Optomechanical Microwave-to-Optical Photon Transducer Chips: Empowering the Quantum Internet Revolution

The first quantum revolution has brought us the classical Internet and information technology. Today, as technology advances rapidly, the second quantum revolution quietly arrives, with a crucial moment for quantum technology to establish large-scale quantum networks. However, solid-state quantum bits (such as superconducting and semiconductor qubits) typically operate in the microwave frequency range, making it challenging to transmit signals over long distances. Therefore, there is an urgent need to develop quantum transducer chips capable of converting microwaves into optical photons in the communication band, since the thermal noise of optical photons at room temperature is negligible, rendering them an ideal information carrier for large-scale spatial communication. Such devices are important for connecting different physical platforms and efficiently transmitting quantum information. This paper focuses on the fast-developing field of optomechanical quantum transducers, which has flourished over the past decade, yielding numerous advanced achievements. We categorize transducers based on various mechanical resonators and discuss their principles of operation and their achievements. Based on existing research on optomechanical transducers, we compare the parameters of several mechanical resonators and analyze their advantages and limitations, as well as provide prospects for the future development of quantum transducers.

Body mass index, weight change, and cancer prognosis: a meta-analysis and systematic review of 73 cohort studies

BACKGROUND

Identifying the association between body mass index (BMI) or weight change and cancer prognosis is essential for the development of effective cancer treatments. We aimed to assess the strength and validity of the evidence of the association between BMI or weight change and cancer prognosis by a systematic evaluation and meta-analysis of relevant cohort studies.

METHODS

We systematically searched the PubMed, Web of Science, EconLit, Embase, Food Sciences and Technology Abstracts, PsycINFO, and Cochrane databases for literature published up to July 2023. Inclusion criteria were cohort studies with BMI or weight change as an exposure factor, cancer as a diagnostic outcome, and data type as an unadjusted hazard ratio (HR) or headcount ratio. Random- or fixed-effects models were used to calculate the pooled HR along with the 95% confidence interval (CI).

RESULTS

Seventy-three cohort studies were included in the meta-analysis. Compared with normal weight, overweight or obesity was a risk factor for overall survival (OS) in patients with breast cancer (HR 1.37, 95% CI 1.22-1.53; P < 0.0001), while obesity was a protective factor for OS in patients with gastrointestinal tumors (HR 0.67, 95% CI 0.56-0.80; P < 0.0001) and lung cancer (HR 0.67, 95% CI 0.48-0.92; P = 0.01) compared with patients without obesity. Compared with normal weight, underweight was a risk factor for OS in patients with breast cancer (HR 1.15, 95% CI 0.98-1.35; P = 0.08), gastrointestinal tumors (HR 1.54, 95% CI 1.32-1.80; P < 0.0001), and lung cancer (HR 1.28, 95% CI 1.22-1.35; P < 0.0001). Compared with nonweight change, weight loss was a risk factor for OS in patients with gastrointestinal cancer.

CONCLUSIONS

Based on the results of the meta-analysis, we concluded that BMI, weight change, and tumor prognosis were significantly correlated. These findings may provide a more reliable argument for the development of more effective oncology treatment protocols.

Towards a photonic integrated all-optical phase regenerator

All-optical phase regeneration aims at restoring the phase information of coherently encoded data signals directly in the optical domain so as to compensate for phase distortions caused by transceiver imperfections and nonlinear impairments along the transmission link. Although it was proposed two decades ago, all-optical phase regeneration has not been seen in realistic networks to date, mainly because this technique entails complex bulk modules and relies on high-precision phase sensitive nonlinear dynamics, both of which are adverse to field deployment. Here, we demonstrate a new, to the best of our knowledge, architecture to implement all-optical phase regeneration using integrated photonic devices. In particular, we realize quadrature phase quantization by exploring the phase-sensitive parametric wave mixing within on-chip silicon waveguides, while multiple coherent pump laser tones are provided by a chip-scale micro-cavity Kerr frequency comb. Multi-channel all-optical phase regeneration is experimentally demonstrated for 40 Gbps QPSK data, achieving the best SNR improvement of more than 6 dB. Our study showcases a promising avenue to enable the practical implementation of all-optical phase regeneration in realistic long-distance fiber transmission networks.

Telecom-band-integrated multimode photonic quantum memory

Telecom-band-integrated quantum memory is an elementary building block for developing quantum networks compatible with fiber communication infrastructures. Toward such a network with large capacity, an integrated multimode photonic quantum memory at telecom band has yet been demonstrated. Here, we report a fiber-integrated multimode quantum storage of single photon at telecom band on a laser-written chip. The storage device is a fiber-pigtailed Er³⁺:LiNbO₃ waveguide and allows a storage of up to 330 temporal modes of heralded single photon with 4-GHz-wide bandwidth at 1532 nm and a 167-fold increasing of coincidence detection rate with respect to single mode. Our memory system with all-fiber addressing is performed using telecom-band fiber-integrated and on-chip components. The results represent an important step for the future quantum networks using integrated photonics devices.

Discrete frequency-bin entanglement generation via cascaded second-order nonlinear processes in Sagnac interferometer

Discrete frequency-bin entanglement is an essential resource for applications in quantum information processing. In this Letter, we propose and demonstrate a scheme to generate discrete frequency-bin entanglement with a single piece of periodically poled lithium niobate waveguide in a modified Sagnac interferometer. Correlated two-photon states in both directions of the Sagnac interferometer are generated through cascaded second-order optical nonlinear processes. A relative phase difference between the two states is introduced by changing the polarization state of pump light, thus manipulating the two-photon state at the output of the Sagnac interferometer. The generated two-photon state is sent into a fiber polarization splitter, and then a pure discrete frequency-bin entangled two-photon state is obtained by setting the pump light. The frequency entanglement property is measured by a spatial quantum beating with a visibility of 96.0±6.1%. The density matrix is further obtained with a fidelity of 98.0±3.0% to the ideal state. Our demonstration provides a promising method for the generation of pure discrete frequency-bin entanglement at the telecom band, which is desired in quantum photonics.

Hertz-rate metropolitan quantum teleportation

Quantum teleportation can transfer an unknown quantum state between distant quantum nodes, which holds great promise in enabling large-scale quantum networks. To advance the full potential of quantum teleportation, quantum states must be faithfully transferred at a high rate over long distance. Despite recent impressive advances, a high-rate quantum teleportation system across metropolitan fiber networks is extremely desired. Here, we demonstrate a quantum teleportation system which transfers quantum states carried by independent photons at a rate of 7.1 ± 0.4 Hz over 64-km-long fiber channel. An average single-photon fidelity of ≥90.6 ± 2.6% is achieved, which exceeds the maximum fidelity of 2/3 in classical regime. Our result marks an important milestone towards quantum networks and opens the door to exploring quantum entanglement based informatic applications for the future quantum internet.

High-precision angular rate detection based on an optomechanical micro hemispherical shell resonator gyroscope

Cavity optomechanics with picometer displacement measurement resolution has shown vital applications in high-precision sensing areas. In this paper, an optomechanical micro hemispherical shell resonator gyroscope (MHSRG) is proposed, for the first time. The MHSRG is driven by the strong opto-mechanical coupling effect based on the established whispering gallery mode (WGM). And the angular rate is characterized by measuring the transmission amplitude changing of laser coupled in and out from the optomechanical MHSRG based on the dispersive resonance wavelength shift and/or dissipative losses varying. The detailed operating principle of high-precision angular rate detection is theoretically explored and the fully characteristic parameters are numerically investigated. Simulation results show that the optomechanical MHSRG can achieve scale factor of 414.8 mV/ (°/ s) and angular random walk of 0.0555 °/ h^1/2 when the input laser power is 3 mW and resonator mass is just 98 ng. Such proposed optomechanical MHSRG can be widely used for chip-scale inertial navigation, attitude measurement, and stabilization.

Wavelength-division multiplexing communications using integrated soliton microcomb laser source

In this Letter, we report an investigation of the feasibility and performance of wavelength-division multiplexed (WDM) optical communications using an integrated perfect soliton crystal as the multi-channel laser source. First, we confirm that perfect soliton crystals pumped directly by a distributed-feedback (DFB) laser self-injection locked to the host microcavity has sufficiently low frequency and amplitude noise to encode advanced data formats. Second, perfect soliton crystals are exploited to boost the power level of each microcomb line, so that it can be directly used for data modulation, excluding preamplification. Third, in a proof-of-concept experiment, we demonstrate seven-channel 16-quadrature amplitude modulation (16-QAM) and 4-level pulse amplitude modulation (PAM4) data transmissions using an integrated perfect soliton crystal as the laser carrier; excellent data receiving performance is obtained for various fiber link distances and amplifier configurations. Our study reveals that fully integrated Kerr soliton microcombs are viable and advantageous for optical data communications.

Phase noise of Kerr soliton dual microcombs

Dissipative Kerr soliton microcombs are believed to be a promising technique to build a dual-comb source for applications including precision laser metrology, fast laser spectroscopy, and high-speed optical signal processing. In this Letter, we conduct a detailed experimental investigation on the phase coherence between two on-chip Kerr soliton microcombs, where the underlying physical and technical origins that lead to the mutual phase noise between microcombs are analyzed. Moreover, the techniques of 2-point locking and optical frequency division are explored to enhance the dual-microcomb phase coherence, and we demonstrate the best phase noise down to -50 dBc/Hz at 1-Hz offset, -90 dBc/Hz at 1-kHz offset, and -120 dBc/Hz at 1-MHz offset. Our study provides a basic reference for both fundamental studies and practical applications of Kerr soliton dual microcombs that entail high mutual phase coherence.

[Talin1 is highly expressed in the fallopian tube and chorionic villi to promote trophoblast invasion in tubal pregnancy]

OBJECTIVE

To investigate the expression of Talin1 in the fallopian tube and chorionic villi in patients with tubal pregnancy and its role in regulating invasion and migration of trophoblasts.

METHODS

Immunohistochemistry and Western blotting were used to detect the localization and expression level of Talin1 in the fallopian tube and chorionic villi in patients with tubal pregnancy and in women with normal pregnancy. In the cell experiment, HTR-8/SVneo cells was transfected with Talin1 siRNA and the changes in cell invasion and migration were assessed using scratch assay and Transwell assay. The expressions of MMP-2, MMP-9, N-cadherin and Snail in the transfected cells were detected by qRT-PCR and Western blotting.

RESULTS

Positive expression of Talin1 was detected in both normal fallopian tube tissues and tissues from women tubal pregnancy, and its expression was localized mainly in the cytoplasm of cilia cells. The expression level of Talin1 was significantly higher in both the fallopian tube and chorionic villi in women with tubal pregnancy than in normal fallopian tube and chorionic villi samples (P < 0.01). In HTR-8/SVneo cells, transfection with Talin1 siRNA significantly inhibited cell invasion (P < 0.01) and migration (P < 0.05), down-regulated the expression of N-cadherin, MMP-2 and Snail (P < 0.05), and up-regulated the expression of MMP-9 in the cells (P < 0.05).

CONCLUSION

The expression of Talin1 in the fallopian tube and chorionic villi is significantly increased in women with tubal pregnancy, suggesting the association of Talin1-regulated trophoblast cell invasion with the occurrence of tubal pregnancy.

How Are Consumers Affected by Taste and Hygiene Ratings When Ordering Food Online? A Behavioral and Event-Related Potential Study

With the rapid development of the take-out industry, taste and hygiene ratings as social-based information have been frequently used by online food-ordering platforms to facilitate consumer purchases. The present study aims to uncover the effects of taste and hygiene ratings on online food-ordering decision by incorporating behavioral and neural approaches. The behavioral results showed that a high taste rating induced a higher ordering intention than a low taste rating, and that a high hygiene rating induced a higher ordering intention than a low hygiene rating. The effect of hygiene rating on ordering intention was moderated by taste rating. Hygiene rating had a greater impact on ordering intention when the taste rating was high (vs. low). In addition, inconsistency between taste and hygiene ratings increased the cognitive load and took more time for decision-making. The event-related potential (ERP) data revealed that consumers paid more attention to a high (vs. low) taste rating in the early cognitive process, which was reflected by a larger P2. Subsequently, a more negative N2 was elicited by conflicting ratings than consistent ratings when the taste rating was low. In the relatively late decision-making process, a larger P3 was evoked by consistent than conflicting ratings, suggesting that consumers had more confidence in their decisions for consistent ratings. These findings could help restaurants understand the roles of taste and hygiene rating cues in affecting consumer behavior and prompt those restaurants to adopt effective measures to increase online sales.

The combination of sucrose dilaurate and sucrose laurate suppresses HMGB1: an enhancer of melanocyte dendricity and melanosome transfer to keratinocytes

BACKGROUND

Hyperpigmented spots are common issues in all ethnicities, involving multiple intrinsic and extrinsic factors such as UVB exposure, hormone balance, inflammatory status and ageing.

OBJECTIVES

To determine (i) melanocyte dendricity in multiple facial spot types, (ii) impact of High Mobility Group Box 1 (HMGB1), and the combination of sucrose dilaurate and sucrose laurate (SDL) on melanogenesis and melanocyte dendricity, and (iii) SDL effect on facial spots in a human use test.

METHODS

Facial spot and adjacent non-spot skin biopsies were collected from Chinese women (age 20-70). Histological assessment of melanocyte dendricity was performed for 3 spot types (solar lentigo, melasma and postinflammatory hyperpigmentation) by immunofluorescent staining for c-kit/MITF. Keratinocyte, melanocyte and melanocyte-keratinocyte co-culture models were used to assess HMGB1 release by UVB radiation, the effects of HMGB1 and SDL on melanin production, melanocyte dendricity and melanosome transfer. The effect of an SDL-containing moisturizer on appearance of facial hyperpigmented spots was assessed against a vehicle control in an 8-week human use test.

RESULTS

Melanocytes in spot areas are more dendritic than melanocytes in adjacent non-spot skin across three investigated spot types. In cell culture models, a moderate UVB-radiation exposure caused release of HMGB1 from keratinocytes. HMGB1 did not alter melanin production in melanocytes, but enhanced melanocyte dendricity and melanosome transfer. SDL reduced HMGB1 release from keratinocytes, inhibited melanin production, reversibly suppressed melanocyte dendricity and reduced melanosome transfer. In the human use test, SDL-containing moisturizer reduced appearance of spots versus vehicle.

CONCLUSION

Increased melanocyte dendricity was observed in multiple types of facial spots. Addition of HMGB1 protein increased melanocyte dendricity and melanosome transfer in cell cultures, implicating potential involvement in spot formation. SDL suppressed melanin production, melanocyte dendricity and melanosome transfer in vitro and reduced appearance of spots in the use test, suggesting SDL is an effective solution to address hyperpigmented spot concerns.

Comprehensive insights into the occurrence, source, distribution and risk assessment of polycyclic aromatic hydrocarbons in a large drinking reservoir system

The resource, environment, and ecological value of drinking reservoirs have received widespread concerns due to the pollution of persistent organic pollutants such as polycyclic aromatic hydrocarbons (PAHs). Therefore, we comprehensively studied the occurrence, source, distribution, and risk assessment of representative PAHs in Fengshuba Reservoir (FSBR) (large drinking reservoir, China). The total concentrations of 16 USEPA PAHs in the water phase, porewater phase, sediment phase, and soil phase were in ranges of 109.72-393.19 ng/L, 5.75-35.15 μg/L, 364.4-743.71 μg/kg, and 367.81-639.89 μg/kg, respectively. The naphthalene (Nap) was the dominant PAHs in the water phase, while it was Nap and phenanthrene (Phe) in porewater, sediment, and soil phase. The main sources of PAHs in FSBR were biomass combustion. Redundancy analysis indicated that the NTU, NO₂^-, NH₄⁺, Chl-α, and IC were the dominant factors influencing the PAH distribution in water phase, and the PAHs in sediment phase was affected by T and NO₃^-. Pseudo-partitioning coefficients indicated that the PAHs in the porewater phase were more likely to migrate to the sediment phase. Risk assessment indicated that the PAHs both in the water and sediment phases were generally in a low-risk state, while the PAHs in the soil phase were in a moderate-risk state, and the Nap was in a high-risk state, and exposure to the PAHs in FSBR through drinking and skin exposure had little impact on consumers' health. In summary, Nap could be used as a key indicator to evaluate the existence and potential risk of PAHs in FSBR.

Automating inventorying of blood stations: A system based on ultrahigh-frequency radio-frequency identification (UHF RFID) technology

Inventorying blood products is an essential process in blood station management. Traditional methods need to integrate barcodes with refrigerators, which suffer from low time efficiency, high error rate and high labour cost. Several methods have been proposed to automate this process in blood stations. However, none of them is ideal enough. In this paper, we analyse the difficulties of automation in blood inventory, and propose an automated blood inventory system based on UHF RFID technology. Comparisons over our method with manual inventory and handheld RFID inventory are conducted. The result shows that our method is nearly 10 times higher than manual inventory in time efficiency while increases the accuracy to 100%.

Linking doctor-patient relationship to medical residents' work engagement: The influences of role overload and conflict avoidance

Background

Chinese residents’ practical work experiences are different from those described in Western studies. To explore potential mechanisms underlying the effects of doctor-patient relationships on medical residents’ work engagement, verifying a posited mediating effect of role overload, and moderating effect of conflict avoidance, in the Chinese context.

Methods

Based on the conservation of resources theory, a composite model was constructed. This study’s data were collected from four different Chinese tertiary hospitals; 195 residents undergoing regularization training took this survey. Hierarchical moderated and mediated regression analyses were utilized.

Results

Doctor-patient relationship were found to be positively related to residents’ work engagement (β=0.31, p≤0.001). Role overload partially mediated the effect of these relationships on work engagement, and the moderating role of conflict avoidance in the relationship between doctor-patient relationship and conflict avoidance was negative.

Conclusion

Maintaining good doctor-patient relationship can prompt residents to increase their engagement in work in order to meet their patients’ needs. Furthermore, role overload has a particular influence in early career stages. Not only is it necessary for residents to gain a sense of recognition and support while they carry out their job responsibilities, especially while dealing with complex doctor-patient relationship, but it is also important to create work environments that can help residents shape their professional competency.

Autophagy activators stimulate the removal of advanced glycation end products in human keratinocytes

BACKGROUND

The accumulation of advanced glycation end products (AGEs) can impact cellular homoeostasis and protein structure, thus is implicated in numerous skin conditions including yellow, dull appearance. AGE formation is irreversible; thus, understanding of the recycling process of AGEs in the skin is critical for addressing skin appearance conditions.

OBJECTIVE

To determine whether (i) accumulation of AGEs occurs in dull appearance group among young population (age 20-29) (ii) in vitro autophagy stimulation results in reduction of AGEs in keratinocytes.

METHODS

Facial cheek biopsies were collected from Chinese women (age 20-50) exhibiting either dull or non-dull appearing skin. Histological assessment of glycation was performed for representative subjects among the 20-29 years sub-group by immunofluorescence staining of AGEs. LC-MS methods and keratinocyte cell culture were used to assess impact of autophagy modulators and skin care materials on carboxymethyl lysine (CML) amount, a representative AGE.

RESULTS

Notable amounts of AGEs were observed in the epidermal samples among young females. Interestingly, the amount of AGEs was significantly higher among the dull skin appearance group. Treatment of keratinocytes with glyceraldehyde (GLA) enhanced CML in the cells, and postglycation treatment with autophagy activators reduced CML. Two skin care materials, Nymphaea alba flower extract (a.k.a. white water lily extract) and sucrose dilaurate, were identified based from in vitro autophagy activation and found to reduce CML in keratinocytes.

CONCLUSION

We found AGEs accumulate in the facial epidermis even among young people, correlating to a yellow and dull appearance. We also demonstrated in vitro activation of autophagy can reduce AGEs in keratinocytes, and autophagy activating skin care materials, N. alba flower extract and sucrose dilaurate, also reduce AGEs in the keratinocyte in vitro model. These data suggest epidermal AGEs contribute to the dull skin appearance, and autophagy activators may provide an effective solution to improve dull appearance by removing and recycling the accumulated glycation in the skin.

[Analysis of the effect of percutaneous vertebroplasty combined with (125)I seed implantation in the treatment of spinal metastatic epidural spinal cord compression]

Objective: To investigate the clinical efficacy of percutaneous vertebroplasty (PVP) combined with iodine-125 ((125)I) seed brachytherapy in the treatment of spinal metastatic epidural spinal cord compression (MESCC) and toassess the changes inthe grade of epidural spinal cord compression (ESCC) by magnetic resonance imaging (MRI). Methods: A total of 37 MESCC patients treated with PVP combined with (125)I seed brachytherapy in the interventional and vascular surgery department of Zhongda Hospital affiliated to Southeast University from January 2014 to June 2019 were retrospectively analyzed, including 23 cases of bilateral lower limbs paralysis. Total diseased vertebrae are 39 segments. Visual analogue scale (VAS) and paralysis of lower extremities were evaluated regularly before and after treatment, and VAS values at different follow-up time points were compared. At the same time, MRI was used to evaluate the changes of ESCC grade in the spinal canal and calculate the local lesion efficiency after operation. The postoperative local lesion efficiency at different follow-up times was compared. Results: PVP combined with (125)I seed implantation in all diseased vertebral bodies was successful. The average injection volume of polymethylmethacrylate (PMMA) was (3.2±1.3) ml/segment, the average number of (125)I seed implanted was (25.0±8.6) seeds/segment and the average radiation dose was (15.0±5.1) mCi/segment. The VAS before operation was 8.5, and postoperative VAS were respectively 3.6±1.3, 3.8±1.5, 3.4±1.4, 5.5±1.0, 5.9±1.4 at 5 days, 1 month, 3 months, 6 months, and 1 year after operation. The differences between all follow-up time points and preoperative VAS values were statistically significant (all P<0.001). Compared with 5 days, 1 month and 3 months after operation, VAS increased significantly at 6 months and 1 year after operation, and the difference was statistically significant (all P<0.001); there was no significant difference between the VAS value at 6 months after operation and 1 year after operation (P=0.405). At a follow-up of 3 months, 22 of 23 patients with paralysis of bilateral lower limbs regained the functions of autonomous walking and voiding; the effective rates of MESCC local lesions evaluated by MRI at 1 month, 3 months, 6 months, and>1 year were 89.7%, 91.9%, 90.6%, and 94.7%, respectively, and there was no statistically significant differences among those follow-up time points (all P>0.05). Conclusions: PVP combined with (125)I seed brachytherapy in the treatment of MESCC has significant improvement in immediate pain relief and spinal cord function. After combined treatment, MRI showed that the tumors around the spinal cord regressed dramatically, which could considerably reduce the MESCC grade and remain stable for a long time.

Enhancing the long-term stability of dissipative Kerr soliton microcomb

A temporal dissipative Kerr soliton (DKS) frequency comb can be generated in an optical micro-cavity relying on the rigid balance between cavity decay (dispersion) and parametric gain (nonlinear phase modulation) induced by an intense pump laser. In practice, to maintain such delicate double balances experienced by the intracavity soliton pulses, it requires precise control of the pump laser frequency and power, as well as the micro-cavity parameters. However, to date there still lacks experimental demonstration that simultaneously stabilizes all these key parameters to enhance the long-term DKS stability. Here, we demonstrate continuous working of a on-chip DKS microcomb for a record-breaking 14 days without showing any sign of breakdown. Such improved microcomb stability is enabled mainly by robust pump power coupling to the micro-cavity utilizing packaged planar-lightwave-circuit mode converters, and faithful locking of the pump frequency detuning via an auxiliary laser heating method. In addition to superior stability, the demonstrated DKS microcomb system also achieves favorable compactness, with all the accessory modules being assembled into a standard 4U case. We hope that our demonstration could prompt the practical utilization of Kerr microcombs in real-world applications.

Quantum random number generator based on single-photon emitter in gallium nitride

We experimentally demonstrate a real-time quantum random number generator by using a room-temperature single-photon emitter from the defect in a commercial gallium nitride wafer. Due to the brightness of our single-photon emitter, the raw bit generation rate is about 1.8 MHz, and the unbiased bit generation rate is about 420 kHz after the von Neumann's randomness extraction procedure. Our results show that the commercial gallium nitride wafer has great potential for the development of integrated high-speed quantum random number generator devices.

Stimulated Brillouin laser-based carrier recovery in a high-Q microcavity for coherent detection

We demonstrate all-optical carrier recovery exploring a stimulated Brillouin laser (SBL) in a high-Q whispering-gallery-mode microcavity, to achieve coherent data detection without requiring an independent local oscillator laser. An ultra-high optical signal-to-noise ratio better than 70 dB is achieved for the recovered carrier, thanks to the fact that the generated SBL counter-propagates with the incoming data signal and experiences high SBS efficiency. High-frequency stability is obtained between the recovered carrier tone and the original data signal, enabling high-performance coherent detection without the need of electrical frequency drift compensation. This Letter offers a low complexity, high energy efficiency, and high robust carrier recovery solution.

Dispersion independent long-haul photon-counting optical time-domain reflectometry

Photon-counting optical time-domain reflectometry (PC-OTDR) based on single photon detection is an effective scheme to attain the high spatial resolution for optical fiber fault monitoring. Currently, due to the spatial resolution of PC-OTDR being proportional to the pulse width of a laser beam, short laser pulses are essential for a high spatial resolution. However, short laser pulses have a large bandwidth, which would be widened by the dispersion of fiber, causing inevitable deterioration in the spatial resolution, especially for long-haul fiber links. In this Letter, we propose a scheme of dispersion independent PC-OTDR based on an infinite backscatter technique. Our experimental results-with more than 45 km long fiber-show that the spatial resolution of the PC-OTDR system is independent with the total dispersion of the fiber under test. Our method provides an avenue for developing long-haul PC-OTDR with high performance.

Infrared attenuated total reflection spectroscopic analysis and quantitative detection of forage spectral features in ruminant systems

This study aimed to (1) access protein molecular structure profile and metabolic characteristics of model forages [Foreign sourced-origin (coded as: "FSO", n = 7 vs. Chinese sourced-origin alfalfa hay "CSO", n = 5] in ruminant systems; (2) Quantify the relationship between forage protein molecular structures and protein utilization and availability. Advanced non-invasive vibrational molecular spectroscopic technique (ATR-FTIR: Attenuated Total Reflection Fourier Transform Infrared spectroscopy) with chemometrics was applied to reveal forage protein molecular structure. Both univariate and multivariate molecular spectral analyses were applied to study molecular structure features in model forages. The molecular structure study provided the detailed protein structure profiles of Amide I and Amide II areas and height, total Amide I and II area ratios, Amide I to II height ratio as well as Amide I to II area ratio using ATR-FTIR spectroscopy. The results showed FSO and CSO had similar (P > 0.05) protein rumen degradation kinetics. However, FSO had superior quality than CSO in intestinal (IDP) and total digestible protein (TDP) and truly absorbed nutrient supply (P < 0.05). As intestinal digestion of protein, FSO was higher (P < 0.05) in protein digestion in terms of: intestinal digestibility of rumen undegraded protein (dIDP: 47.5 vs. 38.3 %RUP); Intestinal digestible protein (IDP: 17.6 vs. 13.7 %CP). As truly absorbed nutrient supply, FSO contained higher (P < 0.05) truly absorbed rumen synthesized microbial protein, absorbable rumen undegradable feed protein in the small intestine, total truly digested protein in the small intestine, metabolizable protein and Feed Milk Value (FMV^DVE: 1.2 vs. 1.1 g/kg DM). The molecular structure-nutrition interactive relationship study showed that protein molecular structure profiles were highly associated to protein rumen degradation kinetics, significantly correlated to protein subfractions, protein intestinal digestion, and truly absorbed nutrient supply in ruminant systems.

Linking hospital culture to the training performance of residents: The roles of leader-member exchange and transactional leadership style

BACKGROUND

Hospital culture is a crucial aspect of residents' training. However, the mechanisms related to stakeholder culture (SC) and teacher-resident interaction remain unclear. The study investigated the relationship between hospital culture and training performance of residents. Also, it explored the mediating effect of teacher-resident exchange and the moderating effect of the teacher's transactional leadership style within a Chinese context.

METHODS

Based on stakeholder and leadership member exchange theories, we constructed a composite model. Data were collected from 296 residents from five tertiary hospitals in China. Hierarchical moderated regression analyses were used to test the hypotheses.

RESULTS

(a) Both the employee-orientation culture (EOC) (β = .14, P ≤ .05) and patient-orientation culture (POC) (β = .47, P ≤ .001) in the hospital were significantly related to residents' training performance. (b) Teacher-resident exchange fully mediated the relationship between EOC and training performance and partially mediated the relationship between POC and training performance. (c) The moderating role of transactional leadership style (TLS) in the relationship between EOC and leader-member exchange (LMX) (β = -.17, P ≤ .05) was negative; it was not significant in the interaction between POC and TLS (β = .06, P > .1).

CONCLUSION

The results suggest that trainers should consider the value of multiple cultures and ensure balance among stakeholders rather than focusing on a single one. Furthermore, a positive interaction improves teacher-student relationship and training performance. Most importantly, educational departments should pay attention to establishing assessment tools, using rewards and incentives in residents' training.

Strategic elements of residency training in China: transactional leadership, self-efficacy, and employee-orientation culture

BACKGROUND

The standardized training of resident physicians in China is significant and robust. During the training, clinical teachers act as leaders. The training taking place in public hospitals requires a transactional leadership style (TLS), but existing research studies seldom analyze how to promote residents' performance from this perspective.

METHODS

Two hundred and ninety six new residents undertaking standardized training were recruited from five tertiary hospitals in two provinces of China. Hierarchical moderated and mediated regression analyses were used to test the hypotheses. The hypotheses include that TLS is positively related to the training performance; mediating effect of self-efficacy and moderating effect of employee-orientation organizational culture (EOC) are significant.

RESULTS

(1) Two kinds of teachers' TLS, punishment and reward, have significant positive influence on residents' performance. (2) Self-efficacy of residents partly mediates the positive relationship. (3) EOC moderates the relationship between the punitive behavior of clinical teachers with TLS and the self-efficacy of the residents.

CONCLUSIONS

Empirical evidence has shown the positive relationship between teachers' TLS and residents' performance outcomes in China. Teachers can enhance training performance by promoting self-efficacy of residents. This study also advances our understanding of EOC by examining the demonstrated moderating effects of cultural background in the relationship between teachers' TLS and the self-efficacy of residents.

Improvement of the taper degree of laser-drilled holes via a double-pulse train

Laser drilling has been widely used in various application fields because of advantages such as environmental friendliness, scalability, non-contact, etc. Nevertheless, it still has some drawbacks. One of the most concerning is the taper degree caused by the ablation process resulting from a laser Gaussian beam. In this study, we utilize a nanosecond double-pulse laser (at 532 nm) to experimentally acquire a series of holes on stainless thin plates. With the double-pulse train, the taper degree of a drilled hole becomes half of that drilled by using a single-pulse train. Different combinations of the power component of the two pulses for the double-pulse laser have been investigated to earn the optimum power ratio of the two pulses. For instance, by using a double-pulse laser train with a repetition rate of 5 kHz and a total power of 8 W, we observe that the optimized combination of the two pulses is 2 W and 6 W. Furthermore, we theoretically analyze the variations of the density, temperature, and pressure around the processing area during both the double-pulse and single-pulse laser processing based on a constrained interpolation profile procedure. The theoretical results show that drilled holes with smaller taper degree can be realized by using the double-pulse approach. Our results have great potential in laser drilling and precision laser machining.

FoxP3 in Treg cell biology: a molecular and structural perspective

Regulatory T cells (T_regs) are specialized in immune suppression and play a dominant role in peripheral immune tolerance. T_reg cell lineage development and function maintenance is determined by the forkhead box protein 3 (FoxP3) transcriptional factor, whose activity is fine‐tuned by its post‐translational modifications (PTMs) and interaction partners. In this review, we summarize current studies in the crystal structures, the PTMs and interaction partners of FoxP3 protein, and discuss how these insights may provide a roadmap for new approaches to modulate T_reg suppression, and new therapies to enhance immune tolerance in autoimmune diseases.

Wavelength-tunable passively mode-locked all-fiber laser at 1.5 μm

We have experimentally demonstrated a wavelength-tunable passively mode-locked all-fiber laser at 1.5 μm wavelength by using an erbium-doped fiber amplifier, a fiber-pigtailed semiconductor saturable absorber mirror, and a tunable birefringence Sagnac filter. In our work, by properly setting the polarization state of the propagating light in the birefringence Sagnac filter, the mode-locked lasing wavelength can be continuously tuned from 1544.1 to 1560.8 nm, corresponding to a tuning range of 16.7 nm. At a central wavelength of 1548.5 nm, the fiber laser delivers pulses as short as 713.2 fs with a repetition rate of 4.65 MHz, a 3 dB bandwidth of 5.7 nm, and an average output power of 4.86 mW. Our results show that such a mode-locked all-fiber laser has great potential in applications in nonlinear optics at the 1.5 μm band.

Recent Advances in 2D Lateral Heterostructures

Recent developments in synthesis and nanofabrication technologies offer the tantalizing prospect of realizing various applications from two-dimensional (2D) materials. A revolutionary development is to flexibly construct many different kinds of heterostructures with a diversity of 2D materials. These 2D heterostructures play an important role in semiconductor and condensed matter physics studies and are promising candidates for new device designs in the fields of integrated circuits and quantum sciences. Theoretical and experimental studies have focused on both vertical and lateral 2D heterostructures; the lateral heterostructures are considered to be easier for planner integration and exhibit unique electronic and photoelectronic properties. In this review, we give a summary of the properties of lateral heterostructures with homogeneous junction and heterogeneous junction, where the homogeneous junctions have the same host materials and the heterogeneous junctions are combined with different materials. Afterward, we discuss the applications and experimental synthesis of lateral 2D heterostructures. Moreover, a perspective on lateral 2D heterostructures is given at the end.

Single dose of 17β-estradiol provides transient neuroprotection in female juvenile mice after cardiac-arrest and cardiopulmonary resuscitation

Each year there are approximately 7000 out of hospital cardiac arrests in the pediatric population, with 30% resuscitation rate and a 6-10% rate of survival to hospital discharge. Survivors of cardiac arrest exhibit learning and memory deficits that are devastating during the school years. Delayed neuronal cell death occurs in the hippocampus following cardiac arrest and likely contributes to memory impairments. Circulating endogenous estrogen in young adult females has been shown to provide protection against ischemic cell death, as does chronic exogenous administration of 17β-estradiol (E2). Chronic estrogen benefit can have undesirable feminizing effects, particularly in pre-adolescents. Here, we tested if a single-dose of E2 is neuroprotective in our pediatric cardiac arrest mouse model performed in juvenile mice. We subjected P21P25 C57Blk6 male and female mice to 8 min of cardiac arrest followed by cardiopulmonary resuscitation (CA/CPR). This developmental stage preceded the hormonal onset and serum estradiol and testosterone levels were not different in males and females. A single dose of E2 (100μg/kg) or vehicle was administered 30 min after resuscitation. Neuronal cell death measured 3 days after CA/CPR showed reduced hippocampal cell death in E2-treated females, but not males. Benefit of E2 in females was blocked by the P38 MAPK inhibitor, SB203580. Hippocampal-dependent memory function was equally impaired in E2-and vehicle-treated females measured in the contextual fear conditioning task at 7 days. Our findings demonstrate female-specific transient neuroprotection with E2 that does not provide sustained functional benefit.

Cost-effective high-spatial-resolution photon-counting optical time-domain reflectometry at 850 nm

Optical time-domain reflectometry (OTDR) is a widely employed instrument for monitoring the property of fiber links. Traditional OTDR always suffers from the trade-off between its spatial resolution and the sensitivity of light detection. Therefore, it cannot be applied in critical applications, such as in aviation, where OTDR with a high spatial resolution of several centimeters is required. In this paper, we develop a cost-effective photon-counting OTDR based on our homemade gain-switching pulsed laser at 850 nm. Thanks to the short pulse width of the laser and the relatively small time jitter of the photon detector, our photon-counting OTDR achieves a spatial resolution of less than 9 cm and satisfies the requirements for monitoring short fiber links in various types of airplanes. Finally, we realize a fully running system for monitoring an optical cable with 32 fiber channels on a plane.

[Cement augmentation for vertebral osteolytic metastatic lesions: an evaluation on postoperative CT]

Objective: To evaluate the effectiveness of cement augmentation on the osteolytic lesion in patients with vertebral metastasis. Methods: A total of consecutive 132 patients with 268 vertebral metastatic lesions treated with PVP from January 2008 to December 2016 in Zhongda Hospital were enrolled in this study. Retrospective analysis of preoperative, postoperative 3 days, 3 months, 6 months, 12 months and ≥ 18 months imaging data on CT, the local control and progression of the tumor were evaluated by MDA response criteria. The local control rates were compared between the groups with the different rate of cement filling by Chi²-test. Results: Vertebroplasty procedures were performed successfully in all 268 vertebrae under DSA guidance, and the mean volume of PMMA injected in each vertebra was 0.7-8.5(3.9±1.5)ml.The rate of local control at 3 months, 6 months, 12 months and ≥18 months after PVP was respectively 98.9%, 95.1%, 91.8%, and 85.2%, the difference was statistically significant(all P<0.05). The local control rate showed a statistically significant relationship to the groups with the rate of cement filling at 6 months, 12 months and ≥18 months after PVP, but there was no statistical difference at postoperative 3 months. The rate of local control was higher in 68 patients with lung or gastrointestinal cancer than in 17 patients with liver or kidney cancer at 3 months, 6 months and 12 months, the difference was statistically significant (P<0.05). Conclusion: Cement augmentation has a local anti-tumor effect on vertebral osteolytic metastatic lesion, and the anti-tumor effect will decrease as the follow-up time extended.

Exosomes promote cetuximab resistance via the PTEN/Akt pathway in colon cancer cells

Cetuximab is widely used in patients with metastatic colon cancer expressing wildtype KRAS. However, acquired drug resistance limits its clinical efficacy. Exosomes are nanosized vesicles secreted by various cell types. Tumor cell-derived exosomes participate in many biological processes, including tumor invasion, metastasis, and drug resistance. In this study, exosomes derived from cetuximab-resistant RKO colon cancer cells induced cetuximab resistance in cetuximab-sensitive Caco-2 cells. Meanwhile, exosomes from RKO and Caco-2 cells showed different levels of phosphatase and tensin homolog (PTEN) and phosphor-Akt. Furthermore, reduced PTEN and increased phosphorylated Akt levels were found in Caco-2 cells after exposure to RKO cell-derived exosomes. Moreover, an Akt inhibitor prevented RKO cell-derived exosome-induced drug resistance in Caco-2 cells. These findings provide novel evidence that exosomes derived from cetuximab-resistant cells could induce cetuximab resistance in cetuximab-sensitive cells, by downregulating PTEN and increasing phosphorylated Akt levels.

Concurrent chemoradiotherapy with weekly nedaplatin versus radiotherapy alone in elderly patients with non-small-cell lung cancer

PURPOSE

We conduct this study to compare the efficacy and toxicity of intensity-modulated radiotherapy (IMRT) concurrent weekly nedaplatin (NDP) versus IMRT alone in the stage III/IV non-surgical elderly patients with non-small-cell lung cancer (NSCLC).

METHODS

117 patients were enrolled into our study. The patients were assigned into two different groups: radiotherapy (RT) group and chemoradiotherapy (CRT) group. Patients in RT group were treated with IMRT at a single daily dose of 2 Gy for 5 days per week, totally 52-66 Gy. The CRT group, IMRT concurrent weekly NDP at a dose of 25 mg/m².

RESULTS

In CRT group, the median survival was 11.0 months (95% confidence interval [CI], 8.894-13.106 months) and in RT group, it was 7.0 months (95% CI 5.771-8.229 months). The 1-year, 2-year, 3-year, survival rates in the combined treatment arm were higher than the radiation therapy arm (46.8 vs 25.9%, 25.1 vs 11.8%, 14.7 vs 8.0%; p < 0.001). The Cox's multiple regression analysis showed that CRT had significantly better overall survival than RT (HR 0.523; 95.0% CI 0.338-0.807; p = 0.003). The objective response rate provided that 73.3% treated with CRT compared with 51.1% (p = 0.018) received RT alone. Of the hematologic toxicities, leukocytes (35.0 vs 0%; p < 0.001), neutrophils (33.3 vs 0%; p < 0.001) were significantly more common in the CRT group than the RT group.

CONCLUSIONS

We first discovered that NDP concurrent IMRT for treating stage III/IV non-surgical elderly patients with NSCLC was good curative effect of better objective response rate and well-tolerated. However, within the low number of patients, only stage IV gained a survival benefit.

Sofosbuvir Monotherapy for Asymptomatic and Noncirrhotic Hepatitis C Infection in a Renal Retransplantation Recipient: A Case Report

Renal transplant recipients infected with hepatitis C virus (HCV) have a high risk of progressing to cirrhosis, end-stage liver diseases, and hepatocellular carcinoma. It is also considered as an independent risk for graft loss and is correlated with proteinuria, transplant glomerulopathy, HCV-associated glomerulonephritis, and chronic rejection. Previous therapy involving interferon alfa and ribavirin led to treatment complications, including toxicity, anemia, sepsis, and drug-drug interactions with calcineurin inhibitors, as well as reduced tolerability and efficacy. New direct-acting antiviral drugs simplify and shorten the treatment along with increasing tolerability and efficacy. Nevertheless, limited data and no specific regimen with direct-acting antiviral drugs have been described in the literature for renal transplant recipients with chronic HCV. We describe here the case of a 52-year-old Chinese man who diagnosed with chronic renal failure in 1997 and underwent renal transplantation the same year. In 2012, he was diagnosed with renal graft failure and again underwent hemodialysis. The patient then underwent his second renal transplantation and was administered an immunosuppressive cyclosporine-based regimen in 2015. During hemodialysis, he acquired asymptomatic genotype 1b HCV infection. Serologic test results reflecting liver cirrhosis were all negative, and ultrasound showed no abnormalities in the liver. The patient later required oral sofosbuvir monotherapy for 12 weeks after the second kidney transplantation. Curing HCV in renal transplant recipients is necessary. Although our treatment did not successfully result in a sustained virologic response, it suggests that genotype 1b HCV may have a poor response to a sofosbuvir monotherapy regimen. Specific and effective regimens for renal transplant recipients with HCV infection need to be confirmed in the future.

MicroRNA-383 located in frequently deleted chromosomal locus 8p22 regulates CD44 in prostate cancer

A major genomic alteration in prostate cancer (PCa) is frequent loss of chromosome (chr) 8p with a common region of loss of heterozygosity (LOH) at chr8p22 locus. Genomic studies implicate this locus in the initiation of clinically significant PCa and with progression to metastatic disease. However, the genes within this region have not been fully characterized to date. Here we demonstrate for the first time that a microRNA component of this region –miR-383- is frequently downregulated in prostate cancer, plays a critical role in determining tumor initiating potential and is involved in prostate cancer metastasis via direct regulation of CD44, a ubiquitous marker of PCa tumor initiating cells (TICs)/ stem cells. Expression analyses of miR-383 in PCa clinical tissues established that low miR-383 expression is associated with poor prognosis. Functional data suggests that miR-383 regulates PCa tumor initiating/ stem-like cells via CD44 regulation. Ectopic expression of miR-383 inhibited tumor initiating capacity of CD44+ PCa cells. Also, ‘anti-metastatic’ effects of ectopic miR-383 expression were observed in a PCa experimental metastasis model. In view of our results, we propose that frequent loss of miR-383 at chr8p22 region leads to tumor initiation and prostate cancer metastasis. Thus, we have identified a novel finding that associates a long observed genomic alteration to PCa stemness and metastasis. Our data suggests that restoration of miR-383 expression may be an effective therapeutic modality against PCa. Importantly, we identified miR-383 as a novel PCa tissue diagnostic biomarker with a potential that outperforms that of serum PSA.

Experimental Observation and Theoretical Description of Multisoliton Fission in Shallow Water

We observe the dispersive breaking of cosine-type long waves [Phys. Rev. Lett. 15, 240 (1965)] in shallow water, characterizing the highly nonlinear "multisoliton" fission over variable conditions. We provide new insight into the interpretation of the results by analyzing the data in terms of the periodic inverse scattering transform for the Korteweg-de Vries equation. In a wide range of dispersion and nonlinearity, the data compare favorably with our analytical estimate, based on a rigorous WKB approach, of the number of emerging solitons. We are also able to observe experimentally the universal Fermi-Pasta-Ulam recurrence in the regime of moderately weak dispersion.

Therapeutic hypothermia protects against ischemia-induced impairment of synaptic plasticity following juvenile cardiac arrest in sex-dependent manner

Pediatric cardiac arrest (CA) often leads to poor neurologic outcomes, including deficits in learning and memory. The only approved treatment for CA is therapeutic hypothermia, although its utility in the pediatric population remains unclear. This study analyzed the effect of mild therapeutic hypothermia after CA in juvenile mice on hippocampal neuronal injury and the cellular model of learning and memory, termed long-term potentiation (LTP). Juvenile mice were subjected to cardiac arrest and cardiopulmonary resuscitation (CA/CPR) followed by normothermia (37°C) and hypothermia (30°C, 32°C). Histological injury of hippocampal CA1 neurons was performed 3days after resuscitation using hematoxylin and eosin (H&E) staining. Field excitatory post-synaptic potentials (fEPSPs) were recorded from acute hippocampal slices 7days after CA/CPR to determine LTP. Synaptic function was impaired 7days after CA/CPR. Mice exposed to hypothermia showed equivalent neuroprotection, but exhibited sexually dimorphic protection against ischemia-induced impairment of LTP. Hypothermia (32°C) protects synaptic plasticity more effectively in females, with males requiring a deeper level of hypothermia (30°C) for equivalent protection. In conclusion, male and female juvenile mice exhibit equivalent neuronal injury following CA/CPR and hypothermia protects both males and females. We made the surprising finding that juvenile mice have a sexually dimorphic response to mild therapeutic hypothermia protection of synaptic function, where males may need a deeper level of hypothermia for equivalent synaptic protection.

Increasing small conductance Ca2+-activated potassium channel activity reverses ischemia-induced impairment of long-term potentiation

Global cerebral ischemia following cardiac arrest and cardiopulmonary resuscitation (CA/CPR) causes injury to hippocampal CA1 pyramidal neurons and impairs cognition. Small conductance Ca(2+)-activated potassium channels type 2 (SK2), expressed in CA1 pyramidal neurons, have been implicated as potential protective targets. Here we showed that, in mice, hippocampal long-term potentiation (LTP) was impaired as early as 3 h after recovery from CA/CPR and LTP remained impaired for at least 30 days. Treatment with the SK2 channel agonist 1-Ethyl-2-benzimidazolinone (1-EBIO) at 30 min after CA provided sustained protection from plasticity deficits, with LTP being maintained at control levels at 30 days after recovery from CA/CPR. Minimal changes in glutamate release probability were observed at delayed times after CA/CPR, implicating post-synaptic mechanisms. Real-time quantitative reverse transcriptase-polymerase chain reaction indicated that CA/CPR did not cause a loss of N-methyl-D-aspartate (NMDA) receptor mRNA at 7 or 30 days after CA/CPR. Similarly, no change in synaptic NMDA receptor protein levels was observed at 7 or 30 days after CA/CPR. Further, patch-clamp experiments demonstrated no change in functional synaptic NMDA receptors at 7 or 30 days after CA/CPR. Electrophysiology recordings showed that synaptic SK channel activity was reduced for the duration of experiments performed (up to 30 days) and that, surprisingly, treatment with 1-EBIO did not prevent the CA/CPR-induced loss of synaptic SK channel function. We concluded that CA/CPR caused alterations in post-synaptic signaling that were prevented by treatment with the SK2 agonist 1-EBIO, indicating that activators of SK2 channels may be useful therapeutic agents to prevent ischemic injury and cognitive impairments.