Experimental quantum natural gradient optimization in photonics.

Variational quantum algorithms (VQAs) combining the advantages of parameterized quantum circuits and classical optimizers, promise practical quantum applications in the noisy intermediate-scale quantum era. The performance of VQAs heavily depends on the optimization method. Compared with gradient-free and ordinary gradient descent methods, the quantum natural gradient (QNG), which mirrors the geometric structure of the parameter space, can achieve faster convergence and avoid local minima more easily, thereby reducing the cost of circuit executions. We utilized a fully programmable photonic chip to experimentally estimate the QNG in photonics for the first time, to the best of our knowledge. We obtained the dissociation curve of the He-H+ cation and achieved chemical accuracy, verifying the outperformance of QNG optimization on a photonic device. Our work opens up a vista of utilizing QNG in photonics to implement practical near-term quantum applications.

Quantum generative adversarial learning in photonics.

Quantum generative adversarial networks (QGANs), an intersection of quantum computing and machine learning, have attracted widespread attention due to their potential advantages over classical analogs. However, in the current era of noisy intermediate-scale quantum (NISQ) computing, it is essential to investigate whether QGANs can perform learning tasks on near-term quantum devices usually affected by noise and even defects. In this Letter, using a programmable silicon quantum photonic chip, we experimentally demonstrate the QGAN model in photonics for the first time to our knowledge and investigate the effects of noise and defects on its performance. Our results show that QGANs can generate high-quality quantum data with a fidelity higher than 90%, even under conditions where up to half of the generator's phase shifters are damaged, or all of the generator and discriminator's phase shifters are subjected to phase noise up to 0.04π. Our work sheds light on the feasibility of implementing QGANs on the NISQ-era quantum hardware.

Pd/Co Catalyst with High Pd Atom Utilization Efficiency for Nitrobenzene Hydrogenation at Room Temperature: Experimental and DFT Studies.

Enhancing catalytic performance as well as reducing catalyst cost are the eternal pursuit for the catalysis community. Herein, a simple and effective palladium-doped cobalt (Pd/Co) catalyst with high Pd atom utilization efficiency was synthesized via galvanic replacement reaction for the selective hydrogenation of nitrobenzene with H2 at room temperature, delivering >99 % yield of aniline with up to 158 times higher catalytic activity than commercial palladium powder. Detailed characterizations and DFT calculations revealed that Co-Pd interaction leads to a decrease in electron density of Pd and the distance between Pd atoms that results in the enhanced catalytic performance. Further experiments indicated that the Pd/Co catalyst serves as a highly efficient, selective, and recyclable catalyst for a range of nitroarene substrates. This work might provide a green and sustainable methodology to design and synthesize highly active catalysts with high utilization efficiency of the noble metals in fundamental and applied research.

UNC93B1 facilitates TLR18-mediated NF-κB signal activation in Schizothorax prenanti.

Toll-like receptor 18 (TLR18), a non-mammalian TLR, has been believed to play an important role in anti-bacterial immunity of teleost fishes. UNC93B1 is a classical molecular chaperone that mediates TLRs transport from endoplasmic reticulum to the located membrane. However, TLR18-mediated signal transduction mechanism and the regulatory effect of UNC93B1 to TLR18 are still unclear in teleost fishes. In this study, the coding sequences of TLR18 and UNC93B1 were cloned from Schizothorax prenanti, named spTLR18 and spUNC93B1, respectively. The spTLR18 and spUNC93B1 are 2583 bp and 1878 bp in length, encode 860 and 625 amino acids, respectively. The spTLR18 widely expressed in various tissues with the highest expression level in liver. After stimulation of Aeromonas hydrophila, lipopolysaccharide (LPS) and Poly(I:C), the expression levels of spTLR18 were significantly increased in spleen and head kidney. The spTLR18 located in the cell membrane, while spUNC93B1 located in the cytoplasm. Luciferase and overexpression analysis showed that spTLR18 activated NF-κB and type I IFN signal pathways, and spTLR18-mediated NF-κB activation might depend on the adaptor molecule MyD88. Besides, spUNC93B1 positively regulates spTLR18-mediated NF-κB signal. Our study first uncovers TLR18-UNC93B1-mediated signal transduction mechanism, which contributes to the understanding of TLR signaling pathway in teleost fishes.

PNX14 but not PNX20 as a novel regulator of preadipocyte differentiation via activating Epac-ERK signaling pathway in Gallus gallus.

Small integral membrane protein 20 (SMIM20) could generate two main peptides, PNX14 and PNX20, which participate in multiple biological roles such as reproduction, inflammation and energy metabolism in mammals. However, little is known about their physiological functions in non-mammalian vertebrates. Using chicken (c-) as an animal model, we found cSMIM20 was moderately expressed in adipose tissues, and its expression was gradually increased during the differentiation of chicken preadipocytes, suggesting that it may play an important role in chicken adipogenesis. Further research showed cPNX14 could facilitate the differentiation of chicken preadipocytes into mature adipocytes by enhancing expression of adipogenic genes including PPARγ, CEBPα and FABP4, and promoting the formation of lipid droplets. This pro-adipogenic effect of cPNX14 was completely attenuated by Epac-specific and ERK inhibitor. Interestingly, cPNX20 failed to regulate the adipogenic genes and lipid droplet content. Collectively, our findings reveal that cPNX14 but not cPNX20 can serve as a novel adipogenesis mediator by activating the Epac-ERK signaling pathway in chickens.

Phenylbutyrate and Dichloroacetate Enhance the Liquid-Stored Boar Sperm Quality via PDK1 and PDK3.

Artificial insemination (AI) with liquid-stored semen is the most prevalent and efficient assisted reproduction technique in the modern pork industry. Pyruvate dehydrogenase complex component X (PDHX) was demonstrated to be associated with sperm metabolism and affected the boar sperm viability, motility, and fertility. Pyruvate Dehydrogenase Kinases (PDKs) are the key metabolic enzymes that regulate pyruvate dehydrogenase complex (PDHC) activity and also the conversion from glycolysis to oxidative phosphorylation. In the present study, two PDK inhibitors, Dichloroacetate (DCA) and Phenylbutyrate (4-PBA), were added to an extender and investigated to determine their regulatory roles in liquid-stored boar sperm at 17 °C. The results indicated that PDK1 and PDK3 were predominantly located at the head and flagella of the boar sperm. The addition of 2 mM DCA and 0.5 mM 4-PBA significantly enhanced the sperm motility, plasma membrane integrity (PMI), mitochondrial membrane potential (MMP), and ATP content. In addition, DCA and 4-PBA exerted their effects by inhibiting PDK1 and PDK3, respectively. In conclusion, DCA and 4-PBA were found to regulate the boar sperm metabolic activities via PDK1 and PDK3. These both can improve the quality parameters of liquid-stored boar sperm, which will help to improve and optimize liquid-stored boar semen after their addition in the extender.

Cryopreservation Induces Acetylation of Metabolism-Related Proteins in Boar Sperm.

Cryodamage affects the normal physiological functions and survivability of boar sperm during cryopreservation. Lysine acetylation is thought to be an important regulatory mechanism in sperm functions. However, little is known about protein acetylation and its effects on cryotolerance or cryodamage in boar sperm. In this study, the characterization and protein acetylation dynamics of boar sperm during cryopreservation were determined using liquid chromatography-mass spectrometry (LC-MS). A total of 1440 proteins were identified out of 4705 modified proteins, and 2764 quantifiable sites were elucidated. Among the differentially modified sites, 1252 were found to be upregulated compared to 172 downregulated sites in fresh and frozen sperms. Gene ontology indicated that these differentially modified proteins are involved in metabolic processes and catalytic and antioxidant activities, which are involved in pyruvate metabolism, phosphorylation and lysine degradation. In addition, the present study demonstrated that the mRNA and protein expressions of SIRT5, IDH2, MDH2 and LDHC, associated with sperm quality parameters, are downregulated after cryopreservation. In conclusion, cryopreservation induces the acetylation and deacetylation of energy metabolism-related proteins, which may contribute to the post-thawed boar sperm quality parameters.

Spexin2 Is a Novel Food Regulator in Gallus gallus.

Spexin2 (SPX2), a paralog of SPX1, is a newly identified gene in non-mammalian vertebrates. Limited studies in fish have evidenced its important role in food intake and energy balance modulation. However, little is known about its biological functions in birds. Using the chicken (c-) as a model, we cloned the full-length cDNA of SPX2 by using RACE-PCR. It is 1189 base pair (bp) in length and predicted to generate a protein of 75 amino acids that contains a 14 amino acids mature peptide. Tissue distribution analysis showed that cSPX2 transcripts were detected in a wide array of tissues, with abundant expression in the pituitary, testis, and adrenal gland. cSPX2 was also observed to be ubiquitously expressed in chicken brain regions, with the highest expression in the hypothalamus. Its expression was significantly upregulated in the hypothalamus after 24 or 36 h of food deprivation, and the feeding behavior of chicks was obviously suppressed after peripheral injection with cSPX2. Mechanistically, further studies evidenced that cSPX2 acts as a satiety factor via upregulating cocaine and amphetamine regulated transcript (CART) and downregulating agouti-related neuropeptide (AGRP) in hypothalamus. Using a pGL4-SRE-luciferase reporter system, cSPX2 was demonstrated to effectively activate a chicken galanin II type receptor (cGALR2), a cGALR2-like receptor (cGALR2L), and a galanin III type receptor (cGALR3), with the highest binding affinity for cGALR2L. Collectively, we firstly identified that cSPX2 serves as a novel appetite monitor in chicken. Our findings will help clarify the physiological functions of SPX2 in birds as well as its functional evolution in vertebrates.

A Quantum-Classical Hybrid Solution for Deep Anomaly Detection.

Machine learning (ML) has achieved remarkable success in a wide range of applications. In recent ML research, deep anomaly detection (AD) has been a hot topic with the aim of discriminating among anomalous data with deep neural networks (DNNs). Notably, image AD is one of the most representative tasks in current deep AD research. ML's interaction with quantum computing is giving rise to a heated topic named quantum machine learning (QML), which enjoys great prospects according to recent academic research. This paper attempts to address the image AD problem in a deep manner with a novel QML solution. Specifically, we design a quantum-classical hybrid DNN (QHDNN) that aims to learn directly from normal raw images to train a normality model and then exclude images that do not conform to this model as anomalies during its inference. To enable the QHDNN to perform satisfactorily in deep image AD, we explore multiple quantum layer architectures and design a VQC-based QHDNN solution. Extensive experiments were conducted on commonly used benchmarks to test the proposed QML solution, whose results demonstrate the feasibility of addressing deep image AD with QML. Importantly, the experimental results show that our quantum-classical hybrid solution can even yield superior performance to that of its classical counterpart when they share the same number of learnable parameters.

Optimization of quantum light sources and four-wave mixing based on a reconfigurable silicon ring resonator.

Being a key component on a photonic chip, the microring usually specializes in a certain nonlinear optical process and can not simultaneously meet different working conditions for different processes. Here, we theoretically and experimentally investigate a reconfigurable silicon microring resonator to act as a optimization strategy for both classical four-wave mixing and quantum light sources. Experimental results show that the four-wave mixing efficiency with continuous wave and pulsed pump can be both optimized to a high value well matching numerical analysis. A variety of quantum light sources - including the heralded single-photon source, two-photon source and multi-photon source - are demonstrated to present a high performance and their key parameters including the pair generation rates (PGR), the heralding efficiency (HE) and the coincidence-to-accidental ratio (CAR) are controllable and optimizable. Such tunable nonlinear converter is immune to fabrication variations and can be popularized to other nonlinear optical materials, providing a simple and compact post-fabrication trimming strategy for on-chip all-optical signal processing and photonic quantum technologies.

Variational Entanglement-Assisted Quantum Process Tomography with Arbitrary Ancillary Qubits.

Quantum process tomography is a pivotal technique in fully characterizing quantum dynamics. However, exponential scaling of the Hilbert space with the increasing system size extremely restrains its experimental implementations. Here, we put forward a more efficient, flexible, and error-mitigated method: variational entanglement-assisted quantum process tomography with arbitrary ancillary qubits. Numerically, we simulate up to eight-qubit quantum processes and show that this tomography with m ancillary qubits (0≤m≤n) alleviates the exponential costs on state preparation (from 4^{n} to 2^{n-m}), measurement settings (at least a 1 order of magnitude reduction), and data postprocessing (efficient and robust parameter optimization). Experimentally, we first demonstrate our method on a silicon photonic chip by rebuilding randomly generated one-qubit and two-qubit unitary quantum processes. Further using the error mitigation method, two-qubit quantum processes can be rebuilt with average gate fidelity enhanced from 92.38% to 95.56%. Our Letter provides an efficient and practical approach to process tomography on the noisy quantum computing platforms.

Linguistic barriers and healthcare in China: Chaoshan vs. Mandarin.

BACKGROUND: China has 129 dialects with Mandarin as the standard and Chaoshan as the major dialect of the Chaoshan region in Guangdong. This study aimed to describe the dialect competence and usage, communication difficulty, impact of linguistic barriers, and subjective experience in healthcare. METHODS: Healthcare providers (n = 234) and healthcare consumers (n = 483) at two tertiary teaching hospitals in Shantou, Chaoshan region participated in an anonymous survey. RESULTS: Chaoshan and Mandarin were spoken respectively by ca. 80% and 6.1% of the participants. Monolinguals accounted for 28.5%, including 16.8% of Chaoshan-speaking healthcare providers and 18% of Mandarin-speaking healthcare consumers. The monolinguals preferentially used their competent dialect (Ps < 0.001) and had significant communication difficulties (Ps < 0.0001), with the mean (SD) score of 3.06 (0.96) out of 4 with Mandarin for healthcare providers and 2.18 (1.78) and 1.64 (1.40) with Mandarin and Chaoshan, respectively, for healthcare consumers. The monolingual healthcare providers perceived significant negative impacts of linguistic barriers on the entire healthcare delivery process (Ps < 0.0001). Regression analyses showed the length of stay in the Chaoshan region as a protective factor of linguistic barrier with a limited protective effect. CONCLUSIONS: This is the first report of significant linguistic barriers in healthcare imposed by Mandarin and Chaoshan dialects in Chaoshan, China. With perceived adverse impacts on the entire healthcare delivery and risks to the healthcare quality and burden, interventions such as professional interpreter service, service-learning interpreter program, or mobile interpreting apps that are medically accurate and culturally sensitive are suggested for dialectally diverse China.

A Review of Security Evaluation of Practical Quantum Key Distribution System.

Although the unconditional security of quantum key distribution (QKD) has been widely studied, the imperfections of the practical devices leave potential loopholes for Eve to spy the final key. Thus, how to evaluate the security of QKD with realistic devices is always an interesting and opening question. In this paper, we briefly review the development of quantum hacking and security evaluation technology for a practical decoy state BB84 QKD system. The security requirement and parameters in each module (source, encoder, decoder and detector) are discussed, and the relationship between quantum hacking and security parameter are also shown.

Online health information-seeking behaviors and skills of Chinese college students.

BACKGROUND: Seeking online health information (OHI) has become a common practice globally. The information seekers could face health risks if they are not proficient in OHI literacy. The OHI-seeking behaviors and skills of Chinese college students, the largest proportion of college students in the world, are understudied. This study was aimed to describe OHI-seeking behaviors and skills of college students in Guangdong, China. METHODS: College students in the Guangdong province with OHI-seeking experience were invited via WeChat, QQ, and Sina Weibo using QR code posters and flyers for participation in this online anonymized questionnaire-based study. Data on demographics, OHI literacy, information resources, search approaches, and behaviors were collected. The relationship between perceived OHI literacy and high-risk behaviors was investigated by bivariate logistic regression analysis. RESULTS: Respondents were 1203 college students with a mean age of 20.6 years, females (60.2%), and undergraduates (97.2%). They sought health information via websites (20.3%), WeChat (2.6%), or both (77.1%). Baidu was the main search engine, and baike.baidu.com (80.3%), Zhihu.com (48.4%), and Zhidao.baidu.com (35.8%) were top three among 20 searched websites for information about self-care (80.7%), general health (79.5%), disease prevention (77.7%), self-medication (61.2%), family treatment (40.9%), drugs (37.7%), western medications (26.6%), hospitals (22.7%), physicians (21.4%), and Traditional Chinese Medicine (15.6%). Despite most respondents (78%) lacked confidence in the evidence quality and satisfaction with the results, only 32.4% further consulted doctors. Many (> 50%) would recommend the retrieved information to others. About 20% experienced hacking/Internet fraud. Cronbach's alpha for the internal consistency of OHI literacy was 0.786. Bivariate logistic regression analysis showed that students who believed they can judge the evidence level of OHI were more likely to self-diagnose (OR = 2.2, 95%CI, 1.6-3.1) and look for drug usage (OR = 3.1, 95%CI, 1.9-5.0). CONCLUSIONS: This study reveals Chinese college students' heavy reliance on OHI to manage their own and others' health without sufficient knowledge/skills to identify misinformation and disinformation. The apparent risky information-seeking behaviors of Chinese college students warrant the provision of regulated, accurate, and actionable health information; assurance of cybersecurity; and health information literacy promotion in colleges by concerned authorities.

Maladaptive metacognitive beliefs mediated the effect of intolerance of uncertainty on depression.

Both elevated intolerance of uncertainty (IU) and maladaptive metacognitive beliefs (MBs) were associated with depression. However, the relationship between MBs and IU in clinical depression is unclear. The current study aimed to investigate the putative impairment of MBs and IU in major depressive disorder (MDD) and explore the relationship between these two factors with depressive symptoms. Metacognition Questionnaire-30 Items (MCQ-30), Intolerance of Uncertainty Scale-Short Form (IUS-12) and clinical rating scales were administered to 53 patients with MDD and 56 healthy controls (HCs). Stepwise regressions were performed to explore independent contributions of MBs and IU on depression. Mediation analysis was used to examine associations among variables. Patients with MDD reported higher IUS-12 and MCQ-30 scores than HCs. Stepwise regressions revealed a unique contribution of negative MBs concerning the consequences of not controlling thoughts (MCQ-NC) on depression symptoms while controlling the effects of age, gender, anxiety symptoms and IU. MCQ-NC and negative MBs concerning the uncontrollability and danger of negative thinking (MCQ-NEG) completely mediated the effects of IU on depression and anxiety symptoms. Our results provided clear evidence that maladaptive negative MBs are directly associated with depression symptoms, and mediated the effect of IU on depression and anxiety symptoms, suggesting that IU and MBs influence clinical symptoms in a hierarchical manner.

Wave-Particle Duality Relation with a Quantum Which-Path Detector.

According to the relevant theories on duality relation, the summation of the extractable information of a quanton's wave and particle properties, which are characterized by interference visibility V and path distinguishability D, respectively, is limited. However, this relation is violated upon quantum superposition between the wave-state and particle-state of the quanton, which is caused by the quantum beamsplitter (QBS). Along another line, recent studies have considered quantum coherence C in the l1-norm measure as a candidate for the wave property. In this study, we propose an interferometer with a quantum which-path detector (QWPD) and examine the generalized duality relation based on C. We find that this relationship still holds under such a circumstance, but the interference between these two properties causes the full-particle property to be observed when the QWPD system is partially present. Using a pair of polarization-entangled photons, we experimentally verify our analysis in the two-path case. This study extends the duality relation between coherence and path information to the quantum case and reveals the effect of quantum superposition on the duality relation.

Hacking single-photon avalanche detectors in quantum key distribution via pulse illumination.

Quantum key distribution (QKD) has been proved to be information-theoretically secure in theory. Unfortunately, the imperfect devices in practice compromise its security. Thus, to improve the security property of practical QKD systems, a commonly used method is to patch the loopholes in the existing QKD systems. However, in this work, we show an adversary's capability of exploiting the imperfection of the patch itself to bypass the patch. Specifically, we experimentally demonstrate that, in the detector under test, the patch of photocurrent monitor against the detector blinding attack can be defeated by the pulse illumination attack proposed in this paper. We also analyze the secret key rate under the pulse illumination attack, which theoretically confirmed that Eve can conduct the attack to learn the secret key. This work indicates the importance of inspecting the security loopholes in a detection unit to further understand their impacts on a QKD system. The method of pulse illumination attack can be a general testing item in the security evaluation standard of QKD.

Remote-controlled quantum computing by quantum entanglement.

Quantum entanglement enables measurement on one party to affect the other's state. Based on this peculiar feature, we propose a model of remote-controlled quantum computing and design an optical scheme to realize this model for a single qubit. As an experimental demonstration of this scheme, we further implement three Pauli operators, Hardmard gate, phase gate, and π/8 gate. The minimal fidelity obtained by quantum process tomography reaches 82%. Besides, as a potential application, our model contributes to secure remote quantum information processing.

Transcriptome-based evaluation and validation of suitable housekeeping gene for quantification real-time PCR under specific experiment condition in teleost fishes.

Quantification real-time PCR (qRT-PCR) is a common method in analysis of gene expression, but the stable reference genes for the normalization analysis have not been appreciated before identifying expression pattern of genes in teleost fishes. In this study, we selected eight candidate reference genes (18S, Actin, EF-1α, 40S, B2M, TUBA, UBCE and GAPDH) basing on transcriptome analysis and the traditional housekeeping genes, and analyzed the stability of the reference genes in spleen, head kidney and head kidney leukocytes (HKL) after pathogen challenge in Schizothorax prenanti (S. prenanti). Three common programs (geNorm, NormFinder and Bestkeeper) were used to evaluate the stability of the candidate reference genes. Two reference genes, Actin and EF-1α presented higher stability, while 18S and GAPDH were the lower stable genes, both in in vitro and in vivo. An important immune gene, toll-like receptor 22a (TLR22a), was selected to validate the stability of the proposed reference genes (Actin and EF-1α) across different experiment treatments. The results reveal that Actin and EF-1α are quite suitable reference genes for the normalization analysis. Otherwise, using the most stable gene Actin to validate the reliable of transcriptome data showed the high correlation between the fold change of transcriptome data and qRT-PCR data. In conclusion, our study not only acquired the suitable reference gene for the qRT-PCR assay under specific experiment condition, but also provided a comprehensive method to evaluate and validate the reference gene based on transcriptome analysis in teleost fishes.

The potential sensing molecules and signal cascades for protecting teleost fishes against lipopolysaccharide.

Lipopolysaccharide (LPS) is a classical pathogen-associated molecular pattern that can trigger strong inflammatory response mainly by TLR4-mediated signaling pathway in mammals, but the molecular mechanism of anti-LPS immunity is unclear in teleost fishes. In this study, we analyzed the gene expression features based on transcriptome analysis in Schizothorax prenanti (S. prenanti), after stimulation with two sources of LPS from Aeromonas hydrophila and Escherichia coli (Ah. LPS and Ecoli. LPS). 921 different expression genes (DEGs) after Ah. LPS stimulation and 975 DEGs after Ecoli.LPS stimulation were acquired, but only 706 and 750 DEGs were successfully annotated into the databases, respectively. Both of two groups of DGEs were significantly enriched into immune-related pathways by KEGG enrichment analysis, such as "Toll-like receptor signaling pathway", "Cytokine-cytokine receptor interaction" and "JAK-STAT signaling pathway". The annotated DEGs from Ah. LPS and Ecoli. LPS stimulation shared 470 DEGs, including 88 immune-related DEGs (IRGs) identified mainly by KEGG enrichment to immune-related signaling pathways. Among the shared IRGs, four pattern-recognition genes (TLR5, TLR25, PTX3 and C1q) were induced with high expression foldchange, and IFN-γ and relative genes also showed higher expression levels than control. Meanwhile, inflammatory signals were highlighted by upregulating the expression of inflammatory cytokines (IL-1ß, IL-10 and IL-8). Moreover, some non-shared IRGs (including TLR2 and TLR4) were identified, suggesting that different sources of LPS own different potentials for the induction of immune gene expression. In conclusion, TLR5, TLR25, PTX3 and C1q may function as the sensing molecules to catch the invasion signal of LPS. The anti-LPS immune response may be involved into TLR25/TLR5-mediated inflammatory signals that regulate subsequently the activation of PTX3/C1q-modulated complement pathway upon the induction of PTX3 expression, and the crosstalk between IFN-γ and TLR signaling pathways in teleost fishes. This study will contribute to further explore the molecular mechanism of LPS-induced immunity in teleost fishes.