Stable and wavelength-tunable multiwavelength laser for high-rate measurement device independent quantum key distribution.

Measurement device independent quantum key distribution (MDI QKD) has attracted growing attention for its immunity to attacks at the measurement unit, but its unique structure limits the secret key rate. Utilizing the wavelength division multiplexing (WDM) technique and reducing error rates are effective strategies for enhancing the secret key rate. Reducing error rates often requires active feedback control of wavelengths using precise external references. However, for a multiwavelength laser, employing multiple references to stabilize each wavelength output places stringent demands on these references and significantly increases system complexity. Here, we demonstrate a stable, wavelength-tunable multiwavelength laser with an output wavelength ranging from 1270 to 1610 nm. Through precise temperature control and stable drive current, we passively lock the laser wavelength, achieving remarkable wavelength stability. This significantly reduce the error rate, leading to an almost doubling of the secret key rate compared to previous experiments. Furthermore, the exceptional wavelength stability offered by our multiwavelength laser, combined with the WDM technique, has further boosted the secret key rate of MDI QKD. With a wide wavelength tuning range of 5.1 nm, our multiwavelength laser facilitates flexible operation across multiple dense wavelength division multiplexing channels. Coupled with high wavelength stability and multiple wavelength outputs simultaneously, this laser offers a promising solution for a high-rate MDI QKD system.

Quantum imaging of the reconfigurable VO2 synaptic electronics for neuromorphic computing.

Neuromorphic computing has shown remarkable capabilities in silicon-based artificial intelligence, which can be optimized by using Mott materials for functional synaptic connections. However, the research efforts focus on two-terminal artificial synapses and envisioned the networks controlled by silicon-based circuits, which is difficult to develop and integrate. Here, we propose a dynamic network with laser-controlled conducting filaments based on electric field-induced local insulator-metal transition of vanadium dioxide. Quantum sensing is used to realize conductivity-sensitive imaging of conducting filament. We find that the location of filament formation is manipulated by focused laser, which is applicable to simulate the dynamical synaptic connections between the neurons. The ability to process signals with both long-term and short-term potentiation is further demonstrated with ~60 times on/off ratio while switching the pathways. This study opens the door to the development of dynamic network structures depending on easily controlled conduction pathways, mimicking the biological nervous systems.

Experimental Demonstration of Fully Passive Quantum Key Distribution.

The passive approach to quantum key distribution (QKD) consists of removing all active modulation from the users' devices, a highly desirable countermeasure to get rid of modulator side channels. Nevertheless, active modulation has not been completely removed in QKD systems so far, due to both theoretical and practical limitations. In this Letter, we present a fully passive time-bin encoding QKD system and report on the successful implementation of a modulator-free QKD link. According to the latest theoretical analysis, our prototype is capable of delivering competitive secret key rates in the finite key regime.

Afterpulse effects in quantum key distribution without monitoring signal disturbance.

The round-robin differential phase shift (RRDPS) quantum key distribution (QKD) protocol is the only one that does not require monitoring of signal disturbance. Moreover, it has been proven that RRDPS has excellent performance of resistance to finite-key effects and high error rate tolerance. However, the existing theories and experiments do not take the afterpulse effects into account, which cannot be neglected in high-speed QKD systems. Here, we propose a tight finite-key analysis with afterpulse effects. The results show that the non-Markovian afterpulse RRDPS model optimizes the system performance considering afterpulse effects. The advantage of RRDPS over decoy-state BB84 under short-time communication still holds at typical values of afterpulse.

Transmittance-invariant phase modulator for chip-based quantum key distribution.

In chip-based quantum key distribution (QKD) systems, the non-ideal quantum state preparation due to the imperfect electro-optic phase modulators (EOPM) decreases the secret key rate and introduces potential vulnerabilities. We propose and implement an on-chip transmittance-invariant phase modulator (TIPM) to solve this problem. Simulated and experimental results show that TIPM can eliminate the correlation between phase, intensity, and polarization of quantum states caused by phase-dependent loss. The design can tolerate a significant fabrication mismatch and is universal to multi-material platforms. Furthermore, TIPM increases the modulation depth achievable by EOPMs in standard process design kit (PDK). The proposal of TIPM can improve the practical security and performance of the chip-based QKD systems.

Afterpulse effect in measurement-device-independent quantum key distribution.

There is no doubt that measurement-device-independent quantum key distribution (MDI-QKD) is a crucial protocol that is immune to all possible detector side channel attacks. In the preparation phase, a simulation model is usually employed to get a set of optimized parameters, which is utilized for getting a higher secure key rate in reality. With the implementation of high-speed QKD, the afterpulse effect which is an intrinsic characteristic of the single-photon avalanche photodiode is no longer ignorable, this will lead to a great deviation compared with the existing analytical model. Here we develop an afterpulse-compatible MDI-QKD model to get the optimized parameters. Our results indicate that by using our afterpulse-compatible model, we can get a much higher key rate than the prior afterpulse-omitted model. It is significant to take the afterpulse effect into consideration because of the improvement of the system working frequency.

Internal fixation using fully threaded cannulated compression screws for fresh femoral neck fractures in adults.

OBJECTIVES: Internal fixation with multiple cannulated compression screws is an optional treatment for femoral neck fracture. Recently, fully threaded cannulated compression screws (FTCCS) have been introduced to fix fresh femoral neck fractures (FNF). The purpose of this study was to investigate the effectiveness of FTCCS. PATIENTS AND METHODS: Patients with FNF fixed by multiple FTCCS from February 1st, 2014 to August 31st, 2017 were included in this study. They were followed for at least 12 months postoperatively. Nonunion, osteonecrosis of the femoral head (ONFH), fixation failure, reoperation, and femoral neck shortening (FNS) were used to evaluate the outcomes. Risk factors including age, sex, fracture side, fracture displacement, fracture stability, fixation configuration, and screw numbers were analyzed. RESULTS: A total of 113 patients including 67 males and 46 females with an average age of 48.4 ± 13.4 years were included. The mean duration of follow-up was 27.1 months (range: 12-51 months). The incidence of nonunion, ONFH, fixation failure, and reoperation was 15.9%, 22.1%, 8.8%, and 24.8%, respectively. The rates of nonunion and reoperation were significantly higher in displaced fractures and unstable fractures. And patients with an unstable fracture had a higher risk of internal fixation failure. The median length of FNS was 2.9 mm (interquartile range: 0.9-6.5 mm, range: 0-17.5 mm). Age was a significant risk factor for FNS. CONCLUSIONS: The screw fixation method with FTCCS provided encouraging clinical results which may be a rational choice for the treatment of fresh FNF. Displaced fractures and unstable fractures were attributed to the higher incidence of complications. TRIAL REGISTRATION: ChiCTR, ChiCTR1800017200. Registered 17 July 2018-Retrospectively registered, http: www.chictr.org.cn/showprojen.aspx?proj=29182 .

Discovery of EGFR-Targeted Environment-Sensitive fluorescent probes for cell imaging and efficient tumor detection.

Overexpression of human epidermal growth factor receptor (EGFR) plays an important role in several signaling pathways inside and outside the cell, especially in the processes of cell proliferation, differentiation, and death in various cancers. Due to the complexity of the structure and function of EGFR, research on the fluorescence visualization of EGFR protein visualization has proved challenging. One possible strategy for designing a receptor-targeting fluorescent probe with a switching mechanism is to introduce an environment-sensitive fluorophore into the drug ligand. Based on this strategic molecular design, we introduced two environment-sensitive small molecular fluorophores, dansyl chloride (DNS) and nitrobenzoxadiazole (NBD), to replace the morpholine group of gefitinib, achieving a series of fluorescent molecular probes bearing a switching mechanism. The GN probes exhibited prominent environment sensitivity, suggesting good performance as turn-on EGFR-targeting fluorescent ligands. The representative probe GN3 specifically responded to tumor cells overexpressing EGFR, which was validated with live-cell fluorescence imaging and in vivo xenograft tumor imaging. Ligand-induced EGFR phosphorylation in A431 cells was considerably inhibited by probe GN3, demonstrating that this probe still functions as an EGFR inhibitor. Owing to the turn-on response of GN3 to EGFR in tumor cells, and the competitive replacement behavior to the EGFR inhibitor gefitinib, these probes have the potential to be used for fluorescence imaging of cells overexpressing EGFR.

Salidroside alleviates oxidative stress and apoptosis via AMPK/Nrf2 pathway in DHT-induced human granulosa cell line KGN.

In the past few years, emerging evidence established persistent oxidative stress to be a key player in the pathogenesis of polycystic ovary syndrome (PCOS). Particularly, it damages the function of granulosa cells, and thus hinders the development of follicles. The present study aimed to explore and establish the protective effects of salidroside on dihydrotestosterone (DHT)-induced Granulosa-like tumor cell line (KGN), mediated via antioxidant mechanisms. The study assessed the positive effects of salidroside on DHT-induced apoptosis, reactive oxygen species (ROS) accumulation, damage of antioxidant capacity, and mitochondrial membrane potential depolarization. Interestingly, salidroside partly reversed DHT mediated effects, via stimulation of nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathway and the downstream antioxidant proteins heme oxygenase-1(HO-1) and quinine oxidoreductase 1(NQO1). Additionally, the knockdown of Nrf2 partly moderated the antioxidant and anti-apoptosis effects of salidroside in DHT-treated KGN cells. Mechanistically, AMP-activated protein kinase (AMPK) was identified to be the upstream signaling involved in salidroside-induced Nrf2 activation, as silencing of AMPK partly prevented the upregulation of Nrf2 and the downstream proteins HO-1 and NQO1. Altogether, the present study is the first to effectively demonstrate the inhibitory effect of salidroside on DHT-stimulated oxidative stress and apoptosis in KGN cells, which was dependent on Nrf2 activation that involved AMPK.

Charge state depletion nanoscopy with a nitrogen-vacancy center in nanodiamonds.

The development of super-resolution imaging has driven research into biological labeling, new materials' characterization, and nanoscale sensing. Here, we studied the photoinduced charge state conversion of nitrogen-vacancy (NV) centers in nanodiamonds (NDs), which show the potential for multifunction sensing and labeling at the nanoscale. Charge state depletion (CSD) nanoscopy is subsequently demonstrated for the diffraction-unlimited imaging of NDs in biological cells. A resolution of 77 nm is obtained with 50 nm NDs. The depletion laser power of CSD nanoscopy is approximately 1/16 of stimulated emission depletion (STED) microscopy with the same resolution. The results can be used to improve the spatial resolution of biological labeling and sensing with NDs and other nanoparticles.

Reinforced Supramolecular Hydrogels from Attapulgite and Cyclodextrin Pseudopolyrotaxane for Sustained Intra-Articular Drug Delivery.

Injectable hydrogels for nonsteroidal anti-inflammatory drugs' (NSAIDs) delivery to minimize the side effects of NSAIDs and achieve long-term sustained release at the targeted site of synovial joint are attractive for osteoarthritis therapy, but how to improve its mechanical strength remains a challenge. In this work, a kind of 1D natural clay mineral material, attapulgite (ATP), is introduced to a classical cyclodextrin pseudopolyrotaxane (PPR) system to form a reinforced supramolecular hydrogel for sustained release of diclofenac sodium (DS) due to its rigid, rod-like morphology, and unique structure, which has great potential in tissue regeneration, repair, and engineering. Investigation on the interior morphology and rheological property of the obtained hydrogel points out that the ATP distributed in PPR hydrogel plays a role similar to the "reinforcement in concrete" and exhibits a positive effect on improving the mechanical properties of PPR hydrogel by regulating their interior morphology from a randomly distributed style to the well-ordered porous frame structure. The hybrid hydrogels demonstrate good shear-thinning and thixotropic properties, excellent biocompability, and sustained release behavior both in vitro and in vivo. Furthermore, preliminary in vivo treatment in an acute inflammatory rat model reveals that the ATP hybrid hydrogels present sustained anti-inflammatory effect.

Accurate location and minimally invasive treatment of lumbar lateral recess stenosis with combined SNRB and PTED.

OBJECTIVE: To establish a management strategy for multi-segment lumbar lateral recess stenosis. METHODS: A retrospective study was performed in patients in whom suspected responsible nerve roots underwent sequential selective nerve root block (SNRB). Based on pain remission rate after blocking, the contribution of nerve root compression to symptoms was classified as absolutely (≥70%) or relatively (30-70%) responsible or non-responsible (<30%). Conservative treatment was continued if visual analogue scale (VAS) at 3 days after blocking a single nerve root or VAS at 3 days after blocking multiple nerve roots was ≥50%; otherwise, percutaneous transforaminal endoscopic discectomy (PTED) was performed. Pain and functional scores were evaluated on day 3, 6 months and 1 year after SNRB or PTED. RESULTS: Fifty-seven of 80 patients had a single absolutely responsible root, 20 had 2 responsible roots, and 3 had 3 responsible roots. Among them, 41, 10, and 1 patient underwent PTED, respectively. Both the PTED and conservative groups improved significantly in VAS remission rate and functional scores compared with admission. Moreover, the PTED group had a better VAS remission rate compared with the conservative group. CONCLUSION: A combination of SNRB with PTED was effective for diagnosing and treating multi-segment lumbar lateral recess stenosis.

High-resolution multiphoton microscopy with a low-power continuous wave laser pump.

Multiphoton microscopy (MPM) has been widely used for three-dimensional biological imaging. Here, based on the photon-induced charge state conversion process, we demonstrated a low-power high-resolution MPM with a nitrogen vacancy (NV) center in diamond. Continuous wave green and orange lasers were used to pump and detect the two-photon charge state conversion, respectively. The power of the laser for multiphoton excitation was 40 µW. Both the axial and lateral resolutions were improved approximately 1.5 times compared with confocal microscopy. The results can be used to improve the resolution of the NV center-based quantum sensing and biological imaging.

[Comparison of clinical efficacy between minimally invasive total hip artliroplasty and traditional total hip arthroplasty: a systematic review].

OBJECTIVE: To systematically review the effectiveness of minimally invasive total hip arthroplasty (MIS-THA) versus traditional total hip arthroplasty (THA) in patients with hip diseases. METHODS: Through a method of combining Free words and keywords,we searched databases including PubMed,The Cochrane Library, EMbase,Web of Science, CBM , CNKI and Wanfang Data for randomized controlled trials (RCTs) on the comparison between MIS-THA and THA for hip disease from inception to June, 2014. Two reviewers independently screened literatures according to the inclusion and exclusion criteria, extracted data and assessed the quality of the included studies according to the "bias risk assessment" tool recommended by Cochrane Handbook 5.0 for Systematic Reviews. Then, meta-analysis was performed using RevMan 5.3 software. RESULTS: Thirteen RCTs involving 1 213 cases of surgeries and total 1 284 hips (MIS-THA: n = 631; THA: n = 653) were identified. The results of meta-analysis showed that statistically significant differences were found in Harris hip score on the 3rd month after operation [MD = 8.37, 95% CI (6.02,10.72)], Hematocrit [MD = 0.02, 95% CI (0.01, 0.03)] and Hemoglobin [MD = 0.50, 95% CI (0.16, 0.85)] at the 48th hour after operation, changed value of femoral offset [MD = 0.30, 95% CI (0.04, 0.56)] between two groups. In the change value of femoral offset, THA was better than MIS-THA; There were no statistically significant differences between two groups in Harris hip score at 1st year after operation [MD = 3.26, 95% CI (-3.25, 9.76)], WOMAC score [MD = -0.53, 95% CI (-3.67, 2.60)] and Oxford score [MD = 1.34, 95% CI (-3.46, 6.13)] at the 6th week after operation, Hematocrit at the 8th hour after operation [MD = -0.01, 95% CI (-0.02, 0.00)], the incidence of hip varus [RR = 0.82, 95% CI (0.45,1.52)] and dislocation [RR = 1.40, 95% CI (0.48, 4.12)]. CONCLUSION: THA brings less trauma, less hemorrhage and better early clinical outcome compared with MIS-THA, but the difference of the complication rates between the two groups is similar.

Quality assessment of clinical guidelines in China: 1993 - 2010.

BACKGROUND: Clinical practice guidelines (CPGs) play an important role in healthcare in China as well as in the world. However, the current status and trends of Chinese CPGs are unknown. The aim of this study was to systematically review the present situation and the quality of Chinese CPGs published in the peer-reviewed medical literature. METHODS: To identify Chinese CPGs, a systematic search of relevant literature databases (CBM, WANFANG, VIP, and CNKI) was performed for the period January 1978 to December 2010. We used the AGREE II instrument to assess the quality of the included guidelines. RESULTS: We evaluated 269 guidelines published in 115 medical journals from 1993 to 2010 and produced by 256 different developers. Only four guidelines (1%) described the systematic methods for searching and selecting the evidence, 14 (5%) guidelines indicated an explicit link between the supporting evidence and the recommendations, only one guideline used the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system. Thirty-one guidelines (12%) mentioned updates and the average frequency of update was 5.5 years; none described a procedure for updating the guideline. From the assessment with the Appraisal of Guidelines for Research and Ecaluation II (AGREE II), the mean scores were low for the domains "scope and purpose" (19%) and "clarity of presentation" (26%) and very low for the other domains ("rigour of development" 7%, "stakeholder involvement" 8%, "applicability" 6% and "editorial independence" 2%). CONCLUSIONS: Compared with other studies on the quality of guidelines assessed with the AGREE instrument in other countries, Chinese CPGs received lower scores, which indicates a relatively poor quality of the guidelines. However, there was some increase over time.