Clustered regularly interspaced short palindromic repeats interference (CRISPRi) is used to edit eukaryotic genomes. Here, we show that CRISPRi can also be used for fine-tuning prokaryotic gene ...expression while simultaneously regulating multiple essential gene expression with less labor and time consumption. As a case study, CRISPRi was used to control polyhydroxyalkanoate (PHA) biosynthesis pathway flux and to adjust PHA composition. A pathway was constructed in Escherichia coli for the production of poly(3-hydroxybutyrate-co-4-hydroxybutyrate) P(3HB-co-4HB) from glucose. The native gene sad encoding E. coli succinate semi-aldehyde dehydrogenase was expressed under the control of CRISPRi using five specially designed single guide RNAs (sgRNAs) for regulating carbon flux to 4-hydroxybutyrate (4HB) biosynthesis. The system allowed formation of P(3HB-co-4HB) consisting of 1–9mol% 4HB. Additionally, succinate, generated by succinyl-coA synthetase and succinate dehydrogenase (respectively encoded by genes sucC, sucD and sdhA, sdhB) was channeled preferentially to the 4HB precursor by using selected sgRNAs such as sucC2, sucD2, sdhB2 and sdhA1 via CRISPRi. The resulting 4HB content in P(3HB-co-4HB) was found to range from 1.4 to 18.4mol% depending on the expression levels of down-regulated genes. The results show that CRISPRi is a feasible method to simultaneously manipulate multiple genes in E. coli.
•CRISPRi system is useful for prokaryotic metabolic engineering.•CRISPRi system can simultaneously regulate multiple genes in prokaryotes.•P(3HB-co-4HB) consisting of 1–18mol% 4HB was obtained using CRISPRi.•CRISPRi system will become a powerful tool for synthetic biology.
•This study investigated the energy harvesting potential of a magneto-electric and fluid-structure interaction system, where a magnet repulsive force was applied on a PZT located at a nonlinear ...beam.•The magnet repulsive force significantly enhanced the electric generation capability of the system. Specifically, when the PZT was positioned at the curved area of the pipe, the energy generation increased by 193.197% compared to the system without a magnet.•To ensure optimal energy conversion, it is important to accurately estimate the frequency of parametric resonance in the flow-induced vibration system and ensure that the energy harvesting system operates within that frequency range.
This research proposes an innovative design of a fluid-solid coupling vibration energy harvesting system (VEH system) that includes a downstream waterwheel driven by the flow field, which, in turn, drives gears and connecting rods to rotate a wheel equipped with magnets to generate electricity by changing the magnetic field. A piezoelectric patch (PZT) is installed upstream of the pipeline with a magnet attached to it. The repulsive force between the magnet on the wheel and the magnet on the PZT generates additional force while also creating vibration through fluid-solid coupling of the pipeline. The study derives a theoretical model of the nonlinear vibrating beam and couples it with the piezoelectric and magneto-electric equations to simulate the vibration of the fixed-fixed elastic pipe. The method of multiple scales (MOMS), fixed points plots, phase plots, and Poincaré maps are employed to verify the theoretically predicted parametric excitation properties of the system. The study uses the Biot-Savart Law to calculate the theoretical magnetic force and combines it with the fluid-conveying nonlinear beam and the PZT to create a magneto-electric coupling fluid pipeline vibration energy harvesting model. The study conducts a simple experiment to verify the feasibility of the theoretical model and demonstrates that the repulsive force of the magnet significantly enhances the electric generation benefit of the system. Regardless of whether the PZT is located in the curved or flat area (straight part) of the nonlinear beam, the addition of magnets to the system significantly increases voltage generation efficiency by more than 190% when compared to systems without magnets.
Antibiotic compounds have caused serious environmental concerns. In this study, we developed an effective technology for treatment of chlortetracycline (CTC), a widely used antibiotic compound. A ...natural heteroatom-doped spent tea leaves-based biochar (STLB) with excellent adsorption and catalytic property was prepared by simple thermal treatment. An adsorption-promoted persulfate-based advanced oxidation process (PS-AOP) using STLB was studied for CTC removal. The results showed that the as-prepared STLB presented favorable adsorption affinity towards CTC with the maximum adsorption capacity of 627 mg g−1. Meanwhile, CTC enriched on the surface of STLB was good for in-situ decomposition of CTC and nearly 97.4 % of CTC was removed within 30 min of pre-adsorption and 60 min of subsequent degradation. The STLB had excellent recyclability and wide pH tolerance range of 3.0–9.0 in combined pre-adsorption and PS-AOP. Reactive oxygen species analysis confirmed that CTC degradation was mainly due to non-radical (singlet oxygen, 1O2) and radicals (SO4- and OH). This study suggests that STLB is a promising adsorption-enhanced PS activator for the treatment of refractory wastewater and also provides a strategy of waste control by spent tea leaves.
Display omitted
•The STLB as a sustainable adsorption-enhanced activator was prepared.•CTC was effectively removed by adsorption-promoted PS-AOP in a broad pH range.•CTC adsorption on STLB was good for the subsequent in-situ degradation.•CTC degradation was due to the reactive species including SO4−, OH, and 1O2.•This study provided a new strategy of treating waste with spent tea leaves.
We report the highly enantioselective synthesis of
-chiral tertiary phosphine oxides featuring an ethynyl group
Cu(i)-catalyzed azide-alkyne cycloaddition. Newly developed chiral ...pyridinebisoxazolines (PYBOX) bearing a bulky C4 shielding group play an important role in achieving excellent enantioselectivity while suppressing side bis-triazoles formation in desymmetrizing prochiral diethynylphosphine oxides. Notably, by tuning the size of the C4 shielding group, it is possible to achieve excellent remote enantiofacial control in desymmetrizing phosphole oxide-diynes with the prochiral
-center farther from the ethynyl group
. Time-dependent enantioselectivity is observed for these desymmetric CuAAC reactions, suggesting a synergic combination of a desymmetrization and a kinetic resolution, and our ligands prove to be better than unmodified PYBOX in both steps. This finding contributes to a highly enantioselective kinetic resolution of racemic ethynylphosphine oxides. The resulting chiral ethynylphosphine oxides are versatile
-chiral synthons, which can undergo a number of diversifying reactions to enrich structural diversity.
Thioridazine (THD) is a common phenothiazine antipsychotic drug reported to suppress growth in several types of cancer cells. We previously showed that THD acts as an antiglioblastoma and anticancer ...stem-like cell agent. However, the signaling pathway underlying autophagy and apoptosis induction remains unclear. THD treatment significantly induced autophagy with upregulated AMPK activity and engendered cell death with increased sub-G1 in glioblastoma multiform (GBM) cell lines. Notably, through whole gene expression screening with THD treatment, frizzled (Fzd) proteins, a family of G-protein-coupled receptors, were found, suggesting the participation of Wnt/β-catenin signaling. After THD treatment, Fzd-1 and GSK3β-S9 phosphorylation (inactivated form) was reduced to promote β-catenin degradation, which attenuated P62 inhibition. The autophagy marker LC3-II markedly increased when P62 was released from β-catenin inhibition. Additionally, the P62-dependent caspase-8 activation that induced P53-independent apoptosis was confirmed by inhibiting T-cell factor/β-catenin and autophagy flux. Moreover, treatment with THD combined with temozolomide (TMZ) engendered increased LC3-II expression and caspase-3 activity, indicating promising drug synergism. In conclusion, THD induces autophagy in GBM cells by not only upregulating AMPK activity, but also enhancing P62-mediated autophagy and apoptosis through Wnt/β-catenin signaling. Therefore, THD is a potential alternative therapeutic agent for drug repositioning in GBM.
The excellent molecular recognition capabilities of monoclonal antibodies (mAbs) have opened up exciting opportunities for biotherapeutic discovery. Taking advantage of the full potential of this ...tool necessitates affinity ligands capable of conjugating directly with small molecules to a defined degree of biorthogonality, especially when modifying natural Abs. Herein, a bioorthogonal boronate‐affinity‐based Ab ligand featuring a 4‐(dimethylamino)pyridine and an S‐aryl thioester to label full‐length Abs is reported. The photoactivatable linker in the acyl donor facilitated purification of azide‐labelled Ab (N3‐Ab) was quantitatively cleaved upon brief exposure to UV light while retaining the original Ab activity. Click reactions enabled the precise addition of biotin, a fluorophore, and a pharmacological agent to the purified N3‐Abs. The resulting immunoconjugate showed selectivity against targeted cells. Bioorthogonal traceless design and reagentless purification allow this strategy to be a powerful tool to engineer native antibodies amenable to therapeutic intervention.
Adding function: A boronate‐affinity ligand and an S‐aryl thioester have been developed that are capable of labelling native Abs with a functional molecule. Additionally, a photoactivatable crosslinker allows purification of labelled Abs in a reagentless manner, thereby producing homogeneous Ab‐drug conjugates.
•All-solid-state complementary ITO/WO3/Ta2O5/NiO/ITO ECD.•UV curing LiClO4+PC+UV as a solid electrolyte.•NiO is an auxiliary layer for a complementary ECD.•ECD deposited by ion-beam assisted ...electron-beam evaporation
This research investigates the optical, nanostructure, electrochemical, and binding-energy performances of a Nickel Oxide (NiO) auxiliary layer for a complementary ultraviolet (UV)-cured all-solid-state electrochromic device (ECD). The complementary ITO/WO3/Ta2O5/Electrolyte/NiO/ITO ECD was separated into two sub-modules, one being the colored NiO anode, the other being the colored WO3 cathode. These were combined using UV curing LiClO4+PC+UV glue as a solid electrolyte. The NiO film was deposited by ion-beam assisted (IAD) electron-beam evaporation under different oxygen flow rates ranging from 5 to 20 sccm, and the evaporation formed columnar nanostructures that allowed the Li+ ions to enter and leave. These experimental results exhibited location shifts for the binding-energy of Ni3d and O1s has the blue shift at the oxygen flow far away of 15 sccm. Depositing the NiO film under an oxygen flow of 15 sccm (111) showed the highest color/bleach variation of ΔT=45.9%@550nm, the greatest cyclic voltammetry (CV) cladding area of Q=31.39 mC, an alternating current (AC) impedance of 28 kΩ, and an ionic conduction rate of 4.46×10−7 S cm−1. The columnar NiO film deposited using IAD electron-beam evaporation has the potential to be used as an auxiliary layer for an all-solid-state ECD.
Display omitted
As the growing demand on artificial intelligence (AI) Internet-of-Things (IoT) devices, smart vision sensors with energy-efficient computing capability are required. This article presents a low-power ...and low-voltage dual mode 0.5-V computational CMOS image sensor (C 2 IS) with array-parallel computing capability for feature extraction using convolution. In the feature extraction mode, by applying the pulsewidth modulation (PWM) pixel and switch-current integration (SCI) circuit, the in-sensor eight-directional matrix-parallel multiply-accumulate (MAC) operation is realized. Furthermore, the analog-domain convolution-on-readout (COR) operation, the programmable <inline-formula> <tex-math notation="LaTeX">3\times3 </tex-math></inline-formula> kernel with ±3-bit weights, and the tunable-resolution column-parallel analog-to-digital converter (ADC) (1-8 bit) are implemented to achieve the real-time feature extraction without using additional memory and sacrificing frame rate. In the image capturing mode, the sensor provides the linear-response 8-bit raw image data. The C 2 IS prototype has been fabricated in the TSMC 0.18-<inline-formula> <tex-math notation="LaTeX">\mu \text{m} </tex-math></inline-formula> standard process technology and verified to demonstrate the raw and feature images at 480 frames/s with a power consumption of 77/<inline-formula> <tex-math notation="LaTeX">117~\mu \text{W} </tex-math></inline-formula> and the resultant FoM of 9.8/14.8 pJ/pixel/frame, respectively. The prototype sensor is used as a real-time edge feature detection frond-end camera and accompanied with a simplified convolutional neural network (CNN) architecture to demonstrate the hand gesture recognition. The prototype system achieves more than 95% validation accuracy.
Abstract
Glucose transporter GLUT1 is a transmembrane protein responsible for the uptake of glucose into the cells of many tissues through facilitative diffusion. Plasma membrane (PM) localization is ...essential for glucose uptake by GLUT1. However, the mechanism underlying GLUT1 PM localization remains enigmatic. We find that GLUT1 is palmitoylated at Cys207, and S-palmitoylation is required for maintaining GLUT1 PM localization. Furthermore, we identify DHHC9 as the palmitoyl transferase responsible for this critical posttranslational modification. Knockout of DHHC9 or mutation of GLUT1 Cys207 to serine abrogates palmitoylation and PM distribution of GLUT1, and impairs glycolysis, cell proliferation, and glioblastoma (GBM) tumorigenesis. In addition, DHHC9 expression positively correlates with GLUT1 PM localization in GBM specimens and indicates a poor prognosis in GBM patients. These findings underscore that DHHC9-mediated GLUT1 S-palmitoylation is critical for glucose supply during GBM tumorigenesis.
PDF
