Genetic algorithm-based semisupervised convolutional neural network for real-time monitoring of Escherichia coli fermentation of recombinant protein production using a Raman sensor.

As a non-destructive sensing technique, Raman spectroscopy is often combined with regression models for real-time detection of key components in microbial cultivation processes. However, achieving accurate model predictions often requires a large amount of offline measurement data for training, which is both time-consuming and labor-intensive. In order to overcome the limitations of traditional models that rely on large datasets and complex spectral preprocessing, in addition to the difficulty of training models with limited samples, we have explored a genetic algorithm-based semi-supervised convolutional neural network (GA-SCNN). GA-SCNN integrates unsupervised process spectral labeling, feature extraction, regression prediction, and transfer learning. Using only an extremely small number of offline samples of the target protein, this framework can accurately predict protein concentration, which represents a significant challenge for other models. The effectiveness of the framework has been validated in a system of Escherichia coli expressing recombinant ProA5M protein. By utilizing the labeling technique of this framework, the available dataset for glucose, lactate, ammonium ions, and optical density at 600 nm (OD600) has been expanded from 52 samples to 1302 samples. Furthermore, by introducing a small component of offline detection data for recombinant proteins into the OD600 model through transfer learning, a model for target protein detection has been retrained, providing a new direction for the development of associated models. Comparative analysis with traditional algorithms demonstrates that the GA-SCNN framework exhibits good adaptability when there is no complex spectral preprocessing. Cross-validation results confirm the robustness and high accuracy of the framework, with the predicted values of the model highly consistent with the offline measurement results.

Asymmetric Biomimetic Transamination of Trifluoromethyl Ketones.

In the presence of chiral pyridoxamine 4b as the catalyst and 2,2-diphenylglycine (3) as the amine source, asymmetric biomimetic transamination of trifluoromethyl ketones produces optically active α-trifluoromethyl amines 6 in 81-98% yields with 88-95% ee's under mild conditions.

A Conformational Restriction Strategy for the Control of CRISPR/Cas Gene Editing with Photoactivatable Guide RNAs.

The CRISPR/Cas system is one of the most powerful tools for gene editing. However, approaches for precise control of genome editing and regulatory events are still desirable. Here, we report the spatiotemporal and efficient control of CRISPR/Cas9- and Cas12a-mediated editing with conformationally restricted guide RNAs (gRNAs). This approach relied on only two or three pre-installed photo-labile substituents followed by an intramolecular cyclization, representing a robust synthetic method in comparison to the heavily modified linear gRNAs that often require extensive screening and time-consuming optimization. This tactic could direct the precise cleavage of the genes encoding green fluorescent protein (GFP) and the vascular endothelial growth factor A (VEGFA) protein within a predefined cutting region without notable editing leakage in live cells. We also achieved light-mediated myostatin (MSTN) gene editing in embryos, wherein a new bow-knot-type gRNA was constructed with excellent OFF/ON switch efficiency. Overall, our work provides a significant new strategy in CRISPR/Cas editing with modified circular gRNAs to precisely manipulate where and when genes are edited.

Orthogonal Chemical Activation of Enzyme-Inducible CRISPR/Cas9 for Cell-Selective Genome Editing.

The precision and therapeutic potential of CRISPR/Cas9 genome editing are greatly challenged by the less control over Cas9-mediated DNA cleavage. Herein, we introduce a conditional and cell-selective genome editing system controlled by disease-associated enzymes, termed enzyme-inducible CRISPR (eiCRISPR). eiCRISPR comprises Cas9 protein, a self-blocked inactive single-guide RNA (bsgRNA), and a chemically caged deoxyribozyme (DNAzyme) that activates bsgRNA and eiCRISPR in a controllable manner. We design chemical modifications of DNAzyme to suppress its ability to cleave the blocking region of bsgRNA, while the decaging of DNAzyme triggered by the tumor cell-overexpressed enzyme, for instance, NAD(P)H:quinone oxidoreductase (NQO1), restores the activity of bsgRNA and switches on eiCRISPR selectively for genome editing in cancer cells. Moreover, using a biodegradable lipid nanoparticle to deliver eiCRISPR in a tumor-bearing xenograft, we show that the in vivo activation of eiCRISPR enables the editing of human papillomavirus 18 E6 for potential cancer therapy. The strategy of postsynthetic and site-specific modification of DNAzyme is compatible with endogenous chemistries for regulating eiCRISPR for cell-selective genome editing and targeted gene therapy.

Spatiotemporal Delivery of CRISPR/Cas9 Genome Editing Machinery Using Stimuli-Responsive Vehicles.

Recent innovations in genome editing have enabled the precise manipulation of the genetic information of mammalians, and benefitted the development of next-generation gene therapy. Despite these advances, several barriers to the clinical translation of genome editing remain, including the intracellular delivery of genome editing machinery, and the risk of off-target editing effect. Here, we review the recent advance of spatiotemporal delivery of CRISPR/Cas9 genome editing machinery, which is composed of programmable Cas9 nuclease and a single-guide RNA (sgRNA) using stimuli-responsive nanoparticles. We discuss the specific chemistries that have been used for controlled Cas9/sgRNA delivery and intracellular release in the presence of endogenous or external signals. These methodologies can leverage biological signals found locally within disease cells, or exogenous signals administrated with spatiotemporal control, through which an improved genome editing could be achieved. We also discuss the future in exploiting these approaches for fundamental biomedical applications and therapeutic genome editing.

EIA metamaterials based on hybrid metal/dielectric structures with dark-mode-enhanced absorption.

Metamaterial analogue of electromagnetically induced absorption (EIA) has promising applications in spectroscopy and sensing. Here we propose an EIA metamaterial based on hybrid metal/dielectric structures, which are composed of a metallic wire and a dielectric block, and investigate the EIA-like effect by simulations, experiments, and the two-oscillator model. An EIA-like effect emerges in virtue of the near-field coupling between metallic wire and dielectric block, and the dielectric block exhibiting magnetic dipolar resonance makes a major contribution to the resonance absorption. The magnetic flux through the dielectric block engendered by the near filed of the metallic wire determines the coupling between dielectric block and metallic wire. With the variation of the separation between dielectric block and metallic wire, the EIA-like effect is preserved and does not convert into the EIT-like effect although the coupling and consequently the absorbance are altered. Based on the two-oscillator model, the absorption spectrum of the EIA metamaterial is quantitatively analyzed and the parameters of the oscillator system are retrieved.

Enzyme-Instructed Activation of Pro-protein Therapeutics In Vivo.

The selective and temporal control of protein activity in living cells provides a powerful tool to manipulate cellular function and to develop pro-protein therapeutics (PPT) for targeted therapy. In this work, we reported a facile but general chemical approach to design PPT by modulating protein activity in response to endogenous enzyme of disease cells, and its potential for targeted cancer therapy. We demonstrated that the chemical modification of a protein with quinone propionic acid (QPN), a ligand that could be reduced by tumor-cell-specific NAD(P)H dehydrogenase [quinone] 1 (NQO1), was reversible in the presence of NQO1. Importantly, the QPN-modified cytochrome c (Cyt c-QPN) and ribonuclease A (RNase A-QPN) showed NQO1-regulated protein activity in a highly selective manner. Furthermore, the intracellular delivery of RNase A-QPN using a novel type of lipid-based nanoparticles, and subsequent protein activation by cellular NQO1, selectively inhibit cancer cell growth in vitro and effectively suppress tumor growth in vivo. We believe that our approach increases the number of potentially useful chemical tools for reversibly controlling the structure and function of protein using a disease-cell-specific enzyme, opening opportunities in the study of dynamic biological processes and developing precise protein therapeutics.

Aminative Umpolung cyclization for synthesis of chiral exocyclic vicinal diamines.

Chiral exocylic vicinal diamines are biologically and chemically important compounds, but they are not easy to make. In this paper, an interesting aminative Umpolung cyclization process has been developed. Aromatic aldehydes 6 bearing an electrophilic chiral sulfinimine group underwent imine formation with 2,2-diphenylglycine (2), decarboxylation, and subsequent Umpolung cyclization, producing various trans-diamines 10 in 84-96% yields with high trans/cis ratios under very mild conditions. This work not only provides an efficient, clean, and mild method for the synthesis of chiral exocyclic vicinal diamines in one step but also represents a new application of aminative Umpolung strategy on intramolecular reactions.

Association of gestational hepatitis B virus infection and antiviral therapy with pregnancy outcomes: A retrospective study.

OBJECTIVE: To explore the relationships between gestational hepatitis B virus (HBV) infection, antiviral therapy, and pregnancy outcomes. METHODS: We retrospectively selected hepatitis B surface antigen (HBsAg)-positive pregnant women hospitalized for delivery at Fujian Medical University Affiliated Hospital from October 1, 2016 to October 1, 2020. The control group included randomly selected healthy pregnant women hospitalized for delivery during the same time. RESULTS: Overall, 1115 participants were enrolled and grouped into control (n = 380) and HBsAg-positive groups (n = 735), which were further divided into groups I (n = 407; low viral load), II (n = 207; high viral load without antiviral therapy), and III (n = 121; high viral load with antiviral therapy). Pregnant women with HBV were positively correlated with the incidence of intrahepatic cholestasis of pregnancy (ICP) (adjusted odds ratio [aOR] 5.1, 95% confidence interval [CI] 2.62-9.92, P < 0.001), neonatal jaundice (aOR 10.56, 95% CI 4.49-24.83, P < 0.001), and neonatal asphyxia (aOR 5.03, 95% CI 1.46-17.27, P = 0.01). Aspartate aminotransferase (AST) greater than the upper limit of normal (ULN) was an independent risk factor for increased ICP incidence (aOR 3.49, 95% CI 1.26-9.67, P = 0.019). Antiviral therapy considerably reduced HBV DNA and improved liver function. High viral load and antiviral therapy did not correlate significantly with adverse pregnancy outcomes (P < 0.05). CONCLUSION: Pregnant women with HBV have significantly elevated incidence of ICP, neonatal jaundice, and neonatal asphyxia not significantly correlated with viral load. AST greater than ULN independently increases the risk of ICP. Antiviral therapy effectively reduces viral replication and improves liver function without increasing the risk of adverse outcomes.

Biodegradable Hydrogen-Bonded Organic Framework for Cytosolic Protein Delivery.

Hydrogen-bonded organic frameworks (HOFs) are a novel class of porous nanomaterials that show great potential for intracellular delivery of protein therapeutics. However, the inherent challenges in interfacing protein with HOFs, and the need for spatiotemporally controlling the release of protein within cells, have constrained their therapeutic potential. In this study, we report novel biodegradable hydrogen-bonded organic frameworks, termed DS-HOFs, specially designed for the cytosolic delivery of protein therapeutics in cancer cells. The synthesis of DS-HOFs involves the self-assembly of 4-[tris(4-carbamimidoylphenyl) methyl] benzenecarboximidamide (TAM) and 4,4'-dithiobisbenzoic acid (DTBA), governed by intermolecular hydrogen-bonding interactions. DS-HOFs exhibit high efficiency in encapsulating a diverse range of protein cargos, underpinned by the hydrogen-bonding interactions between the protein residue and DS-HOF subcomponents. Notably, DS-HOFs are selectively degraded in cancer cells triggered by the distinct intracellular reductive microenvironments, enabling an enhanced and selective release of protein inside cancer cells. Additionally, we demonstrate that the efficient delivery of bacterial effector protein DUF5 using DS-HOFs depletes the mutant RAS in cancer cells to prohibit tumor cell growth both in vitro and in vivo. The design of biodegradable HOFs for cytosolic protein delivery provides a powerful and promising strategy to expand the therapeutic potential of proteins for cancer therapy.

Transamination of Aromatic Aldehydes to Primary Arylmethylamines.

In the presence of 2-amino-2-phenylpropanoate salt (2a or 2e) as the amine source, aromatic aldehydes underwent decarboxylative transamination under very mild conditions to produce a variety of arylmethylamines in 44-99% yields. The work has provided an efficient new method for the synthesis of primary arylmethylamines.

Integration of Palladium Nanoparticles with Surface Engineered Metal-Organic Frameworks for Cell-Selective Bioorthogonal Catalysis and Protein Activity Regulation.

Bioorthogonal catalysis provides a powerful tool to perform non-natural chemical reactions in living systems to dissect complex intracellular processes. Its potency to precisely regulate cellular function, however, is limited by the lack of bioorthogonal catalysts with cell selectivity. Herein, we report that palladium nanoparticles deposited on metal-organic frameworks, Pd@UiO-66, are highly efficient for intracellular bioorthogonal catalysis. In addition, introducing a cancer cell-targeting aptamer, AS1411, onto Pd@UiO-66 enables a threefold enhancement of catalysis efficiency in cancer cells. Moreover, AS1411@Pd@UiO-66 is effective in activating chemically caged 4-hydroxytamoxifen to regulate the activity of a protein destabilizing domain, ER50, and therefore protein function selectively in cancer cells. We show that the control over the activity of a bacterial effector, OspF, using AS1411@Pd@UiO-66 inactivates mitogen-activated protein kinase (MAPK) signaling of cancer cells to selectively prohibit tumor cell growth. We believe that the strategy developed herein for cell-selective bioorthogonal catalysis can expand the chemical biology toolbox for spatiotemporal control of protein function for advanced therapeutic applications.

High-efficiency modulation of broadband polarization conversion with a reconfigurable chiral metasurface.

We demonstrate an electrically biased reconfigurable chiral metasurface for controlling the polarization conversion and asymmetric transmission in a broadband manner. The reconfigurable metasurface is constructed with coupled three-layer complementary split-ring resonator (CSRR) arrays and is loaded with tunable electronic components to achieve dynamic control of reconfigurable chiral coupling in the CSRRs by simply tuning the external voltage on the structure. It is found that the polarization conversion in the metasurface can be effectively and continuously tuned in both experiments and simulations in a broadband frequency range. Meanwhile, the reconfigurable metasurface shows an asymmetric transmission (AT) effect in a broadband range for a polarized wave. The proposed reconfigurable chiral metasurface based on the active tuning of connection in the meta-structure with few functional layers is confirmed as an effective strategy for multi-functional polarization manipulation. The reported broadband properties of the chiral metasurface are promising for polarization manipulation in optical bands and applications in wireless communication.

Asymmetric biomimetic transamination of α-keto amides to peptides.

Peptides are important compounds with broad applications in many areas. Asymmetric transamination of α-keto amides can provide an efficient strategy to synthesize peptides, however, the process has not been well developed yet and still remains a great challenge in both enzymatic and catalytic chemistry. For biological transamination, the high activity is attributed to manifold structural and electronic factors of transaminases. Based on the concept of multiple imitation of transaminases, here we report N-quaternized axially chiral pyridoxamines 1 for enantioselective transamination of α-keto amides, to produce various peptides in good yields with excellent enantio- and diastereoselectivities. The reaction is especially attractive for the synthesis of peptides made of unnatural amino acids since it doesn't need great efforts to make chiral unnatural amino acids before amide bond formation.

Fano-Resonant Hybrid Metamaterial for Enhanced Nonlinear Tunability and Hysteresis Behavior.

Artificial resonant metamaterial with subwavelength localized filed is promising for advanced nonlinear photonic applications. In this article, we demonstrate enhanced nonlinear frequency-agile response and hysteresis tunability in a Fano-resonant hybrid metamaterial. A ceramic cuboid is electromagnetically coupled with metal cut-wire structure to excite the high-Q Fano-resonant mode in the dielectric/metal hybrid metamaterial. It is found that the significant nonlinear response of the ceramic cuboid can be employed for realization of tunable metamaterials by exciting its magnetic mode, and the trapped mode with an asymmetric Fano-like resonance is beneficial to achieve notable nonlinear modulation on the scattering spectrum. The nonlinear tunability of both the ceramic structure and the ceramic/metal hybrid metamaterial is promising to extend the operation band of metamaterials, providing possibility in practical applications with enhanced light-matter interactions.

Metropolitan all-pass and inter-city quantum communication network.

We have demonstrated a metropolitan all-pass quantum communication network in field fiber for four nodes. Any two nodes of them can be connected in the network to perform quantum key distribution (QKD). An optical switching module is presented that enables arbitrary 2-connectivity among output ports. Integrated QKD terminals are worked out, which can operate either as a transmitter, a receiver, or even both at the same time. Furthermore, an additional link in another city of 60 km fiber (up to 130 km) is seamless integrated into this network based on a trusted relay architecture. On all the links, we have implemented protocol of decoy state scheme. All of necessary electrical hardware, synchronization, feedback control, network software, execution of QKD protocols are made by tailored designing, which allow a completely automatical and stable running. Our system has been put into operation in Hefei in August 2009, and publicly demonstrated during an evaluation conference on quantum network organized by the Chinese Academy of Sciences on August 29, 2009. Real-time voice telephone with one-time pad encoding between any two of the five nodes (four all-pass nodes plus one additional node through relay) is successfully established in the network within 60 km.

Engineering nucleic acid chemistry for precise and controllable CRISPR/Cas9 genome editing.

The clustered regularly interspaced short palindromic repeats (CRISPR)/associated protein 9 (CRISPR/Cas9) genome editing technology is revolutionizing our approach and capability to precisely manipulate the genetic flow of mammalians. The facile programmability of Cas9 protein and guide RNA (gRNA) sequence has recently expanded biomedical application of CRISPR/Cas9 technology from editing mammalian genome to various genetic manipulations. The therapeutic and clinical translation potential of CRISPR/Cas9 genome editing, however, are challenged by its off-target effect and low genome editing efficiency. In this regard, developing new Cas9 variants and conditional control of Cas9/gRNA activity are of great potential for improving genome editing accuracy and on-target efficiency. In this review, we summarize chemical strategies that have been developed recently to engineer the nucleic acid chemistry of gRNA to enhance CRISPR/Cas9 genome editing efficacy, specificity and controllability. This review aims to highlight the endeavor that has been made to solve bottleneck problems in the field of CRISPR/Cas9 and inspire innovative researches to fulfill the gap between bench and bed.

Thermally controllable Mie resonances in a water-based metamaterial.

Active control of metamaterial properties is of great significance for designing miniaturized and versatile devices in practical engineering applications. Taking advantage of the highly temperature-dependent permittivity of water, we demonstrate a water-based metamaterial comprising water cubes with thermally tunable Mie resonances. The dynamic tunability of the water-based metamaterial was investigated via numerical simulations and experiments. A water cube exhibits both magnetic and electric response in the frequency range of interest. The magnetic response is primarily magnetic dipole resonance, while the electric response is a superposition of electric dipole resonance and a smooth Fabry-Pérot background. Using temporal coupled-mode theory (TCMT), the role of direct scattering is evaluated and the Mie resonance modes are analyzed. As the temperature of water cube varies from 20 °C to 80 °C, the magnetic and electric resonance frequencies exhibit obvious blue shifts of 0.10 and 0.14 GHz, respectively.

Anti-Ki-67 peptide nucleic acid affects the proliferation and apoptosis of human renal carcinoma cells in vitro.

We treated in vitro human renal carcinoma cells (cell line 786-0) with the lipid-delivered peptide nucleic acids (PNAs) against Ki-67 gene. Corresponding control groups were treated with the antisense oligonucleotides (ASOs) of the same nucleobase sequence, and with mismatched PNAs. In cells treated by anti-Ki-67 PNAs, the Ki-67 expression rate, Ki-67 protein level, cell growth and the DNA synthesis-indicative 3H-thymidine incorporation rate were lower than in the ASO-treated groups, and reduced significantly compared to untreated controls, whereas the rate of apoptosis was markedly increased by PNA treatment. We conclude that anti-Ki-67 PNA has more strong (than ASO) and dose-dependent effects on the proliferation and apoptosis of human renal carcinoma cells. Our results indicate that the strategy of using PNA against the Ki-67 gene might be a promising approach in renal carcinoma therapy.