulting in a significant increase in the ECL signal. Furthermore, by taking advantage of the specific binding effect between NHS-M and uranyl (UO22+), an ECL system with both a low detection limit (1 nM) and high selectivity for monitoring UO22+ in mining wastewater is established. The presence of UO22+ disrupted the charge-transfer effect within PeNCs@NHS-M, weakening the ECL signals. This work provides an efficient design strategy for obtaining stable and efficient ECLs from perovskite nanocrystals, offering a new perspective for the discovery and application of perovskite-based ECL systems.

Hydrogen-Bonded Cocrystals Encapsulating CsPbBr3 Perovskite Nanocrystals with Enhancement of Charge Transport for Photocatalytic Reduction of Uranium.

At present, poor stability and carrier transfer efficiency are the main problems that limit the development of perovskite-based photoelectric technologies. In this work, hydrogen-bonded cocrystal-coated perovskite composite (PeNCs@NHS-M) is easily obtained by inducing rapid crystallization of melamine (M) and N-hydroxysuccinimide (NHS) with PeNCs as the nuclei. The outer NHS-M cocrystal passivates the undercoordinated lead atoms by forming covalent bonds, thereby greatly reducing the trap density while maintaining good structure stability for perovskite nanocrystals. Moreover, benefiting from the interfacial covalent band linkage and long-range ordered structures of cocrystals, the charge transfer efficiency is effectively enhanced and PeNCs@NHS-M displays superior photoelectric performance. Based on the excellent photoelectric performance and abundant active sites of PeNCs@NHS-M, photocatalytic reduction of uranium is realized. PeNCs@NHS-M exhibits U(VI) reduction removal capability of up to 810.1 mg g-1 in the presence of light. The strategy of cocrystals trapping perovskite nanocrystals provides a simple synthesis method for composites and opens up a new idea for simultaneously improving the stability and photovoltaic performance of perovskite.

Construction of a Bifunctional Redox-Site Conjugated Covalent-Organic Framework for Photoinduced Precision Trapping of Uranyl Ions.

The performance of covalent-organic frameworks (COFs) for the photocatalytic extraction of uranium is greatly limited by the number of adsorption sites. Herein, inspired by electronegative redox reactions, we designed a nitrogen-oxygen rich pyrazine connected COF (TQY-COF) with multiple redox sites as a platform for extracting uranium via combining superaffinity and enhanced photoinduction. The preorganized bisnitrogen-bisoxygen donor configuration on TQY-COF is entirely matched with the typical geometric coordination of hexavalent uranyl ions, which demonstrates high affinity (tetra-coordination). In addition, the presence of the carbonyl group and pyrazine ring effectively stores and controls electron flow, which efficaciously facilitates the separation of e-/h+ and enhances photocatalytic performance. The experimental results show that TQY-COF removes up to 99.8% of uranyl ions from actual uranium mine wastewater under the light conditions without a sacrificial agent, and the separation coefficient reaches 1.73 × 106 mL g-1 in the presence of multiple metal ions, which realizes the precise separation in the complex environment. Importantly, DFT calculations further elucidate the coordination mechanism of uranium and demonstrate the necessity of the presence of N/O atoms in the photocatalytic adsorption of uranium.

Regulation of Released Alkali from Gel Polymer Electrolyte in Quasi-Solid State Zn-Air Battery.

Gel polymer electrolyte (GPE) in quasi-solid state Zn-air battery (QSZAB) will release alkali during cycling, resulting in gradual dehydration of GPE, corrosion of Zn electrode, Zn dendrites growth, and therefore inferior performance. Here, hollow Sn microspheres are prepared on Zn substrate by the technique of colloidal self-assembly. The inner surfaces of hollow Sn microspheres are modified by 2-hydroxypropyl-ß-cyclodextrin (hollow Sn-inner HPßCD) to regulate the released alkali at GPE|anode interface. The hollow Sn-inner HPßCD can lessen the leakage of released alkali, make stored alkali diffuse back to GPE during the charging process, and mitigate the loss of soluble Zn(OH)4 2- to suppress Zn dendrites growth. Resultantly, GPE in QSZAB with hollow Sn-inner HPßCD exhibits a high retention capacity for alkaline solution. The cell also exhibits a long cyclic lifespan of 127 h due to the effective regulation of released alkali, which outperforms QSZAB without hollow Sn-inner HPßCD by 7.94 times. This work rivets the regulation of released alkali at GPE|anode interface, providing new insight to improve QSZABs' performance.

3D Ionic Olefin-Linked Conjugated Microporous Polymers for Selective Detection and Removal of TcO4-/ReO4- from Wastewater.

Technetium (99Tc) is a highly toxic radioactive nuclear wastewater contaminant. Real-time detection of 99Tc is very difficult due to its difficult-to-complex nature. Herein, a novel three-dimensional ionic olefin-linked conjugated microporous polymer (TFPM-EP-Br) is constructed using tetrakis(4-aldehyde phenyl)methane (TFPM) as the central monomer. The unique cationic cavity and highly hydrophobic framework enable TFPM-EP-Br to act as a fluorescent sensor for TcO4-. The fluorophores of TFPM-EP-Br can be quenched due to electron transfer from TFPM-EP-Br to TcO4- and the formation of strongly nonfluorescent complexes. Meanwhile, the regular pore channels are beneficial for the fast mass transfer of TcO4-, resulting in an ultrafast response time (less than 2 s) with an ultralow detection limit (33.3 nM). In addition, the ultrahigh specific surface area enables TFPM-EP-Br to combine the ability to synergistically detect and remove radioactive 99Tc. From this perspective, the novel conjugated microporous polymer has made a breakthrough in the detection and extraction of radioactive contaminants.

Recombinant expression of an oriental river prawn anti-lipopolysaccharide factor gene in Pichia pastoris and its characteristic analysis.

Anti-lipopolysaccharide factors (ALFs), as main host-defense molecules of crustaceans, form a unique family of antimicrobial peptides (AMPs). MnALF4 is one isoform of ALFs isolated from the freshwater prawn Macrobrachium nipponense. In the present study, MnALF4 gene was successfully expressed in the yeast Pichia pastoris and the recombinant MnALF4 protein exhibited efficient and broad-spectrum antimicrobial activities against both Gram-positive bacteria and Gram-negative bacteria in vitro. When prawns were injected with rMnALF4 before bacterial challenge with E. coli, the recombinant protein effectively promote the elimination of bacteria by the host. It manifested that rMnALF4 could effectively kill the invading bacteria in vivo. Treatment with rMnALF4 led to remarkable changes in bacterial morphology, such as spheroidization, oversized bacteria, and cell lysis. In addition, rMnALF4 showed weak hemolysis activity to the rabbit red blood cells. Our work suggests that MnALF4 plays an important role in Macrobrachium immunity and is worthy of further investigation as a potential antibacterial agent with high efficacy against bacterial infection and low toxicity to host cells.

Shuffling-type gradient method with bandwidth-based step sizes for finite-sum optimization.

Shuffling-type gradient method is a popular machine learning algorithm that solves finite-sum optimization problems by randomly shuffling samples during iterations. In this paper, we explore the convergence properties of shuffling-type gradient method under mild assumptions. Specifically, we employ the bandwidth-based step size strategy that covers both monotonic and non-monotonic step sizes, thereby providing a unified convergence guarantee in terms of step size. Additionally, we replace the lower bound assumption of the objective function with that of the loss function, thereby eliminating the restrictions on the variance and the second-order moment of stochastic gradient that are difficult to verify in practice. For non-convex objectives, we recover the last iteration convergence of shuffling-type gradient algorithm with a less cumbersome proof. Meanwhile, we also establish the convergence rate for the minimum iteration of gradient norms. Under the Polyak-Lojasiewicz (PL) condition, we prove that the function value of last iteration converges to the lower bound of the objective function. By selecting appropriate boundary functions, we further improve the previous sublinear convergence rate results. Overall, this paper contributes to the understanding of shuffling-type gradient method and its convergence properties, providing insights for optimizing finite-sum problems in machine learning. Finally, numerical experiments demonstrate the efficiency of shuffling-type gradient method with bandwidth-based step size and validate our theoretical results.

Vitamin C inhibits NLRP3 inflammasome activation and delays the development of age-related hearing loss in male C57BL/6 mice.

The efficacy of vitamin C in age-related hearing loss, i.e., presbycusis, remains debatable. On a separate note, inflammation induced by the NOD-like receptor family pyrin domain containing 3 (NLRP3) inflammasome is involved in the progression of presbycusis. In this study, we investigated the effect of vitamin C on male C57BL/6 mice's presbycusis and NLRP3 inflammasome. The results showed that vitamin C treatment improved hearing, reduced the production of inflammatory factors, inhibited NLRP3 inflammasome activation, and decreased cytosolic mitochondrial DNA (mtDNA) in the C57BL/6 mouse cochlea, inferior colliculus, and auditory cortex. According to this study, vitamin C protects auditory function in male C57BL/6 presbycusis mice through reducing mtDNA release, inhibiting the NLRP3 inflammasome activation in the auditory pathway. Our study provides a theoretical basis for applying vitamin C to treat presbycusis.

Stochastic momentum methods for non-convex learning without bounded assumptions.

Stochastic momentum methods are widely used to solve stochastic optimization problems in machine learning. However, most of the existing theoretical analyses rely on either bounded assumptions or strong stepsize conditions. In this paper, we focus on a class of non-convex objective functions satisfying the Polyak-Lojasiewicz (PL) condition and present a unified convergence rate analysis for stochastic momentum methods without any bounded assumptions, which covers stochastic heavy ball (SHB) and stochastic Nesterov accelerated gradient (SNAG). Our analysis achieves the more challenging last-iterate convergence rate of function values under the relaxed growth (RG) condition, which is a weaker assumption than those used in related work. Specifically, we attain the sub-linear rate for stochastic momentum methods with diminishing stepsizes, and the linear convergence rate for constant stepsizes if the strong growth (SG) condition holds. We also examine the iteration complexity for obtaining an ϵ-accurate solution of the last-iterate. Moreover, we provide a more flexible stepsize scheme for stochastic momentum methods in three points: (i) relaxing the last-iterate convergence stepsize from square summable to zero limitation; (ii) extending the minimum-iterate convergence rate stepsize to the non-monotonic case; (iii) expanding the last-iterate convergence rate stepsize to a more general form. Finally, we conduct numerical experiments on benchmark datasets to validate our theoretical findings.

PM2.5 concentration prediction using weighted CEEMDAN and improved LSTM neural network.

As the core of pollution prevention and management, accurate PM2.5 concentration prediction is crucial for human survival. However, due to the nonstationarity and nonlinearity of PM2.5 concentration data, the accurate prediction for PM2.5 concentration remains a challenge. In this study, a PM2.5 concentration prediction method using weighted complementary ensemble empirical mode decomposition with adaptive noise (WCEEMDAN) and improved long and short-term memory (ILSTM) neural network is proposed. Firstly, a novel WCEEMDAN method is proposed to correctly identify the non-stationary and non-linear characteristics and divide the PM2.5 sequences into various layers. Through the correlation analysis with PM2.5 data, these sub-layers are given different weights. Secondly, the adaptive mutation particle swarm optimization (AMPSO) algorithm is developed to obtain the main hyperparameters of the long short-term memory network (LSTM) neural network, improving the prediction accuracy of PM2.5 concentration. The optimization convergence speed and accuracy are improved by adjusting the inertia weight and introducing the mutation mechanism to enhance the global optimization ability. Finally, three groups of PM2.5 concentration data are utilized to verify the effectiveness of the proposed model. Compared with other methods, the experimental results demonstrate the superiority of the proposed model. The source code can be downloaded from https://github.com/zhangli190227/WCEENDAM-ILSTM .

Sterol regulatory element binding transcription factor 1 promotes proliferation and migration in head and neck squamous cell carcinoma.

Background: Sterol-regulatory element-binding protein 1 (SREBP1) is a transcription factor involved in lipid metabolism that is encoded by sterol regulatory element binding transcription factor 1(SREBF1). SREBP1 overexpression is associated with the progression of several human tumors; however, the role of SREBP1 in head and neck squamous cell carcinoma (HNSC) remains unclear. Methods: SREBF1 expression in pan-cancer was analyzed using the Cancer Genome Atlas (TCGA) and Genotype-Tissue Expression (GTEx) data, and the association between SREBF1 expression and clinical characteristics of HNSC patients was examined using the UALCAN database. Enrichment analysis of SREBF1-related genes was performed using the Cluster Profiler R package. TCGA database was used to investigate the relationship between immune cell infiltration and SREBF1 expression. CCK-8, flow cytometry, and wound healing assays were performed to investigate the effect of SREBF1 knockdown on the proliferation and migration of HNSC cells. Results: SREBF1 was significantly upregulated in several tumor tissues, including HNSC, and SREBF1 overexpression was positively correlated with sample type, cancer stage, tumor grade, and lymph node stage in HNSC patients. Gene enrichment analysis revealed that SREBF1 is associated with DNA replication and homologous recombination. SREBF1 upregulation was positively correlated with the infiltration of cytotoxic cells, B cells, T cells, T helper cells, and NK CD56 bright cells in HNSC. Knockdown of SREBF1 inhibited the proliferation and migration of HNSC cells (Hep2 and TU212) and induced apoptosis by downregulating the expression of steroidogenic acute regulatory protein-related lipid transfer 4 (STARD4). Conclusions: SREBF1 may promote HNSC proliferation, migration and inhibit apoptosis by upregulating STARD4 and affecting the level of immune cell infiltration.

Melatonin Suppresses Cyclic GMP-AMP Synthase-Stimulator of Interferon Genes Signaling and Delays the Development of Hearing Loss in the C57BL/6J Presbycusis Mouse Model.

Melatonin supplementation has been shown to delay age-related hearing loss (ARHL) progression. Previously, melatonin was found to inhibit neuronal mitochondrial DNA (mtDNA) release, as well as inhibit cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) signaling, thereby delaying the onset of central nervous system diseases. Therefore, we hypothesized that melatonin may delay the progression of hearing loss in the C57BL/6J presbycusis mouse model by inhibiting cGAS-STING signaling in the auditory pathway. Oral melatonin at 10 mg/kg/d was administered to 3-month-old C57BL/6J mice until 12 months of age. The auditory brainstem response (ABR) threshold was used to assess their hearing ability. By real-time polymerase chain reaction and Western blot analysis, the levels of cytosolic mtDNA, cGAS/STING, and cytokines were examined in the mouse cochlea, inferior colliculus, and auditory cortex. We found that the 12-month-old control mice exhibited significant hearing loss, increased cytosolic mtDNA, increased expression of inflammatory factors TNF-α, IL-6, IFN-ß, Cxcl10, and Ifit3, up-regulated cGAS and STING expression, and enhanced interferon regulatory factor 3 (IRF3) phosphorylation in the C57BL/6J mouse cochlea, inferior colliculus, and auditory cortex. Melatonin treatment significantly improved hearing, decreased cytosolic mtDNA, suppressed the expression of inflammatory cytokines TNF-α, IL-6, IFN-ß, Ifit3, and Cxcl10, down-regulated cGAS and STING expression, and attenuated IRF3 phosphorylation in the C57BL/6J mouse cochlea, inferior colliculus, and auditory cortex. This study suggested that melatonin had a protective effect on auditory function in the C57BL/6J presbycusis mouse model, which may be mediated through reducing mtDNA release, inhibiting the cGAS-STING signaling pathway in the auditory pathway.

Unlock the innovation potential of meaning of work: An empirical study of scientific and technological workers in China.

Creativity and innovation have significantly increased in the past years. Amabile and Pratt were the leading proponents of creativity who integrated a dynamic componential model of creativity and innovation in organizations. The present study discusses the concept of innovative behavior within the scientific and technological environment based on the dynamic componential model of creativity and innovation and the Triadic Reciprocal Determinism Theory. The study investigates the mediating effect of achievement motivation and the moderating effect of the organizational innovative climate between the meaning of work and innovative behavior. Meaning of work has a positive impact on innovative behavior based on the structural equation modeling and the results of data collected from the survey of 4,666 scientific and technological workers in China. In addition, achievement motivation plays a partial intermediary role between the meaning of work and innovative behavior. However, innovation within organizational climate plays a negative regulatory role between achievement motivation and innovative behavior. The study finds some existing weaknesses through the Importance-Performance Map Analysis. Lastly, we examine the critical findings and present hypothetical suggestions.

Convergence analysis of AdaBound with relaxed bound functions for non-convex optimization.

Clipping on learning rates in Adam leads to an effective stochastic algorithm-AdaBound. In spite of its effectiveness in practice, convergence analysis of AdaBound has not been fully explored, especially for non-convex optimization. To this end, we address the convergence of the last individual output of AdaBound for non-convex stochastic optimization problems, which is called individual convergence. We prove that, with the iteration of the AdaBound, the cost function converges to a finite value and the corresponding gradient converges to zero. The novelty of this proof is that the convergence conditions on the bound functions and momentum factors are much more relaxed than the existing results, especially when we remove the monotonicity and convergence of the bound functions, and only keep their boundedness. The momentum factors can be fixed to be constant, without the restriction of monotonically decreasing. This provides a new perspective on understanding the bound functions and momentum factors of AdaBound. At last, numerical experiments are provided to corroborate our theory and show that the convergence of AdaBound extends to more general bound functions.

Age-related Activation of Cyclic GMP-AMP synthase-Stimulator of Interferon Genes Signaling in the Auditory System is Associated with Presbycusis in C57BL/6J Male Mice.

Presbycusis, or age-related hearing loss (ARHL), is primarily associated with sensory or transduction nerve cell degeneration in the peripheral and/or central auditory systems. During aging, the auditory system shows mitochondrial dysfunction and increased inflammatory responses. Mitochondrial dysfunction promotes leakage of mitochondrial DNA (mtDNA) into the cytosol, which activates the cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) pathway to induce type I interferon and inflammatory responses. However, whether this pathway is involved in the occurrence and development of ARHL is unknown. This study aimed to determine whether there are age-related changes in the levels of cytosolic mtDNA and cGAS-STING pathway activation in the auditory pathway and to explore their relationship with ARHL. The results showed that cGAS-positive immunoreactive cells were observed in the cochlea, inferior colliculus, and auditory cortex. Levels of cytosolic mtDNA, cGAS, STING, phosphorylated interferon regulatory factor 3, and cytokines were significantly increased in the cochlea, inferior colliculus, and auditory cortex of 6-, 9-, and 12-month-old mice compared with 3-month-old mice. These findings suggested that cytosolic mtDNA may play an important role in the pathogenesis of ARHL by activating cGAS-STING-mediated type I interferon and inflammatory responses.

MiRNA-27b Regulates Angiogenesis by Targeting AMPK in Mouse Ischemic Stroke Model.

Stroke is a leading cause of mortality and serious disability worldwide with limited treatment options. Angiogenesis has been reported to be involved in post-stroke recovery. Although the molecular mechanisms that regulate angiogenesis remain ambiguous, microRNAs have emerged as effective regulators of angiogenesis, involved in neurological function outcome. The present study aims to investigate the regulatory effects of miRNA-27b on post-stroke angiogenesis. In primary cultured brain microvascular endothelial cells (BMECs), the inhibition of miRNA-27b induced the activation of adenosine monophosphate-activated protein kinase (AMPK), which increased tube formation and migration. This action was attenuated when AMPKα2 was knocked down. Mice were subjected to middle cerebral artery occlusion (MCAo) surgery and administrated with Lentivirus miR-27b inhibitor. Enhanced angiogenesis in ischemic boundary zone (IBZ) was observed, and the neurological outcome during the entire study period was improved. The number of phosphate-AMPKα2+ cells that co-expressed endothelial cell marker CD31 was significantly increased. Taken together, the present study demonstrated that downregulated miRNA-27b promoted recovery after ischemic stroke via AMPK stimulus.

Systematic Screening of Optimal Signal Peptides for Secretory Production of Heterologous Proteins in Bacillus subtilis.

Bacillus subtilis is widely used for large-scale industrial production of heterologous proteins. Because of its high intrinsic secretory capacity, it can efficiently secrete proteins into the culture supernatant via the general Sec-type secretion pathway. In this study, the α-amylase AmyS was used as a reporter to construct a library encompassing 173 Sec-type signal peptides (SPs) from B. subtilis using a fast, sequence-independent method. The resulting library DNA which harbored different signal peptides in the expression vector was used to transform B. subtilis directly at high efficiency, and 15 SPs which produced a significantly increased yield of AmyS were identified using a starch-iodine-based high-throughput assay. Furthermore, the correlation between the sequences of the best-performing signal peptides and their secretion efficiency was analyzed, which revealed several common properties of these SPs. Finally, high-cell-density fermentation of the α-amylase-producing strain with the best-performing signal peptide yielded a maximum of 5086 U/mL amylase at 66 h with a high productivity of 77.1 U/mL·h.

Delayed active bleeding after radical evacuation of injected polyacrylamide hydrogel and immediate implant based breast reconstruction.

BACKGROUND: Polyacrylamide hydrogel (PAAG) was used in breast augmentation surgery in China during 1997-2006. Its application has led to increasing complications such as localized lumps, asymmetry, diffuse stiffness, infections, and localized tenderness or myalgia. Hence, many patients have sought for surgical gel evacuation in the following years. CASE PRESENTATION: A 37-year-old G2P0A2 slim (BMI = 18.3) woman who had received injected PAAG bilateral breast augmentation in China 15 years ago, visited our hospital for gel removal due to left upper quadrant breast tenderness with burning sensation. We performed simple mastectomy and immediate breast augmentation with silicone prostheses. Her postoperative course was uneventful. However, subcutaneous hematoma formed right after she started breast massage on the day 14 post operatively. The patient promptly received a CT-guided drainage followed by exploratory surgery with coagulation of the lesion located at the second intercostal space 2 cm to the right of the sternum. DISCUSSION: Delayed bleeding in our patient might be contributed to below reasons. First, the usage of PAAG might cause degeneration of muscle tissue structure which made it more fragile than normal muscle tissue. Secondly, the lack of sufficient coverage, cushion and protection of the muscle tissue in slim patient in addition to the external compression and shearing force of massage. CONCLUSION: In slim patients, we suggest that the postoperative breast massage should be postponed for months until the tissue is recovered, or delayed breast reconstruction could also be considered.

[Sequence analysis of Bt insertion flanking fragments in transgenic Bt cotton].

The copies of outside gene and DNA structure of integration locus are important in high expression and avoidance of gene silence. Many research results showed that outside genes were inserted into the plant genome with recombinant type, and the integration was related to border T-DNA sequence in the course of Agrobaterium mediated transformation. SAR structure was also found in the integration location of transformants with direct DNA transformation method. The pollen-tube pathway transformation, one of direct DNA transformation method, was very successfully used in Bt transgenic cotton in China. But until now there has been no report about Bt gene integration. The aim of this research was to investigate flanking DNA structure in order to explain the mechanism of direct transformation method in the future. The structure of flanking DNA fragments of Bt integration in four different transgenic Bt cotton varieties including Simian-3, 161 resistant breeding line, 161 sensitive breeding line and Guokangmian-1 was analyzed with TAIL-PCR and nested PCR. The flanking DNA sequences of different self-crossed progenies from one plant are the same. In contrary, their DNA sequences are diverse for different breeding lines. Upstream flanking fragments in some transgenic cotton contained short transformation plasmid sequences, downstream flanking fragments in all the transgenic cotton varieties were composed of high percentage AT. The percentage of AT in Simian-3 transgenic Bt variety was as high as 92%. All the flanking fragments were of multi-copies and similar to repetitive sequences. No recognition sites of TOP enzyme were found in these fragments.