Optimized optical system with a 1.65 m wide-field corrector for the 6.5 m high-performance MUltiplexed Survey Telescope.

The development of modern large-scale spectroscopic survey telescopes responds to the urgent demand for spectral information in astronomical research. Tsinghua University has previously proposed a 6.5 m MUltiplexed Survey Telescope consisting of a Ritchey-Chretien configuration and a 1.8 m multi-element wide-field corrector, achieving excellent performance and world-leading survey efficiency. However, an optimized 1.65 m multi-element corrector with five lenses is proposed to overcome the constraints on glass uniformity and verification in fabrication of the previous corrector design. It maintains outstanding image quality, with the 80% enclosed energy diameter not more than 0.559 arcsec within 3° FoV over up to a 55° zenith angle. The optimized optical system does not revise the working mode of the ADC or the curvature of the primary mirror while ensuring the reasonability and accuracy of manufacturing of large corrector elements. It provides a more feasible reference optical design for the MUltiplexed Survey Telescope in subsequent iterations and communications with manufacturers.

Hybrid ball-hinged secondary mirror assembly for high-precision surface shape maintenance.

As an essential part of optical telescope, the secondary mirror is subject to the influence of ambient temperature, which leads to temperature-induced distortion on the surface shape. A hybrid ball-hinged secondary mirror assembly (HSMA) is proposed to achieve thermal adaptation over a wide range of temperature. Simulation investigation on the temperature-induced surface shape distortion of the HSMA were carried out by using the finite element model. Simulation results show that the change of secondary mirror surface distortions over a wide range of temperature are minimal and negligible. For the wide ambient temperature range from -30°C to 70°C, the PV and RMS values of the maximum residual distortions can reach as small as 16.31 nm and 3.005 nm, respectively. Furthermore, the influence of gravity-induced distortion on the surface shape is also carried out. Both simulation and experiment results show that the HSMA is able to maintain high-precision surface shape of the secondary mirror over a wide range of temperature and at different attitudes from 0 to 90 ∘.

High robustness single-shot wavefront sensing method using a near-field profile image and fully-connected retrieval neural network for a high power laser facility.

This paper proposes a single-shot high robustness wavefront sensing method based on deep-learning for wavefront distortion measurement in high power lasers. This method could achieve fast and robust wavefront retrieval by using a single-shot near-field profile image and trained network. The deep-learning network uses fully-skip cross connections to extract and integrate multi-scale feature maps from various layers and stages, which improves the wavefront retrieval speed and enhances the robustness of the method. The numerical simulation proves that the method could directly predict the wavefront distortion of high power lasers with high accuracy. The experiment demonstrates the residual RMS between the method and a Shack-Hartmann wavefront sensor is less than 0.01 µm. The simulational and experimental results show that the method could accurately predict the incident wavefront distortion in high power lasers, exhibiting high speed and good robustness in wavefront retrieval.

Anatomic versus non-anatomic resection for early-stage intrahepatic cholangiocarcinoma: a propensity score matching and stabilized inverse probability of treatment weighting analysis.

BACKGROUND: Radical resection is still the most cost-effectiveness curative strategy for intrahepatic cholangiocarcinoma (ICC), but it remains controversial on the survival benefit of anatomic resection (AR). In this study, we sought to compare the oncologic outcomes between AR versus non-AR (NAR) as the primary treatment for early-stage ICC patients. METHODS: Data of ICC patients who underwent hepatectomy and staged at AJCC I were retrospectively collected from 12 hepatobiliary centers in China between Dec 2012 and Dec 2015. Propensity score matching (PSM) and stabilized inverse probability of treatment weighting (IPTW) analysis were performed to minimize the effect of potential confounders, and the perioperative and long-term outcomes between AR and NAR groups were compared. RESULTS: Two hundred seventy-eight ICC patients staged at AJCC I were eligible for this study, including 126 patients receiving AR and 152 patients receiving NAR. Compared to the NAR group, the AR group experienced more intraoperative blood loss before and after PSM or stabilized IPTW (all P > 0.05); AR group also experienced more intraoperative transfusion after stabilized IPTW (P > 0.05). In terms of disease-free survival (DFS) and overall survival (OS), no significant differences were observed between the two groups before and after PSM or stabilized IPTW (all P > 0.05). Multivariable Cox regression analyses found that AR was not an independent prognostic factor for either DFS or OS (all P > 0.05). Further analysis also showed that the survival benefit of AR was not found in any subgroup stratified by Child-Pugh grade (A or B), cirrhosis (presence or absence), tumor diameter (≤ 5 cm or > 5 cm) and pathological type (mass-forming or non-mass-forming) with all P > 0.05. CONCLUSION: Surgical approach does not influence the prognosis of patients with stage I primary ICC, and NAR might be acceptable and oncological safety.

Dynamic evaluation of postoperative survival in intrahepatic cholangiocarcinoma patients who did not undergo lymphadenectomy: a multicenter study.

BACKGROUND: The prognosis of Intrahepatic cholangiocarcinoma (ICC) patients who did not undergo lymphadenectomy is difficult to assess. This study aims to have a dynamic evaluation on the postoperative survival of ICC patients by calculating conditional survival. METHODS: Relevant data were from patients treated in 12 large-scale hospitals from December 2011 to December 2017. The influence of relevant clinical baseline data on the prognosis of ICC patients was analyzed by Cox regression. Conditional survival (CS) is a method that may predict the prognostic probability dynamically. For a patient with x years of survival, the 1-year CS (CS1) may be calculated as CS1= OS(x + 1)/OS(x). RESULT: A total of 361 patients who met the criteria were included in the study. Conditional survival (CS) means that the patients' prognosis varies with survival time, meanwhile, relevant factors affecting the prognosis have a time-varying effect. The probability of survival assessed by CS1 increased year by year and the 1,2,3-year survival improved from 68.4% to 87.8%, while the postoperative actuarial OS decreased from 69.4% at 1 years to 36.9% at 3 years. CONCLUSIONS: In terms of CS, the estimated survival for ICC varies with the increase of survival time after excision. Patients who live longer were likely to live longer. At the same time, with the passage of time, the role of the original adverse factors of the tumor would gradually decrease. Conditional survival allows a more accurate assessment of ICC patients who did not undergo lymphadenectomy.

Synthesis of Uranium Single Atom from Radioactive Wastewater for Enhanced Water Dissociation and Hydrogen Evolution.

As a common nuclide in radioactive wastewater, uranium (U) is generally treated by landfill, which induces the massive abandonment of uranium resources. In this work, a pulse voltammetry method for the synthesis of U single atoms on MoS2 (U/MoS2 ) nanosheets from radioactive wastewater for the electrocatalytic alkaline hydrogen evolution reaction (HER) is reported. The mass loading of U single atoms is facilely controlled with high selectivity for coexisting ions in radioactive wastewater. In the electrolyte of 1 m of KOH, U/MoS2 nanosheets with 5.2% of U single atoms exhibit relatively low overpotentials of 72 mV at 10 mA cm-2 . The mechanistic study reveals that the HER on U/MoS2 includes the water dissociation on U single atoms to form OH* and H transfer from OH* to adjacent S-edge atoms. This procedure exhibits decreased activation energy for transition state in water dissociation and optimized Gibbs free energy for H* adsorption.

Generation of a mode-tunable optical vortex based on a mirror curvature dynamically controlled Z-shaped resonant cavity.

We report a novel, to the best of our knowledge, mode-tunable optical vortex generation method based on a mirror curvature dynamically controlled Z-shaped resonant cavity, a mode conversion beamline, and a reference laser beamline. By changing the mirror curvature of an intra-cavity deformable mirror (DM) at a certain pumping voltage and current, various Hermite-Gaussian (HG) mode beams were obtained in the Z-shaped resonant cavity of a laser diode pumped Yb:CALGO laser. The vortex beams were realized finally by using an external cavity astigmatism converter. In the experiment, the dynamic tuning of the 1st to 9th order HG mode beams and Laguerre-Gaussian mode vortex beams carrying different orbital angular momenta, ranging from 1ℏ to 9ℏ were achieved by dynamically adjusting the driving voltage of the DM.

Impact of surgical margin width on long-term outcomes for intrahepatic cholangiocarcinoma: a multicenter study.

BACKGROUND: The objective of this study was to investigate the survival outcomes of surgical margin width in intrahepatic cholangiocarcinoma (ICC). METHODS: Between November 2011 and August 2017, patients who underwent hepatectomy for ICC were collected from 13 major hepatopancreatobiliary centers in China. The survival outcomes for patients who underwent wide margin hepatectomy (WMH) were compared with those who underwent narrow margin hepatectomy (NMH) using the 1:1 propensity score matching (PSM). RESULTS: Among 478 included patients, 195 (40.8%) underwent WMH whereas 283 (59.2%) underwent NMH. PSM yielded 79 matched patients with similar baseline characteristics. Patients underwent WMH had a significant better OS and DFS compared with those underwent NMH (before PSM: median OS 27 vs 17 months, P < 0.05; median DFS 15 vs 8 months, P = 0.001, after PSM: median OS 41 vs 22 months, p < 0.05; median DFS 16 vs 10 months, p < 0.05). However, subgroup analysis based on the AJCC staging system, WMH could only improve the survival outcomes in AJCC I ICC patients (Stage I: OS, DFS, P<0.05). CONCLUSIONS: Surgeons should strive to achieve a wide surgical margin for patients with AJCC I ICC to optimize the long-term outcome.

Prognostic value and predication model of microvascular invasion in patients with intrahepatic cholangiocarcinoma: a multicenter study from China.

BACKGROUND: At present, hepatectomy is still the most common and effective treatment method for intrahepatic cholangiocarcinoma (ICC) patients. However, the postoperative prognosis is poor. Therefore, the prognostic factors for these patients require further exploration. Whether microvascular invasion (MVI) plays a crucial role in the prognosis of ICC patients is still unclear. Moreover, few studies have focused on preoperative predictions of MVI in ICC patients. METHODS: Clinicopathological data of 704 ICC patients after curative resection were retrospectively collected from 13 hospitals. Independent risk factors were identified by the Cox or logistic proportional hazards model. In addition, the survival curves of the MVI-positive and MVI-negative groups before and after matching were analyzed. Subsequently, 341 patients from a single center (Eastern Hepatobiliary Hospital) in the above multicenter retrospective cohort were used to construct a nomogram prediction model. Then, the model was evaluated by the index of concordance (C-Index) and the calibration curve. RESULTS: After propensity score matching (PSM), Child-Pugh grade and MVI were independent risk factors for overall survival (OS) in ICC patients after curative resection. Major hepatectomy and MVI were independent risk factors for recurrence-free survival (RFS). The survival curves of OS and RFS before and after PSM in the MVI-positive groups were significantly different compared with those in the MVI-negative groups. Multivariate logistic regression results demonstrated that age, gamma-glutamyl transpeptidase (GGT), and preoperative image tumor number were independent risk factors for the occurrence of MVI. Furthermore, the prediction model in the form of a nomogram was constructed, which showed good prediction ability for both the training (C-index = 0.7622) and validation (C-index = 0.7591) groups, and the calibration curve showed good consistency with reality. CONCLUSION: MVI is an independent risk factor for the prognosis of ICC patients after curative resection. Age, GGT, and preoperative image tumor number were independent risk factors for the occurrence of MVI in ICC patients. The prediction model constructed further showed good predictive ability in both the training and validation groups with good consistency with reality.

Risk factors for cholesterol polyp formation in the gallbladder are closely related to lipid metabolism.

BACKGROUND: The purpose of this study was to assess the risk factors for cholesterol polyp formation in the gallbladder. METHODS: This was a multicenter retrospective study based on pathology. From January 2016 to December 2019, patients who underwent cholecystectomy and non-polyp participants confirmed by continuous ultrasound follow-ups were reviewed. Patients in the cholesterol polyp group were recruited from three high-volume centers with a diagnosis of pathologically confirmed cholesterol polyps larger than 10 mm. Population characteristics and medical data were collected within 24 h of admission before surgery. The non-polyp group included participants from the hospital physical examination center database. They had at least two ultrasound examinations with an interval longer than 180 days. Data from the final follow-up of the non-polyp group were analyzed. The risk factors for cholesterol polyp formation were analyzed by comparing the two groups. RESULTS: A total of 4714 participants were recruited, including 376 cholesterol polyp patients and 4338 non-polyp participants. In univariate analysis, clinical risk factors for cholesterol polyps were age, male sex, higher body mass index (BMI), higher low-density lipoprotein (LDL), lower high-density lipoprotein (HDL), and higher aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels. In multivariate logistic analysis, independent risk factors were age > 50 years (odds ratio [OR] = 3.02, 95% confidence interval [CI] 2.33-3.91, P < 0.001], LDL > 2.89 mmol/L (OR = 1.38, 95% CI 1.08-1.78, P = 0.011), lower HDL (OR = 1.78 95% CI 1.32-2.44, P < 0.001), AST > 40 IU/L (OR = 3.55, 95% CI 2.07-6.07, P < 0.001), and BMI > 25 kg/m 2 (OR = 1.32, 95% CI 1.01-1.72, P = 0.037). CONCLUSIONS: Age, LDL, HDL, AST, and BMI are strong risk factors for cholesterol polyp formation. Older overweight patients with polyps, accompanied by abnormal lipid levels, are at high risk for cholesterol polyps.

Treatment of Complex Anal Fistula by Video-Assisted Anal Fistula Treatment Combined with Anal Fistula Plug: A Single-Center Study.

Objective. The surgical treatment of complex anal fistulae is very challenging because of the incidence of incontinence after traditional approaches. There are no studies on the role of video-assisted anal fistula treatment (VAAFT) combined with anal fistula plug (AFP) in the complex anal fistulae. The aim of this study was to demonstrate the efficacy of treating complex anal fistulae using VAAFT combined with AFP. Method. This was a retrospective, nonrandomized observational study. 57 consecutive patients with complex anal fistulae who had undergone the VAAFT with AFP in our hospital between April 2016 and December 2019 were included. The primary outcomes were the cure rate, recurrence rate, and Wexner incontinence scores; the secondary outcomes were surgery time, blood loss, wound healing time postoperatively, pain, and patient satisfaction. Results. All 57 patients completed the surgery and follow-up, with an average follow-up time of 28 months; 6 patients suffered with recurrence (recurrence rate: 10.5%). The average surgery time was 57.9 minutes, and the average wound healing time was 46 days. There were no severe postoperative complications, and anal sphincter function was protected in all patients. Conclusions. The treatment of complex anal fistula by VAAFT combined with AFP is safe and effective, has a high healing rate and few postoperative complications, and is a promising surgery that can effectively protect the patient's anal sphincter function.

Using a Cellular System to Directly Assess the Effects of Cosmetic Microemulsion Encapsulated DeoxyArbutin.

DeoxyArbutin (dA) is a tyrosinase inhibitor that has effective skin-lightening activity and has no obvious cytotoxicity toward melanocytes. With the aim of directly evaluating the effects of microemulsions containing dA on cells, we developed oil-in-water (O/W) microemulsions with relatively lower cytotoxicities by using polysorbate-series surfactants. Measurement of the transparent properties and particle size analysis at different storage time periods revealed that the developed microemulsions were stable. Moreover, the developed microemulsions had direct effects on B16-F10 mouse melanoma cells. The anti-melanogenesis activities of dA-containing microemulsions were evidently better than that of the free dA group. The results demonstrated that the developed microemulsion encapsulating dA may allow the use of deoxyArbutin instead of hydroquinone to treat dermal hyperpigmentation disorders in the future.

Simulation and experimental investigation on the temperature-induced distortion characteristics of the hybrid connection structure deformable mirror.

The stacked array piezoelectric deformable mirror (DM) used in adaptive optics (AO) systems usually has actuator-corresponding high-frequency temperature-induced distortion (TID) on its mirror surface when the working temperature is different from the design temperature, which is harmful to beam quality. To effectively eliminate the actuator-corresponding high-frequency TID, we introduce a hybrid connection structure deformable mirror (H-DM), which adopts a magnetic connection structure besides the conventional adhesive connection structure. The TID characteristics of the H-DM are analyzed using the finite element method, and the wavefront compensation capability of the novel H-DM is also investigated in simulation. In the experiment, the initial surface shape and the TID characteristics of a lab-manufactured H-DM are measured. The experimental results show that the H-DM has a good initial surface shape, and no actuator-corresponding high-frequency distortion exists in the surface shape of the H-DM when the environment temperature changes. Thus it can be seen the TID could be well corrected by the H-DM itself, and thereby the environmental adaptability of the DM could be improved substantially.

The critical role of titanium cation in the enhanced performance of P2-Na0.5Ni0.25Mn0.60Ti0.15O2 cathode material for sodium-ion batteries.

Tremendous effort has been devoted to develop durable electrode materials for sodium ion batteries. This work focuses on enhancing the reversibility of a cathode material Na0.5Ni0.25Mn0.75O2 by adopting the titanium cation doping strategy. The obtained P2-Na0.5Ni0.25Mn0.60Ti0.15O2 material shows smooth charge-discharge curves upon suppressing the Na+/vacancy ordering effect via the partial substitution of Mn4+ for Ti4+, and enhanced cycling performance. It exhibits a reversible capacity of 138 mA h g-1 at 0.5C, as well as a high rate capacity of 81 mA h g-1 at 5C between a cut-off voltage of 2 and 4 V, while long-term cycling stability is demonstrated with a capacity retention of 84% over 200 cycles. An enhanced cycling stability is also observed when the voltage is between 2 and 4.2 V. The feasibility of constructing a symmetrical Na-ion full cell with Na0.5Ni0.25Mn0.60Ti0.15O2 as cathode and anode electrodes is also demonstrated. The titanium cation doping results in reduced charge transfer impedance and an enhanced sodium cation diffusion coefficient, thus suggesting an efficient strategy to obtain a durable cathode material for sodium ion batteries.

Simultaneous measurement of displacement, pitch, and yaw angles of a cavity output mirror based on phase measuring deflectometry.

Accurate and high dynamic range measurement of the three attitude variations (i.e., displacement, pitch, yaw angles) has been widely researched based on various approaches to meet different application requirements. However, none of the existing methods can detect these three attitude variations at the same time. This paper proposes a method based on a classical phase measuring deflectometry (PMD) system and a double iteration algorithm to simultaneously measure the three variations of the output mirror in a laser resonator. The relationship between the attitude variations and the lateral displacement parameters (LDP) of the imaged structural fringes is derived in the PMD system. Through the established relationship, the attitude variations could be calculated once the LDP are detected. Furthermore, a two-step measuring scheme combining the four-step shifting phase and the color-coded fringe is proposed to effectively detect the LDP. Finally, an experiment is conducted to verify the feasibility of the proposed method.

Deformable mirror resolution-matching-based two-stage wavefront sensorless adaptive optics method.

In high-power laser facilities, the application of a traditional wavefront control method is limited under the influence of a continuous phase plate (CPP). In order to obtain a satisfactory far-field intensity distribution at the target of the beamline with the CPP, a novel deformable mirror (DM) resolution-matching-based two-stage wavefront sensorless adaptive optics method is proposed and demonstrated. The principles of the DM resolution-matching method and two-stage wavefront sensorless adaptive optics method are introduced, respectively. Based on the numerical model, the matching relationship between the actuator space of the DM and the spatial period of the CPP is investigated. By using the resolution-matched DM, the feasibility of the two-stage wavefront sensorless adaptive optics method is numerically and experimentally verified. Both the numerical and the experimental results show that the presented DM resolution-matching-based two-stage wavefront sensorless adaptive optics method could achieve the target focal spot control under the influence of the CPP, and the profile and the intensity uniformity of the corrected focal spot are optimized close to the designed ideal focal spot.

Simulational and experimental investigation on the print-through high-frequency aberration of the shear-joint NIF deformable mirror.

A shear-joint deformable mirror (DM) is important in the high-power laser systems such as the National Ignition Facility (NIF). In this paper, the print-through high-frequency aberration (PT-HIFA) that arises from adhesive curing and is corresponding to the actuator array is reported to exist in the initial surface shape of a lab-made shear-joint NIF DM. Meanwhile, experimental results show that the PT-HIFA has a great modulation on the laser intensity. This PT-HIFA could not be corrected effectively by the DM and may result in dangerous damage in the high power laser systems. In order to eliminate the PT-HIFA, we investigate the influence of the structural parameters on the PT-HIFA in a shear-joint DM through simulation and experiment. Simulational results show that the structural parameters have different influences on the PT-HIFA. In the experiment, by optimizing the structural parameters, the PT-HIFA could be eliminated in the shear-joint NIF DM and the modulation effect on the laser intensity could be removed. This investigation could help other researchers to determine appropriate structural parameters and to achieve a fine surface shape in their own shear-joint DMs.

Theoretical research on the novel adaptive optics configuration based on the tubular deformable mirror for the aberration correction of the annular laser beam.

The annular laser beam (ALB) has been widely used in many fields for its unique intensity distribution. Especially, in the materials processing, the power and the beam quality of the large-aperture thin-wall ALB are of vital. However, limited by the aperture, the actuators' spacing or the damage threshold, the existing deformable mirrors (DMs) are not suitable for the correction of the ALB. Considering the stretching effect of the oblique incidence, in this paper, by using the tubular DM (TDM), a novel adaptive optics (AO) configuration is promoted to increase the number of the effective actuators covered by the input ALB. The coordinate transformation equations and correction principle of the novel AO configuration are derived based on the ray tracing. A typical TDM prototype is designed based on the coordinate transformation equations. The influence function characteristics of the TDM is analyzed using the finite element method, and the correction ability of the novel AO configuration based on the TDM is verified. Simulation results show that the TDM could perfectly compensate the wavefront distortions described by the 2th to 15th order Zernike annular aberrations.

High precision wavefront correction using an influence function optimization method based on a hybrid adaptive optics system.

A hybrid adaptive optics (AO) system with an influence function (IF) optimization method is presented for high precision wavefront correction of a traditional Shack-Hartmann AO system. The hybrid AO system consists of a Shack-Hartmann wavefront sensor (SHWFS) and a deflectometry system (DS) to measure the wavefront of the laser beam and the IF of the deformable mirror, respectively. An IF optimization method is used to generate a hybrid IF (H-IF) through a position-calibration algorithm and a resolution-conversion algorithm by use of the original IFs measured by the SHWFS (S-IF) and the DS (D-IF). Configuration of the hybrid AO system is introduced. Principles and calculation results of the IF optimization method are presented. Comparison of the wavefront correction ability between the H-IF and the original IF is carried out in simulation. Closed-loop performance of the hybrid AO system using the H-IF is investigated in experiment. Simulation and experiment results show that for a traditional Shack-Hartmann AO system, the H-IF has better correction ability than the original S-IF and the IF optimization method could help improve closed-loop performance without sacrificing the simplicity of the system structure and the rapidity of the closed-loop correction.

Numerical analysis of a novel two-stage enlargement and adaptive correction approach for the annular aberration compensation.

The annular laser beam (ALB) is widely used in many fields, which could be affected by laser power and beam quality. To effectively and flexibly improve the beam quality of high-power large-aperture thin-wall ALB, a two-stage enlargement and adaptive correction configuration (TEACC) consisting of a novel outer-surface tubular deformable mirror (OTDM) and two extra prism groups (EPGs) is proposed in this paper. The correction principle and design principle of the TEACC are derived and analyzed. Based on the principle, a typical OTDM prototype and EPG structure are designed. Annular aberrations are compensated by applying the OTDM's influence functions and the least-square algorithm in simulation. The results show that the TEACC could perfectly compensate the wavefront distortions described by the 2nd to 36th order Zernike annular aberrations.