Degradation of temporal contrast from post-pedestal interference with a chirped pulse in an optical parametric amplifier.

Pre-pedestal generation is observed in a 0.35-PW laser front end coming from a post-pedestal via instantaneous gain and pump depletion in an optical parametric amplifier during chirped-pulse amplification. Generalized simulations show how this effect arises from gain nonlinearity and applies to all optical parametric chirped-pulse-amplification systems with a post-pedestal. An experiment minimizing the effect of B-integral is used to isolate and study the newly observed conversion of a continuous post-pedestal into a continuous pre-pedestal. Matching numerical simulations confirm experimental results and additionally reveal how third-order dispersion largely controls the slope of the generated pre-pedestal.

Measurements of All-Particle Energy Spectrum and Mean Logarithmic Mass of Cosmic Rays from 0.3 to 30 PeV with LHAASO-KM2A.

We present the measurements of all-particle energy spectrum and mean logarithmic mass of cosmic rays in the energy range of 0.3-30 PeV using data collected from LHAASO-KM2A between September 2021 and December 2022, which is based on a nearly composition-independent energy reconstruction method, achieving unprecedented accuracy. Our analysis reveals the position of the knee at 3.67±0.05±0.15 PeV. Below the knee, the spectral index is found to be -2.7413±0.0004±0.0050, while above the knee, it is -3.128±0.005±0.027, with the sharpness of the transition measured with a statistical error of 2%. The mean logarithmic mass of cosmic rays is almost heavier than helium in the whole measured energy range. It decreases from 1.7 at 0.3 PeV to 1.3 at 3 PeV, representing a 24% decline following a power law with an index of -0.1200±0.0003±0.0341. This is equivalent to an increase in abundance of light components. Above the knee, the mean logarithmic mass exhibits a power law trend towards heavier components, which is reversal to the behavior observed in the all-particle energy spectrum. Additionally, the knee position and the change in power-law index are approximately the same. These findings suggest that the knee observed in the all-particle spectrum corresponds to the knee of the light component, rather than the medium-heavy components.

[Association between unhealthy lifestyles and hypertension, diabetes and dyslipidemia in old adults in China].

Objective: To analyze the individual and cumulative effects of unhealthy lifestyle on the prevalence of hypertension, diabetes and dyslipidemia in old adults in China, and find out the critical lifestyle in the network. Methods: Based on the baseline data of Yunnan Behavior and Disease Surveillance Cohort in 2021, a total of 16 763 older adults aged ≥60 years were included in our study. The unhealthy lifestyle factors including smoking, drinking, unhealthy eating habit, lower physical activity level, abnormal BMI and abnormal waist circumference. We calculated the unhealthy lifestyle score by using the cumulative exposures of each participant. Multiple logistic regression and mixed graphical models were used to describe the association between unhealthy lifestyle and the prevalence of hypertension, diabetes and dyslipidemia. Results: The prevalence of hypertension, diabetes and dyslipidemia were 57.0%, 11.5% and 37.0%, respectively. Most of the unhealthy lifestyles included in the study were risk factors for hypertension, diabetes and dyslipidemia, and the risks of disease increased with the increase of the unhealthy lifestyle score. The participants with the highest score (score: 6) had significantly higher prevalence of hypertension (OR=3.99, 95%CI: 1.81-8.80), diabetes (OR=4.64, 95%CI: 1.64-13.15) and dyslipidemia (OR=4.26, 95%CI: 2.08-8.73) compared with those with lowest score (score: 0). In the network constructed by mixed graphical model, abnormal waist circumference (bridge strength=0.81) and hypertension (bridge strength=0.55) were vital bridge nodes connecting unhealthy lifestyle and hypertension, diabetes and dyslipidemia. Conclusions: The unhealthy lifestyle score was associated with risks for hypertension, diabetes and dyslipidemia. Abnormal waist circumference was the key factor for chronic diseases in old adults.

[Association between unhealthy lifestyles and hyperuricemia in occupational population and modification effect of hypertension and dyslipidemia].

Objective: To understand the relationship between unhealthy lifestyle and hyperuricemia, as well as the modification effects of hypertension and dyslipidemia in occupational population and provide a theoretical basis for the prevention of hyperuricemia. Methods: A cross-sectional survey design was adopted, based on baseline data from the Southwest Occupational Population Cohort from China Railway Chengdu Group Co., Ltd., which included the population in 28 prefectures from Sichuan Province and Guizhou Province, and 33 districts (counties) from Chongqing Municipality between October and December 2021. This study collected the information about the demographics characteristics, lifestyles, and prevalence of chronic non-communicable diseases of the study subjects through questionnaire, physical measurement and laboratory biochemical test. The unhealthy lifestyle score was scored based on smoking, alcohol consumption, dietary patterns, physical activity, and low weight or overweight, with higher scores being associated with more unhealthy lifestyles. The multivariate logistic regression model was used to analyze the relationship between unhealthy lifestyle score, smoking, alcohol consumption, other factors and hyperuricemia, and the stratified analysis was used to explore the modification effect of hypertension and other diseases on the relationship between unhealthy lifestyle and hyperuricemia. Results: A total of 11 748 participants were included in this study, the prevalence of hyperuricemia was 34.4%. Multivariate logistic regression model showed that current/previous smoking, current/previous alcohol consumption and BMI abnormality were risk factors for hyperuricemia, and the unhealthy lifestyle score showed a "cumulative" effect on the risk for hyperuricemia, with higher score increasing the risk of hyperuricemia, and the OR increased from 1.64 (95%CI: 1.34-2.00) to 2.89 (95%CI: 2.39-3.50). Stratified analysis showed that unhealthy lifestyles had a greater impact on the risk for hyperuricemia in people with hypertension and dyslipidemia. Conclusions: The coexistence of multiple unhealthy lifestyles might increase the risk of hyperuricemia, and this effect was stronger in participants with hypertension and dyslipidemia. Timely correction of unhealthy lifestyles, and control of hypertension and dyslipidemia might reduce the risk for hyperuricemia.

[Mediating effects of body mass index and lipid levels on the association between alcohol consumption and hypertension in occupational population].

Objective: To investigate the association between alcohol consumption and hypertension and SBP, DBP and the mediating effects of body mass index (BMI) and lipid level in occupational population, and provide reference for the intervention and prevention of hypertension. Methods: Based on the data of Southwest Occupational Population Cohort from China Railway Chengdu Group Co., Ltd., the information about the demographic characteristics, behavior and lifestyle, blood pressure and lipids level of the participants were collected through questionnaire survey, physical examination and blood biochemical test. Logistic/linear regression was used to analyze the association between alcohol consumption and hypertension, SBP and DBP. The individual and joint mediating effects of BMI, HDL-C, LDL-C, TG, and TC were explored through causal mediating analysis. A network analysis was used to explore the correlation between alcohol consumption, BMI and lipid levels, and hypertension. Results: A total of 22 887 participants were included, in whom 1 825 had newly detected hypertension. Logistic regression analysis found that current/former drinkers had a 33% increase of risk for hypertension compared with never-drinkers (OR=1.33, 95%CI:1.19-1.48). Similarly, alcohol consumption could increase SBP (ß=1.05, 95%CI:0.69-1.40) and DBP (ß=1.10, 95%CI:0.83-1.38). Overall, BMI and lipid levels could mediate the associations between alcohol consumption and hypertension, SBP and DBP by 21.91%, 28.40% and 22.64%, respectively. BMI and TG were the main mediators, and they were also the two nodes with the highest edge weight and bridge strength centrality in the network of alcohol consumption, BMI, lipid levels and hypertension. Conclusions: Alcohol consumption was associated with increased risk for hypertension, and BMI and TG were important mediators and key nodes in the network. It is suggested that paying attention to the alcohol consumption, BMI and TG might help prevent hypertension in occupational population.

[Association between work environment noise perception and cardiovascular diseases, depressive symptoms, and their comorbidity in occupational population].

Objective: To explore the association between occupational noise perception and cardiovascular disease (CVD), depression symptoms, as well as their comorbidity in occupational population and provide evidence for the prevention and control of physical and mental illnesses. Methods: A cross-sectional survey design was adopted, based on baseline data in population in 28 prefectures in Sichuan Province and Guizhou Province, and 33 districts (counties) in Chongqing municipality from Southwest Occupational Population Cohort from China Railway Chengdu Group Co., Ltd. during October to December 2021. A questionnaire survey was conducted to collect information about noise perception, depressive symptoms, and the history of CVD. Latent profile analysis model was used to determine identify noise perception type, and multinomial logistic regression analysis was conducted to explore the relationship between different occupational noise perception types and CVD, depression symptoms and their comorbidity. Results: A total of 30 509 participants were included, the mean age was (36.6±10.5) years, and men accounted for 82.0%. The direct perception of occupational noise, psychological effects and hearing/sleep impact of occupational noise increased the risk for CVD, depressive symptoms, and their comorbidity. By using latent profile analysis, occupational noise perception was classified into four levels: low, medium, high, and very high. As the level of noise perception increased, the association with CVD, depressive symptoms, and their comorbidity increased. In fact, very high level occupational noise perception were found to increase the risk for CVD, depressive symptoms, and their comorbidity by 2.14 (95%CI: 1.73-2.65) times, 8.80 (95%CI: 7.91-9.78) times, and 17.02 (95%CI: 12.78-22.66) times respectively compared with low-level occupational noise perception. Conclusions: Different types of occupational noise perception are associated with CVD and depression symptom, especially in the form of CVD complicated with depression symptom. Furthermore, the intensity of occupational noise in the work environment should be reduced to lower the risk for physical and mental health.

[Establishment and verification of invasion syndrome prediction model in patients with diabetes complicated with Klebsiella pneumoniae liver abscess].

Objective: To analyze the correlative factors of invasion syndrome in patients with diabetes complicated with Klebsiella pneumoniae liver abscess, and to construct and verify the online nomographic prediction model. Methods: A case control study. The clinical data of 213 diabetic patients with Klebsiella pneumoniae liver abscess admitted to the Third Affiliated Hospital of Soochow University from January 1, 2015 to December 31, 2021 were retrospectively analyzed. The patients were divided into the training set (149 cases) and the test set (64 cases) by stratified random sampling method at a ratio of 7∶3. Synthetic minority over-sampling technique(SMOTE) was used to process the imbalanced data, then Lasso regression was used to screen out the optimal feature variables in the training set and multivariate logistic regression model was used to construct the prediction model of invasion syndrome in patients with diabetes complicated with Klebsiella pneumoniae liver abscess, and verify it in the training set and test set. Receiver operating characteristic (ROC) curve, calibration curve and decision curve analysis (DCA) were used to evaluate the prediction efficiency of the model, and the simple and online interactive dynamic web page column graph was constructed. Results: Among the 213 patients, 60 were males and 153 were females, aged of (61.4±12.0) years. A total of 25(11.74%) diabetic patients with Klebsiella pneumoniae liver abscess developed invasion syndrome, which were included in divided into invasive K.pneumoniae liver abscesses syndrome (IKPLAS) group, and the other 188 cases were in without invasive K.pneumoniae liver abscesses syndrome (NIKPLAS) group. SMOTE algorithm was used for oversampling processing, so that the ratio of positive and negative samples was 1∶1. In the oversampling training set, 5 main risk factors were screened based on Lasso regression, namely fasting blood glucose (λ=0.063), hemoglobin (λ=-0.042), blood urea nitrogen (λ=-0.050), abscess size (λ=-0.025) and sequential organ failure assessment (SOFA) score (λ=0.450), respectively. Multivariate logistic regression model showed that fasting blood glucose (OR=1.20, 95%CI: 0.98-1.48, P=0.006), hemoglobin (OR=0.90, 95%CI: 0.86-0.95, P<0.001), blood urea nitrogen (OR=1.22, 95%CI: 1.03-1.43, P=0.017), abscess diameter (OR=0.76, 95%CI: 0.61-0.94, P=0.010), SOFA score (OR=3.08, 95%CI: 2.18-4.36, P<0.001) were associated with invasion syndrome in patients with diabetes complicated with Klebsiella pneumoniae liver abscess. The area under the curve of ROC in the training set was 0.966 (95%CI: 0.943-0.989), the sensitivity was 90.5%, and the specificity was 91.3%. The area under the curve of the validation set ROC was 0.946 (95%CI: 0.902-0.991), with a sensitivity of 79.6% and a specificity of 88.9%. The calibration curves drawn in the training set and the test set fit well with the ideal curve. DCA showed that the neomorph prediction model had a good clinical net benefit when predicting the risk of IKPLAS in patients with diabetes complicated with Klebsiella pneumoniae liver abscess was 0.10-0.40. Conclusions: Fasting blood glucose, hemoglobin, urea nitrogen, abscess size and SOFA score are the related factors for invasion syndrome in patients with diabetes complicated with Klebsiella pneumoniae liver abscess. The constructed column graph can effectively predict the risk of invasion syndrome in patients with diabetes complicated with Klebsiae pneumoniae liver abscess.

A Dosimetric Comparative Study of Carbon-Ion Radiotherapy Versus X-ray Volumetric Modulated Arc Therapy for Stage III Non-Small-Cell Lung Cancer.

BACKGROUND: Compared to photon beam, carbon-ion radiotherapy (CIRT) has both physical and biological advantages. AIM: To examine whether two-dimensional (2D) CIRT is dosimetrically superior to photon beam volume-modulated arc therapy (VMAT) in protecting the normal tissues for stage III non-small-cell lung cancer (NSCLC). SUBJECTS AND METHODS: A retrospective study was conducted. Thirteen patients with stage III NSCLC treated in our center with curative CIRT and a sham photon beam VMAT treatment planning with the same normal tissue dose constraints were included for analysis. Target dose distributions and the homogeneity index (HI) within the planning target volumes were compared. RESULTS: Both CIRT and VMAT plans have good tumor coverage with no significant differences in D98, D95, and D50 of Planning target volume 1 (PTV1) between the two plans. The HIs between the two plans are similar. The HI of PTV2 is superior in the CIRT plan (CIRT vs. VMAT: 0.08 vs. 0.16, P < 0.05). In general, CIRT results in a lower dose of the organ-at-risk (OAR) than the photon plans. The V5, V10, V20, V30, V40, and Dmean of the contralateral lung in the CIRT plan are significantly lower than that of the photon VMAT. For the ipsilateral lung, the V5 of CIRT is significantly lower. The CIRT also had significantly lower spinal cord Dmax, esophageal Dmean and V50, V10 and V30 of bone, and V50 of the trachea and bronchial tree. CONCLUSIONS: Compared with photon VMAT, 2D-CIRT using the passive beam scanning technique significantly reduces the radiation dose to the OARs in curative radiotherapy of stage III NSCLC, suggesting a better protection of the normal tissues.

Application of the Key Characteristics of Carcinogens to Bisphenol A.

The ten key characteristics (KCs) of carcinogens are based on characteristics of known human carcinogens and encompass many types of endpoints. We propose that an objective review of the large amount of cancer mechanistic evidence for the chemical bisphenol A (BPA) can be achieved through use of these KCs. A search on metabolic and mechanistic data relevant to the carcinogenicity of BPA was conducted and web-based software tools were used to screen and organize the results. We applied the KCs to systematically identify, organize, and summarize mechanistic information for BPA, and to bring relevant carcinogenic mechanisms into focus. For some KCs with very large data sets, we utilized reviews focused on specific endpoints. Over 3000 studies for BPA from various data streams (exposed humans, animals, in vitro and cell-free systems) were identified. Mechanistic data relevant to each of the ten KCs were identified, with receptor-mediated effects, epigenetic alterations, oxidative stress, and cell proliferation being especially data rich. Reactive and bioactive metabolites are also associated with a number of KCs. This review demonstrates how the KCs can be applied to evaluate mechanistic data, especially for data-rich chemicals. While individual entities may have different approaches for the incorporation of mechanistic data in cancer hazard identification, the KCs provide a practical framework for conducting an objective examination of the available mechanistic data without a priori assumptions on mode of action. This analysis of the mechanistic data available for BPA suggests multiple and inter-connected mechanisms through which this chemical can act.

Measurement of Ultra-High-Energy Diffuse Gamma-Ray Emission of the Galactic Plane from 10 TeV to 1 PeV with LHAASO-KM2A.

The diffuse Galactic γ-ray emission, mainly produced via interactions between cosmic rays and the interstellar medium and/or radiation field, is a very important probe of the distribution, propagation, and interaction of cosmic rays in the Milky Way. In this Letter, we report the measurements of diffuse γ rays from the Galactic plane between 10 TeV and 1 PeV energies, with the square kilometer array of the Large High Altitude Air Shower Observatory (LHAASO). Diffuse emissions from the inner (15°10 TeV). The energy spectrum in the inner Galaxy regions can be described by a power-law function with an index of -2.99±0.04, which is different from the curved spectrum as expected from hadronic interactions between locally measured cosmic rays and the line-of-sight integrated gas content. Furthermore, the measured flux is higher by a factor of ∼3 than the prediction. A similar spectrum with an index of -2.99±0.07 is found in the outer Galaxy region, and the absolute flux for 10≲E≲60 TeV is again higher than the prediction for hadronic cosmic ray interactions. The latitude distributions of the diffuse emission are consistent with the gas distribution, while the longitude distributions show clear deviation from the gas distribution. The LHAASO measurements imply that either additional emission sources exist or cosmic ray intensities have spatial variations.

Final amplifier of an ultra-intense all-OPCPA system with 13-J output signal energy and 41% pump-to-signal conversion efficiency.

Optical parametric chirped-pulse amplification (OPCPA) using high-energy Nd:glass lasers has the potential to produce ultra-intense pulses (>1023 W/cm2). We report on the performance of the final high-efficiency amplifier in an OPCPA system based on large-aperture (63 × 63-mm2) partially deuterated potassium dihydrogen phosphate (DKDP) crystals. The seed beam (180-nm bandwidth, 110 mJ) was provided by the preceding OPCPA stages. A maximum pump-to-signal conversion efficiency of 41% and signal energy up to 13 J were achieved with a 52-mm-long DKDP crystal due to the flattop super-Gaussian pump beam profile and flat-in-time pulse shape.

A tera-electron volt afterglow from a narrow jet in an extremely bright gamma-ray burst.

Some gamma-ray bursts (GRBs) have a tera-electron volt (TeV) afterglow, but the early onset of this has not been observed. We report observations with the Large High Altitude Air Shower Observatory (LHAASO) of the bright GRB 221009A, which serendipitously occurred within the instrument's field of view. More than 64,000 photons >0.2 TeV were detected within the first 3000 seconds. The TeV flux began several minutes after the GRB trigger and then rose to a peak ~10 seconds later. This was followed by a decay phase, which became more rapid ~650 seconds after the peak. We interpret the emission using a model of a relativistic jet with half-opening angle of ~0.8°. This is consistent with the core of a structured jet and could explain the high isotropic energy of this GRB.

Multi-animal-model study reveals mutations in neural plasticity and nociception genes linked to excessive alcohol drinking.

BACKGROUND: The basis for familial alcohol use disorder (AUD) remains an enigma due to various biological and societal confounds. The present study used three of the most adopted and documented rat models, combining the alcohol-preferring/non-alcohol-preferring (P/NP) lines and high alcohol-drinking/low alcohol-drinking (HAD/LAD) replicated lines, of AUD as examined through the lens of whole genomic analyses. METHODS: We used complete genome sequencing of the P/NP lines and previously published sequences of the HAD/LAD replicates to enhance the discovery of variants associated with AUD and to remove confounding with genetic background and random genetic drift. Specifically, we used high-order statistical methods to search for genetic variants whose frequency changes in whole sets of gene ontologies corresponded with phenotypic changes in the direction of selection, that is, ethanol-drinking preference. RESULTS: Our first finding was that in addition to variants causing translational changes, the principal genetic changes associated with drinking predisposition were silent mutations and mutations in the 3' untranslated regions (3'UTR) of genes. Neither of these types of mutations alters the amino acid sequence of the translated protein but they influence both the rate and conformation of gene transcription, including its stability and posttranslational events that alter gene efficacy. This finding argues for refocusing human genomic studies on changes in gene efficacy. Among the key ontologies identified were the central genes associated with the Na+ voltage-gated channels of neurons and glia (including the Scn1a, Scn2a, Scn2b, Scn3a, Scn7a, and Scn9a subtypes) and excitatory glutamatergic secretion (including Grm2 and Myo6), both of which are essential in neuroplasticity. In addition, we identified "Nociception or Sensory Perception of Pain," which contained variants in nociception (Arrb1, Ccl3, Ephb1) and enlist sodium (Scn1a, Scn2a, Scn2b, Scn3a, Scn7a), pain activation (Scn9a), and potassium channel (Kcna1) genes. CONCLUSION: The multi-model analyses used herein reduced the confounding effects of random drift and the "founders" genetic background. The most differentiated bidirectionally selected genes across all three animal models were Scn9a, Scn1a, and Kcna, all of which are annotated in the nociception ontology. The complexity of neuroplasticity and nociception adds strength to the hypothesis that neuroplasticity and pain (physical or psychological) are prominent phenotypes genetically linked to the development of AUD.

Efficacy and safety of video-assisted thoracoscopic surgery for pulmonary TB.

OBJECTIVE: Compared with thoracotomy, video-assisted thoracoscopic surgery (VATS) has the advantage of post-operative recovery for patients undergoing surgery. However, studies comparing the efficacy of VATS with conventional traditional thoracotomy for treating patients with pulmonary TB (PTB) are inconsistent.METHODS: Five electronic databases were used to search studies on VATS and conventional thoracotomy for PTB up to 15 March 2022. Standardised mean differences (SMDs) and odds ratios (ORs) were calculated for comparison.RESULTS: A total of 14 were included. Compared with traditional thoracotomy, patients with drug-resistant TB treated using VATS had shorter operative time, less intra-operative bleeding, faster post-operative recovery and fewer post-operative complications (operation time: SMD -0.87, 95% CI -1.29 to -0.45; blood loss: SMD -1.31, 95% CI -1.71 to -0.92; duration of hospital stay: SMD -1.68, 95% CI -2.46 to -0.90; catheterisation time: SMD -1.56, 95% CI -2.39 to -0.73; post-operative complication: OR 0.40, 95% CI 0.27 to 0.60).CONCLUSION: Compared with conventional thoracotomy, VATS for patients with multidrug-resistant PTB undergoing lobectomy and wedge resection has the advantages of minor bleeding, shorter operative time, shorter hospital stay and post-operative pleural cavity drainage duration, and fewer post-operative complications, which can accelerate the post-operative recovery of patients.

Achieving 100 GW idler pulses from an existing petawatt optical parametric chirped pulse amplifier.

Optical parametric chirped-pulse-amplification produces two broadband pulses, a signal and an idler, that can both provide peak powers >100 GW. In most cases the signal is used, but compressing the longer-wavelength idler opens up opportunities for experiments where the driving laser wavelength is a key parameter. This paper will describe several subsystems that were added to a petawatt class, Multi-Terawatt optical parametric amplifier line (MTW-OPAL) at the Laboratory for Laser Energetics to address two long-standing issues introduced by the use of the idler, angular dispersion, and spectral phase reversal. To the best of our knowledge, this is the first time that compensation of angular dispersion and phase reversal has been achieved in a single system and results in a 100 GW, 120-fs duration, pulse at 1170 nm.

A Prospective Longitudinal Study of Early Childhood Caries Onset in Initially Caries-Free Children.

INTRODUCTION: Early childhood caries (ECC) is a complex oral disease that is prevalent in US children. OBJECTIVES: The purpose of this 2-y prospective cohort study was to examine baseline and time-dependent risk factors for ECC onset in initially caries-free preschool children. METHODS: A cohort of 189 initially caries-free children aged 1 to 3 y was recruited. At each 6-mo study visit, children were examined using the ICDAS index; salivary samples were collected to assess mutans streptococci (MS), lactobacilli, Candida species, salivary cortisol (prior and after a stressor), and salivary IgA. Diet and oral health behavior were assessed from parent report. Child and family stress exposure was assessed from measures of psychological symptoms, stressful life event exposure, family organization and violence exposure, and social support. Sociodemographic factors were also considered. A Kaplan-Meier estimator of survival function of time to ECC and a Cox proportional hazards model were used to identify predictors of ECC onset. RESULTS: Onset of ECC was associated with high salivary MS levels at baseline (log-rank test, P < 0.0001). Cox proportional hazards regression showed that the risk of dental caries significantly increased with salivary MS in log scale over the 6-mo period (hazard ratio, 1.08; P = 0.01). Other risk factors in the model did not reach statistical significance. CONCLUSION: Our results provide prospective evidence that an increase in salivary MS predicts ECC onset in young, initially caries-free children, confirming that a high salivary MS count likely plays a causal role in ECC onset, independent of covariates. KNOWLEDGE TRANSFER STATEMENT: These results suggest that we must focus on reducing salivary MS counts in young children and preventing or delaying MS colonization in infants and young children determined to be at risk for ECC.

Measurement of Paα line from pellet ablation cloud in Heliotron J.

The Paα line (1875.13 nm) in the near-infrared (NIR) region was evaluated to apply Stark broadening of the line spectrum to the electron density measurement of the small-pellet ablation cloud in Heliotron J, a medium-sized helical-axis heliotron device. Paα is three-to-four times broader than the visible Hß line (486.13 nm) for the same electron density. Using a portable NIR spectrometer, preliminary proof-of-concept experiments determined the marginal density, below which the broadening was undetectable. The lower detection density limit can be decreased using a narrower entrance slit or a denser grating.

Comparison of the safety and efficacy of unilateral biportal endoscopic lumbar interbody fusion and uniportal endoscopic lumbar interbody fusion: a 1-year follow-up.

OBJECTIVES: To compare the short-term outcomes of unilateral biportal endoscopic lumbar interbody fusion (BLIF) and uniportal endoscopic lumbar interbody fusion (ULIF). METHODS: Sixty patients diagnosed with L4/5 spinal stenosis who underwent BLIF and ULIF were included (30 in each group). Clinical evaluation was performed preoperatively and postoperatively in the 1st week, 1st month, and 1st year. Factors such as the visual analogue score (VAS), Oswestry Disability Index (ODI), operative time, surgical complications, and radiological outcomes (fusion rate, screw loosening, and cage subsidence) were compared between the two groups. RESULTS: All patients showed improved mean VAS and ODI at all three postoperative follow-ups, and no statistically significant differences were detected between the BLIF and ULIF groups. The mean operative time in the BLIF group was shorter than that in the ULIF group. Nerve root injury occurred in two patients in the BLIF group, while leakage of cerebrospinal fluid occurred in one patient in the ULIF group. All adverse events were treated adequately prior to discharge. The fusion rates with definite and probable grades were significantly higher in the BLIF group than that in the ULIF group. One case of cage subsidence with no screw loosening occurred in each group. CONCLUSION: Both BLIF and ULIF are safe and effective surgical techniques. Compared with ULIF, BLIF has the advantages of shorter operative time and a higher fusion rate. Other merits of BLIF include a wider surgical field, greater maneuverability of instruments, visibility during cage implantation, and transverse orientation of the cage.

Effect of the pump beam profile and wavefront on the amplified signal wavefront in optical parametric amplifiers.

We present a theoretical and experimental analysis of the signal phase introduced by the pump-beam wavefront and spatial profile during optical parametric amplification (OPA) process. The theory predicts the appearance of an additional wavefront in the amplified signal beam that is proportional to the spatial derivative of the pump-beam wavefront. The effect of the pump-beam profile on the signal-beam wavefront is also investigated. Our experiments tested these theoretical predictions by comparing the wavefront of the signal beam before and after amplification in a multi-joule broadband OPA. The measured signal wavefront was shown to have the expected dependence on the pump-beam profile and wavefront. These results can be considered when designing petawatt-scale ultrabroadband optical parametric chirped-pulse-amplification systems.