Long-distance continuous-variable quantum key distribution over 100-km fiber with local local oscillator.

Quantum key distribution (QKD) enables two remote parties to share encryption keys with security based on the laws of physics. Continuous-variable (CV) QKD with coherent states and coherent detection integrates well with existing telecommunication networks. Thus far, long-distance CV-QKD has only been demonstrated using a highly complex scheme where the local oscillator is transmitted, opening security loopholes for eavesdroppers and limiting potential applications. Here, we report a long-distance CV-QKD experiment with a locally generated local oscillator over a 100-kilometer fiber channel with a total loss of 15.4 decibels. This record-breaking distance is achieved by controlling the phase noise-induced excess noise through a machine learning framework for carrier recovery and optimizing the modulation variance. We implement the full CV-QKD protocol and demonstrate the generation of keys secure against collective attacks in the finite-size regime. Our results mark a substantial milestone for realizing CV quantum access networks with a high loss budget and pave the way for large-scale deployment of secure QKD.

Niche and interspecific association of dominant tree species in karst forest of Junzi Mountain, Eastern Yunnan, China.

To understand the interspecific relationships of tree species in the karst forest of Junzi Mountain in Eas-tern Yunnan, we evaluated the niche and interspecific association of dominant tree species based on field survey plot data with the combining approaches of niche determination, χ2 test, association coefficient (AC), and Spearman rank correlation test. The results showed that the niche breadth of Quercus glaucoides was the largest and that of Juglans mandshurica was the smallest. The ranking of niche breadth was more consistent with the ranking of frequency than with that of importance values. The degree of niche overlap was generally low, with a mean value of 0.21, suggesting a low similarity in resource utilization among tree species. The overall association of dominant tree species was significantly positive, and the ratio of positive and negative association was 1.07, indicating that the communities were at a relatively stable and the late succession stage. The χ2 test and Spearman rank correlation test for tree dominant species showed that 65.3% species pairs were not significantly associated with each other, indicating a weak interspecific association. Both association coefficient (AC) and Spearman rank correlation coefficient showed significantly positive correlations with the corresponding niche overlap index. The species pairs of Q. glaucoides-Rhamnella martini, Viburnum propinquum-Zanthoxylum myriacanthum, Cladrastis delavayi-Carrierea calycina, Z. myriacanthum-C. delavayi had strong interspecific associations and wide ecological niches, thus may have potential application value in ecological restoration of karst region in eastern Yunnan and the vicinity areas.

A conductive catecholate-based framework coordinated with unsaturated bismuth boosts CO2 electroreduction to formate.

Bismuth-based metal-organic frameworks (Bi-MOFs) have received attention in electrochemical CO2-to-formate conversion. However, the low conductivity and saturated coordination of Bi-MOFs usually lead to poor performance, which severely limits their widespread application. Herein, a conductive catecholate-based framework with Bi-enriched sites (HHTP, 2,3,6,7,10,11-hexahydroxytriphenylene) is constructed and the zigzagging corrugated topology of Bi-HHTP is first unraveled via single-crystal X-ray diffraction. Bi-HHTP possesses excellent electrical conductivity (1.65 S m-1) and unsaturated coordination Bi sites are confirmed by electron paramagnetic resonance spectroscopy. Bi-HHTP exhibited an outstanding performance for selective formate production of 95% with a maximum turnover frequency of 576 h-1 in a flow cell, which surpassed most of the previously reported Bi-MOFs. Significantly, the structure of Bi-HHTP could be well maintained after catalysis. In situ attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) confirms that the key intermediate is *COOH species. Density functional theory (DFT) calculations reveal that the rate-determining step is *COOH species generation, which is consistent with the in situ ATR-FTIR results. DFT calculations confirmed that the unsaturated coordination Bi sites acted as active sites for electrochemical CO2-to-formate conversion. This work provides new insights into the rational design of conductive, stable, and active Bi-MOFs to improve their performance towards electrochemical CO2 reduction.

Practical continuous-variable quantum key distribution with composable security.

A quantum key distribution (QKD) system must fulfill the requirement of universal composability to ensure that any cryptographic application (using the QKD system) is also secure. Furthermore, the theoretical proof responsible for security analysis and key generation should cater to the number N of the distributed quantum states being finite in practice. Continuous-variable (CV) QKD based on coherent states, despite being a suitable candidate for integration in the telecom infrastructure, has so far been unable to demonstrate composability as existing proofs require a rather large N for successful key generation. Here we report a Gaussian-modulated coherent state CVQKD system that is able to overcome these challenges and can generate composable keys secure against collective attacks with N ≈ 2 × 108 coherent states. With this advance, possible due to improvements to the security proof and a fast, yet low-noise and highly stable system operation, CVQKD implementations take a significant step towards their discrete-variable counterparts in practicality, performance, and security.

Cu-Based Organic-Inorganic Composite Materials for Electrochemical CO2 Reduction.

Electrochemical CO2 reduction reaction (CO2 RR) is an attractive pathway to convert CO2 into value-added chemicals and fuels. Copper (Cu) is the most effective monometallic catalyst for converting CO2 into multi-carbon products, but suffers from high overpotentials and poor selectivity. Therefore, it is essential to design efficient Cu-based catalyst to improve the selectivity of specific products. Due to the combination of advantages of organic and inorganic composite materials, organic-inorganic composites exhibit high catalytic performance towards CO2 RR, and have been extensively studied. In this review, the research advances of various Cu-based organic-inorganic composite materials in CO2 RR, i. e., organic molecular modified-metal Cu composites, Cu-based molecular catalyst/carbon carrier composites, Cu-based metal organic framework (MOF) composites, and Cu-based covalent organic framework (COF) composites are systematically summarized. Particularly, the synthesis strategies of Cu-based composites, structure-performance relationship, and catalytic mechanisms are discussed. Finally, the opportunities and challenges of Cu-based organic-inorganic composite materials in CO2 RR are proposed.

Insight into the effects of the crystal phase of Ru over ultrathin Ru@Pt core-shell nanosheets for methanol electrooxidation.

Coating a second metal on the surface of ultrathin 2D nanosheets (NSs) could induce lattice strain and modify the electronic structure, thereby changing the surface reactivity. Herein, we report the effects of different crystal phases of Ru on the electrocatalytic performance of ultrathin Ru@Pt core-shell NSs for the methanol oxidation reaction (MOR). Importantly, Ru with a novel face-centered-cubic phase was found to have more effect on the electronic structure of Pt than Ru with a conventional hexagonal close-packed phase, thereby leading to improved electrocatalytic activity toward the MOR under acidic and basic conditions. It is believed that the strategy presented here would offer a new approach to the construction of bimetallic core-shell nanostructures with various promising applications.

[Meta-analysis of efficacy and safety of Liuwei Wuling Tablets combined with conventional drugs in treatment of liver fibrosis and cirrhosis in chronic hepatitis B].

The present study evaluated the clinical efficacy and safety of Liuwei Wuling Tablets combined with conventional drugs for the treatment of liver fibrosis and cirrhosis in chronic hepatitis B. CNKI, Wanfang, VIP, CBM, PubMed, EMbase and Cochrane Library were searched for the relevant randomized controlled trials(RCTs) published from database inception to February 2021. All the retrieved papers were independently screened, extracted and evaluated by two researchers, followed by Meta-analysis by Review Manager 5.4. Finally, 18 RCTs were included, involving 2 168 patients(1 106 in the treatment group and 1 062 in the control group). The Meta-analysis results showed that compared with conventional drugs alone, Liuwei Wuling Tablets combined with conventional drugs could increase the effective rate of clinical treatment by reducing serum hyaluronic acid(HA), laminin(LN), procollagen type Ⅲ(PCⅢ), and type Ⅳ collagen(Ⅳ-C) to improve liver function, decreasing the levels of total bilirubin(TBiL), alanine amino-transferase(ALT), and aspartate aminotransferase(AST), and improving the negative conversion ratio of hepatitis B virus(HBV) DNA. In terms of safety, there were no serious adverse reactions in the treatment group and the control group. The results showed that Liuwei Wuling Tablets combined with antiviral or other conventional liver-protecting drugs could improve liver function, treat liver cirrhosis, and reduce liver fibrosis with high safety. However, due to the influence of literature quality and quantity, multi-center and high-quality RCTs with large sample size are needed for verification.

ADESSO detects SARS-CoV-2 and its variants: extensive clinical validation of an optimised CRISPR-Cas13-based COVID-19 test

SARS-CoV-2 is the causative agent for a pandemic that has had immense consequences for the health and economic sectors worldwide. While PCR testing and later antigen tests have proven critical for helping to stem the spread of the virus, these methods suffer from general applicability and sensitivity, respectively. Moreover, the emergence of variant strains creates the need for flexibility to correctly and efficiently diagnose the presence of substrains in the population. To address these needs we have developed the diagnostic test ADESSO (Accurate Detection of Evolving SARS-CoV-2 through SHERLOCK Optimization) which employs the Cas13 system to diagnose patients in as little as 1 hour without sophisticated equipment. Using an extensive panel of clinical samples, we demonstrate that ADESSO correctly identifies COVID-19 positive samples at a sensitivity and specificity comparable to RT-qPCR on extracted RNA and higher than antigen tests for unextracted samples. Taken together, ADESSO is a fast, sensitive and cheap method that can be applied in a point of care (POC) setting to diagnose COVID-19 and can be quickly adjusted to detect new variants.

Bombyx mori can synthesize ascorbic acid through the l-gulose pathway to varying degrees depending on developmental stage.

Vitamin C (VC) is an essential nutrient for many animals. However, whether insects, including Bombyx mori, can synthesize VC remains unclear. In this article, the optimized HPLC method was used to determine the content of l-ascorbic acid (AsA) in silkworm eggs, larvae and pupae, and the activity of l-gulono-1,4-lactone oxidase (GULO), a key enzyme in VC synthesis. The RNA interference method was used to determine the effect of the BmGulo-like gene on embryonic development and GULO activity in the pupal fat body. The AsA content increased significantly during E144 h-E168 h in the late embryonic stage and P48 h-P144 h in the middle-late pupal stage, in which exogenous VC was not ingested. Furthermore, the body AsA content in larvae fed VC-free feed also increased with larval stage. The GULO enzymatic activity was present in eggs and the fat bodies of larvae and pupae, even when the larvae were reared with fresh mulberry leaves. Moreover, the activity was higher in the later embryonic stages (E144 h-E168 h) and the early pupal stage (before P24 h). The GULO activity in the pupal fat body dramatically decreased when the screened BmGulo-like gene (BGIBMGA005735) was knocked down with small interfering RNA; in addition, the survival rate and hatching rate of eggs significantly decreased 21% and 44%, respectively, and embryonic development was delayed. Thus, Bombyx mori can synthesize AsA through the l-gulose pathway, albeit with low activity, and this synthesis ability varies with developmental stages.

Design, Synthesis and Biological Evaluation of 4, 6-Coumarin Derivatives as Anti- Cancer and Apoptosis-Inducing Agents.

BACKGROUND: Coumarin structures were widely employed in anti-cancer drug design. Herein we focused on the modifications of C4 and C6 positions on coumarin scaffold to get novel anti-cancer agents. OBJECTIVE: The objective of the current work was the synthesis and biological evaluation of a series of 4, 6-coumarin derivatives to get novel anticancer agents. METHODS: Thirty-seven coumarin derivatives were designed and synthesized, the antiproliferative activity of the compounds was evaluated against human cancer cell lines and non-cancerous cells by MTT assay. The bioactivities and underlying mechanisms of active molecules were studied and the ADMET characters were predicted. RESULTS: Among the compounds, 4-p-hydroxy phenol-6-pinacol borane coumarin (25) exhibited a promising anti- cancer activity to cancer cell lines in a dose-dependent manner and the toxicity to normal cells was low. The mechanism of action was observed by inducing G2/M phase arrest and apoptosis which was further confirmed via western blot. In silico ADMET prediction revealed that compound 25 is a drug-like small molecule with a favorable safety profile. CONCLUSION: The findings in this work may give vital information for further development of 6-pinacol borane coumarin derivatives as novel anti-cancer agents.

A large-area luminescent downshifting layer containing an Eu3+ complex for crystalline silicon solar cells.

The spectral mismatch between the distribution of sunlight (AM1.5G) and crystalline silicon (c-Si) solar cells is one of the most important limiting factors of the conversion efficiency of photovoltaic (PV) devices. As an effective solution, the use of the luminescence down-shifting (LDS) technique is an important way to improve the short-wavelength response of a solar cell by shifting high-energy photons to the visible range. Herein, a large-area (17 × 17 cm2) luminescent thin film consisting of a ternary europium (Eu3+) complex and polyvinyl alcohol (PVA) was successfully constructed through a solution casting method and further developed as an effective LDS layer to improve the photoelectric conversion efficiency of c-Si solar cells with a large active area (235 cm2). The self-standing LDS layer is flexible, transparent and easily attachable to the surface of the solar cell module. Compared with the uncoated c-Si solar cell, the one coated with the LDS layer displayed an enhancement of ∼15% in external quantum efficiency (EQE) due to the high luminescence quantum yield of the Eu3+ complex doped inside the layer. These results demonstrate that use of a large area luminescent film embedding an Eu3+ complex is a versatile and effective strategy to improve the conversion efficiency of large size PV devices, giving rise to its great potential application as an LDS material.

Nitric oxide in red blood cell adaptation to hypoxia.

Nitric oxide (NO) appears to be involved in virtually every aspect of cardiovascular biology. Most attention has been focused on the role of endothelial-derived NO in basal blood flow regulation by relaxing vascular smooth muscle; however, it is now known that NO derived from red blood cells (RBCs) plays a fundamental role in vascular homeostasis by enhancing oxygen (O2) release at the cellular and physiological level. Hypoxia is an often seen problem in diverse conditions; systemic adaptations to hypoxia permit people to adjust to the hypoxic environment at high altitudes and to disease processes. In addition to the cardiopulmonary and hematologic adaptations that support systemic O2 delivery in hypoxia, RBCs assist through newly described NO-based mechanisms, in line with their vital role in O2 transport and delivery. Furthermore, to increase the local blood flow in proportion to metabolic demand, NO regulates membrane mechanical properties thereby modulating RBC deformability and O2 carrying-releasing function. In this review article, we focus on the effect of NO bioactivity on RBC-based mechanisms that regulate blood flow and RBC deformability. RBC adaptations to hypoxia are summarized, with particular attention to NO-dependent S-nitrosylation of membrane proteins and hemoglobin (S-nitrosohemoglobin). The NO/S-nitrosylation/RBC vasoregulatory cascade contributes fundamentally to the molecular understanding of the role of NO in human adaptation to hypoxia and may inform novel therapeutic strategies.

Unraveling proteome changes of Holstein beef M. semitendinosus and its relationship to meat discoloration during post-mortem storage analyzed by label-free mass spectrometry.

Label-free proteomics was applied to characterize the effect of post-mortem storage time (0, 4, and 9days at 4°C±1°C) on the proteome changes of M. semitendinosus (SM) in Holstein cattle, and correlations between differentially abundant proteins and meat color traits were investigated. The redness (a*) value decreased significantly (P<0.05) during post-mortem storage, meanwhile, the relative proportion of metmyoglobin increased significantly (P<0.05) from 16.99% at day 0 to 40.26% at day 9. A total of 118 proteins with significant changes (fold change>1.5, P<0.05) was identified by comparisons of day 4 vs. day 0, day 9 vs. day 0, and day 9 vs. day 4. Principal component and hierarchical cluster analyses of these proteins were performed, and results exhibited clear distinctions among samples from different storage times. Eighteen differentially abundant proteins were correlated closely with the a* value of meat. Bioinformatics analyses revealed that most of these proteins were involved in glycolysis and energy metabolism, electron-transfer processes, and the antioxidation function, which implied an underlying connection between meat discoloration and these biological processes. SIGNIFICANCE: It is always a challenge for scientists to improve the stability of meat color during post-mortem storage and retail display. However, the mechanism involved in meat discoloration has not been unraveled completely, and the application of label-free proteomics in studying meat discoloration has not been reported. Our work discovers some key proteins in SM muscle of Holstein cattle that were correlated with a* value of meat via label-free proteomics. Bioinformatics analyses revealed that some of these differentially abundant proteins were involved in glycolysis and energy metabolism, electron-transfer processes, and the antioxidation function, which implied an underlying connection between meat discoloration and these biological processes. These results provide the theoretic basis on understanding of complicated biochemical changes and underlying molecular mechanisms responsible for meat discoloration.

Bacterial diversity analysis of pork longissimus lumborum following long term ohmic cooking and water bath cooking by amplicon sequencing of 16S rRNA gene.

The bacterial ecology of long term ohmic- (LTOH) and water bath- (WB) cooked pork longissimus lumborum during refrigerated storage was investigated by culture-dependent and amplicon sequencing of 16S rRNA gene. High bacterial diversity was observed in both LTOH- and WB-cooked meat, and the diversity decreased with prolonged storage, however, it was more complex in LTOH-cooked meat compared with WB treated ones. Bacillus, Pseudomonas, Enterococcus and Lactococcus were the most prevalent genera in the first two weeks and were replaced by Carnobacterium by the end of storage. Brevundimonas, Bacteroidaceae, Lactobacillaceae, uncultured Clostridiales Family_XIII, Alcaligenaceae and Micrococcales were more abundant in LTOH-cooked meat, while only Moraxellaceae were more abundant in WB-cooked samples. The different abundances may have resulted from the reaction of bacteria to different heating mechanisms. Overall, LTOH-cooked meat has a similar shelf-life with shorter processing time compared to WB treated ones.

Estimating divergently routed nonlinearly interfering channel powers using cross phase modulation.

The deployment of coherent transceivers in legacy networks requires significant investment in installation. We propose a method enabling autonomous (re-)configuration of an optical channel, which would be advantageous in legacy networks and necessary in proposed future networks utilizing a flexible frequency grid and software defined components such as reconfigurable optical add drop multiplexers (ROADM). We consider potential interfering optical channels propagating with the prospective channel along part of the fiber link which are dropped before arrival at the receiver. The method uses a commercially available line card transmitting a 40Gbit/s polarization multiplexed quadrature phase shift keying (PM-QPSK) probe channel to characterize an optical channel. The power of the nearest neighboring channels is then inferred by examining its bit error rate (BER) which is impacted by cross phase modulation (XPM) from the aggressor channels. In a 4 node network with 2 ROADMs using up to 6 aggressor OOK channels, we successfully deduce the neighboring channel power down to -2 dBm, and an extra improvement down to -3.5 dBm is gained, by measuring at an offset to the international telecommunication union (ITU) grid which also reveals inequality in neighbor channel powers.

Antimicrobial peptide LL-37 and IDR-1 ameliorate MRSA pneumonia in vivo.

BACKGROUND: The only human cathelicidin, LL-37, and the innate defense regulator peptide IDR-1, which have been proven to have antimicrobial activity, represent essential elements of immunity. Our previous study showed that the peptide LL-37 was protective in vitro to attenuate LTA-induced inflammatory effects. Methicillin-resistant staphylococcus aureus (MRSA) causes a multitude of serious and sometimes life-threatening diseases around the globe. However, the effect of LL-37 and IDR-1 in MRSA-induced pneumonia is unknown. In the present study, we explored the potential of LL-37 and IDR-1 in ameliorating MRSA-induced pneumonia in vivo. METHODS: C57BL/6 mice were randomly divided into four groups and perfused intratracheally with PBS, peptide, MRSA and MRSA plus peptide, respectively. Pulmonary tissue pathology, ELISA and quantitative RT-PCR were employed. The relative signal pathways were further explored by western blot analysis. RESULTS: Pathological analysis of the lung tissue sections demonstrated that, when compared with the MRSA-treated group, both the LL-37 and IDR-1 could ameliorate the MRSA-induced pneumonia. The phosphorylation of JNK and Akt were markedly decreased in the peptide plus MRSA-treated group compared with the MRSA-treated group. Furthermore, both of them also reduced TNF-α and IL-6 production in the bronchoalveolar lavage fluid (BALF) and serum in vivo. CONCLUSION: We report the first evidence of peptides inhibiting inflammation, decreasing the release of inflammatory cytokines and restoring pulmonary function in vivo. The antimicrobial peptide LL-37 and IDR-1 could ameliorate MRSA-induced pneumonia by exerting an anti-inflammatory property and attenuating pro-inflammatory cytokine release, thus providing support for the hypothesis that both innate and synthetic peptides could protect against MRSA in vivo.

Antimicrobial peptide LL-37 attenuates LTA induced inflammatory effect in macrophages.

LL-37/hCAP-18, as the only human cathelicidin, plays an important role in inflammation. Lipoteichoic acid (LTA) is an important bacterial component of Staphylococcus aureus, which is one of the common human pathogens for severe respiratory infection with increasing morbidity in recent years. The present study is to investigate the role of LL-37 in LTA induced inflammatory reaction in macrophages. We examined TNF-α and IL-6 production after LL-37 treatment and discussed its signal transduction pathways such as p38MAPK and Akt activation in macrophages. The expression of pro-inflammatory cytokines was analyzed by quantitative real-time RT-PCR and enzyme-linked immunosorbent assay (ELISA). The LL-37 expression was determined by Western blot and immunofluorescence staining. The results showed that LL-37 was upregulated after LTA treatment. It could inhibit LTA induced p38MAPK and Akt phosphorylation and attenuate TNF-α and IL-6 production in macrophages in some specific concentration. These results suggest that LL-37 exerts an anti-inflammatory property and attenuates the pro-inflammatory cytokine release in macrophages.

Using extended Wilson model to study the relationship between critical relative humidity and solubility of electrolytes.

Based on thermodynamic principle, the critical relative humidity of electrolytes is closely related to their solubility. The authors explored the relationship theoretically and calculated critical relative humidity of 21 electrolytes from their solubility in the light of Raoult's law and extended Wilson model. The results indicate that the critical relative humidity values calculated by Raoult's law can not accord with the reported ones and there is a systematic error in the high concentration range; while these calculated by extended Wilson model are comparable to the reported ones.