Research on LIBS online monitoring criteria for aircraft skin laser paint removal based on OPLS-DA.

Online monitoring technology plays a pivotal role in advancing the utilization of laser paint removal in aircraft maintenance and automation. Through the utilization of a high-frequency infrared pulse laser paint removal laser-induced breakdown spectroscopy (LIBS) online monitoring platform, this research conducted data collection encompassing 60 sets of LIBS spectra during the paint removal process. Classification and identification models were established employing principal component analysis (PCA), partial least squares discriminant analysis (PLS-DA), and orthogonal partial least squares discriminant analysis (OPLS-DA). These models served as the foundation for creating criteria and rules for the online LIBS monitoring of the controlled paint removal process for aircraft skin. In this research, 12 selected characteristic spectral lines were used to construct the OPLS-DA model, with a predictive root mean square error (RMSEP) of 0.2873. Both full spectrum and feature spectral line data achieved a predictive accuracy of 94.4%. The selection of feature spectral lines maintains predictive performance while significantly reducing the amount of input data. Consequently, this research offers a methodological reference for further advancements in online monitoring technology for laser paint removal in aircraft skin.

A Phase 1b Clinical Trial of Neoadjuvant Radio-immunotherapy for Esophageal Squamous Cell Cancer.

PURPOSE: Neoadjuvant chemoradiotherapy is the recommended treatment for patients with resectable esophageal cancer but is associated with a higher incidence of adverse effects. Given the efficacy of immunotherapy, we propose a chemotherapy-free regimen of neoadjuvant radio-immunotherapy (NRIT) to balance therapeutic efficacy and potential side effects or overtreatment. METHODS AND MATERIALS: In this phase 1b clinical trial, we assessed the safety and efficacy of NRIT in esophageal squamous cell cancer. The enrolled patients received 41.4 Gy of radiation and 4 cycles of 240 mg of toripalimab injection before surgery. The primary endpoint was treatment-related adverse events and the secondary endpoints were pathologic complete response and major pathologic response. Immunohistochemistry and multiplex immunofluorescence staining were used to evaluate the tumor microenvironment before and after neoadjuvant treatment. RESULTS: Of the 22 patients enrolled, 19 underwent R0 surgery. One patient discontinued neoadjuvant immune therapy due to experiencing a grade 3 treatment-related adverse event. Three patients did not undergo surgery due to tumor progression or side effects. Among the patients who underwent surgery, 3 patients experienced serious complications shortly after surgery. Upon pathologic evaluation, the pathologic complete response and major pathologic response rates were 47.4% and 68.4%, respectively. CONCLUSIONS: The NRIT regimen is safe and feasible for patients with esophageal squamous cell cancer.

Local-orbital ptychography for ultrahigh-resolution imaging.

Technical advances paired with developments in methodology have enabled electron microscopy to reach atomic resolution. Further improving the information limit in microscopic imaging requires further improvements in methodology. Here we report a ptychographic method that describes the object as the sum of discrete atomic-orbital-like functions (for example, Gaussian functions) and the probe in terms of aberration functions. Using this method, we realize an improved information limit of microscopic imaging, reaching down to 14 pm. High-quality probes and objects contribute to superior signal-to-noise ratios at low electron doses, allowing for relaxation of the sample thickness restriction to 50 nm for dense materials. Additionally, our method has the capability to decompose the total phase into element components, revealing that the information limit is element dependent. With enhanced spatial resolution, signal-to-noise ratio and thickness threshold compared with conventional ptychography methods, our local-orbital ptychography may find applications in atomic-resolution imaging of metals, ceramics, electronic devices or beam-sensitive material.

Integrating transcriptomics and biochemical analysis to understand the interactive mechanisms of the coexisting exposure of nanoplastics and erythromycin on Chlorella pyrenoidosa.

Nanoplastics and antibiotics frequently co-exist in water polluted by algal blooms, but little information is available about interaction between substances. Erythromycin, as a representative of antibiotics, has been frequently detected in aquatic environments. This investigation attempted to reveal the interaction mechanism of nanoplastics and erythromycin on Chlorella pyrenoidosa. Results demonstrated that the joint toxicity of erythromycin and nanoplastics was dynamic and depended on nanoplastics concentration. Antagonistic effects of 1/2 or 1 EC50 erythromycin and nanoplastic concentration (10 mg/L) on the growth of C. pyrenoidosa was observed. The joint toxicity of 1/2 or 1 EC50 erythromycin and nanoplastic concentration (50 mg/L) was initially synergistic during 24-48 h and then turned to antagonistic during 72-96 h. Consequently, antagonistic effect was the endpoint for joint toxicity. Integration of transcriptomics and physiological biochemical analysis indicated that the co-existence of nanoplastics and erythromycin affected the signal transduction and molecular transport of algal cell membrane, induced intracellular oxidative stress, and hindered photosynthetic efficiency. Overall, this study provided a theoretical basis for evaluating the interactive mechanisms of nanoplastics and antibiotics.

Antiferromagnetic imaging via ptychographic phase retrieval.

Antiferromagnetic imaging is critical for understanding and optimizing the properties of antiferromagnetic materials and devices. Despite the widespread use of high-energy electrons for atomic-scale imaging, they have low sensitivity to spin textures. Typically, the magnetic contribution to the phase of a high-energy electron wave is weaker than one percent of the electrostatic potential. Here, we demonstrate direct imaging of antiferromagnetic lattice through precise phase retrieval via electron ptychography, paving the way for magnetic lattice imaging of antiferromagnetic materials and devices.

Identification of circRNAs and circRNA-mRNA network of Epinephelus coioides during Singapore grouper iridovirus infection.

Circular RNA (circRNA), one of the important non-coding RNA molecules with a closed-loop structure, plays a key regulatory role in cell processing. In this study, circRNAs of Epinephelus coioides, an important marine cultured fish in China, were isolated and characterized, and the network of circRNAs and mRNA was explored during Singapore grouper iridovirus (SGIV) infection, one of the most important double stranded DNA virus pathogens of marine fish. 10 g of raw data was obtained by high-throughput sequencing, and 2599 circRNAs were classified. During SGIV infection, 123 and 37 circRNAs occurred differential expression in spleen and spleen cells, indicating that circRNAs would be involved in the viral infection. GO annotation and KEGG demonstrated that circRNAs could target E. coioides genes to regulate cell activity and the activation of immune factors. The results provide some insights into the circRNAs mediated immune regulatory network during bony fish virus infection.

Real-time LIBS monitoring of laser-based layered controlled paint removal from aircraft skin based on random forest.

Laser-induced breakdown spectroscopy (LIBS) is expected to be used for real-time monitoring and closed-loop control of laser-based layered controlled paint removal (LLCPR) from aircraft skin. However, the LIBS spectrum must be rapidly and accurately analyzed, and the monitoring criteria should be established based on machine learning algorithms. Hence, this study develops a self-built LIBS monitoring platform for the paint removal process utilizing a high-frequency (kilohertz-level) nanosecond infrared pulsed laser and collects the LIBS spectrum during the laser removal process of the top coating (TC), primer (PR), and aluminum substrate (AS). After subtracting the spectrum's continuous background and screening the key features, we construct a classification model of three types of spectra (TC, PR, and AS) based on a random forest algorithm, and the real-time monitoring criterion based on the classification model and multiple LIBS spectra was established and verified experimentally. The results show that the classification accuracy is 98.89%, the time-consuming classification is about 0.03 ms per spectrum, and the monitoring results of the paint removal process are consistent with the macroscopic observation and microscopic profile analysis results of the samples. Overall, this research provides core technical support for the real-time monitoring and closed-loop control of LLCPR from aircraft skin.

Ptychographic measurements of varying size and shape along zeolite channels.

Sub-angstrom resolution imaging of porous materials like zeolites is important to reveal their structure-property relationships involved in ion exchange, molecule adsorption and separation, and catalysis. Using multislice electron ptychography, we successfully measured the atomic structure of zeolite at sub-angstrom lateral resolution for 100-nanometer-thick samples. Both lateral and depth deformations of the straight channels are mapped, showing the three-dimensional structural inhomogeneity and flexibility. Since most zeolites in industrial applications are usually tens to hundreds of nanometers thick, the sub-angstrom resolution imaging and accurate measurements of depth-dependent local structures with electron ptychography at low-dose condition will find wide applications in porous materials close to their industrially relevant conditions.

Compressible Polymer Composites with Enhanced Dielectric Temperature Stability.

High-dielectric-constant polymer composites have broad application prospects in flexible electronics and electrostatic energy storage capacitors. Substantial enhancement in dielectric constants (εr ) of polymer composites so far can only be obtained at a high loading of nanofillers, resulting in high dielectric loss and high elastic modulus of polymer composites. Addressing the polarization shielding and the consequent polarization discontinuity at polymer/filler interfaces has been a long-standing challenge to achieve flexible polymer composite with high εr . Herein, a polymer composite with interconnected BaTiO3 (BT) ceramic scaffold is proposed and demonstrated, which exhibits a high εr of ≈210 at a low BT volume fraction of ≈18 vol%, approaching the upper limit predicted by the parallel model. By incorporating relaxor Ba(Zrx Ti1-x )O3 phase in BT scaffold, dielectric temperature stability is further achieved with Δεr below ±10% within a broad temperature range (25-140 °C). Moreover, the dielectric performances remain stable under a compressive strain of up to 80%. This work provides a facile approach to construct large-scale polymer composites with robust dielectric performance against changes in thermal and mechanical conditions, which are promising for high-temperature applications in flexible electronics.

Sub-nanometer-scale mapping of crystal orientation and depth-dependent structure of dislocation cores in SrTiO3.

Defects in crystals play a fundamental role in modulating mechanical, electrical, luminescent, and magnetic behaviors of materials. However, accurate measurement of defect structures is hindered by symmetry breaking and the corresponding complex modifications in atomic configuration and/or crystal tilt at the defects. Here, we report the deep-sub-angstrom resolution imaging of dislocation cores via multislice electron ptychography with adaptive propagator, which allows sub-nanometer scale mapping of crystal tilt in the vicinity of dislocation cores and simultaneous recovery of depth-dependent atomic structure of dislocations. The realization of deep-sub-angstrom resolution and depth-dependent imaging of defects shows great potential in revealing microstructures and properties of real materials and devices.

Update on therapeutic strategy for esophageal anastomotic leak: A systematic literature review.

Anastomotic leak is still a severe complication in esophageal surgery due to high mortality. This article reviews the updates on the treatment of anastomotic leak after esophagectomy in order to provide reference for clinical treatment and research. The relevant studies published in the Chinese Zhiwang, Wanfang, and MEDLINE databases to December 21, 2021 were retrieved, and esophageal carcinoma, esophagectomy, anastomotic leakage, and fistula selected as the keywords. A total of 78 studies were finally included. The treatments include traditional surgical drainage, new reverse drainage trans-fistula, stent plugging, endoscopic clamping, biological protein glue injection plugging, endoluminal vacuum therapy (EVT), and reoperation, etc. Early diagnosis, accurate classification and optimal treatment can promote the rapid healing of anastomotic leaks. EVT may be the most valuable approach, simultaneously with good commercial prospects. Reoperation should be considered in patients with complex fistula in which conservative treatment is insufficient or has failed.

Microalgal cultivation for the upgraded biogas by removing CO2, coupled with the treatment of slurry from anaerobic digestion: A review.

Biogas is the gaseous by product generated from anaerobic digestion (AD), which is mainly composed of methane and CO2. Numerous independent studies have suggested that microalgae cultivation could achieve high efficiency for nutrient uptake or CO2 capture from AD, respectively. However, there is no comprehensive review on the purifying slurry from AD and simultaneously upgrading biogas via microalgal cultivation technology. This paper aims to fill this gap by presenting and discussing an information integration system based on microalgal technology. Furthermore, the review elaborates the mechanisms, configurations, and influencing factors of integrated system and analyzes the possible challenges for practical engineering applications and provides some feasibility suggestions eventually. There is hope that this review will offer a worthwhile and practical guideline to researchers, authorities and potential stakeholders, to promote this industry for sustainable development.

Platelet-to-Portal Vein Width Ratio and Platelet-to-Spleen Thickness Ratio Can Be Used to Predict Progressive Liver Fibrosis Among Patients With HBV Infection With HBeAg-Negativity and a Normal ALT Level.

Background: Some people infected with the hepatitis B virus (HBV) with a normal level of alanine aminotransferase (ALT) are at risk of disease progression. We evaluated the value of platelet-to-portal vein width ratio (PPR) and platelet-to-spleen thickness ratio (PSR) to predict progressive liver fibrosis among patients with HBV infection with HBV e antigen (HBeAg)-negativity and a normal ALT level. Methods: HBV surface antigen (HBsAg)-positive and HBeAg-negative individuals with a normal ALT level were enrolled. The inflammation grade (G) and fibrosis stage(S) were analyzed according to pathological features. Then, two groups ( 0.05). The platelet count, PPR, and PSR were significantly different between the two groups [(145.92 ± 14.55) ×109/L vs. (126.38 ± 23.85) ×109/L, p = 0.008; 10.80 ± 1.30 vs. 9.01 ± 1.97, p = 0.004; 4.21 ± 0.65 vs. 3.33 ± 0.89, p = 0.02, respectively]. The PPR and PSR decreased gradually upon fibrosis aggravation (p < 0.05). Based on the cut off value of the PPR (9.07) and PSR (3.54), their sensitivity and specificity was 0.917 and 0.525, and 0.833 and 0.541, respectively. Conclusion: The PPR and PSR can be employed to assess earlier fibrosis progression among patients with HBV infection with HBeAg-negativity and a normal ALT level.

Surgery combined with photodynamic therapy versus surgery alone for the treatment of non-melanoma skin cancer and actinic keratosis: A retrospective cohort study.

Photodynamic therapy (PDT) is an effective treatment for some non-melanoma skin cancers (NMSC) and actinic keratosis. To compare recurrence-free survival (RFS) rates between surgery alone and surgery with postoperative PDT in patients with NMSC in China. This retrospective cohort study included patients with pathologically confirmed NMSC or actinic keratosis treated by surgical excision with/without PDT. A total of 125 patients were included, including 72 patients (43 females) aged 57-75 years in the surgery alone group and 53 patients (32 females) aged 61-76 years in the surgery+PDT group. The most common NMSC types were squamous cell carcinoma and basal cell carcinoma, the most common lesion site was the head and neck, and the vast majority of patients had a primary disease and solitary lesions. There were no significant differences between groups in baseline characteristics. RFS rates in the surgery alone and surgery+PDT groups were, respectively, 100.0% and 98.1% at 1 week, 98.6% and 98.1% at 4 weeks, 97.2% and 98.1% at 8 weeks, 97.2% and 98.1% at 12 weeks, and 90.3% and 90.4% at 24 weeks, with no significant differences between groups. Adjuvant PDT after surgical excision of NMSC or actinic keratosis does not provide short-term improvement in RFS, but the results need to be confirmed by a formal randomized controlled trial.

Comparison of the effects of continuous and accumulative exposure to nanoplastics on microalga Chlorella pyrenoidosa during chronic toxicity.

Most previous studies have focused on the continuous exposure of aquatic organisms to nanoplastics. However, persistent pollutants in natural aquatic surroundings are a threat, and their concentrations are continuously increasing. The discussion and research into the effects of accumulative exposure to these materials are limited. Therefore, this study aimed to compare the effects of continuous and accumulative exposure to polystyrene (PS) nanoplastics (80 nm) on Chlorella pyrenoidosa during chronic toxicity. The results indicated that under conditions of continuous exposure, this alga exhibited self-recovery to defend against the negative effects of PS nanoplastics during 15-21 days of exposure (the 21-d inhibitory rate was 1.41%). However, one unanticipated finding was that during the same period of accumulative exposure, nanoplastics retained a substantial and stable inhibitory effect on the algal growth (the 21-d inhibitory rate was 6.79% in accumulative exposure for twice), indicating the invalid self-recovery of algae. The results of scanning electron microscopy demonstrated that on day 21, the degree of damage to the algal cells under accumulative exposure was more severe than that under continuous exposure. Hence, nanoplastics exerted an irreversibly negative effect on aquatic organisms depending on the pattern, frequency, concentration, and duration of exposure. This project evaluated the practical significance of nanoplastics in aquatic ecosystems.

Transcriptome analysis of the toxic mechanism of nanoplastics on growth, photosynthesis and oxidative stress of microalga Chlorella pyrenoidosa during chronic exposure.

The toxicity of nanoplastics to aquatic organisms has been widely studied in terms of biochemical indicators. However, there is little discussion about the underlying toxic mechanism of nanoplastics on microalgae. Therefore, the chronic effect of polystyrene (PS) nanoplastics (80 nm) on Chlorella pyrenoidosa was investigated, in terms of responses at the biochemical and molecular/omic level. It was surprising that both inhibitory and promoting effects of nanoplastcis on C. pyrenoidosa were found during chronic exposure. Before 13 days, the maximum growth inhibition rate was 7.55% during 10 mg/L PS nanoplastics treatment at 9 d. However, the inhibitory effect gradually weakened with the prolongation of exposure time. Interestingly, algal growth was promoted for 1-5 mg/L nanoplastics during 15-21 d exposure. Transcriptomic analysis explained that the inhibitory effect of nanoplastics could be attributed to suppressed gene expression of aminoacyl-tRNA synthetase that resulted in the reduced synthesis of related enzymes. The promotion phenomenon may be due to that C. pyrenoidosa defended against nanoplastics stress by promoting cell proliferation, regulating intracellular osmotic pressure, and accelerating the degradation of damaged proteins and organs. This study is conducive to provide theoretical basis for evaluating the actual hazard of nanoplastics to aquatic organisms.

A Modified Flexor Tendon Suture Technique Combining Kessler and Loop Lock Flexor Tendon Sutures.

OBJECTIVES: In the present study, a novel single knot tenorrhaphy was developed by combining the modified Kessler flexor tendon suture (MK) with the loop lock technique. METHODS: A total of 48 porcine flexor digitorum profundus tendons were collected and randomly divided into six groups. The tendons were transversely cut and then repaired using six different techniques, the MK method, double knot Kessler-loop lock flexor tendon suture (DK), and single knot Kessler-loop lock flexor tendon suture (SK), each in combination with the epitendinous suture (P), and the same three techniques without P. Furthermore, by performing the load-to-failure tests, the biomechanical properties and the time taken to complete a repair, for each tenorrhaphy, were assessed. RESULTS: Compared to the MK+P method, DK+P was more improved, thereby enhancing the ultimate tensile strength. The SK+P method, which required fewer knots than DK+P, was easier to perform. Moreover, the SK+P repair increased the force at a 2-mm gap formation, while requiring lesser knots than DK+P. CONCLUSION: As opposed to the traditional MK+P method, the SK+P method was improved and exhibited better biomechanical properties, which may facilitate early mobilization after the repair.

Mechanism of the inhibition and detoxification effects of the interaction between nanoplastics and microalgae Chlorella pyrenoidosa.

Most previous studies have focused on the toxicity of microplastics on aquatic organisms. However, research on nanoplastics is still limited and poses significant threat to aquatic organisms than microplastics. Therefore, this study investigated the effects of nanoplastics (80 nm) on the microalgae Chlorella pyrenoidosa. One unanticipated finding was that inhibition and detoxification effects existed in the interaction between nanoplastics and C. pyrenoidosa. Nanoplastics contributed the maximum inhibition rates of 27.73%, 29.64%, and 11.76% on algal growth, chlorophyll a, and Fv/Fm, respectively, which were much higher than those of microplastics. However, the inhibitory effect of nanoplastics gradually decreased with prolonged exposure time after reaching a maximum. The transcriptomic analysis explained that the inhibition effect of nanoplastics was due to the blockage of the gene expression of aminoacyl tRNA synthetase and the synthesis of related enzymes and proteins at low concentrations (10 mg·L-1). Moreover, it affected DNA damage repair and hindered photosynthesis at high concentrations (50 mg·L-1). The detoxification phenomenon is attributed to the promotion of cell proliferation, the acceleration of the degradation of damaged proteins and organs, and the regulation of intracellular osmotic pressure in algae. The results of this study provide an understanding of the mechanism underlying the interaction between nanoplastics and microalgae.

Chemical- and species-specific toxicity of nonylphenol and octylphenol to microalgae Chlorella pyrenoidosa and Scenedesmus obliquus.

As typical endocrine disrupters, nonylphenol (NP) and octylphenol (OP) are emerging pollutants that have attracted wide attention. This study investigated the toxicity effects of NP and OP on microalgae Chlorella pyrenoidosa and Scenedesmus obliquus, particularly on their growth inhibition, photosynthetic pigment, chlorophyll fluorescence, and superoxide dismutase and malondialdehyde levels. Results showed that the 96 h EC50 of NP and OP was 2.89 and 5.21 mg/L on C. pyrenoidosa, respectively, and 1.54 and 8.48 mg/L on S. obliquus, respectively. NP exerted a stronger inhibitory effect on cell growth, photosynthesis, and PSII activity, and it contributed more oxidative stress on C. pyrenoidosa than on S. obliquus. By contrast, OP exerted a stronger inhibitory effect on S. obliquus than on C. pyrenoidosa. Furthermore, the toxicity of OP to the tested microalgae was lower than that of NP. Principal component analysis (PCA) and Pearson's correlation indicate that the accumulation of reactive oxygen species is the dominant mechanism of NP and OP cellular toxicity. The principal components of NP and OP affecting microalgae are distinct in the PCA plot, and different endocrine disrupters have varying chemical-specific influences on algal cells. This study confirmed that the toxicity of NP and OP to microalgae C. pyrenoidosa and S. obliquus is chemical- and species-specific. These findings should be considered when assessing the health risk of environmental pollution.

Effects of moxifloxacin and gatifloxacin stress on growth, photosynthesis, antioxidant responses, and microcystin release in Microcystis aeruginosa.

Moxifloxacin (MOX) and gatifloxacin (GAT) are fourth-generation fluoroquinolone antibiotics that are frequently detected in surface water environments and pose a threat to aquatic organisms. However, research into their toxicity to Microcystis aeruginosa, a cyanobacterium, has thus far been limited. In the present study, we investigated the effects of these antibiotics on M. aeruginosa growth, photosynthesis, oxidative stress, and microcystin (MC) release. The results of the 96 h EC50 values of MOX and GAT were 60.34 and 25.30 µg/L, respectively, and the risk quotients calculated indicated that these antibiotics could pose considerable ecological risks at actual environmental concentrations. Photosynthetic fluorescence intensity was shown to decline markedly, and Fv/Fm significantly decreased without any evidence of recovery, suggesting that the organism's photosystems were irreversibly damaged. Chlorophyll a and carotenoid content decreased, whereas the ratio of carotenoids to chlorophyll a increased, indicating that carotenoids were less susceptible to damage than chlorophyll a. The reactive oxygen species and malondialdehyde content significantly increased, as well as the superoxide dismutase and catalase activities, indicating that exposure caused serious oxidative stress. Additionally, MC release increased. These results demonstrate that the environmental risks posed by MOX and GAT should be given serious consideration, particularly as their use is increasing.