Translation, cultural adaptation, and validation of the Chinese standardized outcomes in nephrology-hemodialysis fatigue (C-SONG-HD fatigue) scale: a study of Chinese patients undergoing hemodialysis.

OBJECTIVE: This study aimed to translate and culturally adapt the standardized outcomes in nephrology-hemodialysis fatigue (SONG-HD fatigue) scale and to assess the psychometric properties of the Chinese version of the SONG-HD fatigue (C-SONG-HD fatigue) scale. METHODS: Forward and back translations were used to translate the SONG-HD fatigue scale into Chinese. We used the C-SONG-HD fatigue scale to survey Chinese patients undergoing hemodialysis (HD) in China. We examined the distribution of responses and floor and ceiling effects. Cronbach's alpha and McDonald's omega coefficient, intraclass coefficients, and Spearman correlations were used to assess internal consistency reliability, test-retest reliability, and convergent validity, respectively. Responsiveness was also evaluated. RESULTS: In total, 489 participants across southeast China, northwest China, and central China completed the study. The C-SONG-HD fatigue scale had good internal consistency (Cronbach's alpha coefficient 0.861, omega coefficient 0.916), test-retest reliability (intraclass correlation coefficient 0.695), and convergent validity (Spearman correlation 0.691). The analysis of all first-time HD patients did not show notable responsiveness, and only patients with temporary vascular access had good responsiveness with an effect size (ES) of 0.54, a standardized response mean (SRM) of 0.85, and a standard error of measurement (SEM) of 0.77. CONCLUSION: The Chinese version of the SONG-HD fatigue scale showed satisfactory reliability and validity in patients undergoing hemodialysis (HD) in China. It could be used as a tool to measure the fatigue of Chinese HD patients.

Efficient Integration of Rate-Adaptive Reconciliation with Syndrome-Based Error Estimation and Subblock Confirmation for Quantum Key Distribution.

An effective post-processing algorithm is essential for achieving high rates of secret key generation in quantum key distribution. This work introduces an approach to quantum key distribution post-processing by integrating the three main steps into a unified procedure: syndrome-based error estimation, rate-adaptive reconciliation, and subblock confirmation. The proposed scheme employs low-density parity-check codes to estimate the quantum bit error rate using the syndrome information, and to optimize the channel coding rates based on the Slepian-Wolf coding scheme for the rate-adaptive method. Additionally, this scheme incorporates polynomial-based hash verification in the subblock confirmation process. The numerical results show that the syndrome-based estimation significantly enhances the accuracy and consistency of the estimated quantum bit error rate, enabling effective code rate optimization for rate-adaptive reconciliation. The unified approach, which integrates rate-adaptive reconciliation with syndrome-based estimation and subblock confirmation, exhibits superior efficiency, minimizes practical information leakage, reduces communication rounds, and guarantees convergence to the identical key. Furthermore, the simulations indicate that the secret key throughput of this approach achieves the theoretical limit in the context of a BB84 quantum key distribution system.

Improved reference-frame-independent quantum key distribution: erratum.

We present an erratum to our Letter [Opt. Lett.47, 4219 (2022)10.1364/OL.470558]. This erratum corrects the error results of Figs. 2 and 4 due to the error in the simulation code. The corrections have no influence on the conclusions of the original Letter.

Reference-frame-independent quantum key distribution with advantage distillation.

Advantage distillation (AD) provides a means of separating highly correlated raw key bits from weakly correlated information in quantum key distribution (QKD). In this Letter, we apply the AD method to improve the performance of reference-frame-independent QKD (RFI-QKD). Simulation results show that, compared with RFI-QKD without AD, RFI-QKD with AD can tolerate higher system errors and obtain better performance on the secret key rate and transmission distance. Furthermore, we extend the AD method to RFI measurement-device-independent QKD (RFI-MDI-QKD) and demonstrate that the AD method can improve the performance of RFI-MDI-QKD more significantly.

Antifungal Volatile Organic Compounds from Streptomyces setonii WY228 Control Black Spot Disease of Sweet Potato.

Volatile organic compounds (VOCs) produced by microorganisms are considered promising environmental-safety fumigants for controlling postharvest diseases. Ceratocystis fimbriata, the pathogen of black spot disease, seriously affects the quality and yield of sweet potato in the field and postharvest. This study tested the effects of VOCs produced by Streptomyces setonii WY228 on the control of C. fimbriata in vitro and in vivo. The VOCs exhibited strong antifungal activity and significantly inhibited the growth of C. fimbriata. During the 20-day storage, VOC fumigation significantly controlled the occurrence of the pathogen, increased the content of antioxidants and defense-related enzymes and flavonoids, and boosted the starch content so as to maintain the quality of the sweet potatoes. Headspace analysis showed that the volatiles 2-ethyl-5-methylpyrazine and dimethyl disulfide significantly inhibited the mycelial growth and spore germination of C. fimbriata in a dose-dependent manner. Fumigation with 100 µL/L 2-ethyl-5-methylpyrazine completely controlled the pathogen in vivo after 10 days of storage. Transcriptome analysis showed that volatiles mainly downregulated the ribosomal synthesis genes and activated the proteasome system of the pathogen in response to VOC stress, while the genes related to spore development, cell membrane synthesis, mitochondrial function, and hydrolase and toxin synthesis were also downregulated, indicating that WY228-produced VOCs have diverse modes of action for pathogen control. Our study demonstrates that fumigation of sweet potato tuberous roots with S. setonii WY228 or use of formulations based on the VOCs is a promising new strategy to control sweet potato and other food and fruit pathogens during storage and shipment. IMPORTANCE Black spot disease caused by Ceratocystis fimbriata has caused huge economic losses to worldwide sweet potato production. At present, the control of C. fimbriata mainly depends on toxic fungicides, and there is a lack of effective alternative strategies. The research on biological control of sweet potato black spot disease is also very limited. An efficient biocontrol technique against pathogens using microbial volatile organic compounds could be an alternative method to control this disease. Our study revealed the significant biological control effect of volatile organic compounds of Streptomyces setonii WY228 on black spot disease of postharvest sweet potato and the complex antifungal mechanism against C. fimbriata. Our data demonstrated that Streptomyces setonii WY228 and its volatile 2-ethyl-5-methylpyrazine could be a candidate strain and compound for the creation of fumigants and showed the important potential of biotechnology applications in the field of food and agriculture.

Abundant and diverse endophytic bacteria associated with medicinal plant Arctium lappa L. and their potential for host plant growth promoting.

Arctium lappa L. is one of the medicinal and food homologous plants in China, which is rich in nutrients and medicinal ingredients. The use of plant growth-promoting (PGP) endophytic bacteria is an alternative to reducing chemical fertilizers in agricultural production. The aim of this study was to analyze the diversity of endophytic bacteria in different cultivars of A. lappa L. collected from two geographical locations in China and evaluate PGP traits of the isolates and their potential PGP ability in greenhouse condition. Endophytic bacterial community was investigated by culture-dependent and culture-independent methods. Isolates were screened and investigated for multiple PGP traits, and representative strains were inoculated host seedlings to evaluate the growth promoting effect. A total of 348 endophytic bacteria were obtained and they were distributed into 4 phyla and 30 genera. In addition, high throughput sequencing revealed more abundant bacterial community, including 17 bacterial phyla and 207 genera. A high proportion of PGP traits were detected, including production of indole acetic acid, siderophore, ammonia and phosphate solubilization. Four representative strains with multiple PGP traits of the most dominant genera (Bacillus, Pantoea, Microbacterium and Pseudomonas) were further selected for host inoculation and growth promoting evaluation, and they significantly increase seedlings length, root length and fresh weight. This study demonstrated that A. lappa L. harbors abundant endophytic bacteria, and some endophytic bacteria showed good potential for the development of microbial fertilizer in the future.

Complete Genome Sequence of the Biocontrol Agent Pseudomonas chlororaphis subsp. aureofaciens SPS-41.

Pseudomonas chlororaphis subsp. aureofaciens SPS-41 is a plant growth-promoting rhizobacterium with biocontrol potential that was isolated from the rhizosphere of sweet potato in Xuzhou, Jiangsu Province, China. Our previous study demonstrated that volatile organic compounds (VOCs) produced by SPS-41 inhibited black spot disease fungi Ceratocystis fimbriata in postharvest sweet potatoes and a variety of other plant pathogens, and the VOCs also displayed strong nematocidal activity. In order to further explore the application potential of this strain, we here report the complete genome sequence of strain SPS-41. The genome consists of one chromosome (6,757,898 bp) with a G+C content 63.10%, which contains 5,951 coding genes, 67 transfer RNA genes, 16 ribosome RNA genes, and 85 other non-coding RNA genes. No plasmid was detected. The information of the genome will provide resources for studying the biocontrol mechanism of this strain.[Formula: see text] Copyright © 2021 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.

Improved analysis of measurement-device-independent quantum key distribution with non-phase-randomized coherent states.

Measurement-device-independent quantum key distribution (MDI-QKD) can remove all detector side-channel attacks, which can be implemented with phase-randomized coherent states (PRCS) or non-phase-randomized coherent states (NPRCS). In this paper, we focus on the MDI-QKD protocol with NPRCS and provide an improved analysis. In contrast with the original MDI-QKD with NPRCS which modulates the same intensity of coherent states in the key and test bases, we propose to modulate different intensities of coherent states in the key and test bases. Simulation results show that the secret key rate and transmission distance of MDI-QKD with NPRCS can be significantly improved. Furthermore, it is noteworthy that the modulation of different intensities does not bring extra complexity for experimental researchers, which can be easily done by adding an intensity modulator.

Twin-field quantum digital signatures.

Digital signature is a key technique in information security, especially for identity authentications. Compared to classical correspondence, quantum digital signatures (QDSs) provide a considerably higher level of security. At present, its performance is limited by key generation protocols, which are fundamentally limited in terms of channel capacity. Based on the idea of twin-field quantum key distribution, this Letter presents a twin-field QDS protocol and details a corresponding security analysis. In its distribution stage, a specific key generation protocol, the sending-or-not-sending twin-field protocol, has been adopted. Besides, we present a systematic model to evaluate the performance of a QDS protocol and compare the performance of our protocol to other typical QDS protocols. Numerical simulation results show that the new protocol exhibits outstanding security and practicality compared to other existing protocols. Therefore, our protocol paves the way toward real-world applications of QDSs.

Biodegradation of phenol by a halotolerant versatile yeast Candida tropicalis SDP-1 in wastewater and soil under high salinity conditions.

In this study, a novel halotolerant phenol-degrading yeast strain, SDP-1, was isolated from a coastal soil in Jiangsu, China, and identified as Candida tropicalis by morphology and rRNA internal transcribed space region sequence analysis. Strain SDP-1 can efficiently remove phenol at wide ranges of pH (3.0-9.0), temperature (20-40 °C), and NaCl (0-5%, w/v), as well as the tolerance of Mn2+, Zn2+ and Cr3+ in aquatic phase. It also utilized multiple phenol derivatives and aromatic hydrocarbons as sole carbon source and energy for growth. Free cells of SDP-1 were able to degrade the maximum phenol concentration of 1800 mg/L within 56 h under the optimum culture conditions of 10% inoculum volume, pH 8.0, 35 °C and 200 rpm agitation speed. Meanwhile, SDP-1 was immobilized on sodium alginate, and the capability of efficiently phenol degradation of free cells and immobilized SDP-1 were evaluated. Shortened degradation time and long-term utilization and recycling for immobilized SDP-1 was achieved compared to free cells. The 1200 mg/L of phenol under 5% NaCl stress could be completely degraded within 40 h by immobilized cells. In actual industrial coking wastewater, immobilized cells were able to completely remove 383 mg/L phenol within 20 h, and the corresponding chemical oxygen demand (COD) value was decreased by 50.38%. Besides, in phenol-contained salinity soil (3% NaCl), 100% of phenol (500 and 1000 mg/kg) removal efficiency was achieved by immobilized SDP-1 within 12 and 26 days, respectively. Our study suggested that versatile yeast Candida tropicalis SDP-1 could be potentially used for enhanced treatment of phenol-contaminated wastewater and soil under hypersaline or no-salt environmental conditions.

Experimental three-state measurement-device-independent quantum key distribution with uncharacterized sources.

Measurement-device-independent quantum key distribution (MDI-QKD) removes all detector side-channel attacks and guarantees a promising way for remote secret keys sharing. Several proof-of-principal experiments have been demonstrated to show its security and practicality. However, these practical implementations demand mostly, for example, perfect state preparation or completely characterized sources to ensure security, which are difficult to realize with prior art. Here, we investigate a three-state MDI-QKD using uncharacterized sources, with the simple requirement that the encoding state is bidimensional, which eliminates security threats from both the source flaws and detection loopholes. As a demonstration, a proof-of-principal experiment over 170 km transmission distance based on Faraday-Michelson interferometers is achieved, representing, to the best of our knowledge, the longest transmission distance recorded under the same security level.

280-km experimental demonstration of a quantum digital signature with one decoy state.

A quantum digital signature (QDS) guarantees the unforgeability, nonrepudiation, and transferability of signature messages with information-theoretic security, and hence has attracted much attention recently. However, most previous implementations of QDS showed relatively low signature rates and/or short transmission distance. In this Letter, we report a proof-of-principle phase-encoding QDS demonstration using only one decoy state. First, such a method avoids the modulation of the vacuum state, thus reducing experimental complexity and random number consumption. Moreover, incorporated with low-loss asymmetric Mach-Zehnder interferometers and a real-time polarization calibration technique, we have successfully achieved a higher signature rate, e.g., 0.98 bit/s at 103 km, and to date, a record-breaking, to the best of our knowledge, transmission distance of over 280-km installed fibers. Our work represents a significant step towards real-world applications of QDS.

Root exudates-driven rhizosphere recruitment of the plant growth-promoting rhizobacterium Bacillus flexus KLBMP 4941 and its growth-promoting effect on the coastal halophyte Limonium sinense under salt stress.

Halophytes play an important role in the bioremediation of saline soils. Increased evidence has revealed that plant growth-promoting rhizobacteria (PGPR) have colonized the halophytic rhizosphere, and they have evolved the capacity to reduce salt stress damage to the host. However, the mechanism by which halophytes attract and recruit beneficial PGPR has rarely been reported. This study reports the interaction between the halophyte Limonium sinense and its rhizosphere PGPR strain Bacillus flexus KLBMP 4941, as well as the mechanism by which KLBMP 4941 promotes host plant growth under salt stress. After salt stress treatment, we collected the root exudates (REs) of L. sinense and found that the REs could promote the growth and chemotaxis of the bacterium KLBMP 4941. In addition, the components of the REs under salt stress were analyzed, and some organic acids (2-methylbutyric acid, stearic acid, palmitic acid, palmitoleic acid, and oleic acid) were detected as the major components. Further assessment showed that each of these components had positive effects on the growth, motility, chemotaxis, and root colonization of strain KLBMP 4941. Further pot experiments revealed the potential PGP mechanisms induced by strain KLBMP 4941 on the host plant under salt stress. Inoculation with KLBMP 4941 promoted the accumulation of chlorophyll to enhance photosynthesis, increased osmotic regulator contents, enhanced flavonoid and antioxidant enzymes, and regulated Na+/K+ homeostasis to help the host ameliorate salinity stress damage. Our findings indicate that the halophyte L. sinense can attract and recruit beneficial rhizosphere bacteria by REs under salt stress, and the recruited B. flexus KLBMP 4941 elicited PGP effects under salinity stress through complex plant physiological regulatory mechanisms. This study provides a foundation for the enhancement of the rhizosphere colonization ability of the PGP strain KLBMP 4941, which shows potential applications in phytoremediation of saline soils.

Weak randomness impacts the security of reference-frame-independent quantum key distribution.

Perfect randomness is of great significance in various quantum key distribution (QKD) protocols. In this Letter, we investigate the effect of weak randomness on the state preparation in reference-frame-independent QKD (RFI-QKD), which may be implemented with imperfect random numbers or quantum-state encoding devices. In the scenario of weak randomness, the maximal amount of information the eavesdropper can acquire should be carefully evaluated. With practical experimental parameters, we demonstrate that even a small proportion of weak randomness will impact the security of RFI-QKD seriously. Furthermore, we briefly study the side effect of weak randomness on RFI measurement-device-independent QKD (RFI-MDI-QKD), and simulation results show that weak randomness damages the performance of RFI-MDI-QKD more critically than that of RFI-QKD.

Twin-field quantum key distribution with modified coherent states.

The twin-field quantum key distribution (TF-QKD) protocol is designed to beat the rate-distance limit of quantum key distributions without employing quantum repeaters; meanwhile, it can offer the measurement-device-independent secure level. In this Letter, we propose to improve the performance of TF-QKD protocols by employing modified coherent states. Based on the Wang et al. sending-or-not scheme [Phys. Rev. A98, 062323 (2018)PLRAAN1050-294710.1103/PhysRevA.98.062323], we study the key rate with the modified coherent states in finite data size and do comparisons with the one using weak coherent states. Through numerical simulations, we demonstrate that modified coherent states can substantially increase the performance of QKD more than the latter.

Experimental quantum key distribution with uncharacterized sources and projective measurements.

In theory, quantum key distribution (QKD) can offer information-theoretic secure communication based on the laws of quantum mechanics. However, the vast majority of practical QKD implementations assume the perfect state preparation to ensure security, which is a demanding requirement with current technology. Here, by incorporating the mismatched-basis data, we report an experimental decoy-state QKD demonstration with uncharacterized encoding sources, which only requires that the encoding states are two-dimensional. Furthermore, the measurement operation of the receiver is loosened to be projective measurements. With a rigorous statistical fluctuation analysis, we can distribute secret keys when the transmission distances of the standard fiber link are 101 and 202 km. Our experimental demonstration represents a significant step toward realizing long-distance quantum communication, even with uncharacterized sources and projective measurements.

Practical quantum digital signature with a gigahertz BB84 quantum key distribution system: erratum.

In this erratum the formulas (6) and (8) of Opt. Lett.44, 139 (2019) OPLEDP0146-959210.1364/OL.44.000139 have been updated.

Practical quantum digital signature with a gigahertz BB84 quantum key distribution system.

Quantum digital signature (QDS) can guarantee message integrity and non-repudiation with information-theoretical security, and it has attracted more attention recently. Since proposed by Andersson et al. [Phys. Rev. A93, 032325 (2016)PLRAAN1050-294710.1103/PhysRevA.93.032325], a quantum digital signature protocol using an insecure channel has been realized with several different quantum key distribution (QKD) systems. Here we report an experimental QDS based on a BB84 QKD system. An asymmetric Faraday-Sagnac-Michelson interferometer structure has been designed in our system, which is intrinsically stable against channel disturbance. The innovatory structure supports the system to work at high speed and, in practice, the repetition rate is in gigahertz. A 0.044 bit/s signature rate has been attained with a 25 dB channel loss composed of a 25 km installed fiber with additional optical attenuation in a 10-10 security level. Thus, our QDS device is stable and highly efficient. This Letter provides a further step for the practical application of QDS.

Biased three-intensity decoy-state scheme on the measurement-device-independent quantum key distribution using heralded single-photon sources.

At present, most of the measurement-device-independent quantum key distributions (MDI-QKD) are based on weak coherent sources and limited in the transmission distance under realistic experimental conditions, e.g., considering the finite-size-key effects. Hence in this paper, we propose a new biased decoy-state scheme using heralded single-photon sources for the three-intensity MDI-QKD, where we prepare the decoy pulses only in X basis and adopt both the collective constraints and joint parameter estimation techniques. Compared with former schemes with WCS or HSPS, after implementing full parameter optimizations, our scheme gives distinct reduced quantum bit error rate in the X basis and thus show excellent performance, especially when the data size is relatively small.

Improved statistical fluctuation analysis for measurement-device-independent quantum key distribution with four-intensity decoy-state method.

Recently Zhang et al [ Phys. Rev. A95, 012333 (2017)] developed a new approach to estimate the failure probability for the decoy-state BB84 QKD system when taking finite-size key effect into account, which offers security comparable to Chernoff bound, while results in an improved key rate and transmission distance. Based on Zhang et al's work, now we extend this approach to the case of the measurement-device-independent quantum key distribution (MDI-QKD), and for the first time implement it onto the four-intensity decoy-state MDI-QKD system. Moreover, through utilizing joint constraints and collective error-estimation techniques, we can obviously increase the performance of practical MDI-QKD systems compared with either three- or four-intensity decoy-state MDI-QKD using Chernoff bound analysis, and achieve much higher level security compared with those applying Gaussian approximation analysis.