A risk-scoring model based on endobronchial ultrasound multimodal imaging for predicting metastatic lymph nodes in lung cancer patients.

Background and Objectives: Endobronchial ultrasound (EBUS) imaging is a valuable tool for predicting lymph node (LN) metastasis in lung cancer patients. This study aimed to develop a risk-scoring model based on EBUS multimodal imaging (grayscale, Doppler mode, elastography) to predict LN metastasis in lung cancer patients. Patients and Methods: This retrospective study analyzed 350 metastatic LNs in 314 patients with lung cancer and 124 reactive LNs in 96 patients with nonspecific inflammation. The sonographic findings were compared with the final pathology results and clinical follow-up. Univariate and multivariate logistic regression analyses were performed to evaluate the independent risk factors of metastatic LNs. According to the ß coefficients of corresponding indicators in logistic regression analysis, a risk-scoring model was established. Receiver operating characteristic curve was applied to evaluate the predictive capability of model. Results: Multivariate analysis showed that short axis >10 mm, distinct margin, absence of central hilar structure, presence of necrosis, nonhilar vascularity, and elastography score 4 to 5 were independent predictors of metastatic LNs. Both short axis and margin were scored 1 point, and the rest of independent predictors were scored 2 points. The combination of 3 EBUS modes had the highest area under the receiver operating characteristic and accuracy of 0.884 (95% confidence interval, 0.846-0.922) and 87.55%, respectively. The risk stratification was as follows: 0 to 2 points, malignancy rate of 11.11%, low suspicion; 3 to 10 points, malignancy rate of 86.77%, high suspicion. Conclusions: The risk-scoring model based on EBUS multimodal imaging can effectively evaluate metastatic LNs in lung cancer patients to support clinical decision making.

Efficacy and safety of local ablative therapy for patients with NSCLC and coexisting interstitial lung disease.

BACKGROUND: The effective therapeutic approach is still an unmet need for patients diagnosed with both lung cancer and interstitial lung disease (ILD). This is primarily due to the possible risk of ILD exacerbation caused by surgery or radiotherapy. The current study aimed to investigate the efficacy and safety of local ablative therapy (LAT) for this specific population. METHODS: Consecutive patients with non-small cell lung cancer (NSCLC) and ILD who received LAT between January 2018 and August 2022 were enrolled, and propensity score matching (PSM) was utilized to match the non-ILD group. The primary endpoint was recurrence-free survival (RFS), and secondary endpoints included overall survival (OS), adverse events (AEs) and hospital length of stay (HLOS). RESULTS: The PSM algorithm yielded matched pairs in the ILD group (n = 25) and non-ILD group (n = 72) at a ratio of 1:3. There were no statistically significant differences in RFS (median 16.4 vs. 18 months; HR = 1.452, p = 0.259) and OS (median: not reached vs. 47.9 months; HR = 1.096, p = 0.884) between the two groups. Meanwhile, no acute exacerbation of ILD was observed in the ILD group. However, the incidence of pneumothorax, especially pneumothorax requiring chest tube drainage, was significantly higher (36.0% vs. 11.2%, p = 0.005) among patients with NSCLC and co-existing ILD, which resulted in longer HLOS (p = 0.045). CONCLUSION: Although ILD was associated with a higher incidence of pneumothorax, the efficacy of LAT for NSCLC patients with ILD was comparable to those without ILD, suggesting that LAT might be a reliable and effective treatment option for this population, particularly in the early stage.

Recent advance of next-generation sequencing in patients with lung cancer.

INTRODUCTION: Precision medicine based on the driver genes mutation status is the current systemic therapeutic paradigm in patients with lung cancer. Next-generation sequencing (NGS) has emerged as a powerful platform for molecular diagnosis by virtue of high-throughput and massively parallel sequencing. Liquid biopsy also enabled the dynamic monitoring and comprehensive profiling of lung cancer in a noninvasive manner. However, challenges remain in the field of technology and clinical applications, especially in the era of immunotherapy. AREAS COVERED: Here, we update the role of NGS in the context of lung cancer screening, molecular diagnosis, predictive and prognostic biomarkers, and guiding personalized treatment. EXPERT OPINION: The NGS application for actable genomic alternation has greatly changed the therapeutic landscape in patients with lung cancer including perioperative setting and advanced stage. Meanwhile, emerging evidence has shown the potential of other applications such as early screening and detection, and MRD. However, challenges remain such as the lack of standardized protocols across different platforms and bioinformatics analysis pipelines, and the complexity of interpreting and leveraging numerous genomic mutation messages for therapy selection. Future research is needed to overcome these challenges and expand the applications of NGS to other aspects such as immunotherapy.

Automatic Representative Frame Selection and Intrathoracic Lymph Node Diagnosis With Endobronchial Ultrasound Elastography Videos.

Endobronchial ultrasound (EBUS) elastography videos have shown great potential to supplement intrathoracic lymph node diagnosis. However, it is laborious and subjective for the specialists to select the representative frames from the tedious videos and make a diagnosis, and there lacks a framework for automatic representative frame selection and diagnosis. To this end, we propose a novel deep learning framework that achieves reliable diagnosis by explicitly selecting sparse representative frames and guaranteeing the invariance of diagnostic results to the permutations of video frames. Specifically, we develop a differentiable sparse graph attention mechanism that jointly considers frame-level features and the interactions across frames to select sparse representative frames and exclude disturbed frames. Furthermore, instead of adopting deep learning-based frame-level features, we introduce the normalized color histogram that considers the domain knowledge of EBUS elastography images and achieves superior performance. To our best knowledge, the proposed framework is the first to simultaneously achieve automatic representative frame selection and diagnosis with EBUS elastography videos. Experimental results demonstrate that it achieves an average accuracy of 81.29% and area under the receiver operating characteristic curve (AUC) of 0.8749 on the collected dataset of 727 EBUS elastography videos, which is comparable to the performance of the expert-based clinical methods based on manually-selected representative frames.

Molecular Design, Preparation, and Characterization of Fluoro-Containing Polyimide Ultrafine Fibrous Membranes with High Whiteness, High Thermal Stability, and Good Hydrophobicity.

Polymeric ultrafine fibrous membranes (UFMs) with high thermal stability and high whiteness are highly desired in modern optoelectronic applications. A series of fluoro-containing polyimide (FPI) UFMs with high whiteness, good thermal stability, and good hydrophobicity were prepared via a one-step electrospinning procedure from the organo-soluble FPI resins derived from a fluoro-containing dianhydride, 4,4'-(hexafluoroisopropylidene) diphthalic anhydride (6FDA), and various diamines containing either pendant trifluoromethyl (-CF3) groups or alicyclic units in the side chains. The obtained FPI UFMs, including FPI-1 from 6FDA and 3,5-diaminobenzotrifluoride (TFMDA), FPI-2 from 6FDA and 2'-trifluoromethyl-3,4'-oxydianiline (3FODA), FPI-3 from 6FDA and 1,4-bis[(4-amino-2-trifluoromethyl)phenoxy]benzene (6FAPB), FPI-4 from 4,4'-bis[(4-amino-2-trifluoromethyl)phenoxy]biphenyl (6FBAB), and FPI-5 from 6FDA and 4'-tert-butyl-cyclohexyl-3,5-diaminobenzoate (DABC) showed whiteness indices (WI) higher than 87.00 and optical reflectance values higher than 80% at the wavelength of 457 nm (R457), respectively. The FPI-5 UFM, especially, showed the highest WI of 92.88. Meanwhile, the prepared PI UFMs exhibited good hydrophobic features with water contact angles (WCA) higher than 105°. At last, the PI UFMs exhibited good thermal stability with glass transition temperatures (Tg) higher than 255 °C, and the 5% weight-loss temperatures (T5%) higher than 510 °C in nitrogen.

Intrinsically Negative Photosensitive Polyimides with Enhanced High-Temperature Dimensional Stability and Optical Transparency for Advanced Optical Applications via Simultaneous Incorporation of Trifluoromethyl and Benzanilide Units: Preparation and Properties.

Negative photosensitive polyimides (PSPIs) with the photo-patterned ability via the photocrosslinking reactions induced by the i-line (365 nm) and h-line (426 nm) emitting wavelengths in high-pressure mercury lamps have been paid increasing attention in semiconductor fabrication, optical fiber communications, and other advanced optoelectronic areas. In the current work, in view of the optical and thermo-mechanical disadvantages of the currently used negative PSPIs, such as the intrinsically photosensitive or auto-photosensitive systems derived from 3,3',4,4'-benzophenonetetracarboxylic dianhydride (BTDA) and the ortho-alkyl- substituted aromatic diamines, a series of modified negative PSPIs with the enhanced optical transparency in the wavelength of 365~436 nm and apparently reduced coefficients of linear thermal expansion (CTE) were developed. For this purpose, a specific aromatic diamine with both of trifluoromethyl and benzanilide units in the molecular structures, 2,2'-bis(trifluoromethyl)-4,4'-bis[4-(4-amino-3-methyl)benzamide]biphenyl (MABTFMB) was copolymerized with BTDA and the standard 3,3',5,5'-tetramethyl-4,4'-diaminodiphenylmethane (TMMDA) diamine via a two-step chemical imidization procedure. As compared with the pristine PI-1 (BTDA-TMMDA) system, the new-developed fluoro-containing PSPI systems (FPI-2~FPI-7) exhibited the same-level solubility in polar aprotic solvents, including N-methyl-2-pyrrolidone (NMP) and N,N- dimethylacetamide (DMAc). The FPI films cast from the corresponding FPI solutions in NMP showed the optical transmittances of 78.3-81.3% at the wavelength of 436 nm (T436, h-line), which were much higher than that of the PI-1 (T436 = 60.9%). The FPI films showed the CTE values in the range of 40.7 × 10-6/K to 54.0 × 10-6/K in the temperature range of 50 to 250 °C, which were obviously lower than that of PI-1 (CTE = 56.5 × 10-6/K). At last, the photosensitivity of the FPI systems was maintained and the micro-pattern with the line width of 10 µm could be clearly obtained via the standard photolithography process of FPI-7 with the molar ratio of 50% for MABTFMB in the diamine moiety.

Formation of Nano-Fibrous Patterns on Aluminum Substrates via Photolithographic Fabrication of Electrospun Photosensitive Polyimide Fibrous Membranes.

The formation of polymeric micro-patterns on various substrates via a photolithography procedure has been widely used in semiconductor fabrication. Standard polymer patterns are usually fabricated via photosensitive polymer varnishes, in which large amounts of potentially harmful solvents with weight ratios over 50 wt% have to be removed. In the current work, a novel pattern-formation methodology via solvent-free electrospun photosensitive polymeric fibrous membranes (NFMs) instead of the conventional photosensitive solutions as the starting photoresists was proposed and practiced. For this purpose, a series of preimidized negative auto-photosensitive polyimide (PSPI) resins were first prepared via the two-step chemical imidization procedure from the copolymerization reactions of 3,3',4,4'-benzophenonetetracarboxylic- dianhydride (BTDA) and two ortho-methyl-substituted aromatic diamines, including 3,3',5,5'-tetramethyl-4,4'-diaminodiphenylmethane (TMMDA) and 3,7-diamino-2,8-dimethyl- dibenzothiophene sulfone (TSN). The derived homopolymer PI-1 (BTDA-TMMDA) and the copolymers, including SPI-2~SPI-6, with the molar ratio of 5~25% for TSN in the diamine units, showed good solubility in polar solvents. Then, a series of PSPI NFMs were fabricated via standard electrospinning procedure with the developed PSPI solutions in N,N-dimethylacetamide (DMAc) with a solid content of 25 wt% as the starting materials. The derived PSPI NFMs showed good thermal stability with 5% weight loss temperatures higher than 500 °C in nitrogen. Meanwhile, the derived PSPIs showed good photosensitivity to the ultraviolet (UV) emitting wavelengths of i-line (365 nm), g-line (405 nm) and h-line (436 nm) of the high-pressure mercury lamps in both forms of transparent films and opaque NFMs. Fine micro-patterns with a line width of around 100 µm were directly obtained from the representative SPI-4 NFM via standard photolithography procedure.

Combination of 18F-FDG PET/CT and convex probe endobronchial ultrasound elastography for intrathoracic malignant and benign lymph nodes prediction.

Background: Positron emission tomography-computed tomography (PET/CT) and convex probe endobronchial ultrasound (CP-EBUS) elastography are important diagnostic methods in predicting intrathoracic lymph nodes (LNs) metastasis, but a joint analysis of the two examinations is still lacking. This study aimed to compare the diagnostic efficiency of the two methods and explore whether the combination can improve the diagnostic efficiency in differentiating intrathoracic benign LNs from malignant LNs. Materials and Methods: LNs examined by EBUS-guided transbronchial needle aspiration (EBUS-TBNA) and PET/CT from March 2018 to June 2019 in Shanghai Chest Hospital were retrospectively analyzed as the model group. Four PET/CT parameters, namely, maximal standardized uptake value mean standardized uptake value (SUVmean), SUVmean, metabolic tumor volume (MTV), and tumor lesion glycolysis (TLG); four quantitative elastography indicators (stiff area ratio, mean hue value, RGB, and mean gray value); and the elastography grading score of targeted LNs were analyzed. A prediction model was constructed subsequently and the dataset from July to November 2019 was used to validate the diagnostic capability of the model. Results: A total of 154 LNs from 135 patients and 53 LNs from 47 patients were enrolled in the model and validation groups, respectively. Mean hue value and grading score were independent malignancy predictors of elastography, as well as SUVmax and TLG of PET/CT. In model and validation groups, the combination of PET/CT and elastography demonstrated sensitivity, specificity, positive and negative predictive values, and accuracy for malignant LNs diagnosis of 85.87%, 88.71%, 91.86%, 80.88%, and 87.01%, and 94.44%, 76.47%, 89.47%, 86.67%, and 88.68%, respectively. Moreover, elastography had better diagnostic accuracies than PET/CT in both model and validation groups (85.71% vs. 79.22%, 86.79% vs. 75.47%). Conclusion: EBUS elastography demonstrated better efficiency than PET/CT and the combination of the two methods had the best diagnostic efficacy in differentiating intrathoracic benign from malignant LNs, which may be helpful for clinical application.

Enhancement of Ultraviolet Light Resistance of Colorless and Transparent Semi-Alicyclic Polyimide Nanocomposite Films via the Incorporation of Hindered Amine Light Stabilizers for Potential Applications in Flexible Optoelectronics.

Optically transparent polymer films with excellent thermal and ultraviolet (UV) resistance have been highly desired in advanced optoelectronic fields, such as flexible substrates for photovoltaic devices. Colorless and transparent polyimide (CPI) films simultaneously possess the good thermal stability and optical transparency. However, conventional CPI films usually suffered from the UV exposure and have to face the deterioration of optical properties during the long-term service in UV environments. In the current work, the commercially available hindered amine light stabilizers (HALS) were tried to be incorporated into the semi-alicyclic CPI matrix with the aim of enhancing the UV exposure stability. For this target, a CPI-0 film was first prepared from hydrogenated pyromellitic dianhydride (HPMDA) and 2,2'-dimethylbenzidine (DMBZ) via a one-step polycondensation procedure. Then, the commercially available HALS were incorporated into the CPI-0 (HPMDA-DMBZ) film matrix to afford four series of CPI/HALS composite films. Experimental results indicated that the Tinuvin® 791 HALS showed the best miscibility with the CPI-0 film matrix and the derived CPI-D series of composite films exhibited the best optical transmittances. The CPI-D nanocomposite films showed apparently enhanced UV exposure stability via incorporation of the 791 additives. For the pristine CPI-0 film, after the UV exposure for 6 h, the optical properties, including the transmittance at the wavelength of 350 nm (T350), lightness (L*), yellow indices (b*), and haze obviously deteriorated with the T350 values from 55.7% to 17.5%, the L* values from 95.12 to 91.38, the b* values from 3.38 to 21.95, and the haze values from 1.46% to 9.33%. However, for the CPI-D-10 film (791: CPI-0 = 1.0 wt%, weight percent), the optical parameters were highly maintained with the T350 values from 61.4% to 53.8%, the L* values from 95.46 to 95.36, the b* values from 1.84 to 1.51, and the haze values from 0.69% to 3.34% under the same UV aging conditions.

Preparation and Characterization of Transparent Polyimide Nanocomposite Films with Potential Applications as Spacecraft Antenna Substrates with Low Dielectric Features and Good Sustainability in Atomic-Oxygen Environments.

Optically transparent polyimide (PI) films with good dielectric properties and long-term sustainability in atomic-oxygen (AO) environments have been highly desired as antenna substrates in low earth orbit (LEO) aerospace applications. However, PI substrates with low dielectric constant (low-Dk), low dielectric dissipation factor (low-Df) and high AO resistance have rarely been reported due to the difficulties in achieving both high AO survivability and good dielectric parameters simultaneously. In the present work, an intrinsically low-Dk and low-Df optically transparent PI film matrix, poly[4,4'-(hexafluoroisopropylidene)diphthalic anhydride-co-2,2-bis(4-(4-aminophenoxy)phenyl)hexafluoropropane] (6FPI) was combined with a nanocage trisilanolphenyl polyhedral oligomeric silsesquioxane (TSP-POSS) additive in order to afford novel organic-inorganic nanocomposite films with enhanced AO-resistant properties and reduced dielectric parameters. The derived 6FPI/POSS films exhibited the Dk and Df values as low as 2.52 and 0.006 at the frequency of 1 MHz, respectively. Meanwhile, the composite films showed good AO resistance with the erosion yield as low as 4.0 × 10-25 cm3/atom at the exposure flux of 4.02 × 1020 atom/cm2, which decreased by nearly one order of magnitude compared with the value of 3.0 × 10-24 cm3/atom of the standard PI-ref Kapton® film.

Electrospun Semi-Alicyclic Polyimide Nanofibrous Membrane: High-Reflectance and High-Whiteness with Superior Thermal and Ultraviolet Radiation Stability for Potential Applications in High-Power UV-LEDs.

Polymeric nanofibrous membranes (NFMs) with both high whiteness and high thermal and ultraviolet (UV) stability are highly desired as reflectors for ultraviolet light-emitting diodes (UV-LEDs) devices. In the current work, a semi-alicyclic and fluoro-containing polyimide (PI) NFM with potential application in such kinds of circumstances was successfully fabricated from the organo-soluble PI resin solution via a one-step electrospinning procedure. In order to achieve the target, a semi-alicyclic PI resin was first designed and synthesized from an alicyclic dianhydride, 3,4-dicarboxy-1,2,3,4,5,6,7,8-decahydro-1-naphthalenesuccinic dianhydride (or hydrogenated tetralin dianhydride, HTDA), and a fluoro-containing diamine, 2,2-bis[4-(4-amino-phenoxy)phenyl]hexafluoropropane (BDAF), via an imidization procedure. The derived PI (HTDA-BDAF) resin possessed a number-average molecular weight (Mn) higher than 33,000 g/mol and was highly soluble in polar aprotic solvents, such as N,N-dimethylacetamide (DMAc). The electrospinning solution was prepared by dissolving the PI resin in DMAc at a solid content of 25-35 wt%. For comparison, the conventional high-whiteness polystyrene (PS) NFM was prepared according to a similar electrospinning procedure. The thermal and UV stability of the derived PI and PS NFMs were investigated by exposure under the UV-LED (wavelength: 365 nm) irradiation. Various thermal evaluation results indicated that the developed PI (HTDA-BDAF) NFM could maintain both the high reflectance and high whiteness at elevated temperatures. For example, after thermal treatment at 200 °C for 1 h in air, the PI (HTDA-BDAF) NFM exhibited a reflectance at a wavelength of 457 nm (R457) of 89.0%, which was comparable to that of the pristine PI NMF (R457 = 90.2%). The PI (HTDA-BDAF) NFM exhibited a whiteness index (WI) of 90.88, which was also close to that of the pristine sample (WI = 91.22). However, for the PS NFM counterpart, the R457 value decreased from the pristine 88.4% to 18.1% after thermal treatment at 150 °C for 1 h, and the sample became transparent. The PI NFM maintained good optical and mechanical properties during the high dose (2670 J/cm2) of UV exposure, while the properties of the PS NFM apparently deteriorated under the same UV aging.

Preparation and Properties of Electrospun Phenylethynyl-Terminated Polyimide Nano-Fibrous Membranes with Potential Applications as Solvent-Free and High-Temperature Resistant Adhesives for Harsh Environments.

High-temperature-resistant polymeric adhesives with high servicing temperatures and high adhesion strengths are highly desired in aerospace, aviation, microelectronic and other high-tech areas. The currently used high-temperature resistant polymeric adhesives, such as polyamic acid (PAA), are usually made from the high contents of solvents in the composition, which might cause adhesion failure due to the undesirable voids caused by the evaporation of the solvents. In the current work, electrospun preimidized polyimide (PI) nano-fibrous membranes (NFMs) were proposed to be used as solvent-free or solvent-less adhesives for stainless steel adhesion. In order to enhance the adhesion reliability of the PI NFMs, thermally crosslinkable phenylethynyl end-cappers were incorporated into the PIs derived from 3,3',4,4'-oxydiphthalic anhydride (ODPA) and 3,3-bis[4-(4-aminophenoxy)phenyl]phthalide (BAPPT). The derived phenylethynyl-terminated PETI-10K and PETI-20K with the controlled molecular weights of 10,000 g mol-1 and 20,000 g mol-1, respectively, showed good solubility in polar aprotic solvents, such as N-methyl-2-pyrrolidinone (NMP) and N,N-dimethylacetamide (DMAc). The PI NFMs were successfully fabricated by electrospinning with the PETI/DMAc solutions. The ultrafine PETI NFMs showed the average fiber diameters (dav) of 627 nm for PETI-10K 695 nm for PETI-20K, respectively. The PETI NFMs showed good thermal resistance, which is reflected in the glass transition temperatures (Tgs) above 270 °C. The PETI NFMs exhibited excellent thermoplasticity at elevated temperatures. The stainless steel adherends were successfully adhered using the PETI NFMs as the adhesives. The PI NFMs provided good adhesion to the stainless steels with the single lap shear strengths (LSS) higher than 20.0 MPa either at room temperature (25 °C) or at an elevated temperature (200 °C).

Photo-Patternable, High-Speed Electrospun Ultrafine Fibers Fabricated by Intrinsically Negative Photosensitive Polyimide.

This work describes polyimide (PI) ultrafine fibrous membranes (UFMs) with aligned fibrous structures, fabricated via the high-speed electrospinning procedure. Organo-soluble intrinsically photosensitive PI is utilized as the fiber-forming agent. The effects of different rotating speeds on the fiber morphology and properties are studied. The aligned UFMs possess hydrophobicity, favorable optical properties, and improved deformation durability. The extension strength of the UFMs reinforces obviously with the increased rotating speed and reaches the maximum of 9.18 MPa at 2500 rpm. In addition, due to the photo-cross-link nature of the PI resin, the UFMs present lithography capability, which can obtain micro-sized patterns on aluminum substrates, and even part of the fibrous structure was retained after development. This work shows promise in manufacturing fiber-based photolithographic hierarchical structures on flexible substrates, which exhibit potential in achieving multiple functions on fiber-based electronic devices.

Automatic Image Selection Model Based on Machine Learning for Endobronchial Ultrasound Strain Elastography Videos.

BACKGROUND: Endoscopic ultrasound (EBUS) strain elastography can diagnose intrathoracic benign and malignant lymph nodes (LNs) by reflecting the relative stiffness of tissues. Due to strong subjectivity, it is difficult to give full play to the diagnostic efficiency of strain elastography. This study aims to use machine learning to automatically select high-quality and stable representative images from EBUS strain elastography videos. METHODS: LNs with qualified strain elastography videos from June 2019 to November 2019 were enrolled in the training and validation sets randomly at a quantity ratio of 3:1 to train an automatic image selection model using machine learning algorithm. The strain elastography videos in December 2019 were used as the test set, from which three representative images were selected for each LN by the model. Meanwhile, three experts and three trainees selected one representative image severally for each LN on the test set. Qualitative grading score and four quantitative methods were used to evaluate images above to assess the performance of the automatic image selection model. RESULTS: A total of 415 LNs were included in the training and validation sets and 91 LNs in the test set. Result of the qualitative grading score showed that there was no statistical difference between the three images selected by the machine learning model. Coefficient of variation (CV) values of the four quantitative methods in the machine learning group were all lower than the corresponding CV values in the expert and trainee groups, which demonstrated great stability of the machine learning model. Diagnostic performance analysis on the four quantitative methods showed that the diagnostic accuracies were range from 70.33% to 73.63% in the trainee group, 78.02% to 83.52% in the machine learning group, and 80.22% to 82.42% in the expert group. Moreover, there were no statistical differences in corresponding mean values of the four quantitative methods between the machine learning and expert groups (p >0.05). CONCLUSION: The automatic image selection model established in this study can help select stable and high-quality representative images from EBUS strain elastography videos, which has great potential in the diagnosis of intrathoracic LNs.

Endobronchial Ultrasound Multimodal Imaging for the Diagnosis of Intrathoracic Lymph Nodes.

BACKGROUND: Endobronchial ultrasound (EBUS) imaging is valuable in diagnosing intrathoracic lymph nodes (LNs), but there has been little analysis of multimodal imaging. This study aimed to comprehensively compare the diagnostic performance of single and multimodal combinations of EBUS imaging in differentiating benign and malignant intrathoracic LNs. METHODS: Subjects from July 2018 to June 2019 were consecutively enrolled in the model group and July 2019 to August 2019 in the validation group. Sonographic features of three EBUS modes were analysed in the model group for the identification of malignant LNs from benign LNs. The validation group was used to verify the diagnostic efficiency of single and multimodal diagnostic methods built in the model group. RESULTS: 373 LNs (215 malignant and 158 benign) from 335 subjects and 138 LNs (79 malignant and 59 benign) from 116 subjects were analysed in the model and validation groups, respectively. For single mode, elastography had the best diagnostic value, followed by grayscale and Doppler. The corresponding accuracies in the validation group were 83.3%, 76.8%, and 71.0%, respectively. Grayscale with elastography had the best diagnostic efficiency of multimodal methods. When at least two of the three features (absence of central hilar structure, heterogeneity, and qualitative elastography score 4-5) were positive, the sensitivity, specificity, and accuracy in the validation group were 88.6%, 78.0%, and 84.1%, respectively. CONCLUSIONS: In both model and validation groups, elastography performed the best in single EBUS modes, as well as grayscale combined with elastography in multimodal imaging. Elastography alone or combined with grayscale are feasible to help predict intrathoracic benign and malignant LNs.

Preparation and Characterization of Electrospun Fluoro-Containing Poly(imide-benzoxazole) Nano-Fibrous Membranes with Low Dielectric Constants and High Thermal Stability.

The rapid development of advanced high-frequency mobile communication techniques has advanced urgent requirements for polymer materials with high-temperature resistance and good dielectric properties, including low dielectric constants (low-Dk) and low dielectric dissipation factors (low-Df). The relatively poor dielectric properties of common polymer candidates, such as standard polyimides (PIs) greatly limited their application in high-frequency areas. In the current work, benzoxazole units were successfully incorporated into the molecular structures of the fluoro-containing PIs to afford the poly(imide-benzoxazole) (PIBO) nano-fibrous membranes (NFMs) via electrospinning fabrication. First, the PI NFMs were prepared by the electrospinning procedure from organo-soluble PI resins derived from 2,2'-bis(3,4-dicarboxy-phenyl)hexafluoropropane dianhydride (6FDA) and aromatic diamines containing ortho-hydroxy-substituted benzamide units, including 2,2-bis[3-(4-aminobenzamide)-4-hydroxylphenyl]hexafluoropropane (p6FAHP) and 2,2-bis[3-(3-aminobenzamide)-4-hydroxyphenyl]hexafluoropropane (m6FAHP). Then, the PI NFMs were thermally dehydrated at 350 °C in nitrogen to afford the PIBO NFMs. The average fiber diameters (dav) for the PIBO NFMs were 1225 nm for PIBO-1 derived from PI-1 (6FDA-p6FAHP) precursor and 816 nm for PIBO-2 derived from PI-2 (6FDA-m6FAHP). The derived PIBO NFMs showed good thermal stability with the glass transition temperatures (Tgs) over 310 °C and the 5% weight loss temperatures (T5%) higher than 500 °C in nitrogen. The PIBO NFMs showed low dielectric features with the Dk value of 1.64 for PIBO-1 and 1.82 for PIBO-2 at the frequency of 1 MHz, respectively. The Df values were in the range of 0.010~0.018 for the PIBO NFMs.

Deep learning with convex probe endobronchial ultrasound multimodal imaging: A validated tool for automated intrathoracic lymph nodes diagnosis.

BACKGROUND AND OBJECTIVES: Along with the rapid improvement of imaging technology, convex probe endobronchial ultrasound (CP-EBUS) sonographic features play an increasingly important role in the diagnosis of intrathoracic lymph nodes (LNs). Conventional qualitative and quantitative methods for EBUS multimodal imaging are time-consuming and rely heavily on the experience of endoscopists. With the development of deep-learning (DL) models, there is great promise in the diagnostic field of medical imaging. MATERIALS AND METHODS: We developed DL models to retrospectively analyze CP-EBUS images of 294 LNs from 267 patients collected between July 2018 and May 2019. The DL models were trained on 245 LNs to differentiate benign and malignant LNs using both unimodal and multimodal CP-EBUS images and independently evaluated on the remaining 49 LNs to validate their diagnostic efficiency. The human comparator group consisting of three experts and three trainees reviewed the same test set as the DL models. RESULTS: The multimodal DL framework achieves an accuracy of 88.57% (95% confidence interval [CI] [86.91%-90.24%]) and area under the curve (AUC) of 0.9547 (95% CI [0.9451-0.9643]) using the three modes of CP-EBUS imaging in comparison to the accuracy of 80.82% (95% CI [77.42%-84.21%]) and AUC of 0.8696 (95% CI [0.8369-0.9023]) by experts. Statistical comparison of their average receiver operating curves shows a statistically significant difference (P < 0.001). Moreover, the multimodal DL framework is more consistent than experts (kappa values 0.7605 vs. 0.5800). CONCLUSIONS: The DL models based on CP-EBUS imaging demonstrated an accurate automated tool for diagnosis of the intrathoracic LNs with higher diagnostic efficiency and consistency compared with experts.

Diagnostic value of endobronchial ultrasound image features: A specialized review.

Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) technology is important in the diagnosis of intrathoracic benign and malignant lymph nodes (LNs). With the development of EBUS imaging technology, its role in noninvasive diagnosis, as a supplement to pathology diagnosis, has been given increasing attention in recent years. Many studies have explored qualitative and quantitative methods for the three EBUS modes, as well as a variety of multimodal analysis methods, to find the optimal method for the noninvasive diagnosis using EBUS for LNs. Here, we review and comment on the research methods and predictive diagnostic value, discuss the existing problems, and look ahead to the future application of EBUS imaging.

Preparation and Properties of Inherently Black Polyimide Films with Extremely Low Coefficients of Thermal Expansion and Potential Applications for Black Flexible Copper Clad Laminates.

In the current work, a series of black polyimide (PI) films with excellent thermal and dimensional stability at elevated temperatures were successfully developed. For this purpose, two aromatic diamines including 4,4'-iminodianline (NDA) and 2-(4-aminophenyl)-5- aminobenzimidazole (APBI) were copolymerized with pyromellitic dianhydride (PMDA) to afford PIs containing imino groups (-NH-) in the molecular structures. The referenced PI film, PI-ref, was simultaneously prepared from PMDA and 4,4'-oxydianiline (ODA). The introduction of imino groups endowed the PI films with excellent blackness and opaqueness with the optical transmittance lower than 2% at the wavelength of 600 nm at a thickness of 25 µm and lightness (L*) below 10 for the CIE (Commission International Eclairage) Lab optical parameters. Meanwhile, the introduction of rigid benzimidazole units apparently improved the thermal and dimensional stability of the PI films. The PI-d film based on PMDA and mixed diamines (NDA:APBI = 70:30, molar ratio) showed a glass transition temperature (Tg) of 445.5 °C and a coefficient of thermal expansion (CTE) of 8.9 × 10-6/K in the temperature range of 50 to 250 °C, respectively. It is obviously superior to those of the PI-a (PMDA-NDA, Tg = 431.6 °C; CTE = 18.8 × 10-6/K) and PI-ref (PMDA-ODA, Tg = 418.8 °C; CTE: 29.5 × 10-6/K) films.

Preparation and Characterization of Semi-Alicyclic Polyimide Resins and the Derived Alignment Layers for Liquid Crystal Display Technology.

Uniform alignment of rigid-rod liquid crystal (LC) molecules under applied voltage is critical for achievement of high-quality display for thin-film transistor-driven liquid crystal display devices (TFT-LCDs). The polymeric components that can induce the alignment of randomly aligned LC molecules are called alignment layers (ALs). In the current work, a series of organo-soluble polyimide (SPI) ALs were designed and prepared from an alicyclic dianhydride, hydrogenated 3,3',4,4'-biphenyltetracarboxylic dianhydride (HBPDA), and various aromatic diamines, including 4,4'-methylenedianiline (MDA) for SPI-1, 4,4'-aminodianiline (NDA) for SPI-2, 3,3',5,5'-tetramethyl-4,4'-diaminodiphenylmethane (TMMDA) for SPI-3, and 3,3'-diethyl-5,5'-dimethyl-4,4'-diaminodiphenylmethane (DMDEDA) for SPI-4. The derived SPI resins were all soluble in N-methyl-2-pyrrolidone (NMP). Four SPI alignment agents with the solid content of 6 wt.% were prepared by dissolving the SPI resins in the mixed solvent of NMP and butyl cellulose (BC) (NMP/BC = 80:20, weight ratio). Liquid crystal minicells were successfully fabricated using the developed SPI varnishes as the LC molecule alignment components. The SPI ALs showed good alignment ability for the LC molecules with the pretilt angles in the range of 1.58°-1.97°. The LC minicells exhibited good optoelectronic characteristics with voltage holding ratio (VHR) values higher than 96%. The good alignment ability of the SPI ALs is mainly attributed to the good comprehensive properties of the SPI layers, including high volume resistivity, high degree of imidization at the processing temperature (230 °C), good rubbing resistance, good thermal stability with glass transition temperatures (Tgs) higher than 260 °C, and excellent optical transparency with the transmittance higher than 97% at the wavelength of 550 nm.