Prototype development and evaluation of a hyperspectral lidar optical receiving system.

As a new type of active Earth observation technology, airborne hyperspectral lidar combines the advantages of traditional lidar 3D information acquisition and passive hyperspectral imaging technology, and it can achieve integrated imaging detection with a high spatial and hyperspectral resolution. Thus, it has become an important future direction of Earth surface remote sensing technology. This article introduces the design and development of an airborne hyperspectral imaging lidar system. The hyperspectral lidar adopts a focal plane splitting method, combined with an array of 168 optical fibers, to couple wide-spectral-range laser echo signals one by one to the corresponding single tube detector, achieving efficient splitting and precise coupling of supercontinuum laser pulse echo signals. This article proposes a fast synchronous calibration method that is suitable for hyperspectral imaging lidar systems. Results show that the spectral range of the hyperspectral lidar system is 400-900 nm, and the spectral resolution of single-fiber detection is greater than 3 nm. Notably, this article focuses on analyzing the abnormal detection channels based on the calibration results. With the test results of adjacent channels combined, the reason for the abnormal spectral bandwidth of channel 17 is analyzed as an example. This research points out the direction for verifying the design parameters of the hyperspectral lidar prototype and lays an important foundation for airborne flight test of the hyperspectral lidar.

Infrared detector module for airborne hyperspectral LiDAR: design and demonstration.

Realizing the integrated acquisition and identification of the elevation information and spectral information of the observation target is at the frontier and a future trend of Earth observation technology. This study designs and develops a set of airborne hyperspectral imaging lidar optical receiving systems and investigates the detection of the infrared band echo signal of the lidar system. A set of avalanche photodiode (APD) detectors is independently designed to detect the weak echo signal of  800-900 nm band. The actual radius of the photosensitive surface of the APD detector is 0.25 mm. We design and demonstrate the optical focusing system of the APD detector in the laboratory and obtain that the image plane size of the optical fiber end faces of the APD detector from channel 47 to channel 56 is close to 0.3 mm. Results show that the optical focusing system of the self-designed APD detector is reliable. On the basis of the focal plane splitting technology of the fiber array, we couple the echo signal of  800-900 nm band to the corresponding APD detector through the fiber array and conduct a series of test experiments for the APD detector. Field test results of the ground-based platform show that the APD detectors in all channels can complete the remote sensing measurement of 500 m. The development of this APD detector solves the problem of hyperspectral imaging under weak light signals and realizes the accurate detection of ground targets in the infrared band by airborne hyperspectral imaging lidar.

Optical system design for a hyperspectral imaging lidar using supercontinuum laser and its preliminary performance.

To meet the urgent need for surveying and mapping using remote sensing instruments, a hyperspectral imaging lidar using a supercontinuum laser is proposed. This novel lidar system can solve the problem of the mismatching of the traditional lidar retrieved elevation data and hyperspectral data obtained by passive imaging instruments. The optical design of the lidar receiving system is described, developed, and tested in this study. An off-axis parabolic mirror is used as the receiving telescope of the system, and a transmissive grating is used to split the received hyperspectral light to each detection channel. A fiber array equipped with a micro-lens is used to guide the split light to the detectors. In practice, several fibers can be coupled to one detector according to the wavelength sensitivity of different objects. A reference laser is used to monitor the possible energy jitter of each transmitted laser pulse in real time. A spectrum calibration of the receiving system is accomplished in the laboratory, and radiation calibration is applied by receiving the backscattered light reflected by a standard white board. The spectral resolution of a single fiber is approximately 3 nm. An outdoor 500-m distance experiment was carried out for green and yellow leaves in day and evening settings. During the experiment, the wavelength of the laser was 460-900 nm. The reflection spectra collected by the lidar system in day and evening were consistent, indicating that the design of the optical receiving system is reliable and can be used for airborne hyperspectral imaging lidar.

Multiple organ involvement in severe fever with thrombocytopenia syndrome: an immunohistochemical finding in a fatal case.

BACKGROUND: Severe fever with thrombocytopenia syndrome (SFTS) is an emerging infectious disease caused by SFTS bunyavirus (SFTSV), a tick borne bunyavirus. However, Immunohistochemistry of SFTS patients are not well studied. METHODS: We obtained multiple of tissues from a fatal case with SFTS, including blood, lungs, kidneys, heart, and spleen. The blood samples were used to isolate the causative agent for detection of viral RNA and further expression of recombinant viral protein as primary antibody. Immunohistochemistry of the heart, lungs, spleen and kidneys was used to characterize the viral antigen in tissue sections. RESULTS: A 79-year-old man, together with his wife, was admitted because of fever. Both patients were diagnosed with SFTS by the positive SFTSV RNA in the blood. The gentleman died of multiple organ failure 8 days after hospitalization. However, his wife recovered and was discharged. Immunohistochemistry indicated that SFTSV antigens were present in all studied organs including the heart, kidney, lung and spleen, of which the spleen presented with the highest amount of SFTSV antigens. The kidney was next while the heart and lungs showed lower amount of SFTSV antigens. CONCLUSIONS: SFTSV can direct infect multiple organs, resulting in multiple organ failure and ultimately in an unfavorable outcome.

[Study on the hemodynamic changes in solid thyroid nodules by ultrasound contrast quantitative analysis].

OBJECTIVE: To compare the difference between the different perfusional regions in solid thyroid nodules. METHODS: From October 2013 to May 2015, CEUS was performed in 59 patients who hospitalizated in Zhoushan Hospital with solid thyroid nodules before operation. The time-intensity curve (TIC) of normal thyroid tissue, tumor edge and tumor center was drawn to collect perfusion index like the peak intensity (PI), time to peak (TP), area under the curve (AUC), mean transit time (MTT). After surgery, immunohistochemical staining was performed to evaluate the MVD in surgical specimens.Quantitative parameters and MVD were assessed by the Spearman correlation analysis. RESULTS: There were 31 thyroid papillary carcinomas and 28 nodular goiters. In malignant tumor group, the PI of normal thyroid tissue, tumor edge and tumor center were 28% ± 6%, 21% ± 7% and 14% ± 5%, respectively, while the AUC and MVD of the same regions were (1 865 ± 1 079)%S, (1 376 ± 595)%S, (805 ± 412)%S and(33 ± 6), (27 ± 6)/HP, (17 ± 6)/HP, respectively. The differences were statistically significant. However, in benign tumor group, there was no obvious statistic difference in the quantitative parameters and MVD between the three regions. The PI values of thyroid carcinomas and nodular goiters all were positively correlated with MVD (r=0.819, r=0.838, P<0.05). CONCLUSIONS: The variance of perfusion parameters were valuable diagnostic basis in differential diagnosis between benign and malignant thyroid nodules. They were associated with MVD, which might reflect the microvessel distributional characteristics of neoplasm and might be one of bases used to evaluate neoplasm angiogenesis.

Prognostic significance of alveolar collapse in lung invasive adenocarcinoma and its relationship with tumor infiltrating lymphocytes.

This study aims to investigate the correlations between alveolar collapse, tumor size, and tumor infiltrating lymphocytes (TILs), while also evaluating the prognostic significance of alveolar collapse in invasive lung adenocarcinoma. 355 patients with solitary invasive lung adenocarcinoma were divided into two groups based on the maximum diameter of alveolar collapse: alveolar collapse ≤ 5 mm group and alveolar collapse > 5 mm group. Differences in clinicopathological characteristics, tumor size, TILs, and prognosis were compared between the two groups. The alveolar collapse > 5 mm group had a higher mean age, larger tumor diameter, and increased TILs levels compared to the alveolar collapse ≤ 5 mm group (P < 0.05). A moderate positive correlation was observed between alveolar collapse and tumor size (r = 0.646, P < 0.001). Lung adenocarcinoma with alveolar collapse > 5 mm demonstrated superior 5-year survival and acted as an independent prognostic indicator (HR=0.152, P = 0.004) in multivariate Cox regression analysis, alongside tumor size (HR=10.172, P = 0.034) and lymph node metastasis (HR=2.88, P = 0.017). The size of alveolar collapse is associated with TILs abundance, suggesting that the immune microenvironment may play a crucial role in alveolar collapse formation. Pathologists should take note of alveolar collapse in lung adenocarcinoma.

Prognostic impact of CD68+ tumor-associated macrophages in hepatocellular carcinoma: A meta-analysis.

BACKGROUND: Evidence from clinical research suggests that the tumor-associated macrophages (TAMs) were associated with prognosis in hepatocellular carcinoma (HCC). The aim of the present meta-analysis was to conduct a qualitative analysis to explore the prognostic value of CD68 + TAMs in HCC. METHODS: This study conducted a systematic search in Pubmed, Embase, the Cochrane Library and China National Knowledge Internet from inception of the databases to November 2023. The hazard ratio (HR) and 95% confidence interval (CI) were calculated employing fixed-effect or random-effect models depending on the heterogeneity of the included trials. The Newcastle-Ottawa Scale was used to evaluate the risk of prejudice. RESULTS: We analyzed 4362 HCC patients. The present research indicated that the expression levels Of CD68 + TAMs were significantly associated with overall survival (OS) (HR = 1.55, 95% CI: 1.30-1.84) and disease-free survival (DFS) (HR = 1.44, 95% CI: 1.17-1.78). Subgroup analysis based on cutoff values showed that the "Median" subgroup showed a pooled HR of 1.66 with a 95% CI ranging from 1.32 to 2.08, which was slightly higher than the "Others" subgroup that exhibited a pooled HR of 1.40 and a 95% CI of 1.07 to 1.84. The "PT" subgroup had the highest pooled HR of 1.68 (95% CI: 1.19-2.37), indicating a worse OS compared to the "IT" (pooled HR: 1.50, 95% CI: 1.13-2.01) and "Mix" (pooled HR: 1.52, 95% CI: 1.03-2.26) subgroups. Moreover, in the sample size-based analysis, studies with more than 100 samples (>100) exhibited a higher pooled HR of 1.57 (95% CI: 1.28 to 1.93) compared to studies with fewer than 100 samples (<100), which had a pooled HR of 1.45 (95% CI: 1.00-2.10). CONCLUSIONS: The analysis suggests that CD68 + TAMs were significantly associated with unfavorable OS and DFS in HCC patients, and may be served as a promising prognostic biomarker in HCC. However, more large-scale trials are needed to study the clinical value of TAMs in HCC.

Micropapillary Pattern in Invasive Mucinous Adenocarcinoma of the Lung: Comparison With Invasive Non-Mucinous Adenocarcinoma.

Background. The presence of a micropapillary pattern is associated with poor outcomes in lung adenocarcinoma. This study aimed to assess the clinicopathological features of micropapillary pattern in mucinous adenocarcinoma of the lung. Methods. The patients were stratified into three groups: the invasive mucinous adenocarcinoma group (60 patients), the mixed invasive mucinous adenocarcinoma group (33 patients), and the invasive non-mucinous adenocarcinoma group (237 patients). The presence of micropapillary pattern and its clinicopathological features were analyzed and compared between the three groups. Results. Compared to mixed invasive mucinous adenocarcinoma, invasive mucinous adenocarcinoma had lower frequencies of micropapillary pattern (28.3% vs 87.9%, respectively; P < .001) and lymph node metastasis (00.0% vs 15.1%, respectively; P = .005). The frequency of tumor spread through air space (STAS) in invasive mucinous adenocarcinoma (23.3%) was higher than that in invasive non-mucinous adenocarcinoma (6.3%; P < .001), while lower than that in mixed invasive mucinous adenocarcinoma (60.6%; P < .001). When the three groups were all accompanied by micropapillary pattern, there was no obvious difference in STAS between invasive mucinous adenocarcinoma with micropapillary pattern and mixed mucinous adenocarcinoma with micropapillary pattern (P > .05). No filigree pattern occurred in invasive mucinous adenocarcinoma with micropapillary pattern. Conclusions. The micropapillary pattern is frequently observed in invasive mucinous adenocarcinoma and has a better prognosis compared to mixed invasive mucinous adenocarcinoma and invasive non-mucinous adenocarcinoma. However, the malignancy of the micropapillary pattern in mixed mucinous adenocarcinoma was similar to that in invasive non-mucinous adenocarcinoma, even with the presence of mucus. These findings suggest that the development mechanisms of the micropapillary pattern in invasive mucinous adenocarcinoma and mixed mucinous adenocarcinoma may differ.

Prognostic Value of Hyperechoic Echo Halo in cN0 Papillary Thyroid Microcarcinoma and Its Correlation with Age and Gender.

Purpose. To investigate the pathology and prognostic value of hyperechoic echo halo in cN0 papillary thyroid microcarcinoma (PTMC) and the relationship between age, gender, and the formation of abnormal hyperechoic echo halo and cervical lymph node metastasis. Data of 97 patients who underwent surgical treatment for the first time for single PTMC between April 2016 and March 2017 were analyzed retrospectively. The boundary status of the PTMC was determined preoperatively. Grayscale values of the nodular center, hyperechoic echo halo, and normal thyroid tissue were acquired with Adobe Photoshop CS6 software. The histopathology of the boundary and status of the cervical lymph node metastasis were analyzed. Formation of abnormal hyperechoic halo and cervical lymph node metastasis in relation to age and gender were explored. The abnormal hyperechoic halo mainly represents cancer cell infiltration with reactive hyperplasia of inflammatory cells and fibrous tissue. In the hyperechoic halo group, the grayscale values for the nodular center, hyperechoic echo halo, and normal thyroid tissue were 1552.6 ± 578.6, 5792.0 ± 747.6, and 3582.7 ± 759.0, respectively (P < 0.05). The cervical lymph node metastasis rate was significantly lower in patients with hyperechoic halo (15.0%) than in those without (41.6%; P < 0.05) and significantly higher in those aged <45 years (53.3%) than in those aged ≥45 years (28.4%; P < 0.05). There were no significant correlations between gender and cervical lymph node metastasis or between age, gender, and hyperechoic halo formation (P > 0.05). cN0 PTMC patients with abnormal hyperechoic halo and age >45 years have a significantly reduced risk of cervical lymph node metastasis and relatively good prognosis.