Unmodificated stepless regulation of CRISPR/Cas12a multi-performance.

As CRISPR technology is promoted to more fine-divided molecular biology applications, its inherent performance finds it increasingly difficult to cope with diverse needs in these different fields, and how to more accurately control the performance has become a key issue to develop CRISPR technology to a new stage. Herein, we propose a CRISPR/Cas12a regulation strategy based on the powerful programmability of nucleic acid nanotechnology. Unlike previous difficult and rigid regulation of core components Cas nuclease and crRNA, only a simple switch of different external RNA accessories is required to change the reaction kinetics or thermodynamics, thereby finely and almost steplessly regulating multi-performance of CRISPR/Cas12a including activity, speed, specificity, compatibility, programmability and sensitivity. In particular, the significantly improved specificity is expected to mark advance the accuracy of molecular detection and the safety of gene editing. In addition, this strategy was applied to regulate the delayed activation of Cas12a, overcoming the compatibility problem of the one-pot assay without any physical separation or external stimulation, and demonstrating great potential for fine-grained control of CRISPR. This simple but powerful CRISPR regulation strategy without any component modification has pioneering flexibility and versatility, and will unlock the potential for deeper applications of CRISPR technology in many finely divided fields.

DEAD-box helicase 1 inhibited CD8+ T cell antitumor activity by inducing PD-L1 expression in hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) does not respond well to current treatments, even immune checkpoint inhibitors. PD-L1 (programmed cell death ligand 1 or CD274 molecule)-mediated immune escape of tumor cells may be a key factor affecting the efficacy of immune checkpoint inhibitor (ICI) therapy. However, the regulatory mechanisms of PD-L1 expression and immune escape require further exploration. Here, we observed that DDX1 (DEAD-box helicase 1) was overexpressed in HCC tissues and associated with poor prognosis in patients with HCC. Additionally, DDX1 expression correlated negatively with CD8+ T cell frequency. DDX1 overexpression significantly increased interferon gamma (IFN-γ)-mediated PD-L1 expression in HCC cell lines. DDX1 overexpression decreased IFN-γ and granzyme B production in CD8+ T cells and inhibited CD8+ T cell cytotoxic function in vitro and in vivo. In conclusion, DDX1 plays an essential role in developing the immune escape microenvironment, rendering it a potential predictor of ICI therapy efficacy in HCC.

Large Enhancement of Polarization in a Layered Hybrid Perovskite Ferroelectric Semiconductor via Molecular Engineering.

Switchable spontaneous polarization is the vital property of ferroelectrics, which leads to other key physical properties such as piezoelectricity, pyroelectricity, and nonlinear optical effects, etc. Recently, organic-inorganic hybrid perovskites with 2D layered structure have become an emerging branch of ferroelectric materials. However, most of the 2D hybrid ferroelectrics own relatively low polarizations (<15 µC cm-2 ). Here, a strategy to enhance the polarization of these hybrid perovskites by using ortho-, meta-, para-halogen substitution is developed. Based on (benzylammonium)2 PbCl4 (BZACL), the para-chlorine substituted (4-chlorobenzylammonium)2 PbCl4 (4-CBZACL) ferroelectric semiconductor shows a large spontaneous polarization (23.3 µC cm-2 ), which is 79% larger than the polarization of BZACL. This large enhancement of polarization is successfully explained via ab initio calculations. The study provides a convenient and efficient strategy to promote the ferroelectric property in the hybrid perovskite family.

Halogen-Regulated Tc and X-ray Radiation Detection in 2D Hybrid Perovskite Ferroelastic Semiconductor.

Organic-inorganic hybrid perovskites (OIHPs) have received particular attention due to their characteristic structural tunability and flexibility. These features make OIHPs behave with excellent modifications on macroscopic properties, such as ferroicity or semiconductor performances, etc. Herein, we report two 2D hybrid stibium-based halide perovskite (C3H7N)3Sb2X9 (X = Br, 1; Cl, 2) ferroelastic semiconductor possessing dual switching properties of dielectric and second harmonic generation (SHG). Notably, these two hybrids exhibit halogen-regulated ferroelasticity and semiconductor properties. There is a significant difference in Curie temperature (Tc) and X-ray radiation detection sensitivity (S), i.e., the ΔTc and ΔS are 38 K and 87 µC Gyair-1 cm-2, respectively. Meanwhile, crystals 1 and 2 do not show dark current drift in cyclic measurements of different radiation doses with stable switching ratios of 30 and 10, separately. Meanwhile, these results were proven by scientific experimental results and density functional theory (DFT) calculations. Our work presents a facile and practical method to regulate macroproperties on the molecular level, providing a new vision to develop hybrid perovskite ferroic-photoelectric materials.

DNA-based molecular classifiers for the profiling of gene expression signatures.

Although gene expression signatures offer tremendous potential in diseases diagnostic and prognostic, but massive gene expression signatures caused challenges for experimental detection and computational analysis in clinical setting. Here, we introduce a universal DNA-based molecular classifier for profiling gene expression signatures and generating immediate diagnostic outcomes. The molecular classifier begins with feature transformation, a modular and programmable strategy was used to capture relative relationships of low-concentration RNAs and convert them to general coding inputs. Then, competitive inhibition of the DNA catalytic reaction enables strict weight assignment for different inputs according to their importance, followed by summation, annihilation and reporting to accurately implement the mathematical model of the classifier. We validated the entire workflow by utilizing miRNA expression levels for the diagnosis of hepatocellular carcinoma (HCC) in clinical samples with an accuracy 85.7%. The results demonstrate the molecular classifier provides a universal solution to explore the correlation between gene expression patterns and disease diagnostics, monitoring, and prognosis, and supports personalized healthcare in primary care.

A PAM-free CRISPR/Cas12a ultra-specific activation mode based on toehold-mediated strand displacement and branch migration.

CRISPR (clustered regularly interspaced short palindromic repeats) technology has achieved great breakthroughs in terms of convenience and sensitivity; it is becoming the most promising molecular tool. However, only two CRISPR activation modes (single and double stranded) are available, and they have specificity and universality bottlenecks that limit the application of CRISPR technology in high-precision molecular recognition. Herein, we proposed a novel CRISPR/Cas12a unrestricted activation mode to greatly improve its performance. The new mode totally eliminates the need for a protospacer adjacent motif and accurately activates Cas12a through toehold-mediated strand displacement and branch migration, which is highly universal and ultra-specific. With this mode, we discriminated all mismatch types and detected the EGFR T790M and L858R mutations in very low abundance. Taken together, our activation mode is deeply incorporated with DNA nanotechnology and extensively broadens the application boundaries of CRISPR technology in biomedical and molecular reaction networks.

Molecular Engineering Regulation Achieving Out-of-Plane Polarization in Rare-Earth Hybrid Double Perovskites for Ferroelectrics and Circularly Polarized Luminescence.

Out-of-plane polarization is a highly desired property of two-dimensional (2D) ferroelectrics for application in vertical sandwich-type photoferroelectric devices, especially in ultrathin ferroelectronic devices. Nevertheless, despite great advances that have been made in recent years, out-of-plane polarization remains unrealized in the 2D hybrid double perovskite ferroelectric family. Here, from our previous work 2D hybrid double perovskite HQERN ((S3HQ)4EuRb(NO3)8, S3HQ=S-3-hydroxylquinuclidinium), we designed a molecular strategy of F-substitution on organic component to successfully obtain FQERN ((S3FQ)4EuRb(NO3)8, S3FQ=S-3-fluoroquinuclidinium) showing circularly polarized luminescence (CPL) response. Remarkably, compared to the monopolar axis ferroelectric HQERN, FQERN not only shows multiferroicity with the coexistence of multipolar axis ferroelectricity and ferroelasticity but also realizes out-of-plane ferroelectric polarization and a dramatic enhancement of Curie temperature of 94 K. This is mainly due to the introduction of F-substituted organic cations, which leads to a change in orientation and a reduction in crystal lattice void occupancy. Our study demonstrates that F-substitution is an efficient strategy to realize and optimize ferroelectric functional characteristics, giving more possibility of 2D ferroelectric materials for applications in micro-nano optoelectronic devices.

A Spatially Controlled Proximity Split Tweezer Switch for Enhanced DNA Circuit Construction and Multifunctional Transduction.

DNA strand displacement reactions are vital for constructing intricate nucleic acid circuits, owing to their programmability and predictability. However, the scarcity of effective methods for eliminating circuit leakages has hampered the construction of circuits with increased complexity. Herein, a versatile strategy is developed that relies on a spatially controlled proximity split tweezer (PST) switch to transduce the biomolecular signals into the independent oligonucleotides. Leveraging the double-stranded rigidity of the tweezer works synergistically with the hindering effect of the hairpin lock, effectively minimizing circuit leakage compared with sequence-level methods. In addition, the freely designed output strand is independent of the target binding sequence, allowing the PST switch conformation to be modulated by nucleic acids, small molecules, and proteins, exhibiting remarkable adaptability to a wide range of targets. Using this platform, established logical operations between different types of targets for multifunctional transduction are successfully established. Most importantly, the platform can be directly coupled with DNA catalytic circuits to further enhance transduction performance. The uniqueness of this platform lies in its design straightforwardness, flexibility, scalable intricacy, and system compatibility. These attributes pave a broad path toward nucleic acid-based development of sophisticated transduction networks, making them widely applied in basic science research and biomedical applications.

Crystal Sponge Behavior in a Two-Dimensional Rare-Earth Hybrid Coordinate Polymer.

Stimuli-responsive multifunctional materials (SRMMs) have attracted tremendous attention due to their dynamic responses to external stimuli. However, it remains challenging to simultaneously achieve solvent-induced single-crystal to single-crystal (SCSC) transformation and structural phase transition after desolvation. Here, we report a two-dimensional (2D) rare-earth organic-inorganic hybrid coordinate polymer [(CH3)3NCH2Cl]2[Eu·H2O]2[CH2(SO3)2]4·2H2O (1) that exhibits a reversible SCSC transformation by changing to 2 ([(CH3)3NCH2Cl][Eu·H2O][CH2(SO3)2]2). Impressively, the SCSC transformation process couples with large changes in quantum efficiency dropped from 33.68% of 1 to 20.07% that of 2. Furthermore, polymer 2 shows an isomorphic structural phase transition associated with switching dielectric. Notably, the distance of the 2D layers shows reversible change during the two successive transition processes displaying a crystal sponge behavior. This work reveals the potential of rare-earth 2D hybrid coordination polymers in the design of multifunctional responsive materials and opens a new prospect to explore the construction of novel SRMMs.

Orthogonal Trichromatic Upconversion with High Color Purity in Core-Shell Nanoparticles for a Full-Color Display.

Materials with tunable emission colors has attracted increasing interest in both fundamental research and applications. As a key member of light-emitting materials family, lanthanide doped upconversion nanoparticles (UCNPs) have been intensively demonstrated to emit light in any color upon near-infrared excitation. However, realizing the trichromatic emission in UCNPs with a fixed composition remains a great challenge. Here, without excitation pulsed modulation and three different near-infrared pumping, we report an experimental design to fine-control emission in the full color gamut from core-shell-structured UCNPs by manipulating the energy migration through dual-channel pump scheme. We also demonstrate their potential application in full-color display. These findings may benefit the future development of convenient and versatile optical methos for multicolor tuning and open up the possibility of constructing full-color volumetric display systems with high spatiotemporal resolution.

Laparoscopic in Situ Anatomical Mesohepatectomy for Solitary Massive HCC Using Combined Intrafascial and Extrafascial Approaches With Indocyanine Green Navigation (with Video).

BACKGROUND: Laparoscopic anatomic mesohepatectomy for patients with hepatocellular carcinoma (HCC) remains technically challenging, especially for those with a massive tumor larger than 10 cm. METHODS: In this study, a 65-year-old man with a 13 × 10-cm2 solitary liver tumor located at segments 4, 5, and 8 underwent laparoscopic mesohepatectomy. To reduce the possibility of releasing cancer cells from the primary tumor, the in situ resection strategy for tumor removal was implemented. The intrafascial approach was used to dissect the right Glissonean pedicle, to transect the right anterior hepatic artery, and to ligate the right anterior portal vein. The extrafascial and transfissural approach was performed along the umbilical fissure to transect the Glissonean pedicle of segment 4. Indocyanine green (ICG) then was applied using "reverse staining" to visualize the resection extent and the right posterior hepatic duct (RPHD). During parenchymal resection, the right anterior Glissonean pedicle was adequately exposed and transected via the extrafascial approach above the plane of the RPHD. Finally, the right coronary ligament was dissected, and the tumor was removed. RESULTS: The operation was completed in 360 min, with a blood loss of 200 mL. The histopathologic diagnosis indicated a moderately differentiated HCC. The patient was discharged on postoperative day 8 without any complications. CONCLUSION: Laparoscopic in situ anatomic mesohepatectomy using combined intra- and extrafascial approaches with ICG navigation may be feasible for patients with a centrally located solitary massive HCC.

[An Integrated Digital Magnetic Resonance Imaging Spectrometer].

An integrated digital magnetic resonance imaging spectrometer was proposed in this study. By using the FPGA chip Artix7 200T, timing control, data processing, digital frequency conversion and phase control were implemented into a single-chip, thus effectively improved timing accuracy and phase accuracy, while avoided the structural design complexity caused by multi-board connection and improved system integration and imaging quality.

A new brood-pollination mutualism between Stellera chamaejasme and flower thrips Frankliniella intonsa.

BACKGROUND: Brood pollination mutualism is a special type of plant-pollinator interaction in which adult insects pollinate plants, and the plants provide breeding sites for the insects as a reward. To manifest such a mutualism between Stellera chamaejasme and flower thrips of Frankliniella intonsa, the study tested the mutualistic association of the thrips life cycle with the plant flowering phenology and determined the pollination effectiveness of adult thrips and their relative contribution to the host's fitness by experimental pollinator manipulation. RESULTS: The adult thrips of F. intonsa, along with some long-tongue Lepidoptera, could serve as efficient pollinators of the host S. chamaejasme. The thrips preferentially foraged half-flowering inflorescences of the plants and oviposited in floral tubes. The floral longevity was 11.8 ± 0.55 (mean ± se) days, which might precisely accommodate the thrips life cycle from spawning to prepupation. The exclusion of adult thrips from foraging flowers led to a significant decrease in the fitness (i.e., seed set) of host plants, with a corresponding reduction in thrips fecundity (i.e., larva no.) in the flowers. CONCLUSIONS: The thrips of F. intonsa and the host S. chamaejasme mutualistically interact to contribute to each other's fitness such that the thrips pollinate host plants and, as a reward, the plants provide the insects with brooding sites and food, indicating the coevolution of the thrips life cycle and the reproductive traits (e.g., floral longevity and morphology) of S. chamaejasme.

Application of Real-Time Augmented Reality Laparoscopic Navigation in Splenectomy for Massive Splenomegaly.

OBJECTIVES: To evaluate the clinical impact and technical feasibility of augmented reality laparoscopic navigation (ARLN) system in laparoscopic splenectomy for massive splenomegaly. METHODS: The clinical data of 17 consecutive patients who underwent laparoscopic splenectomy using ARLN (ARLN group) and 26 patients without ARLN guidance (Non-ARLN group) between January 2018 and April 2020 were enrolled. Propensity score matching (PSM) analysis was performed between the patients with and without ARLN guidance at a ratio of 1:1. RESULTS: Mean intraoperative blood loss was significantly lower in the ARLN-group than in the Non-ARLN group (306.6 ml vs. 462.6 ml, p = 0.047). All the patients in the ARLN-group achieved successful splenic artery dissection, while surgical success was achieved in 12 patients in the Non-ARLN group (p = 0.044). Postoperative hospital stay was significantly longer in the Non-ARLN group (3.8 days vs. 4.5 days, p = 0.040). CONCLUSIONS: ARLN can provide feasible and accurate intraoperative image guidance, and it could be helpful in the performance of laparoscopic splenectomy for massive splenomegaly.

A novel method of fluorescent imaging can guide hepatectomy for intrahepatic cholangiocarcinoma with intrahepatic biliary obstruction.

OBJECTIVE: The aim of this study was to present a novel bile-duct obstructed area imaging (BOAI) and to investigate the feasibility and accuracy of this method in guiding hepatectomy for intrahepatic cholangiocarcinoma (ICC) with intrahepatic biliary obstruction. METHODS: From May 2017 to October 2019, eligible patients who underwent hepatectomy guided by BOAI were enrolled. Perioperative outcomes and operative data were analyzed. To assess the feasibility of BOAI and Glissonean pedicle approach, demarcations based on them were compared. To verify the accuracy of BOAI staining of the target territory, simple linear regression analysis, and intraclass correlation coefficient were used to examine the relationship between predicted resected liver volume (PRLV) and actual resected liver volume (ARLV). RESULTS: BOAI staining achieved valid demarcation in 15 (93.8%) of 16 patients, whereas the ischemic line achieved valid demarcation in only nine patients (57.3%; p = .017). ARLV and PRLV had a strong positive correlation (PRLV = 60.06 + 0.925 × ARLV; R = .945; p = .000). Meanwhile, ARLV (intraclass correlation coefficient = .971) achieved an excellent agreement with PRLV (p < .001). CONCLUSIONS: The novel BOAI staining method can provide valid, feasible, and accurate demarcation line and may be an effective method in the surgical treatment of intrahepatic biliary obstruction.

Two new phenylpropanoids from the whole plant of Ainsliaea bonatii.

Two new phenylpropanoids, ainsbons A and B (1 and 2), along with a known analogue coniferyl diisovalerate (3) were isolated from the whole plant of Ainsliaea bonatii. Their structures were elucidated by analysis of NMR spectroscopic data and HRESIMS, and the absolute configuration of 2 was established by the optical rotation calculations. Compounds 1-3 were evaluated for their effects on LPS-induced nitric oxide production, and 1 and 3 showed inhibitory activities with IC50 values of 43.43 and 7.57 µM, respectively.

Dual role of PpV in Drosophila crystal cell proliferation and survival.

Drosophila melanogaster crystal cells are a specialized type of blood cells for innate immune process upon injury. Under normal conditions, crystal cells rarely proliferate and constitute a small proportion of fly blood cells. Notch signaling has been known to guide the cell fate determination of crystal cells and maintain their survival. Here, we reported that protein phosphatase V (PpV), the unique catalytic subunit of protein phosphatase 6 in Drosophila, is a novel regulator of crystal cell proliferation and integrity. We found that PpV proteins highly accumulated in crystal cells in the larval hematopoietic organ termed the lymph gland. Silencing PpV using RNA interference led to increased crystal cell proliferation in a Notch-independent manner and induced crystal cell rupture dependent on Notch signaling. Moreover, additive PpV prevented the rupture of crystal cells in lymph glands upon a needle injury, suggesting the involvement of PpV in wound healing. Altogether, our results indicated that PpV plays a dual role in lymph glands, preventing crystal cell proliferation to limit the cell number, as well as inhibiting crystal cell rupture to maintain their survival.

Protein phosphatase 2A regulates blood cell proliferation and differentiation in Drosophila larval lymph glands.

Protein phosphatase 2A (PP2A), one of the most abundant protein phosphatases, has divergent functions in multiple types of cells. Its inactivation has been closely associated with leukemia diseases. However, the physiological function of PP2A for hematopoiesis has been poorly understood in organisms. Drosophila hematopoiesis parallels the vertebrate counterpart in developmental and functional features but involves a much simpler hematopoietic system. Here, utilizing the Drosophila major larval hematopoietic organ lymph gland, we studied the function of PP2A for hematopoiesis in vivo. By knocking down the expression of Pp2A-29B that encodes the scaffold subunit of the PP2A holoenzyme complex, we found that PP2A silencing in the differentiating hemocytes resulted in their excessive proliferation. Furthermore, this PP2A inhibition downregulated the expression of Smoothened (Smo), a crucial component in the Hedgehog pathway, and smo overexpression was able to rescue the phenotypes of PP2A depletion, indicating that Smo functions as a downstream effector of PP2A to restrict the hemocyte proliferation. PDGF/VEGF-receptor (Pvr) overexpression also restored the Smo expression and lymph gland morphology of PP2A silencing, suggesting a PP2A-Pvr-Smo axis to regulate lymph gland growth and hemocyte proliferation. Moreover, inhibiting PP2A activity in the blood progenitor cells promoted their differentiation, but which was independent with Smo. Together, our data suggested that PP2A plays a dual role in the Drosophila lymph gland by preserving the progenitor population and restraining the hemocyte proliferation, to properly regulate the hematopoietic process.

Adaptive Prototype Learning for Weakly-supervised Temporal Action Localization.

Weakly-supervised Temporal Action Localization (WTAL) aims to localize action instances with only video-level labels during training, where two primary issues are localization incompleteness and background interference. To relieve these two issues, recent methods adopt an attention mechanism to activate action instances and simultaneously suppress background ones, which have achieved remarkable progress. Nevertheless, we argue that these two issues have not been well resolved yet. On the one hand, the attention mechanism adopts fixed weights for different videos, which are incapable of handling the diversity of different videos, thus deficient in addressing the problem of localization incompleteness. On the other hand, previous methods only focus on learning the foreground attention and the attention weights usually suffer from ambiguity, resulting in difficulty of suppressing background interference. To deal with the above issues, in this paper we propose an Adaptive Prototype Learning (APL) method for WTAL, which includes two key designs: (1) an Adaptive Transformer Network (ATN) to explicitly model background and learn video-adaptive prototypes for each specific video, (2) an OT-based Collaborative (OTC) training strategy to guide the learning of prototypes and remove the ambiguity of the foreground-background separation by introducing an Optimal Transport (OT) algorithm into the collaborative training scheme between RGB and FLOW streams. These two key designs can work together to learn video-adaptive prototypes and solve the above two issues, achieving robust localization. Extensive experimental results on two standard benchmarks (THUMOS14 and ActivityNet) demonstrate that our proposed APL performs favorably against state-of-the-art methods.

Roles and Regulation of Quorum Sensing of Acidophiles in Bioleaching: A Review.

Bioleaching has gained significant attention as a cost-effective and environmentally friendly approach for extracting metals from low-grade ores and industrial byproducts. The application of acidophiles in bioleaching has been extensively studied. Among the various mechanisms leaching microorganisms utilize, quorum sensing (QS) is pivotal in regulating their life activities in response to population density. QS has been confirmed to regulate bioleaching, including cell morphology, community structure, biofilm formation, and cell metabolism. Potential applications of QS have also been proposed, such as increasing mineral leaching rates by adding signaling molecules. This review is helpful for comprehensively understanding the role of QS in bioleaching and promoting the practical application of QS-based strategies in bioleaching process optimization.