Electrically pumped topological laser with valley edge modes.

Quantum cascade lasers are compact, electrically pumped light sources in the technologically important mid-infrared and terahertz region of the electromagnetic spectrum1,2. Recently, the concept of topology3 has been expanded from condensed matter physics into photonics4, giving rise to a new type of lasing5-8 using topologically protected photonic modes that can efficiently bypass corners and defects4. Previous demonstrations of topological lasers have required an external laser source for optical pumping and have operated in the conventional optical frequency regime5-8. Here we demonstrate an electrically pumped terahertz quantum cascade laser based on topologically protected valley edge states9-11. Unlike topological lasers that rely on large-scale features to impart topological protection, our compact design makes use of the valley degree of freedom in photonic crystals10,11, analogous to two-dimensional gapped valleytronic materials12. Lasing with regularly spaced emission peaks occurs in a sharp-cornered triangular cavity, even if perturbations are introduced into the underlying structure, owing to the existence of topologically protected valley edge states that circulate around the cavity without experiencing localization. We probe the properties of the topological lasing modes by adding different outcouplers to the topological cavity. The laser based on valley edge states may open routes to the practical use of topological protection in electrically driven laser sources.

Superstitious learning of abstract order from random reinforcement.

Humans and other animals often infer spurious associations among unrelated events. However, such superstitious learning is usually accounted for by conditioned associations, raising the question of whether an animal could develop more complex cognitive structures independent of reinforcement. Here, we tasked monkeys with discovering the serial order of two pictorial sets: a "learnable" set in which the stimuli were implicitly ordered and monkeys were rewarded for choosing the higher-rank stimulus and an "unlearnable" set in which stimuli were unordered and feedback was random regardless of the choice. We replicated prior results that monkeys reliably learned the implicit order of the learnable set. Surprisingly, the monkeys behaved as though some ordering also existed in the unlearnable set, showing consistent choice preference that transferred to novel untrained pairs in this set, even under a preference-discouraging reward schedule that gave rewards more frequently to the stimulus that was selected less often. In simulations, a model-free reinforcement learning algorithm (Q-learning) displayed a degree of consistent ordering among the unlearnable set but, unlike the monkeys, failed to do so under the preference-discouraging reward schedule. Our results suggest that monkeys infer abstract structures from objectively random events using heuristics that extend beyond stimulus-outcome conditional learning to more cognitive model-based learning mechanisms.

An LPS-induced TNF-α factor involved in immune response of oyster Crassostrea gigas by regulating haemocytes apoptosis.

LPS induced TNF-α Factor (LITAF) is a transcription factor widely involving in activation of Tumor Necrosis Factor (TNF) and other cytokines in the inflammatory response. In the present study, a homologue of LITAF with a conserved LITAF domain was identified from the Pacific oyster Crassostrea gigas. The transcripts of CgLITAF were detected in all examined tissues with highest expression in hepatopancrease. The immunofluorescence assay and Western blot showed that LPS stimulation induced an obvious nucleus translocation of CgLITAF protein in haemocytes. While the mRNA level of CgLITAF changed slightly after LPS stimulation. When the siRNA of CgLITAF was injected to inhibit its expression, the apoptotic level of haemocytes decreased observably after LPS stimulation. Consistently, the transcripts of CgTNF3 and CgTNF4 (LOC105343080, LOC105341146), the apoptotic-related molecules including CgBax, CgCytochrome c, CgCaspase9 and CgCaspase3, were significantly suppressed in the CgLITAF-RNAi oysters. While the mRNA expression level of CgBcl was enhanced significantly in the CgLITAF-RNAi oysters. These results indicated that CgLITAF promoted haemocyte apoptosis by regulating the expression of apoptotic-related factors, suggesting its important role in the immune response of oysters.

A High-Nuclearity Copper Sulfide Nanocluster [S-Cu50] Featuring a Double-Shell Structure Configuration with Cu(II)/Cu(I) Valences.

This work represents an important step in the quest for creating atomically precise binary semiconductor nanoclusters (BS-NCs). Compared with coinage metal NCs, the preparation of BS-NCs requires strict control of the reaction kinetics to guarantee the formation of an atomically precise single phase under mild conditions, which otherwise could lead to the generation of multiple phases. Herein, we developed an acid-assisted thiolate dissociation approach that employs suitable acid to induce cleavage of the S-C bonds in the Cu-S-R (R = alkyl) precursor, spontaneously fostering the formation of the [Cu-S-Cu] skeleton upon the addition of extra Cu sources. Through this method, a high-nuclearity copper sulfide nanocluster, Cu50S12(SC(CH3)3)20(CF3COO)12 (abbreviated as [S-Cu50] hereafter), has been successfully prepared in high yield, and its atomic structure was accurately modeled through single-crystal X-ray diffraction. It was revealed that [S-Cu50] exhibits a unique double-shell structural configuration of [Cu14S12]@[Cu36S20], and the innermost [Cu14] moiety displays a rhombic dodecahedron geometry, which has never been observed in previously synthesized Cu metal, hydride, or chalcogenide NCs. Importantly, [S-Cu50] represents the first example incorporating mixed Cu(II)/Cu(I) valences in reported atomically precise copper sulfide NCs, which was unambiguously confirmed by XPS, EPR, and XANES. In addition, the electronic structure of [S-Cu50] was established by a variety of optical investigations, including absorption, photoluminescence, and ultrafast transient absorption spectroscopies, as well as theoretical calculations. Moreover, [S-Cu50] is air-stable and demonstrates electrocatalytic activity in ORR with a four-electron pathway.

Long wavelength mid-infrared multi-gases spectroscopy using tunable single-mode slot waveguide quantum cascade laser.

Single-mode tunable quantum cascade lasers (QCLs) are promising for high-resolution and highly sensitive trace gases sensing across the mid-infrared (MIR) region. We report on the development of a tunable single-mode slot waveguide QCL array in the long wavelength part of the MIR regime (>12 µm). This laser array exhibits a tuning range of around 12 cm-1, from 735.3 to 747.3 cm-1. Using this developed single-mode tunable QCL, we demonstrate individual gas sensing, yielding the detection limit of 940 ppb and 470 ppb for acetylene and o-xylene, respectively. To verify the potential of the developed QCL array in multi-species gas detection, laser absorption measurements of two mixed gases of acetylene and o-xylene were conducted, showing the absorption features of the corresponding gases agree well with the theoretical predictions.

Spatiotemporal lasing dynamics in a Limaçon-shaped microcavity.

Limaçon-shaped microdisk lasers are promising on-chip light sources with low lasing threshold and unidirectional output. We conduct an experimental study on the lasing dynamics of Limaçon-shaped semiconductor microcavities. The edge emission exhibits intensity fluctuations over a wide range of spatial and temporal scales. They result from multiple dynamic processes with different origins and occur on different spatiotemporal scales. The dominant process is an alternate oscillation between two output beams with a period as short as a few nanoseconds.

Impact of Cavity Geometry on Microlaser Dynamics.

We experimentally investigate spatiotemporal lasing dynamics in semiconductor microcavities with various geometries, featuring integrable or chaotic ray dynamics. The classical ray dynamics directly impacts the lasing dynamics, which is primarily determined by the local directionality of long-lived ray trajectories. The directionality of optical propagation dictates the characteristic length scales of intensity variations, which play a pivotal role in nonlinear light-matter interactions. While wavelength-scale intensity variations tend to stabilize lasing dynamics, modulation on much longer scales causes spatial filamentation and irregular pulsation. Our results will pave the way to control the lasing dynamics by engineering the cavity geometry and ray dynamical properties.

An IRF2BP member (CgIRF2BP) involved in negative regulation of CgIFNLP expression in oyster Crassostrea gigas.

The IRF2BP family of transcription regulators act as corepressor molecules by inhibiting both enhancer-activated and basal transcription involving in many biological contexts. In the present study, an IRF2BP homologue (CgIRF2BP) was identified from oyster C. gigas. Its open reading frame is of 1809 bp encoding a polypeptide of 602 amino acids, which contains an IRF-2BP1_2 domain and a RING domain. The mRNA transcripts of CgIRF2BP were detected in all tested tissues with highest level in haemocytes (28.99-fold of that in mantle, p < 0.05). After poly (I:C) stimulation, the expression level of CgIRF2BP was significantly down-regulated at 3 h (0.50-fold of that in control group, p < 0.001) and gradually increased from 6 h to 48 h (2.69-fold of that in control group, p < 0.01). The recombinant protein of CgIRF2BP (rCgIRF2BP) showed high affinity to both rCgIRF1 and rCgIRF8 with Kd value of 1.02 × 10-7 and 2.09 × 10-7, respectively. In CgIRF2BP-RNAi oysters, the mRNA expression of CgIFNLP, CgMx1, CgViperin and CgIFI44L were significantly increased after poly (I:C) stimulation, which were 2.88 (p < 0.01), 1.83 (p < 0.05), 2.47 (p < 0.05), and 1.99-fold (p < 0.01) of that in EGFP group, respectively. These findings suggested that CgIRF2BP negatively regulated CgIFNLP expression by binding with CgIRF1 and CgIRF8.

Chemical Bond Bridging across Two Domains: Generation of Fe(II) and In Situ Formation of FeSx on Zerovalent Iron.

Sulfidation of zerovalent iron (SZVI) can strengthen the decontamination ability by promoting the electron transfer from inner Fe0 to external pollutants by iron sulfide (FeSx). Although FeSx forms easily, the mechanism for the FeSx bonding on the ZVI surface through a liquid precipitation method is elusive. In this work, we demonstrate a key pathway for the sulfidation of ZVI, namely, the in situ formation of FeSx on ZVI surface, which leads to chemical bonding across two domains: the pristine ZVI and the newly formed FeSx phase. The two chemically bridged heterophases display superior activity in electron transportation compared to the physically coated SZVI, eventually bringing about the better performance in reducing Cr(VI) species. It is revealed that the formation of chemically bonded FeSx requires balancing the rates for the two processes of Fe(II) release and sulfidation, which can be achieved by tuning the pH and S(-II) concentration. This study elucidates a mechanism for surface generation of FeSx on ZVI, and it provides new perspectives to design high-quality SZVI for environmental applications.

Widely tunable single-mode slot waveguide quantum cascade laser array.

We report designs and experimental demonstrations of a widely tunable single-mode quantum cascade laser array based on slot waveguide structures in the mid-infrared region. The laser array device realized a continuous tuning range of 71 cm-1 from 9.66 µm to 10.37 µm at 300 K only using the current tuning without any external heatsink temperature adjustments, in good agreement with the design. Stable single-mode operations free of undesired mode-hops have been obtained over the whole tuning range. Another slot waveguide QCL array with a 41 cm-1 continuous tuning range around 7.3 µm has also been realized with the same design principle, demonstrating the universal applicability of the array design. The broadly continuous tuning with simple processing makes the array device a suitable candidate for mid-infrared sensing and spectroscopy application.

A protein inhibitor of activated STAT (CgPIAS) negatively regulates the expression of ISGs by inhibiting STAT activation in oyster Crassostrea gigas.

The protein inhibitor of activated STAT (PIAS) family proteins act as the important negative regulators in janus kinase (JAK)/signal transducer and activator of transcription (STAT) signaling pathway, which can be also involved in regulating the expression of interferon-stimulated genes (ISGs). In the present study, a PIAS homologue (designated as CgPIAS) was identified from oyster Crassostrea gigas. The open reading frame (ORF) of CgPIAS cDNA was of 1887 bp encoding a peptide of 628 amino acid residues. The CgPIAS protein contains a conserved scaffold attachment factor A/B/acinus/PIAS (SAP) domain, a Pro-Ile-Asn-Ile-Thr (PINIT) motif, a RING-finger-like zinc-binding domain (RLD) and two SUMO-interaction Motifs (SIMs). The deduced amino acid sequence of CgPIAS shared 74.58-81.36% similarity with other PIAS family members in the RLD domain. The mRNA transcripts of CgPIAS were detected in all the tested tissues with highest level in haemocytes (32.98-fold of mantles, p < 0.001). After poly (I:C) and recombinant Interferon-like protein (rCgIFNLP) stimulation, the mRNA expression of CgPIAS in haemocytes significantly up-regulated to the highest level at 48 h (7.38-fold, p < 0.001) and at 24 h (13.08-fold, p < 0.01), respectively. Moreover, the nuclear translocation of CgPIAS was observed in haemocytes after poly (I:C) stimulation. Biolayer Interferometry (BLI) assay revealed that the recombinant protein CgPIAS-RLD could interact with the recombinant protein CgSTAT in vitro with the KD value of 3.88 × 10-8 M. In the CgPIAS-RNAi oysters, the green signals of CgSTAT protein in nucleus of haemocytes increased compared with that in NC-RNAi group, and the mRNA expression of myxovirus resistance (CgMx1), oligoadenylate synthase-like proteins (CgOASL), CgViperin and IFN-induced protein 44-like (CgIFI44L-1) in haemocytes significantly increased at 12 h after poly (I:C) stimulation, which were 2.39-fold (p < 0.05), 2.18-fold (p < 0.001), 1.74-fold (p < 0.05), and 2.89-fold (p < 0.01) of that in control group, respectively. The above results indicated that CgPIAS negatively regulated the ISG expression by inhibiting STAT activation in oyster C. gigas.

The involvement of an interferon-induced protein 44-like (CgIFI44L) in the antiviral immune response of Crassostrea gigas.

Interferon-stimulated genes (ISGs) encoding proteins are the essential executors of interferon (IFN) mediated antiviral defense. In the present study, an ISG member, interferon-induced protein 44-like (IFI44L) gene (designed as CgIFI44L-1) was identified from the Pacific oyster Crassostrea gigas. The ORF of CgIFI44L-1 cDNA was of 1437 bp encoding a polypeptide of 479 amino acids with a TLDc domain and an MMR_HSR1 domain. The mRNA transcripts of CgIFI44L-1 were detected in all the tested tissues with highest level in haemocytes, which was 15.78-fold of that in gonad (p < 0.001). Among the haemocytes, the CgIFI44L-1 protein was detected to be highly expressed in granulocytes with dominant distribution in cytoplasm. The mRNA expression level of CgIFI44L-1 in haemocytes was significantly induced by poly (I:C) stimulation, and the expression level peaked at 24 h, which was 24.24-fold (p < 0.0001) of that in control group. After the treatment with the recombinant protein of an oyster IFN-like protein (rCgIFNLP), the mRNA expression level of CgIFI44L-1 was significantly enhanced at 6 h, 12 h and 24 h, which was 2.67-fold (p < 0.001), 5.44-fold (p < 0.001) and 5.16-fold (p < 0.001) of that in control group, respectively. When the expressions of CgSTAT and CgIFNLP were knocked down by RNA interference (RNAi), the mRNA transcripts of CgIFI44L-1 were significantly down-regulated after poly (I:C) stimulation, which was 0.09-fold (p < 0.001) and 0.06-fold (p < 0.001) of those in EGFP group, respectively. These results suggested that CgIFI44L-1 was a conserved ISG in oyster, which was regulated by CgIFNLP and CgSTAT, and involved in the oyster antiviral immune response.

A RAC-alpha serine/threonine-protein kinase (CgAKT1) involved in the synthesis of CgIFNLP in oyster Crassostrea gigas.

The RAC-alpha serine/threonine-protein kinase (AKT) is one of the most important protein kinases involved in many biological processes in eukaryotes. In the present study, a novel AKT homologue named CgAKT1 was identified from the Pacific oyster Crassostrea gigas. The open reading frame (ORF) of CgAKT1 cDNA was of 1482 bp encoding a peptide with 493 amino acid residues. There were classical domains in the predicted CgAKT1 protein, including an N-terminal pleckstrin homology domain, a central catalytic domain and a C-terminal hydrophobic domain. The mRNA transcripts of CgAKT1 were detected in all the examined tissues of C. gigas with higher level in gills (8.24-fold of that in mantle, p < 0.05) and haemocytes (3.62-fold of that in mantle, p < 0.05). After poly (I:C) stimulation, the mRNA expression of CgAKT1 decreased significantly in haemocytes from 3 h (0.44-fold of that in the control group, p < 0.001) to 24 h (0.20-fold of that in the control group, p < 0.001), and then increased significantly at 48 h (3.65-fold of that in the control group, p < 0.05). The expression level of CgAKT1 mRNA increased significantly at 6 h after rCgIFNLP stimulation, which was 3.60-fold of that in the control group (p < 0.001). The Alexa Fluor 488 positive signals of CgAKT1 protein were found to be distributed in the cytoplasm and cell membrane of haemocytes, while those in the cytoplasm became weaker after poly (I:C) stimulation. In CgAKT1-RNAi oysters, the mRNA expression of cyclic GMP-AMP synthase (CgcGAS) and TANK-binding kinase 1 (CgTBK1) did not change significantly, but the mRNA expression level of stimulator of interferon gene (CgSTING), interferon regulatory factor-1 (CgIRF-1), interferon regulatory factor-8 (CgIRF-8) and IFN-like protein (CgIFNLP) increased significantly, which was 1.40-fold, 1.53-fold, 1.72-fold and 1.99-fold of that in EGFP-RNAi oysters (p < 0.05), respectively. In CgIFNLP-RNAi oysters, the transcripts of CgAKT1 decreased significantly compared to those in EGFP-RNAi oysters (0.16-fold, p < 0.01). Moreover, the expression of p-CgTBK1, CgSTING and CgIFNLP at the protein level in the oysters treated with p-AKT1 activator (SC-79) was significantly suppressed after poly (I:C) stimulation. After the transfection of CgAKT1, the expression of p-cGAS protein in HEK293T cells increased significantly, while the cyclic GMP-AMP in the cells and the interferon (IFN-ß) in the cell culture fluid decreased significantly compared with that in the control group. These results indicated that CgAKT1 might play a negative role in antiviral immunity of oyster by regulating the synthesis of CgIFNLP.

A stimulator of interferon gene (CgSTING) involved in antimicrobial immune response of oyster Crassostrea gigas.

The stimulator of interferon gene (STING), an intracellular sensor of cyclic dinucleotides, is critical to the innate immune response, especially the induction of type I interferon (IFN) during pathogenic infection. A STING homologue (CgSTING) regulating the expression of IFN-like protein (CgIFNLP) was previously identified in the Pacific oyster Crassostrea gigas, and its involvement in antibacterial immunity was further investigated in the present study. The mRNA transcripts of CgSTING were ubiquitously detected in all the three subpopulations of haemocytes with the highest expression in semi-granulocytes. After the stimulation with Vibrio splendidus, the mRNA expression of CgSTING in haemocytes was significantly up-regulated and peaked at 72 h, which was 12.91-fold of that in control group (p < 0.01). The CgSTING protein was mainly located in the cytoplasm of haemocytes. After the expression of CgSTING was knocked down (0.12-fold of that in control group, p < 0.05) by RNAi, the mRNA expression levels of interleukin17-1 (CgIL17-1), interleukin17-3 (CgIL17-3), interleukin17-4 (CgIL17-4), defensins (Cgdefh1, Cgdefh2), big defensin (CgBigDef1), interferon-like protein (CgIFNLP), tumor necrosis factor (CgTNF) and nuclear factor-κB (CgRel) all decreased significantly at 12 h after V. splendidus stimulation, which was 0.12-fold-0.72-fold (p < 0.05) of that in control group, respectively. The positive signals of CgRel were observed in the haemocyte nucleus after V. splendidus stimulation. The nuclear translocation of CgRel was suppressed in CgSTING-RNAi oysters, and the green signals of CgRel were mainly observed in the haemocyte cytoplasm after V. splendidus stimulation. Furthermore, the number of V. splendidus in the haemolymph of CgSTING-RNAi oysters increased significantly, which was 26.78-fold (p < 0.01) of that in the control group at 12 h after V. splendidus stimulation. These results indicated that CgSTING played important role in the immune defense against bacterial infection by inducing the expressions of cytokines and defensins.

Identification and characterization of an apoptosis-inducing factor 1 involved in apoptosis and immune defense of oyster, Crassostrea gigas.

The apoptosis-inducing factor (AIF) is a phylogenetically old protein with classic function of inducing caspase-independent apoptosis, which extensively present in all primary kingdoms. In the present study, an AIF homologue (designated as CgAIF1) was identified from oyster Crassostrea gigas. The open reading frame of CgAIF1 cDNA was of 1836 bp encoding a peptide of 611 amino acid residues. There are a Pyr_redox_2 domain and an AIF_C domain in the predicted CgAIF1 protein. The deduced amino acid sequence of CgAIF1 shared 35.44%-79.22% similarity with AIF1s from other species. In the phylogenetic tree, CgAIF1 firstly clustered with mollusc AIF1s, and then with insect AIF1s, displaying separation from vertebrate AIF1s. The mRNA transcripts of CgAIF1 were constitutively distributed in all the tested oyster tissues, with the highest level in gills (12.98-fold of that in haemocytes, p < 0.05). After LPS and Poly (I:C) stimulation, the mRNA transcripts of CgAIF1 in gills were significantly increased at 6 h and 24 h (5.79-fold, p < 0.001, and 21.96-fold compared to the control group, p < 0.05), respectively. In immunocytochemical assay, the CgAIF1 positive signals were mainly distributed in the cytoplasm of haemocytes, while after Poly (I:C) stimulation, the increased CgAIF1 positive signals were observed in the nucleus. Moreover, in the HEK293T cells transfected with pcDNA3.1-CgAIF1 recombinant plasmid, green signal of CgAIF1 were observed in both the cytoplasm and nucleus. The cell mortality rate, cell shrinking and the phosphatidylserine (PS) ectropion (Annexin V+/PI- cells and Annexin V+/PI+ cells) of CgAIF1 transfected HEK293T cells were significantly increased, compared to the groups with or without pcDNA3.1 transfection. These results collectively suggested that CgAIF1 was a conserved AIF1 member in oysters, and participated in immune response by inducing cell apoptosis.

Fluorescence Resonance Energy Transfer-Mediated Immunosensor Based on Design and Synthesis of the Substrate of Amp Cephalosporinase for Biosensing.

The traditional enzyme-linked immunosorbent assay (ELISA) has some disadvantages, such as insufficient sensitivity and low stability of the labeled enzyme, which limit its further applications. In this study, a more stable enzyme, Amp cephalosporinase (AmpC), was selected as the labeled enzyme, and its substrate was designed and synthesized. This substrate contained the cephalosporin ring core as the enzymatic recognition section and the structural motif of the 3-hydroxyflavone (3-HF) as the reporter molecule. AmpC can specifically catalyze the substrate and release 3-HF, which can enter the cavity of ß-cyclodextrin (ß-CD) on the surface of ZnS quantum dots and form a fluorescence resonance energy transfer (FRET) signal amplification system. An AmpC-catalyzed, FRET-mediated ultrasensitive immunosensor (ACF immunosensor) for procalcitonin (PCT) was developed by combining the signal amplification system of the polystyrene microspheres and effective immune-based magnetic separation. The ACF immunosensor has high sensitivity and specificity for the detection of PCT: its linear range is from 0.1 ng mL-1 to 70 ng mL-1, and the limit of detection can reach 0.03 ng mL-1. The spiking recoveries of PCT in human serum samples range from 98.3% to 107%, with relative standard deviations ranging from 2.14% to 12.0%. This approach was applied to detect PCT in real patient serum samples, and the results are consistent with those obtained with a commercial ELISA kit.

Convergent gene pair dSH3 and irr regulate Pi and Fe homeostasis in Bradyrhizobium diazoefficiens USDA110 and symbiotic nitrogen fixation efficiency.

The nitrogen-fixing bacteroids inhabit inside legume root nodules must manage finely the utilization of P and Fe, the two most critical elements, due to their antagonistic interactions. While the balance mechanism for them remains unclear. A double SH3 domain-containing protein (dSH3) in the Bradyrhizobium diazoefficiens USDA110 was found to inhibit the alkaline phosphatase activity, thereby reducing P supply from organophosphates. The dSH3 gene is adjacent to the irr gene, which encodes the iron response repressor and regulates Fe homeostasis under Fe-limited conditions. Their transcription directions converge to a common intergenic sequence (IGS) region, forming a convergent transcription. Extending the IGS region through Tn5 transposon or pVO155 plasmid insertion significantly down-regulated expression of this gene pair, leading to a remarkable accumulation of P and an inability to grow under Fe-limited conditions. Inoculation of soybean with either of the insertion mutants resulted in N2-fixing failure. However, the IGS-deleted mutant showed no visible changes in N2-fixing efficiency on soybean compared to that inoculated with wild type. These findings reveal a novel regulative strategy in the IGS region and its flanking convergent gene pair for antagonistic utilization of P and Fe in rhizobia and coordination of N2-fixing efficiency.

Multidimensional detection enabled by twisted black arsenic-phosphorus homojunctions.

A light field carrying multidimensional optical information, including but not limited to polarization, intensity and wavelength, is essential for numerous applications such as environmental monitoring, thermal imaging, medical diagnosis and free-space communications. Simultaneous acquisition of this multidimensional information could provide comprehensive insights for understanding complex environments but remains a challenge. Here we demonstrate a multidimensional optical information detection device based on zero-bias double twisted black arsenic-phosphorus homojunctions, where the photoresponse is dominated by the photothermoelectric effect. By using a bipolar and phase-offset polarization photoresponse, the device operated in the mid-infrared range can simultaneously detect both the polarization angle and incident intensity information through direct measurement of the photocurrents in the double twisted black arsenic-phosphorus homojunctions. The device's responsivity makes it possible to retrieve wavelength information, typically perceived as difficult to obtain. Moreover, the device exhibits an electrically tunable polarization photoresponse, enabling precise distinction of polarization angles under low-intensity light exposure. These demonstrations offer a promising approach for simultaneous detection of multidimensional optical information, indicating potential for diverse photonic applications.

A trace amine associated receptor mediates antimicrobial immune response in the oyster Crassostrea gigas.

Trace amine-associated receptors (TAARs) are a class of G protein-coupled receptors, playing an immunomodulatory function in the neuroinflammatory responses. In the present study, a TAAR homologue with a 7tm_classA_rhodopsin-like domain (designated as CgTAAR1L) was identified in oyster Crassostrea gigas. The abundant CgTAAR1L transcripts were detected in visceral ganglia and haemocytes compared to other tissues, which were 55.35-fold and 32.95-fold (p < 0.01) of those in adductor muscle, respectively. The mRNA expression level of CgTAAR1L in haemocytes significantly increased and reached the peak level at 3 h after LPS or Poly (I:C) stimulation, which was 4.55-fold and 12.35-fold of that in control group, respectively (p < 0.01). After the expression of CgTAAR1L was inhibited by the injection of its targeted siRNA, the mRNA expression levels of interleukin17s (CgIL17-1, CgIL17-5 and CgIL17-6), and defensin (Cgdefh1) significantly decreased at 3 h after LPS stimulation, which was 0.51-fold (p < 0.001), 0.39-fold (p < 0.01), 0.48-fold (p < 0.05) and 0.41-fold (p < 0.05) of that in the control group, respectively. The nuclear translocation of Cgp65 protein was suppressed in the CgTAAR1L-RNAi oysters. Furthermore, the number of Vibrio splendidus in the haemolymph of CgTAAR1L-RNAi oysters significantly increased (4.11-fold, p < 0.001) compared with that in the control group. In contrast, there was no significant difference in phagocytic rate of haemocytes to V. splendidus in the CgTAAR1L-RNAi oysters. These results indicated that CgTAAR1L played an important role in the immune defense against bacterial infection by inducing the expressions of interleukin and defensin.

The involvement of interferon regulatory factor 8 in regulating the proliferation of haemocytes in oyster Crassostrea gigas.

Interferon regulatory factor 8 (IRF8) is an important transcriptional regulatory factor involving in multiple biological process, such as the antiviral immune response, immune cell proliferation and differentiation. In the present study, the involvement of a previously identified IRF8 homologue (CgIRF8) in regulating haemocyte proliferation of oyster were further investigated. CgIRF8 mRNA transcripts were detectable in all the stages of C. gigas larvae with the highest level in D-veliger (1.76-fold of that in zygote, p < 0.05). Its mRNA transcripts were also detected in all the three haemocyte subpopulations of adult oysters with the highest expression in granulocytes (2.79-fold of that in agranulocytes, p < 0.01). After LPS stimulation, the mRNA transcripts of CgIRF8 in haemocytes significantly increased at 12 h and 48 h, which were 2.04-fold and 1.65-fold (p < 0.05) of that in control group, respectively. Meanwhile, the abundance of CgIRF8 protein in the haemocytes increased significantly at 12 h after LPS stimulation (1.71-fold of that in seawater, p < 0.05). The immunofluorescence assay and Western blot showed that LPS stimulation induced an obvious nucleus translocation of CgIRF8 protein in haemocytes. After the expression of CgIRF8 was inhibited by the injection of CgIRF8 siRNA, the percentage of EdU positive haemocytes, the proportion of granulocytes, and the mRNA expression levels of CgGATA and CgSCL all declined significantly at 12 h after LPS stimulation, which was 0.64-fold (p < 0.05), 0.7-fold (p < 0.05), 0.31-fold and 0.54-fold (p < 0.001) of that in the NC group, respectively. While the expression level of cell proliferation-related protein CgCDK2, CgCDC6, CgCDC45 and CgPCNA were significantly increased (1.99-fold, and 2.41-fold, 3.76-fold and 4.79-fold compared to that in the NC group respectively, p < 0.001). Dual luciferase reporter assay demonstrated that CgIRF8 was able to activate the CgGATA promoter in HEK293T cells after transfection of CgGATA and CgIRF8. These results collectively indicated that CgIRF8 promoted haemocyte proliferation by regulating the expression of CgGATA and other related genes in the immune response of oyster.