Tuning element distribution, structure and properties by composition in high-entropy alloys.

High-entropy alloys are a class of materials that contain five or more elements in near-equiatomic proportions1,2. Their unconventional compositions and chemical structures hold promise for achieving unprecedented combinations of mechanical properties3-8. Rational design of such alloys hinges on an understanding of the composition-structure-property relationships in a near-infinite compositional space9,10. Here we use atomic-resolution chemical mapping to reveal the element distribution of the widely studied face-centred cubic CrMnFeCoNi Cantor alloy2 and of a new face-centred cubic alloy, CrFeCoNiPd. In the Cantor alloy, the distribution of the five constituent elements is relatively random and uniform. By contrast, in the CrFeCoNiPd alloy, in which the palladium atoms have a markedly different atomic size and electronegativity from the other elements, the homogeneity decreases considerably; all five elements tend to show greater aggregation, with a wavelength of incipient concentration waves11,12 as small as 1 to 3 nanometres. The resulting nanoscale alternating tensile and compressive strain fields lead to considerable resistance to dislocation glide. In situ transmission electron microscopy during straining experiments reveals massive dislocation cross-slip from the early stage of plastic deformation, resulting in strong dislocation interactions between multiple slip systems. These deformation mechanisms in the CrFeCoNiPd alloy, which differ markedly from those in the Cantor alloy and other face-centred cubic high-entropy alloys, are promoted by pronounced fluctuations in composition and an increase in stacking-fault energy, leading to higher yield strength without compromising strain hardening and tensile ductility. Mapping atomic-scale element distributions opens opportunities for understanding chemical structures and thus providing a basis for tuning composition and atomic configurations to obtain outstanding mechanical properties.

Automated ASPECTS calculation may equal the performance of experienced clinicians: a machine learning study based on a large cohort.

OBJECTIVES: The Alberta Stroke Program Early CT Score (ASPECTS) is a semi-quantitative method to evaluate the severity of early ischemic change on non-contrast computed tomography (NCCT) in patients with acute ischemic stroke (AIS). In this work, we propose an automated ASPECTS method based on large cohort of data and machine learning. METHODS: For this study, we collected 3626 NCCT cases from multiple centers and annotated directly on this dataset by neurologists. Based on image analysis and machine learning methods, we constructed a two-stage machine learning model. The validity and reliability of this automated ASPECTS method were tested on an independent external validation set of 300 cases. Statistical analyses on the total ASPECTS, dichotomized ASPECTS, and region-level ASPECTS were presented. RESULTS: On an independent external validation set of 300 cases, for the total ASPECTS results, the intraclass correlation coefficient between automated ASPECTS and expert-rated was 0.842. The agreement between ASPECTS threshold of ≥ 6 versus < 6 using a dichotomized method was moderate (κ = 0.438, 0.391-0.477), and the detection rate (sensitivity) was 86.5% for patients with ASPECTS threshold of ≥ 6. Compared with the results of previous studies, our method achieved a slight lead in sensitivity (67.8%) and AUC (0.845), with comparable accuracy (78.9%) and specificity (81.2%). CONCLUSION: The proposed automated ASPECTS method driven by a large cohort of NCCT images performed equally well compared with expert-rated ASPECTS. This work further demonstrates the validity and reliability of automated ASPECTS evaluation method. CLINICAL RELEVANCE STATEMENT: The automated ASPECTS method proposed by this study may help AIS patients to receive rapid intervention, but should not be used as a stand-alone diagnostic basis. KEY POINTS: NCCT-based manual ASPECTS scores were poorly consistent. Machine learning can automate the ASPECTS scoring process. Machine learning model design based on large cohort data can effectively improve the consistency of ASPECTS scores.

Subtyping at-risk adolescents for predicting response toward insomnia prevention program.

BACKGROUND: Previous study has shown that a brief cognitive-behavioral prevention insomnia program could reduce 71% risk of developing insomnia among at-risk adolescents. This study aimed to evaluate the differential response to insomnia prevention in subgroups of at-risk adolescents. METHODS: Adolescents with a family history of insomnia and subthreshold insomnia symptoms were randomly assigned to a 4-week insomnia prevention program or nonactive control group. Assessments were conducted at baseline, 1 week, and 6- and 12-month after the intervention. Baseline sleep, daytime, and mood profiles were used to determine different subgroups by using latent class analysis (LCA). Analyses were conducted based on the intention-to-treat approach. RESULTS: LCA identified three subgroups: (a) insomnia symptoms only, (b) insomnia symptoms with daytime sleepiness and mild anxiety, and (c) insomnia symptoms with daytime sleepiness, mild anxiety, and depression. The incidence rate of insomnia disorder over the 12-month follow-up was significantly reduced for adolescents receiving intervention in subgroup 3 compared with the controls (hazard ratio [HR] = 0.37; 95% confidence interval [CI]: 0.13-0.99; p = .049) and marginally for subgroup 2 (HR = 0.14; 95% CI: 0.02-1.08; p = .059). In addition, adolescents who received intervention in subgroups 2 and 3 had a reduced risk of excessive daytime sleepiness (subgroup 2: adjusted OR [AdjOR] = 0.45, 95% CI: 0.23-0.87; subgroup 3: AdjOR = 0.32, 95% CI: 0.13-0.76) and possible anxiety (subgroup 2: AdjOR = 0.47, 95% CI: 0.27-0.82; subgroup 3: AdjOR = 0.33, 95% CI: 0.14-0.78) compared with the controls over the 12-month follow-up. CONCLUSIONS: Adolescents at risk for insomnia can be classified into different subgroups according to their psychological profiles, which were associated with differential responses to the insomnia prevention program. These findings indicate the need for further phenotyping and subgrouping at-risk adolescents to develop personalized insomnia prevention.

Safety and Efficacy of the Phototherapeutic Keratectomy for Treatment of Recurrent Corneal Erosions: A Systematic Review and Meta-Analysis.

BACKGROUND: Phototherapeutic keratectomy (PTK) has been increasingly used to treat severe recurrent corneal erosion syndrome (RCES) patients who do not respond to other treatments. However, the efficacy and complication of each study are currently uncertain due to varying rates. OBJECTIVES: The objective of this study was to investigate the safety and efficacy of the PTK for recurrent corneal erosions. METHODS: This article performed a systematic literature research in Cochrane, Embase, PubMed, Scopus, and the Web of Science for the literature on PTK treatment of RCES until December 20, 2022. The extracted data including recurrence rate and the adverse event rate were used for meta-analysis. RESULTS: The recurrence rate was 18% (95% CI, 13%-24%) (129/700 eyes). Subgroup analysis showed that the RCE recurrence was 17% (95% CI, 9%-24%) after trauma and 22% (95% CI, 11%-32%) in the corneal dystrophy group. Treatment-related adverse events included subepithelial haze, hyperopic shift, and decrease of the best spectacle-corrected visual acuity. In this study, the incidence of these events was 13% (95% CI, 6%-21%), 20% (95% CI, 11%-28%), and 11% (95% CI, 5%-16%), respectively. CONCLUSIONS: PTK represented a valuable treatment option for patients with recurrent corneal erosions, especially those with traumatic injuries, which had minimal side effects.

Sense of Alienation and Its Associations With Depressive Symptoms and Poor Sleep Quality in Older Adults Who Experienced the Lockdown in Wuhan, China, During the COVID-19 Pandemic.

OBJECTIVE: To examine the epidemiology of sense of alienation (SoA) and its associations with depressive symptoms and poor sleep quality (PSQ) in Chinese older adults who experienced lockdown during the COVID-19 pandemic. BACKGROUND: There is a dearth of data on SoA in older adults during the COVID-19 pandemic. METHODS: Altogether, 543 community-dwelling older adults (50+ years) were recruited via the three-tier mental health network in Wuhan, China, and completed an online questionnaire in April 2020, the first month after the reopening of Wuhan. SoA, depressive symptoms, and sleep quality were measured by using the General Social Alienation Scale, Depression Anxiety and Stress Scale, and a single standardized question, respectively. RESULTS: The prevalence of SoA was 52.3% (95% confidence interval: 48.1-56.5%). Factors associated with higher levels of SoA were religious belief (ß = 1.960, P = .024), monthly family income<4000 RMB (ß = 1.405, P = .022), unemployment (ß = 1.217, P = .039), fair or poor physical health (ß = 2.202, P = .002), never and sometimes receiving community support (ß = 2.297, P < .001 and ß = 3.417, P < .001), perceiving a low possibility of a cure for COVID-19 (ß = 2.379, P < .001), and affirmative and unsure fear of COVID-19 patients (ß = 2.025, P = .007 and ß = 1.101, P = .027). After adjusting for sociodemographic and pandemic-related variables, a one-SD increment in the SoA score was significantly associated with depressive symptoms (Odd Ratio [OR] = 5.59, P < .001) and poor sleep quality (Odd Ratio = 2.00, P < .001). CONCLUSION: Over half of the older adults who experienced lockdown felt alienated, and SoA was independently associated with their depressive symptoms and PSQ. Efforts are warranted to address SoA in older adults who experienced lockdown during the pandemic.

Overexpression of PBK/TOPK relates to poor prognosis of patients with breast cancer: a retrospective analysis.

BACKGROUND: PDZ-binding kinase/T-lymphokine-activated killer cell-derived protein kinase (PBK/TOPK) is a potential prognostic indicator for patients with breast cancer. The objective of the present study was to explore the relationship between PBK/TOPK expression and clinicopathological indicators as well as the survival of patients with breast cancer. METHODS: Immunohistochemical staining was used to detect the expression of PBK/TOPK in 202 cases of breast cancer tissues. The relationship between PBK/TOPK and clinicopathological parameters was evaluated using Spearman's rank-order correlation. The difference in PBK/TOPK expression among different molecular types was analyzed with the chi-square test. Kaplan-Meier analysis was used to create a survival curve and the log rank test was used to analyze the overall survival (OS) and disease-free survival (DFS). Prognostic correlation was assessed using univariate and multivariate Cox regression analyses. RESULTS: Among 202 breast cancer samples, PBK/TOPK was expressed ("+" and "++") in 182 samples (90.1%). In addition, the histological grade, TNM stages, lymph node metastasis, estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER-2), and Ki-67 were positively associated with PBK/TOPK expression. With regard to the molecular type, the expression of PBK/TOPK is different. The expression level of PBK/TOPK was negatively correlated with both the OS and DFS of breast cancer patients. The difference in the above results is meaningful (P < 0.05). CONCLUSIONS: PBK/TOPK is overexpressed in breast cancer, and the expression is closely related to the clinicopathological characteristics of the disease. Breast cancer patients with high expression of PBK/TOPK have a poor prognosis. Therefore, healthcare providers can optimize breast cancer management using this indicator.

Status and influencing factors of nursing and midwifery professionals' core competence- a cross sectional study.

OBJECTIVES: This study aims to understand the current situation and multiple factors affecting the core competence specializing in the maternal, neonatal and under-five nursing in China. BACKGROUND: Highly skilled nurses and midwives are essential worldwide for achieving the Sustainable Development Goals, especially in low- and middle-income countries like China, due to the overwhelming COVID-19 crisis. METHOD: The 890 nurses and midwives from 12 hospitals were investigated in this cross-sectional study, with two questionnaires: the sociodemographic information and competency inventory for the registered nurses. RESULTS: The participants reported a mean total score of 193.78 (±42.19) out of 220 and lowest in critical thinking and research ability (3.01 ± 0.82). The professional title, level, marital status, relationship quality, highest qualification, experience in specialist nurse training, participation in scientific research projects and publishing papers were the influencing factors (P < .05). CONCLUSIONS: The respondents' core competence needs improvement, especially critical regarding thinking and research ability. In addition, marriage and good or excellent relationship quality are factors that can potentially improve competence. IMPLICATIONS FOR NURSING MANAGEMENT: Targeted interventions for higher core nursing competence need to be implemented, especially focusing on nurses' marital status and emotional support from partners.

Para-aortic and Right Obturator Lymphadenectomy for Surgical Staging of Advanced Cervical Cancer through the TU-LESS Extraperitoneal Approach.

OBJECTIVE: To present an innovative transumbilical laparoendoscopic single-site (TU-LESS) extraperitoneal approach for lymphadenectomy in a patient with advanced cervical carcinoma. DESIGN: Demonstration of the novel technique through video. SETTING: In advanced cervical cancer, determining the status of the para-aortic lymph nodes is essential because extended-field radiologic therapy is recommended for a patient with positive para-aortic lymph nodes [1]. Nonetheless, the sensitivity and specificity of currently available imaging workup for positive lymph nodes are limited. Surgical staging enables precise evaluation. However, laparotomy has potential wound complications and leads to treatment delay. Multiport laparoscopic transperitoneal and extraperitoneal approaches limit surgeons' ability to reach the para-aortic area or obturator fossa in the same operation [2]. Thus, we take full use of these approaches' advantages and avoid their disadvantages to design a promising minimally invasive surgery approach [3]. INTERVENTIONS: Para-aortic and obturator lymphadenectomy through the TU-LESS extraperitoneal approach was successfully performed without complications. The patient recovered quickly and received subsequent concurrent chemoradiation on schedule. CONCLUSION: TU-LESS extraperitoneal para-aortic lymphadenectomy provides satisfactory exposure and easy access to both the para-aortic area and obturator fossa. In addition, the bowels are uplifted by an extraperitoneal air cushion to achieve excellent exposure and reduce the risk of bowel injury. With quick recovery, the patient could start accurate radiation treatment promptly.

Association of plasma chromium with metabolic syndrome among Chinese adults: a case-control study.

BACKGROUD: Chromium has been suggested playing a role in alleviating diabetes, insulin resistance and lipid anomalies, but the effect on metabolic syndrome (MetS) in humans remains controversial. METHODS: We conducted a matched case-control study in a Chinese population, involving 2141 MetS cases and 2141 healthy controls, which were 1:1 matched by age (±2 years) and sex. Plasma chromium was measured by inductively coupled plasma mass spectrometry. RESULTS: Plasma chromium levels were lower in MetS group than in control group (mean: 4.36 µg/L and 4.66 µg/L, respectively, P < 0.001), and progressively decreased with the number of MetS components (P for trend < 0.001). After adjustment for potential confounding factors, the odds ratios (95% confidence intervals) for MetS across increasing quartiles of plasma chromium levels were 1 (reference), 0.84 (0.67-1.05), 0.76 (0.61-0.95), and 0.62 (0.49-0.78), respectively (P for trend < 0.001). For the components of MetS (high waist circumference, high triglycerides and high blood glucose), the odds ratios (95% confidence intervals) of the highest quartiles were 0.77 (0.61-0.95), 0.67 (0.55-0.80), and 0.53 (0.44-0.64), respectively (P for trend < 0.05). CONCLUSIONS: Our results indicated that plasma chromium levels were inversely associated with MetS in Chinese adults. The association may be explained by the relations between plasma chromium levels and high waist circumference, and the triglycerides and blood glucose levels.

Laparoendoscopic Single-site Radical Hysterectomy with Vaginal Closure and without Uterine Manipulator for FIGO IB1 Cervical Cancer.

OBJECTIVE: Minimally invasive surgery (MIS) for radical hysterectomy (RH) has been reported with inferior oncologic outcomes in the New England Journal of Medicine [1,2]. Some studies have suggested that the no-touch technique may be a useful procedure to prevent tumor spillage and improve survival. Therefore, we performed RH targeting early-stage cervical cancer using the laparoendoscopic single-site (LESS) approach with an enclosed colpotomy and without a uterine manipulator [3]. DESIGN: Video demonstration of the technique. SETTING: A hospital. INTERVENTIONS: A 48-year-old postmenopausal woman received a diagnosis of stage IB1 (International Federation of Gynecology and Obstetrics, 2018) cervical cancer [4]. After being fully informed of the benefits and risks of different surgical approaches (laparotomy and MIS), she consented to the MIS. The type C RH through the LESS approach was performed successfully. The final pathologic findings confirmed stage IB1 cervical carcinoma. The patient recovered quickly, albeit with slight pain, and the incision scar was hidden perfectly for cosmetic purposes. CONCLUSION: This video demonstrates that LESS-RH with vaginal closure and without a manipulator is feasible and safe. Suspension skills played a significant role in LESS-RH. In addition, this surgical procedure involved 4 specific techniques to prevent tumor spillage: creation of a vaginal cuff, avoidance of a uterine manipulator, standard type C radical hysterectomy, and bagging of the specimen. These adaptations were meant to minimize tumor manipulation and disruption for reducing the increased risk of recurrence. However, further verifications are still required.

Laparoendoscopic Single-site Radical Hysterectomy: Sufficient Exposure via Effective Suspension.

STUDY OBJECTIVE: To perform a radical hysterectomy for early-stage cervical cancer through laparoendoscopic single-site (LESS) approach and demonstrate if the effective suspension could achieve different exposed purposes and space extension. DESIGN: Presentation of the surgery through this technical video. SETTING: Hospital. INTERVENTIONS: A 52-year-old menopausal woman who presented with postcoital bleeding for 3 months was diagnosed with poorly differentiated (G3) cervical squamous cell carcinoma with International Federation of Gynecology and Obstetrics stage IB1. The patient was carefully consulted about the oncologic risks of the different surgical approaches; thereafter, the LESS approach was decided with informed consent. The LESS procedures for staging surgery were completed. The estimated blood loss was 60 mL, and operation time was 250 minutes. Results of the pathology report showed G3 squamous cell carcinoma and no pelvic lymph nodes metastases. The Foley catheter was removed on the 21st day, and the bladder function recovered completely after removal. She was followed up for a year without any evidence of recurrence or complications. CONCLUSION: Because of technical difficulties with a limited number of hands, complex surgeries, such as radical hysterectomy, have rarely been performed using the LESS approach [1]. The dissection of vesicocervical and parametrial space is critical to radical hysterectomy, and inadequate exposure to these spaces during the procedure presents major difficulties [2]. In the video, surgery for cervical cancer was performed successfully and met the International Federation of Gynecology and Obstetrics' standards for type C radical hysterectomy. Our video demonstrated that the varied and flexible suspension played a significant role in providing clear vision and sufficient exposure; furthermore, it was feasible, effective, and safe in the LESS approach [3,4].

Palladium-Catalyzed C-H Bond Functionalization Reactions Using Phosphate/Sulfonate Hypervalent Iodine Reagents.

A new and operationally simple approach for palladium-catalyzed C-H functionalization reactions utilizing an organophosphorus/sulfonate hypervalent iodine reagent as both an oxidant and the source of a functional group has been developed. Through this method, the oxidative phosphorylation-, sulfonation-, and hydroxylation of unactivated benzyl C(sp3)-H bonds, along with the hydroxylation and arylation of aryl C(sp2)-H bonds, are successfully realized under mild conditions and with excellent site-selectivity. The versatile C-OSO2R bond provides a platform for a wide array of subsequent diversification reactions.

Laparoendoscopic Single-site Surgery for Comprehensive Staging of Early Ovarian Cancer.

STUDY OBJECTIVE: To demonstrate the procedure and suspension skills of laparoendoscopic single-site (LESS) staging surgery with infrarenal para-aortic lymphadenectomy for early-stage ovarian cancer. DESIGN: A presentation of the surgery through this technical video. SETTING: A hospital. PATIENT AND INTERVENTIONS: A 45-year-old woman presented with a pelvic mass on gynecologic examination and a serum cancer antigen 125 level of 5910 U/mL (normal = <35 U/mL). A computed tomographic scan revealed a mixture of solid and cystic components (70 × 77 × 71 mm) arising from the right ovary and characterized by the "ovarian vascular pelvic" sign. Clinically early-stage ovarian cancer was suspected. Subsequently, LESS staging surgery was performed by an experienced surgeon in our department. RESULTS: The surgery lasted 280 minutes, and the volume of blood loss was 50 mL; there were no intra- or postoperative complications. We "hid" the incision perfectly for cosmetic purposes. The histopathologic findings supported high-grade serous ovarian cancer of the right ovary with the left fallopian tube involved as well. In addition, a total of 34 negative pelvic and 18 negative para-aortic lymph nodes were identified, and a stage of IIA was diagnosed as a result. CONCLUSION: We performed an LESS staging surgery for early-stage ovarian cancer successfully. Our video shows that the LESS approach provided feasible, cosmetic, and safe access among the selected malignant gynecologic surgery. Therefore, we have experienced that the effective suspension was an auxiliary measure for LESS lymphadenectomy. In addition, compared with multiport laparoscopy, the LESS approach could provide easier access to infrarenal para-aortic regions; furthermore, it was safe and quick to extract an unknown sample.

A micromilled microgrid sensor with delaminated MXene-bismuth nanocomposite assembly for simultaneous electrochemical detection of lead(II), cadmium(II) and zinc(II).

A delaminated MXene-bismuth (Bi@d-Ti3C2) nanocomposite was synthesized for the construction of a microgrid electrochemical sensor via mechanical milling. The Bi@d-Ti3C2 nanocomposite was synthesized by accumulation of Bi(III) on the surface of delaminated Ti3C2 nanosheets through electrostatic attraction and subsequent in-situ growth of bismuth nanorods. Under optimized experimental conditions, the sensor exhibits (a) linear responses to Pb(II), Cd(II) and Zn(II) in the concentration range from 1 to 20 µg L-1, (b) well separated peak potentials at -0.54 V, -0.76 V and - 1.15 V vs. Ag/AgCl, (c) sensitivities of 0.98, 0.84 and 0.60 µA L µg-1, and (d) detection limits of 0.2, 0.4 and 0.5 µg L-1, respectively. This performance is attributed to the uniform dispersion of Bi nanorods on electrically conductive delaminated Ti3C2 MXene, and to the enhanced diffusion due to the microgrid structure. Graphical abstractSchematic representation of a microgrid sensor based on delaminated MXene-bismuth (Bi@d-Ti3C2) nanocomposite for the simultaneous electrochemical determination of Pb(II), Cd(II) and Zn(II).

ADRB2 gene polymorphism modulates the retention of fear extinction memory.

Individual differences in regulation of fear and extinction memory play significant roles in the aetiology development of post-traumatic stress disorder (PTSD). Previous animal based studies showed that the activity of ß-adrenergic receptors (ß-ARs) are involved in memory modulation. However in humans it is not clear that whether genetic variability in ß-ARs contributes to individual differences of fear and extinction memory. In the current study, we investigated the role of a common single-nucleotide polymorphism of ß2-adrenergic receptor (ADRB2) gene in fear memory acquisition, fear memory extinction, extinction recall and fear generalization in human participants. Ninety-one male participants were exposed to a Pavlovian fear conditioning and their fear responses were assessed by the skin conductance response. Participants were genotyped for a polymorphism (rs2400207) located within the promoter region of the human ADRB2. Differences between genotypes were observed in the extinction memory recall test but not in fear acquisition, extinction learning and fear generalization. Particularly, A-allele carriers of rs2400707 displayed successful retention of extinction memory and prevented the return of fear during recall test. The results revealed the involvement of human noradrenergic system in the retention of extinction memory and genetic variability in this system may underlie individual differences in PTSD. Furthermore, rs2400207 polymorphism of ADRB2 gene may play a key role in the treatment efficacy of PTSD and can be a basis for future studies investigating a personalized medicine for fear memory related disorders.

Improving the timing jitter of a superconducting nanowire single-photon detection system.

Low timing jitter is a unique merit of superconducting nanowire single-photon detectors (SNSPDs) for time-correlated applications. Quantitative analysis was performed for the SNSPD system. Aided by an oscilloscope with an optimal signal amplitude, we were able to measure a full width at half-maximum system timing jitter as low as 14.2 ps for a high-switching-current SNSPD using a room-temperature low-noise amplifier. When using a time-correlated single-photon counting module, the system timing jitter was 17.3 ps. The detector's intrinsic timing jitter was estimated at ∼12.0 ps.

Superconducting nanowire single photon detector at 532 nm and demonstration in satellite laser ranging.

Superconducting nanowire single-photon detectors (SNSPDs) at a wavelength of 532 nm were designed and fabricated aiming to satellite laser ranging (SLR) applications. The NbN SNSPDs were fabricated on one-dimensional photonic crystals with a sensitive-area diameter of 42 µm. The devices were coupled with multimode fiber (ϕ = 50 µm) and exhibited a maximum system detection efficiency of 75% at an extremely low dark count rate of <0.1 Hz. An SLR experiment using an SNSPD at a wavelength of 532 nm was successfully demonstrated. The results showed a depth ranging with a precision of ~8.0 mm for the target satellite LARES, which is ~3,000 km away from the ground ranging station at the Sheshan Observatory.

Observation of Quantum Fingerprinting Beating the Classical Limit.

Quantum communication has historically been at the forefront of advancements, from fundamental tests of quantum physics to utilizing the quantum-mechanical properties of physical systems for practical applications. In the field of communication complexity, quantum communication allows the advantage of an exponential reduction in the transmitted information over classical communication to accomplish distributed computational tasks. However, to date, demonstrating this advantage in a practical setting continues to be a central challenge. Here, we report a proof-of-principle experimental demonstration of a quantum fingerprinting protocol that for the first time surpasses the ultimate classical limit to transmitted information. Ultralow noise superconducting single-photon detectors and a stable fiber-based Sagnac interferometer are used to implement a quantum fingerprinting system that is capable of transmitting less information than the classical proven lower bound over 20 km standard telecom fiber for input sizes of up to 2 Gbits. The results pave the way for experimentally exploring the advanced features of quantum communication and open a new window of opportunity for research in communication complexity and testing the foundations of physics.

Measurement-Device-Independent Quantum Key Distribution Over a 404 km Optical Fiber.

Measurement-device-independent quantum key distribution (MDIQKD) with the decoy-state method negates security threats of both the imperfect single-photon source and detection losses. Lengthening the distance and improving the key rate of quantum key distribution (QKD) are vital issues in practical applications of QKD. Herein, we report the results of MDIQKD over 404 km of ultralow-loss optical fiber and 311 km of a standard optical fiber while employing an optimized four-intensity decoy-state method. This record-breaking implementation of the MDIQKD method not only provides a new distance record for both MDIQKD and all types of QKD systems but also, more significantly, achieves a distance that the traditional Bennett-Brassard 1984 QKD would not be able to achieve with the same detection devices even with ideal single-photon sources. This work represents a significant step toward proving and developing feasible long-distance QKD.