Stable high-peak-power fiber supercontinuum generation for adaptive femtosecond biophotonics

Broad and safe access to ultrafast laser technology has been hindered by the absence of optical fiber-delivered pulses with tunable central wavelength,pulse repetition rate,and pulse width in the picosecond–femtosecond regime.To address this long-standing obstacle,we developed a reliable accessory for femtosecond ytterbium fiber chirped pulse amplifiers,termed a fiber-optic nonlinear wavelength converter(FNWC),as an adaptive optical source for the emergent field of femtosecond biophotonics.This accessory empowers the fixed-wavelength laser to produce fiber-delivered∼20 nJ pulses with central wavelength across 950 to 1150 nm,repetition rate across 1 to 10 MHz,and pulse width across 40 to 400 fs,with a long-term stability of>2000 h.As a prototypical label-free application in biology and medicine,we demonstrate the utility of FNWC in real-time intravital imaging synergistically integrated with modern machine learning and largescale fluorescence lifetime imaging microscopy.

Electrostatic-lenses position-sensitive TOF MCP detector for beam diagnostics and new scheme for mass measurements at HIAF

A foil–microchannel plate(MCP)detector,which uses electrostatic lenses and possesses both good position and timing resolutions,has been designed and simulated for beam diagnostics and mass measurements at the next-generation heavy-ion-beam facility HIAF in China.Characterized by low energy loss and good performances of timing and position measurements,it would be located at focal planes in fragment separator HFRS for position monitoring,beam turning,Bq measurement,and trajectory reconstruction.Moreover,it will benefit the building-up of a magnetic-rigidity–energy-loss–time-offlight(BqDETOF)method at HFRS for high-precision in-flight particle identification of radioactive isotope beams on an event-by-event basis.Most importantly,the detector can be utilized for in-ring TOF and position measurements,beam-line TOF measurements at two achromatic foci,and position measurements at a dispersive focus of HFRS,thus making it possible to use two complementary mass measurement methods[isochronous mass spectrometry at the storage ring SRing and magnetic-rigidity–time-of-flight(BqTOF)at the beam-line HFRS]in one single experimental run.

Comparison of OA-2000 and IOL Master 500 using in cataract patients with high myopia

This study was designed to compare optical biometry measurements and predicted refraction in cataract patients with high myopia [axial length(AL) ≥26 mm] using OA-2000 and IOL Master 500. Ocular biometry measurements were performed using both biometers before surgery. Uneventful cataract surgery was performed in all patients. Postoperative manifest refraction was obtained 3 wk after surgery or later. A total of 67 eyes were examined. The AL, keratometry(K), and anterior chamber depth(ACD) of the two biometers showed excellent agreement. Predicted errors were similar and a strong positive correlation was observed(r=0.909). Out of 21 eyes(31.34%) with unsuccessful AL readings using the IOL Master 500, 20 eyes of them could be measured using OA-2000. Therefore, the biometric parameters measured by the two biometers showed good agreement. However, OA-2000 had a lower AL measurement failure rate.

Modeling and Tracking Control for Piezoelectric Actuator Based on a New Asymmetric Hysteresis Model

This paper presents a new asymmetric hysteresis model and its application in the tracking control of piezoelectric actuators. The proposed model is based on a coupled-play operator which can avoid the conventional Prandtl-Ishlinskii(CPI)model's defects, i.e., the symmetric property. The high accuracy for modeling asymmetric hysteresis is validated by comparing simulation results with experimental measurements. In order to further evaluate the performance of the proposed model in closed-loop tracking application, two different hybrid control methods which experimentally demonstrate their performance under the same operating conditions, are compared to validate that the hybrid control strategy with proposed hysteresis model can mitigate the hysteresis more effectively and achieve better tracking precision. The experimental results demonstrate that the proposed modeling and tracking control strategy can realize efficient control of piezoelectric actuator.

Numerical simulation of flow focusing pattern and morphological changes in two-phase flow inside nozzle

The flow focusing nozzle is a new type of nozzle that performs effective atomization of the discrete phase by means of high-speed motion of the continuous phase.The flow pattern and its morphological changes have a significant effect on the atomization, but the influence of different parameters on the morphological change of the flow pattern remains unclear.The flow focusing pattern and morphological changes in the two-phase flow inside the nozzle were simulated numerically, based on the volume of fluid method.The results demonstrate that the ratio of the nozzle-to-capillary distance and capillary diameter, the gas–liquid velocity ratio, and capillary diameter have significant effects on the flow pattern.When the ratio of the nozzle-to-capillary distance H and capillary diameter D increases, or the capillary diameter D increases, the flow pattern tends to transform into a laminar form; however, when the gas–liquid velocity ratio V increases, the flow pattern tends to transform into a turbulence form.Furthermore, we define the cone-shaped expansion rate, cone-shaped focusing rate,and cone angle in order to study the morphological changes in the cone shape inside the nozzle.The results indicate that the morphological change of the cone shape and flow pattern transformation is interrelated.When the cone shape tends to be unstable, the flow pattern changes towards flow blurring, whereas, a stable cone indicates that the flow tends to exhibit a droplet pattern.

Primary adenosquamous carcinoma of the esophagus

AIM:To investigate the clinical characteristics,diagnosis,treatment,and prognosis of primary adenosquamous carcinoma(ASC)of the esophagus.METHODS:A total of 4015 patients with esophageal carcinoma underwent surgical resection between January 1995 and June 2012 at the Cancer Hospital of Shantou University Medical College.In 37 cases,the histological diagnosis was primary ASC.Clinical data were retrospectively analyzed from these 37 patients,who underwent transthoracic esophagectomy with lymphadenectomy.Theχ2or Fisher’s exact test was used to compare the clinicopathological features between patients with ASC and those with squamous cell carcinoma(SCC).The Kaplan-Meier and Log-Rank methods were used to estimate and compare survival rates.A Cox proportional hazard regression model was used to identify independent prognostic factors.RESULTS:Primary esophageal ASC accounted for0.92%of all primary esophageal carcinoma cases(37/4015).The clinical manifestations were identical to those of other types of esophageal cancer.All of the 24patients who underwent preoperative endoscopic biopsy were misdiagnosed with SCC.The median survival time(MST)was 21.0 mo(95%CI:12.6-29.4),and the1-,3-,and 5-year overall survival rates were 67.5%,29.4%,and 22.9%,respectively.In multivariate analysis,only adjuvant radiotherapy(HR=0.317,95%CI:0.114-0.885,P=0.028)was found to be an independent prognostic factor.The MST for ASC patients was significantly lower than that for SCC patients[21.0 mo(95%CI:12.6-29.4)vs 46.0 mo(95%CI:40.8-51.2),P=0.001].In subgroup analyses,the MST for ASC patients was similar to that for poorly differentiated SCC patients.CONCLUSION:Primary esophageal ASC is a rare disease that is prone to be misdiagnosed by endoscopic biopsy.The prognosis is poorer than esophageal SCC but similar to that for poorly differentiated SCC patients.

Turbulence in the near-Venusian space: Venus Express observations

With Venus Express magnetic field measurements at 32 Hz from 2006 to 2012, we investigate statistically the magnetic fluctuations in the near-Venusian space. The global spatial distribution of their spectral scaling features is presented in MHD and kinetic regimes. It can be observed that turbulence is a common phenomenon in the solar wind in both regimes. The solar wind MHD turbulence is modified at the Venusian bow shock;MHD turbulence is absent in the Venusian magnetosheath but present at the magnetosheath boundary layer. Pre-existing kinetic turbulence from the far upstream solar wind is modified in the near solar wind region, while kinetic turbulence can be extensively observed throughout the Venusian magnetosheath and in some regions of the induced magnetosphere. Our results reveal that, in the near-Venusian space, energy cascade can be developed at the boundary between magnetosheath and wake, and the turbulence-related dissipation of magnetic energy occurs extensively in the magnetosheath and the induced magnetosphere.

Lymph node ratio-based staging system for esophageal squamous cell carcinoma

AIM: To analyze a modified staging system utilizing lymph node ratio(LNR) in patients with esophageal squamous cell carcinoma(ESCC).METHODS: Clinical data of 2011 patients with ESCC who underwent surgical resection alone between January 1995 and June 2010 at the Cancer Hospital of Shantou University Medical College were reviewed. The LNR, or node ratio(Nr) was defined as the ratio of metastatic LNs ompared to the total number of resected LNs. Overall survival between groups was compared with the log-rank test. The cutoff point of LNR was established by grouping patients with 10% increment in Nr, and then combining the neighborhood survival curves using the log-rank test. A new TNr M staging system, was constructed by replacing the American Joint Committee on Cancer(AJCC) N categories with the Nr categories in the new TNM staging system. The time-dependent receiver operating characteristic curves were used to evaluate the predictive performance of the seventh edition AJCC staging system and the TNr M staging system.RESULTS: The median number of resected LNs was 12(range: 4-44), and 25% and 75% interquartilerangeswere8 and 16. Patients were classified into four Nr categories with distinctive survival differences(Nr0: LNR = 0; Nr1: 0% < LNR ≤ 10%; Nr2: 10% < LNR ≤ 20%; and Nr3: LNR > 20%). From N categories to Nr categories, 557 patients changed their LN stage. The median survival time(MST) for the four Nr categories(Nr0-Nr3) was 155.0 mo, 39.0 mo, 28.0 mo, and 19.0 mo, respectively, and the 5-year overall survival was 61.1%, 41.1%, 33.0%, and 22.9%, respectively(P < 0.001). Overall survival was significantly different for the AJCC N categories when patients were subgrouped into 15 or more vs fewer than 15 examined nodes, except for the N3 category(P = 0.292). However, overall survival was similar when the patients in all four Nr categories were subgrouped into 15 or more vs fewer than 15 nodes. Using the time-dependent receiver operating characteristic, we found that the Nr category and TNr M stage had higher accuracy in predicting survival than the AJCC N category and TNM stage. CONCLUSION: A staging system based on LNR may have better prognostic stratification of patients with ESCC than the current TNM system, especially for those undergoing limited lymphadenectomy.

Dynamic simulation of tropical coral reef ecosystem being disturbed by multiple situations

In consideration of the rapid degradation of coral reef ecosystems, the establishment of models is helpful to comprehend the degradation mechanism of coral reef ecosystems and predict the development process of coral reef communities. According to the characteristics of complex ecosystem of tropical coral reefs in China, the coral reef functional group is the core level variable;combined with the multiple feedback effects of coral reef functional groups and environmental changes, the study presents a coral reef ecosystem dynamics model with hermatypic corals as the core. Based on the simulation of the assumed initial value and the internal feedback of the system, the results show that in the basic simulation(relative health conditions), the coverage area of live corals and coral reefs generally decreased first and then increased, and increased by 4.67% and 6.38% between2010 and 2050, respectively. Based on the calibration model and the current situation of the studied area, the multi-factor disturbance effects of coral reef communities were simulated and explored by setting up three scenarios involving fishing policy, terrestrial deposition, and inorganic nitrogen emissions. Among them, in the single factor disturbance, the fishing policy exerts the most direct impact on the community decline;and the succession phenomenon is obvious;the terrestrial sedimentation has a faster and more integrated effect on the community decline;the effect of inorganic nitrogen emission on the community decline is relatively slow. In the double/multi-factor disturbance, the superimposed disturbance will aggravate the multi-source feedback effect of the coral reef communities development, accelerate the community decay rate, and make its development trajectory more complicated and diverse. This method provides a scientific and feasible method for simulating the damage of long-term coral reef community and exploring the development law and adaptive management of coral reef ecosystems. In the future, it can be further studied in the ecological restoration process and decisionmaking direction of coral reefs.

Endovascular stent-graft for type B aortic dissection in elderly patients

Objective To report the clinical outcome and complications ofendovascular stent-graft treatment for type B aortic dissection in elderly patients, as compared with younger patients in a single medical center. Methods From May 2002 to July 2008, endovascular stent-graft implantation was performed in 124 patients with type B aortic dissection at the Department of Cardiology, Shenyang Northern Hospital. Among them, 39 patients were 60 yrs or older （ranging ~om 68 to 81 years） while 85 patients were younger than 60 years old （ranging from 31 to 58 years）. Patients were followed up for a mean period of 26 months （ranging from 1 to 78 months）. Clinical data were analyzed between the two groups. Results Comparing with the younger group, the elderly group had higher prevalence of coronary artery disease （59.0% vs 24.7%, P=0.001）. There was no significant difference of complication rates between the 2 groups （38.5% vs 31.8%, P=0.54）. Kaplan-Meier analysis showed a similar 5-year survival rate（80.2% vs 89.6%; Log Rank, P=0.31） between the 2 groups. Conclusions Endovascular stent-graft implantation is safe and effective in the treatment of type B aortic dissection for both elderly and younger patients. The procedure-related complication rate seems independent of age .

基于MSRCR算法的夜间道路图像增强算法

文章提出了一种自适应伽马校正融合MSRCR算法的低照度图像增强算法,旨在解决现有MSRCR算法在处理低照度图像时存在的边缘信息模糊和白化现象等问题。该算法首先根据Retinex模型分别得到V通道图像中的反射图像和光照图像。在光照图像中,对小、中、大尺度图像分别采用MSRCR算法进行增强,然后根据像素的概率分布函数调节伽马校正的伽马值,以自适应校正图像亮度。在反射图像中,采用加权引导滤波进行去噪,有效保留了图像的细节信息和边缘信息。最后,反射图像和光照图像融合形成增强后的V通道图像,HSV色彩空间图融合形成增强后的低照度图像,并通过MSRCR算法的色彩恢复因子恢复丢失的色彩信息。实验结果表明,所提算法具有明显的优越性,相较于其他对比算法能更好地提高低照度图像的质量和视觉效果。

Iterative and accurate determination of small angle X-ray scattering background

X-ray scattering is widely used in material structural characterizations.The weak scattering nature,however,makes it susceptible to background noise and can consequently render the final results unreliable.In this paper,we report an iterative method to determine X-ray scattering background and demonstrate its feasibility by small angle X-ray scattering on gold nanoparticles.This method solely relies on the correct structural modeling of the sample to separate scattering signal from background in data fitting processes,which allows them to be immune from experimental uncertainties.The importance of accurate determination of the scaling factor for background subtraction is also illustrated.

Comparison and interchangeability of macular thickness measured with Cirrus OCT and Stratus OCT in myopic eyes

AIMTo investigate the difference of macular thickness measurements between stratus optical coherence tomography (OCT) and Cirrus OCT (Carl Zeiss Meditec, Dublin, CA, USA) in the same myopic patient and to develop a conversion equation to interchange macular thickness obtained with these two OCT devices.METHODSEighty-nine healthy Chinese adults with spherical equivalent (SE) ranging from -1.13 D to -9.63 D were recruited. The macular thickness was measured by Cirrus OCT and Stratus OCT. The correlation between macular thickness and axial length and the agreement between two OCT measurements were evaluated. A formula was generated to interchange macular thickness obtained with two OCT devices.RESULTSAverage macular thickness measured with Stratus OCT (r=-0.280, P=0.008) and Cirrus OCT (r=-0.224, P=0.034) were found to be negatively correlated with axial length. No statistically significant correlation was found between axial length and central subfield macular thickness (CMT) measured with Stratus OCT (r=0.191, P=0.073) and Cirrus OCT (r=0.169, P=0.113). The mean CMT measured with Cirrus OCT was 53.63±7.94 µm thicker than with Stratus OCT. The formula CMTCirrus OCT=78.328+0.874×CMTStratus OCT was generated to interchange macular thickness obtained with two OCT devices.CONCLUSIONMacular thickness measured with Cirrus OCT were thicker than with Stratus OCT in myopic eyes. A formula can be used to interchange macular thickness measured with two OCT devices in myopic eyes. Studies with different OCT devices and larger samples are warranted to enable the comparison of macular values measured with different OCT devices.

Corrigendum to “Peptide backbone-copper ring structure: A molecular insight into copper-induced amyloid toxicity”

The author list originally given in Wang et al. Chin. Phys. B 31 108702 (2022) has been amended to remove four authors, Hua Li, Bin Wu, Jun Guo and Chenqi Xu, who believe their contributions are more suitable to be credited in the acknowledgments.

Peptide backbone-copper ring structure:A molecular insight into copper-induced amyloid toxicity

Copper ions can promote amyloid diseases that are associated with amyloid peptides, such as type 2 diabetes(T2D),Alzheimer's disease(AD), Parkinson's disease(PD), and amyotrophic lateral sclerosis(ALS). However, the underlying molecular mechanism remains obscure. Here we present that Cu^(2+)is able to specifically bind to the backbone of T2D related human islet amyloid polypeptide(hIAPP) by forming a ring structure, which causes the reduction of Cu^(2+)to Cu^(+) to produce reactive oxygen species(ROS) and the modulation of hIAPP aggregation. Nuclear magnetic resonance spectroscopy showed that Cu^(2+)bound to the backbone of a turn region, His18-Ser21, which is critical for hIAPP aggregation.Ab initio calculations and x-ray absorption fine structure analyses revealed that Cu^(2+)simultaneously bound with both the amide nitrogen and carbonyl oxygen on the peptide backbone, resulting in a ring structure, and causing the reduction of Cu^(2+)to Cu^(+) to form a hIAPP-Cu^(+) complex. 2′,7′-dichlorodihydrofluorescin diacetate fluorescence measurements further indicated that this complex led to enhanced ROS levels in rat insulinoma cells. Additionally, thioflavin T fluorescence and atomic force microscopy measurements denoted that the backbone-Cu ring structure largely modulated hIAPP aggregation,including the inhibition of hIAPP fibrillation and the promotion of peptide oligomerization. These findings shed new light on the molecular mechanism of Cu^(2+)-induced amyloid toxicity involving both the enhancement of ROS and the modulation of hIAPP aggregation.

Percutaneous coronary intervention following repair of type B aortic dissection:a report of 8 cases

Objective Patients with aortic dissection have a significant incidence of coronary artery disease.The purpose of this study is to evaluate the safety and feasibility of percutaneous coronary stent in patients who have undergone endovascular stent,and to assess the effect of anti-coagulant and anti-platelet treatment on patients'thrombosis process.Methods From January 2005 to July 2007,8 patients who had undergone endovascular stent-graft during the past 1 to 7 months for type B aortic dissection repair,underwent percutaneous coronary intervention(PCI)because of coexisting coronary artery disease.Anti-coagulant and anti-platelet treatments were administrated after PCI according to the standard protocol.Patients were followed up for a mean period of 23 months.Clinical and false lumen status data were collected during the follow-up.Results PCI were technically successful in all 8 patients and no severe complications such as death,paraplegia,renal failure occurred during hospitalization.Complete false lumen thrombosis was observed in 5 patients and incomplete false lumen thrombosis in the remained 3 patients at the end of follow up.There were no major complications such as death,dissection rupture or aneurysm development occurred during the follow-up period.Conclusion Our data implied that PCI can be safely performed in patients with type B aortic dissection who have undergone endovascular stent-graft,without interrupt-ing the thrombosis process.

Feasibility study of emergency intervention for vascular injury outside the hospital

Background: Minimally invasive surgery in the field of traumatic vascular injury diagnosis and treatment has achieved good results. This study was designed to determine whether pre-hospital emergency intervention is feasible for vascular injury in a field intervention cabin under the condition of war or a disaster site.Methods: Different types of animal experiments of vascular injury intervention were performed in a field intervention cabin. Treatment capacity was evaluated by data collection, including duration of surgery, clinical evaluation, image clarity, and equipment handling. Environmental adaptability and mobility were evaluated by maneuverability and long-distance mobility.Results: A total of 56 surgeries(7 types) were performed in the field intervention cabin. Digital subtraction angiography(DSA) had good imaging performance. A total of 4800 km of long-distance mobility was performed, and all the equipment operated normally without any equipment failure. We participated in the medical service maneuver twice. The cabin unfolded and worked properly. There was no equipment damage during the medical service maneuver.Conclusion: Use of a field intervention cabin under the conditions of war or disaster is feasible for pre-hospital emergency intervention of vascular injury.

Implementation factors of tuberculosis control program in primary healthcare settings in China: a mixed-methods using the Consolidated Framework for Implementation Research framework

Background Tuberculosis(TB)is a major cause of death worldwide,and Chinese TB burden ranked the second globally.Chinese primary healthcare(PHC)sectors implement the TB Control Program(TCP)to improve active case finding,referral,treatment adherence,and health education.This study aimed to identify barriers and enablers of TCP implementation in high TB burden regions of West China.Methods We conducted a representative study using mixed-methods in 28 counties or districts in Chongqing Municipality and Guizhou Province of West China from October 2021 to May 2022.Questionnaire surveys and semi-structured in-depth interviews were conducted with 2720 TB healthcare workers(HCWs)and 20 interviewees in PHC sectors.Descriptive statistical analysis was used to investigate TB HCWs'characteristics,and path analysis model was utilized to analyze the impact of associated factors on TCP implementation.Thematic framework analysis was developed with the guide of the adapted Consolidated Framework for Implementation Research(CFiR)on factors ofTCPimplementation.Results This study found that 84.6%and 94.1%of community and village HCWs had low professional titles.Based on the results of multiple regression analysis and correlation analysis,lower TB core knowledge scores(-0.09)were identifed as barriers for TCP implementation in community PHC sectors,and low working satisfaction(-0.17)and low working willingness(-0.10)are barriers for TPC implementation in village PHC sectors.The results of in-depth inter-views reported barriers in all domains and enablers in four domains of CFIR.There were identified 19 CFIR constructs associated with TCP implementation,including 22 barriers such as HCWs'heavy workload,and 12 enablers such as HCWs'passion towards TCP planning.Conclusions With the guide of the CFIR framework,complex factors(barriers and enablers)of TCP implementation in PHC sectors of West China were explored,which provided important evidences to promote TB program in high TB burden regions.Further implementation studies to translate those factors into implementation strategies are urgent needed.

AtVQ25 promotes salicylic acid-related leaf senescence by fine-tuning the self-repression of AtWRKY53

Most mechanistic details of chronologically ordered regulation of leaf senescence are unknown.Regulatory networks centered on AtWRKY53 are crucial for orchestrating and integrating various senescence-related signals.Notably,AtWRKY53binds to its own promoter and represses transcription of AtWRKY53,but the biological significance and mechanism underlying this selfrepression remain unclear.In this study,we identified the VQ motif-containing protein AtVQ25as a cooperator of AtWRKY53.The expression level of AtVQ25 peaked at mature stage and was specifically repressed after the onset of leaf senescence.AtVQ25-overexpressing plants and atvq25 mutants displayed precocious and delayed leaf senescence,respectively.Importantly,we identified AtWRKY53 as an interacting partner of AtVQ25.We determined that interaction between AtVQ25 and AtWRKY53 prevented AtWRKY53from binding to W-box elements on the AtWRKY53promoter and thus counteracted the selfrepression of AtWRKY53.In addition,our RNA-sequencing data revealed that the AtVQ25-AtWRKY53 module is related to the salicylic acid(SA)pathway.Precocious leaf senescence and SA-induced leaf senescence in AtVQ25-overexpressing lines were inhibited by an SA pathway mutant,atsid2,and Nah G transgenic plants;AtVQ25-overexpressing/atwrky53 plants were also insensitive to SA-induced leaf senescence.Collectively,we demonstrated that AtVQ25 directly attenuates the self-repression of AtWRKY53 during the onset of leaf senescence,which is substantially helpful for understanding the timing of leaf senescence onset modulated by AtWRKY53.

Reversing artemisinin resistance by leveraging thermo-responsive nanoplatform to downregulating GSH

Artemisinin(ART)resistance has been an emerging clinical problem,severely compromising antimalarial efficacy and threatening the global malaria elimination campaign.Albeit intensive studies about the molecular mechanism for ART resistance are under way,no effective therapeutic targets for reversing resistance have been applied.Here,we explore glutathione(GSH)as a therapeutic target to develop a thermo-responsive nanoplatform to specifically co-deliver ART and GSH synthesis inhibitor(L-buthionine sulfoximine,BSO)in a sustained manner,effectively reversing ART resistance in vivo.By combining with BSO,ART exerts increased antimalarial activity with reduced half-maximal inhibitory concentration(IC50)by 7.43-fold in ART-resistant strains.This work reveals that the GSH in ART-resistant parasites can be a promising therapeutic target for reversing ART resistance,paving the way for developing drug candidates and intelligent nanomedicines in malaria therapy.