Creation of memory-memory entanglement in a metropolitan quantum network.

Towards realizing the future quantum internet1,2, a pivotal milestone entails the transition from two-node proof-of-principle experiments conducted in laboratories to comprehensive multi-node set-ups on large scales. Here we report the creation of memory-memory entanglement in a multi-node quantum network over a metropolitan area. We use three independent memory nodes, each of which is equipped with an atomic ensemble quantum memory3 that has telecom conversion, together with a photonic server where detection of a single photon heralds the success of entanglement generation. The memory nodes are maximally separated apart for 12.5 kilometres. We actively stabilize the phase variance owing to fibre links and control lasers. We demonstrate concurrent entanglement generation between any two memory nodes. The memory lifetime is longer than the round-trip communication time. Our work provides a metropolitan-scale testbed for the evaluation and exploration of multi-node quantum network protocols and starts a stage of quantum internet research.

Postselected Entanglement between Two Atomic Ensembles Separated by 12.5 km.

Quantum internet gives the promise of getting all quantum resources connected, and it will enable applications far beyond a localized scenario. A prototype is a network of quantum memories that are entangled and well separated. In this Letter, we report the establishment of postselected entanglement between two atomic quantum memories physically separated by 12.5 km directly. We create atom-photon entanglement in one node and send the photon to a second node for storage via electromagnetically induced transparency. We harness low-loss transmission through a field-deployed fiber of 20.5 km by making use of frequency down-conversion and up-conversion. The final memory-memory entanglement is verified to have a fidelity of 90% via retrieving to photons. Our experiment makes a significant step forward toward the realization of a practical metropolitan-scale quantum network.

[The myocardial protective effect of propofol on rats with experimental myocardial infarction and its mechanism].

The aim of the present study was to investigate the protective effect of propofol on the experimental myocardial infarction in rats. The myocardial infarction model was established by ligating the anterior descending branch of left coronary artery in rats. Model rats were treated with propofol. Cardiac function was evaluated by echocardiography. Cardiac hemodynamic changes were detected by multiconductor biorecorder. Pathological changes in the infarcted myocardia were detected by HE staining. The expression levels of cardiac hypertrophy marker genes and fibrosis marker proteins were analyzed by real-time quantitative PCR and Western blot. The results showed that, compared with the sham surgery group, the model group exhibited larger infarct size (> 40%), impaired heart function, and significantly increased left ventricular end-diastolic pressure (LVEDP). Propofol reduced cardiac function impairment and decreased LVEDP in the model group. Propofol significantly reduced lung weight/body weight ratio, heart weight/body weight ratio, left ventricular weight/body weight ratio and left atrial weight/body weight ratio in the model group. Furthermore, after myocardial infarction, the administration of propofol significantly improved the diastolic strain rate, down-regulated the mRNA expression levels of myocardial hypertrophy markers, atrial natriuretic peptide and ß-myosin heavy chain, and reversed the up-regulation of matrix metalloproteinase 2 (MMP2), MMP9 and tissue inhibitor of metalloproteinase-2 (TIMP-2) induced by myocardial infarction. These results suggest propofol can reduce adverse ventricular remodeling, cardiac dysfunction, myocardial hypertrophy and fibrosis after myocardial infarction, and has protective effect against the experimental myocardial infarction induced by coronary artery ligation in rats.

Comparison of traditional vascular reconstruction with covered stent in the treatment of subclavian artery injury.

PURPOSE: To explore the significance of traditional vascular reconstruction and covered stent for limb salvage after subclavian artery injury. METHODS: Patients with subclavian artery injury admitted to Beijing Jishuitan Hospital from January 2010 to December 2018 were retrospectively analyzed. All the injuries have been confirmed by intraoperative exploration, computed tomography angiography or digital subtraction angiography. Complete or partial amputation injuries were excluded. Mild artery defect or partial intimal damage was treated by interventional implantation, while other patients received open surgeries, including direct suture of small defect less than 2 cm and transplantation with autologous vein or artificial blood when the defect was more than 2 cm. Patients were divided into open surgery group and stent implantation group based on the treatment they received. Patients were followed up at 2 weeks (first stage) and 6 months (second stage) after operation to investigate limb salvage. Student's t-test was used to compare the general data between two groups and Chi-square test to analyze the rate of limb salvage. RESULTS: Altogether 50 cases of subclavian artery injury were treated, including 36 cases of open surgery and 14 cases of stent implantation. Combination of nerve injury was observed in 27 cases (75.0%) in open surgery group and 12 cases (85.7%) in stent implantation group. Amputation developed in 3 cases with open surgery and 1 case with stent implantation. Consequently the rate of successful limb salvage was respectively 91.7% (33/36) and 92.9% (13/14), revealing no significant difference (p > 0.05). CONCLUSION: Rapid reconstruction of blood circulation is crucial following subclavian artery injury, no matter what kinds of treatment strategies have been adopted. Interventional stent implantation can achieve a good effect for limb salvage.

Treatment strategy for traumatic innominate arterial injury.

PURPOSE: To discuss and share the experience of treatment of traumatic innominate arterial injury. METHODS: A retrospective analysis was performed on patients with innominate arterial injuries admitted from January 2016 to July 2018 at the department of vascular surgery, Beijing Jishuitan Hospital, China. All the arterial injuries were confirmed by arteriography. Clinical data including mechanism of injury, type of injury, demographics, concomitant injuries, time interval from trauma to blood flow reconstruction, and operation methods were collected. Follow-up program included outpatient visit and duplex-ultrasonography. SPSS version 23.0 was adopted for data analysis. Categorical variables are presented as number and/or frequency and continuous variables as mean ± standard deviation. RESULT: Altogether 7 patients were included and 6 (85.7%) were male. The mean age of patients was (29.43 ± 7.98) years, range 19-43 years. Six patients had isolated innominate arterial injuries and the rest 1 combined innominate arterial and vein injuries. The injury causes were road accidents in 3 patients, stab wound in 2, gunshot wound in 1, and crush injury in 1. All the 7 patients presented hemorrhagic shock at admission, which was timely and effectively corrected. No perioperative death or technical complications occurred. Intimal injury (n = 2) and partial transaction (n = 2) of the innominate artery were treated with covered stents. Two patients with complete transection of artery received vascular reconstruction by artificial grafts. One patient with partial transaction received balloon dilation and open surgical repair (hybrid operation). The mean time interval from trauma to blood flow reconstruction was (4.27 ± 0.18) h, range 4.0-4.5 h; while the operation time was (48.57 ± 19.94) min, range 25-75 min. Cerebral infarction occurred in one patient with brain injury due to anticoagulation contraindication. The average follow-up was (13.29 ± 5.65) months, range 6-24 months. No severe stenosis, occlusion, and thrombosis of covered stents or artificial vessels were found by color Doppler ultrasound. CONCLUSION: Urgent control of hemorrhage and restoration of blood supply are critical for the treatment of traumatic innominate arterial injury. Endovascular therapy is a feasible and effective method with short operation time and less trauma.

Literature review of peripheral vascular trauma: Is the era of intervention coming?

Traumatic peripheral vascular injury is a significant cause of disability and death either in civilian environments or on the battlefield. Penetrating trauma and blunt trauma are the most common forms of vascular injuries. Besides, iatrogenic arterial injury (IAI) is another pattern of vascular trauma. The management of peripheral vascular injuries has been improved in different environments and wars. There are different types of vascular injuries, such as vasospasm, contusion, intimal flaps, intimal disruption or hematoma, external compression, laceration, transection and focal wall defects, etc. The main clinical manifestations of vascular injuries are shock following massive hemorrhage and limb necrosis due to tissue and organ ischemia. Ultrasound, computed tomography angiography (CTA) and magnetic resonance angiography (MRA) are most valuable for assessment of peripheral vascular injuries. Angiography remains the gold standard for diagnosing vascular trauma. Immediate hemorrhage control and rapid restoration of blood flow are the primary goals of vascular trauma treatment. There are many operative treatment methods for vascular injuries, such as vascular suture or ligation, vascular wall repair and vascular reconstruction with blood vessel prostheses or vascular grafts. Embolization, balloon dilation and covered stent implantation are the main endovascular techniques. Surgical operation is still the primary treatment for vascular injuries. Endovascular treatment is a promising alternative, proved to be safe and effective, and preferred selection for patients. In summary, rapid diagnosis and timely surgical intervention remain the mainstays of the treatment. However, many issues need to be resolved by further studies.

Semideterministic Entanglement between a Single Photon and an Atomic Ensemble.

Entanglement between a single photon and a matter qubit is an indispensable resource for quantum repeater and quantum networks. With atomic ensembles, the entanglement creation probability is typically very low to inhibit high-order events. In this paper, we propose and experimentally realize a scheme that creates atom-photon entanglement with an intrinsic efficiency of 50%. We make use of Rydberg blockade to generate two collective excitations, lying in separate internal states. By introducing the momentum degree of freedom for the excitations, and interfering them via Raman coupling, we entangle the two excitations. Via retrieving one excitation, we create the entanglement between the polarization of a single photon and the momentum of the remaining atomic excitation, with a measured fidelity of 0.901(8). The retrieved optical field is verified to be genuine single photons. The realized entanglement may be employed to create entanglement between two distant nodes in a fully heralded way and with a much higher efficiency.

[Insertion of double inferior vena cava filter in patients with deep venous thromboembolism].

OBJECTIVE: To explore the characteristic, diagnosis and treatment of deep venous thromboembolism (DVT) patients with congenital double inferior vena cava. METHODS: Retrospective analyses were conducted for the indications, filter types and efficacies of vena cava filter insertion in 7 hospitalized DVT patients with congenital double inferior vena at our hospital from 2006 to 2012. RESULTS: All of them had definite indications for vena cava filter insertion. Temporary and permanent vena caval filters were implanted in one subject while retrievable vena caval filters in another five subjects. One retrievable filter was replaced by a permanent filter due to excessive thrombus entrapped in filter. Other temporary or retrievable filters were extracted successfully. All subjects were prescribed postoperatively with oral anticoagulants. The follow-up period was 1-72 months. No recurrent DVT or pulmonary embolism occurred. CONCLUSION: The complications of double inferior vena cava in DVT subjects are often misdiagnosed due to its low incidence rate and a lack of clinical manifestations. Fatal pulmonary embolism after implantation may be due to an inappropriate location of filter implant. If implanted in a proper position, satisfactory outcomes ensue.

[Efficacy and safety of recombinant tissue plasminogen activator in thrombolytic therapy of vena caval thromboembolism].

OBJECTIVE: To explore the efficacy and safety of recombinant tissue plasminogen activator (rt-PA) in thrombolytic therapy of vena caval thromboembolism. METHODS: Ninety patients diagnosed of vena caval thromboembolism by ultrasound or angiography of inferior vena cava were randomly assigned into 2 groups. rt-PA and parental anticoagulant were given to the patients in the treatment group while those in the control group received only parental anticoagulation. D-dimer, fibrinogen and fibrinogen degradation product were analyzed after 2-week treatment. All subjects were closely monitored for the occurrence of severe complications. RESULTS: The changes from baseline in the above laboratory parameters in the treatment group were significantly greater than those of the control group (P < 0.05). No severe complications occurred in either group. CONCLUSION: rt-PA is both safe and effective for the thrombolytic therapy of vena caval thromboembolism.

Clinical outcomes of AngioJet pharmacomechanical thrombectomy versus catheter-directed thrombolysis for the treatment of filter-related caval thrombosis.

BACKGROUND: The inferior vena cava filter is utilized worldwide to intercept thrombi and to reduce the risk of fatal pulmonary embolism (PE). However, filter-related thrombosis is a complication of filter implantation. Endovascular methods such as AngioJet rheolytic thrombectomy (ART) and catheter-directed thrombolysis (CDT) can treat filter-related caval thrombosis, but the clinical outcomes of both treatment modalities have not been determined. AIM: To compare the treatment outcomes of AngioJet rheolytic thrombectomy vs catheter-directed thrombolysis in patients with filter-related caval thrombosis. METHODS: In this single-center retrospective study, 65 patients (34 males and 31 females; mean age: 59.0 ± 13.43 years) with intrafilter and inferior vena cava thrombosis were enrolled between January 2021 and August 2022. These patients were assigned to either the AngioJet group (n = 44) or the CDT group (n = 21). Clinical data and imaging information were collected. Evaluation measures included thrombus clearance rate, periprocedural complications, urokinase dosage, incidence of PE, limb circumference difference, length of stay, and filter removal rate. RESULTS: Technical success rates were 100% in the AngioJet and CDT groups. In the AngioJet group, grade II and grade III thrombus clearance was achieved in 26 (59.09%) and 14 (31.82%) patients, respectively. In the CDT group, grade II and grade III thrombus clearance was accomplished in 11 (52.38%) patients and 8 (38.10%) patients, respectively (P > 0.05).The peridiameter difference of the thigh was significantly reduced in patients from both groups after treatment (P < 0.05). The median dosage of urokinase was 0.08 (0.02, 0.25) million U in the AngioJet group and 1.50 (1.17, 1.83) million U in the CDT group (P < 0.05). Minor bleeding was shown in 4 (19.05%) patients in the CDT group, and when it was compared with that in the AngioJet group, the difference was statistically significant (P < 0.05). No major bleeding occurred. Seven (15.91%) patients in the AngioJet group had hemoglobinuria and 1 (4.76%) patient in the CDT group had bacteremia. There were 8 (18.18%) patients with PE in the AngioJet group and 4 (19.05%) patients in the CDT group before the intervention (P > 0.05). Computed tomography angiopulmonography (CTA) showed that PE was resolved after the intervention. New PE occurred in 4 (9.09%) patients in the AngioJet group and in 2 (9.52%) patients in the CDT group after theintervention (P > 0.05). These cases of PE were asymptomatic. The mean length of stay was longer in the CDT group (11.67 ± 5.34 d) than in the AngioJet group (10.64 ± 3.52 d) (P < 0.05). The filter was successfully retrieved in the first phase in 10 (47.62%) patients in the CDT group and in 15 (34.09%) patients in the AngioJet group (P > 0.05).Cumulative removal was accomplished in 17 (80.95%) out of 21 patients in the CDT group and in 42 (95.45%) out of 44 patients in the ART group (P > 0.05). The median indwelling time for patients with successful retrieval was 16 (13139) d in the CDT group and 59 (12231) d in the ART group (P > 0.05). CONCLUSION: Compared with catheter-directed thrombolysis, AngioJet rheolytic thrombectomy can achieve similar thrombus clearance effects, improve the filter retrieval rate, reduce the urokinase dosage and lower the risk of bleeding events in patients with filter-related caval thrombosis.

[Analysis of causative factors for lower limb deep vein thrombosis complicated with artery pulmonary embolism in orthopedics patients].

OBJECTIVE: To explore the causative factors of lower limb deep vein thrombosis complicated with pulmonary artery embolism in orthopedics patients. METHODS: The clinical manifestations and causes of thrombosis defluxion of pulmonary artery embolism patients whose diagnosis were confirmed by computed tomography pulmonary angiography (CTPA) during May 2009-May 2012 were retrospectively analyzed. RESULTS: Among 45 cases of CTPA-confirmed pulmonary artery embolism patients, 5 patients had no obvious clinical manifestation. The initial symptoms included chest stuffiness and dyspnea (n = 9) and cough (n = 8). And the major causes of thrombosis defluxion were early postoperative mobilization (n = 11), postoperative functional exercise (n = 9), rollover or defecation in bed (n = 7), sneezing (n = 2) and unknown causes (n = 14). CONCLUSION: The patients with lower limb deep vein thrombosis have a high risk of thrombosis defluxion during unstable period. Despite adequate anticoagulation, early mobilization and functional exercise are likely to cause thrombosis defluxion and lead to pulmonary artery embolism.

Emergence of an NDM-5-Producing Escherichia coli Sequence Type 410 Clone in Infants in a Children's Hospital in China.

PURPOSE: Outbreaks of infection due to carbapenem-resistant Enterobacterales (CRE), including New Delhi metallo-ß-lactamase (NDM)-producing Escherichia coli, have been increasingly reported worldwide, primarily in adults and rarely in children. The goal of this study was to characterize an outbreak of infection caused by NDM-5-producing E. coli in a children's hospital in China. METHODS: A total of 86 CRE isolates were collected from 85 hospitalized children between June 2017 and May 2018. These isolates were subjected to multiple phenotypic and molecular tests, including in vitro antimicrobial susceptibility testing, PCR, pulsed-field gel electrophoresis (PFGE), multilocus sequence typing (MLST), and whole-genome sequencing (WGS). RESULTS: Among the 86 CRE isolates, we identified 9 NDM-5-producing E. coli isolates, with 5 of them sharing the same PFGE pattern, same MLST type (ST410), same plasmid replicon type (IncFII), and nearly the same set of additional resistance genes. All 9 isolates were resistant to most antimicrobial agents, including carbapenems, cephalosporins, and levofloxacin, while being sensitive to trimethoprim/sulfamethoxazole, amikacin, tigecycline, and colistin. According to the clinical background, all 9 isolates were collected in a period of < 3 months from infants among whom there was overlap in the time of hospitalization. None of them had a travel history. CONCLUSION: Our analysis suggests an outbreak of clonal dissemination, presumably due to nosocomial transmission. This study represents the first documented outbreak of NDM-5-producing E. coli mediated by IncFII in infants. Close monitoring is urgently needed to prevent and control the spread of this difficult-to-treat superbug.

Pseudospin-induced chirality with staggered optical graphene.

Pseudospin has an important role in understanding many interesting physical phenomena that are associated with two-dimensional materials such as graphene. Pseudospin has been proposed to be directly related to angular momentum, and orbital angular momentum was recently experimentally demonstrated to be an intrinsic property of pseudospin in a photonic honeycomb lattice. However, in photonics, the interaction between spin and pseudospin for light has not been investigated. In this letter, we propose that in an optical analog of staggered graphene (that is, a photonic honeycomb lattice waveguide with in-plane inversion symmetry breaking), the pseudospin mode can strongly couple to the spin of an optical beam that is incident in certain directions. The spin-pseudospin coupling that is caused by the spin-orbit conversion in the scattering process induces a strong optical chiral effect for the transmitted optical beam. Spin-pseudospin coupling of light opens the door to the design of pseudospin-mediated spin or valley-selective photonic devices.