Seizing the fate of lymph nodes in immunotherapy: To preserve or not?

Lymph node dissection has been a long-standing diagnostic and therapeutic strategy for metastatic cancers. However, questions over myriad related complications and survival outcomes are continuously debated. Immunotherapy, particularly neoadjuvant immunotherapy, has revolutionized the conventional paradigm of cancer treatment, yet has benefited only a fraction of patients. Emerging evidence has unveiled the role of lymph nodes as pivotal responders to immunotherapy, whose absence may contribute to drastic impairment in treatment efficacy, again posing challenges over excessive lymph node dissection. Hence, centering around this theme, we concentrate on the mechanisms of immune activation in lymph nodes and provide an overview of minimally invasive lymph node metastasis diagnosis, current best practices for activating lymph nodes, and the prognostic outcomes of omitting lymph node dissection. In particular, we discuss the potential for future comprehensive cancer treatment with effective activation of immunotherapy driven by lymph node preservation and highlight the challenges ahead to achieve this goal.

Interferon-γ priming enhances the therapeutic effects of menstrual blood-derived stromal cells in a mouse liver ischemia-reperfusion model.

BACKGROUND: Mesenchymal stem cells (MSCs) have been used in liver transplantation and have certain effects in alleviating liver ischemia-reperfusion injury (IRI) and regulating immune rejection. However, some studies have indicated that the effects of MSCs are not very significant. Therefore, approaches that enable MSCs to exert significant and stable therapeutic effects are worth further study. AIM: To enhance the therapeutic potential of human menstrual blood-derived stromal cells (MenSCs) in the mouse liver ischemia-reperfusion (I/R) model via interferon-γ (IFN-γ) priming. METHODS: Apoptosis was analyzed by flow cytometry to evaluate the safety of IFN-γ priming, and indoleamine 2,3-dioxygenase (IDO) levels were measured by quantitative real-time reverse transcription polymerase chain reaction, western blotting, and ELISA to evaluate the efficacy of IFN-γ priming. In vivo, the liver I/R model was established in male C57/BL mice, hematoxylin and eosin and TUNEL staining was performed and serum liver enzyme levels were measured to assess the degree of liver injury, and regulatory T cell (Treg) numbers in spleens were determined by flow cytometry to assess immune tolerance potential. Metabolomics analysis was conducted to elucidate the potential mechanism underlying the regulatory effects of primed MenSCs. In vitro, we established a hypoxia/reoxygenation (H/R) model and analyzed apoptosis by flow cytometry to investigate the mechanism through which primed MenSCs inhibit apoptosis. Transmission electron microscopy, western blotting, and immunofluorescence were used to analyze autophagy levels. RESULTS: IFN-γ-primed MenSCs secreted higher levels of IDO, attenuated liver injury, and increased Treg numbers in the mouse spleens to greater degrees than untreated MenSCs. Metabolomics and autophagy analyses proved that primed MenSCs more strongly induced autophagy in the mouse livers. In the H/R model, autophagy inhibitors increased the level of H/R-induced apoptosis, indicating that autophagy exerted protective effects. In addition, primed MenSCs decreased the level of H/R-induced apoptosis via IDO and autophagy. Further rescue experiments proved that IDO enhanced the protective autophagy by inhibiting the mammalian target of rapamycin (mTOR) pathway and activating the AMPK pathway. CONCLUSION: IFN-γ-primed MenSCs exerted better therapeutic effects in the liver I/R model by secreting higher IDO levels. MenSCs and IDO activated the AMPK-mTOR-autophagy axis to reduce IRI, and IDO increased Treg numbers in the spleen and enhanced the MenSC-mediated induction of immune tolerance. Our study suggests that IFN-γ-primed MenSCs may be a novel and superior MSC product for liver transplantation in the future.

[Application of 1470 nm semiconductor laser in the treatment of benign prostatic hyperplasia in ultra-aged patients].

OBJECTIVE: To investigate the clinical effect and safety of transurethral 1470 nm semiconductor laser vaporization and cutting in the treatment of super high age and high risk benign prostatic hyperplasia. METHODS: The clinical data of 38 patients with super-high-risk prostate who underwent transurethral surgery in our hospital from April 2016 to December 2017 were retrospectively analyzed. All patients had obvious progressive dysuria. The diagnosis of benign prostatic hyperplasia was confirmed by urinary color Doppler ultrasound, anal finger examination, PSA, prostate biopsy, etc., and prostate cancer was excluded. Each patient was aged ≥85 years old and combined with one or more types. Senile basic diseases such as diabetes, hypertension, coronary heart disease, emphysema, sequelae of cerebral infarction, etc. The patients were randomly divided into two groups. The observation group was treated with transurethral 1470 nm semiconductor laser vaporization and the control group was treated with transurethral plasma electrotomy. To observe the changes of vital signs, bleeding, duration of surgery, postoperative bladder irrigation time, urinary catheter retention time, and changes of hemoglobin before and after surgery. Surgical safety. The international prostate symptom score (IPSS), quality of life score (QoL), maximum urinary flow rate (Qmax), and post-void residual urine volume (PVR) were evaluated 2 months after surgery and compared with preoperative evaluation to evaluate the surgical outcome. RESULTS: All 38 operations were successfully completed.The vital signs of the patients were stable during the operation. The average operation time of the observation group and the control group was (79.6±24.7 vs 69.5±19.8) min, P>0.05. The hemoglobin decreased by (6.9±3.0) g/L vs (13.2±4.0) g/L， after operation.P<0.05; postoperative bladder irrigation time (14.7±2.8 vs 23.5±5.3)h, P<0.05; average postoperative urinary catheter retention time (3.8±0.4 vs 5.7±0.9)d, P<0.05; average postoperative hospital stay (5.3±1.1 vs 7.2±1.9)d, P<0.05; all patients were followed up for 2 months, IPSS, QoL, Qmax, PVR and other indicators were significantly improved compared with preoperative, no major bleeding, urinary incontinence, cardiopulmonary failure and Significant urinary tract irritation symptoms occur. CONCLUSION: Compared with plasma electric resection, transurethral 1470 nm semiconductor laser treatment of benign prostatic hyperplasia has the advantages of high safety and remarkable effect, especially suitable for patients with high age and high risk.

Microfluidic-based exosome isolation and highly sensitive aptamer exosome membrane protein detection for lung cancer diagnosis.

Non-invasive methods of detecting cancer by circulating exosomes are challenged by inefficient purification and identification. This study hereby proposed an automated centrifugal microfluidic disc system combined with functionalized membranes (Exo-CMDS) to isolate and enrich exosomes, which will then be processed by a novel aptamer fluorescence system (Exo-AFS) in order to detect the exosome surface proteins in an effective manner. Exo-CMDS features in highly qualified yields with optimal exosomal concentration of 5.1 × 109 particles/mL from trace amount of blood samples (<300 µL) in only 8 min, which truly accomplishes the exosome isolation and purification in one-step methods. Meanwhile, the limit of detection (LOD) of PD-L1 in Exo-AFS reaches as low as 1.58 × 105 particles/mL. In the trial of clinical samples, the diagnostic accuracy of lung cancer achieves 91% (95% CI: 79%-96%) in contrast to the exosome ELISA (area under the curve: 0.9378 versus 0.8733; 30 patients). Exo-CMDS and Exo-AFS display the precedence in the aspects of inexpensiveness, celerity, purity, sensitivity and specificity when compared with the traditional techniques. Such assays potentially grant a practicable way of detecting inchoate cancers and guiding immunotherapy in clinic.

Role of clinical data and multidetector computed tomography findings in acute superior mesenteric artery embolism.

BACKGROUND: Superior mesenteric artery embolism (SMAE) has acute onset and fast progression, which seriously threatens the life of patients. Multidetector computed tomography (MDCT) is one of the most important diagnostic methods for SMAE, which plays an important role in the diagnosis and prognosis of SMAE. AIM: To evaluate the value of combined clinical data and MDCT findings in the diagnosis of acute SMAE and predict the risk factors for SMAE-related death. METHODS: Data from 53 SMAE patients who received abdominal MDCT multi-phase enhancement and superior mesenteric artery digital subtraction angiography examinations were collected. Univariate cox regression and multivariate cox model were used to analyze the correlation between death risk and clinical and computed tomography features in SMAE patients. RESULTS: Univariate Cox regression model showed that intestinal wall thinning, intestinal wall pneumatosis, blood lactate > 2.1 mmol/L and blood pH < 7.35 increased the risk of death in patients with SMAE. After adjusting for age, sex, embolic involvement length and embolic distribution region, multivariate Cox regression model I showed that blood lactate > 2.1 mmol/L (HR = 5.26, 95%CI: 1.04-26.69, P = 0.045) and intestinal wall thinning (HR = 9.40, 95%CI: 1.05-83.46, P = 0.044) were significantly increases the risk of death in patients with SMAE. CONCLUSION: For patients with SAME, increased blood lactate and intestinal wall thinning are the risk factors for death; hence, close monitoring may reduce the mortality rate. Clinical observation combined with MDCT signs can significantly improve SMAE diagnosis.

[Testicular cavernous hemangioma associated with testicular torsion: A case report and review of the literature].

OBJECTIVE: To explore the clinical diagnosis and treatment of testicular cavernous hemangioma (TCH). METHODS: We retrospectively analyzed the clinical data on a case of TCH associated with testicular torsion treated in our hospital and reviewed the relevant literature. RESULTS: The patient underwent "right orchiectomy" after preoperative examinations. Intraoperative pathology indicated testicular parenchyma infarction, and postoperative pathology showed cavernous hemangioma with hemorrhage and infarction. No recurrence was observed during 3 years of postoperative follow-up. CONCLUSION: Testicular cavernous hemangioma is an extremely rare benign tumor of the testis, and rarely associated with testicular torsion. Preoperative and intraoperative pathology provides a basis for the selection of reasonable treatment.

Comparison of Retzius-Sparing Robot-Assisted Radical Prostatectomy vs. Conventional Robot-Assisted Radical Prostatectomy: An Up-to-Date Meta-Analysis.

Background: The Retzius space-sparing robot-assisted radical prostatectomy (RS-RARP) has shown better results in urinary continence, but its efficacy and safety compared to conventional robot-assisted radical prostatectomy (c-RARP) remain controversial. Material and Methods: A research was conducted in Medline via PubMed, Cochrane Library, EMBASE, and Web of Science up to January 4, 2021, to identify studies comparing RS-RARP to c-RARP. We used RevMan 5.3 and STATA 14.0 for meta-analysis. Results: A total of 14 studies involving 3,129 participants were included. Meta-analysis showed no significant difference in positive surgical margins (PSMs), but the RS-RARP group had significantly higher PSM rates in the anterior site [odds ratio (OR) = 2.25, 95% CI: 1.22-4.16, P = 0.01]. Postoperative continence in RS-RARP group at 1 month (OR = 5.72, 95% CI: 3.56-9.19, P < 0.01), 3 months (OR = 6.44, 95% CI: 4.50-9.22, P < 0.01), 6 months (OR = 8.68, 95% CI: 4.01-18.82, P < 0.01), and 12 months (OR = 2.37, 95% CI: 1.20-4.70, P = 0.01) was significantly better than that in the c-RARP group. In addition, the RS-RARP group had a shorter console time (mean difference = -16.28, 95% CI: -27.04 to -5.53, P = 0.003) and a lower incidence of hernia (OR = 0.35, 95% CI: 0.19-0.67, P = 0.001). However, there were no significant differences in estimated blood loss, pelvic lymph node dissection rate, postoperative complications, 1-year-biochemical recurrence rate, and postoperative sexual function. Conclusions: Compared with c-RARP, RS-RARP showed better recovery of continence, shorter console time, and lower incidence of hernia. Although there was no significant difference in overall PSM, we suggest that the surgeon should be more careful if the lesion is in the anterior prostate.

Optical signatures of Mott-superfluid transition in nitrogen-vacancy centers coupled to photonic crystal cavities: publisher's note.

This publisher's note contains corrections to Opt. Lett.44, 2081 (2019)OPLEDP0146-959210.1364/OL.44.002081.

[Performance and Membrane Fouling Properties in an Anaerobic Membrane Bioreactor for Salty Wastewater].

In the research, an anaerobic membrane bioreactor (AnMBR) was used to treat simulated salty organic wastewater, and the effect of salinity on reactor performance and membrane fouling properties was investigated. The results indicated that when the influent salinity increased gradually but was lower than 9.1 g·L-1, the reactor ran stably and the effluent performance was good. When the salinity increased to 10 g·L-1, the COD removal-efficiency, gas production, and methane content decreased significantly; meanwhile, the sludge concentration, sludge volume index (SVI), soluble microbial products (SMP), and extracellular polymeric substance (EPS) levels became elevated at first and then declined with the rising salinity. The system developed compact flocs and a high settling ability. The hollow fiber membrane module was run for three cycles in 118 d. The membrane operating cycle was extended from 31 d to 48 d with the increasing salinity, which favored the control of membrane fouling. SEM-EDX analysis results revealed that there were similar crystalline substances in the film membrane foulants, and Na, Mg, Al, Si, Cl, K, Ca, and Fe were the main inorganic elements. Excitation emission matrix (EEM) analysis results demonstrated that proteins and humic acids were the main components of the organic membrane foulants.

[Responses of soil microbial communities in mulberry rhizophere to intercropping and nitrogen application.] / æ¡‘æ ‘æ ¹é™ åœŸå£¤å¾®ç”Ÿç‰©å¯¹é—´ä½œå’Œæ–½æ°®çš„å“åº”.

In this study, the effects of intercropping with alfalfa and nitrogen application on the functional diversity of soil microbial community in mulberry rhizosphere were examined by Biolog-EcoplateTM technique, and principal component and canonical analyses. Compared to monoculture with no nitrogen (N) addition, monoculture with N application and intercropping with alfalfa remarkably reduced soil pH and significantly increased the contents of soil organic matter, soil available N, soil water content, and activities of peroxidase and urease. Monoculture with N application and intercropping with alfalfa (with or without N application) increased the AWCD values, diversity index, and the carbon source utilization ratios of soil microbes. Higher increments of these parameters were detected in the treatment of intercropping plus N application. The results of principal component analysis showed that N application and intercropping changed the capacity of the rhizosphere microbial community for utilizing carbon sources. The utilization of carbon sources highly related to the principal components by the rhizosphere microbial communities was similar in the treatments of monoculture with N application and intercropping without N application. The utilization of itaconic acid and D-glucamaminic acid in the latter was more than 4% and was significantly higher than that in the former. The results from redundancy analysis showed that the soil microbial diversity in mulberry rhizosphere of the treatment of monoculture without N application was positively correlated with polyphenol oxidase activity and negatively correlated with soil water content, whereas that of monoculture with N application and intercropping without N application was significantly positively correlated with soil pH and soil water content and negatively correlated with soil N avalaibility. The diversity of the microbes in the rhizosphere soil of mulberries under the treatment of intercropping with N application showed positive correlation with soil N availability and was significantly negatively correlated with soil pH.

Optical signatures of Mott-superfluid transition in nitrogen-vacancy centers coupled to photonic crystal cavities.

Detecting optical signatures of quantum phase transitions (QPT) in driven-dissipative systems constitutes a new frontier for many-body physics. Here we propose a practical idea to characterize the extensively studied phenomenon of photonic QPT, based on a many-body system composed of nitrogen-vacancy centers embedded individually in photonic crystal cavities, by detecting the critical behaviors of mean photon number, photon fluctuation, photon correlation, and emitted spectrum. Our results bridge these observables to the distinct optical signatures in different quantum phases and serve as good indicators and invaluable tools for studying dynamical properties of dissipative QPT.

[Intrarectal local anesthesia versus periprostatic nerve block in transrectal prostate biopsy for patients with different prostate volumes: A prospective randomized controlled trial].

OBJECTIVE: To evaluate the analgesic effect of intrarectal local anesthesia (IRLA) versus that of periprostatic nerve block anesthesia (PPNB) in initial transrectal ultrasound-guided prostate biopsy (TRUS-PB) for patients with different prostate volumes (PV). METHODS: A total of 253 patients undergoing initial TRUS-PB in our hospital from January 2014 to November 2017 were divided into three PV groups (<50 ml, 50－100 ml, and >100 ml), each again randomized into three subgroups (control, IRLA, and PPNB) with the random number table method. The pain during the procedure was assessed based on the Visual Analogue Scale (VAS) scores and the blind method was used by the biopsy operator, VAS valuator and data analyst. RESULTS: Among the patients with PV <50 ml, the VAS scores in the blank control, IRLA, and PPNB subgroups were 4.39±0.87, 3.51±0.84 and 3.43±1.07, respectively, remarkably higher in the control than in the IRLA and PPNB groups (P<0.05), but with no statistically significant differences between the latter two (P>0.05). Among those with PV of 50－100 ml, the VAS scores in the three subgroups were 4.50±1.05, 4.38±1.13 and 3.38±1.44, respectively, markedly higher in the control and IRLA than in the PPNB group (P<0.05), but with no statistically significant differences between the former two groups (P>0.05). Among those with PV >100 ml, the VAS scores in the three subgroups were 5.19±1.05, 5.00±1.25 and 4.19±0.91, respectively, remarkably higher in the former two groups than in the latter (P<0.05), but with no statistically significant differences between the former two groups (P>0.05). CONCLUSIONS: Either IRLA or PPNB can be recommended for initial TRUS-PB in patients with PV <50 ml, PPNB for those with PV of 50－100 ml, and PPNB with other painkillers for those with PV >100 ml.

Lower serum CA125 level, negative vascular invasion, and wild BRAF were strongly associated with better 2-year disease-free survival in patients with stage III colorectal cancer who received adjuvant chemotherapy.

BACKGROUND: Adjuvant chemotherapy plays important role in the comprehensive treatment of patients with stage III colorectal cancer. However, there is few molecular markers for predicting the therapeutic effect. OBJECTIVE: To identify factors that could predict adjuvant chemotherapy benefits in patients with stage III colorectal cancer. METHODS: The medical records of 294 patients were reviewed and analyzed using the Kaplan-Meier method and Cox analysis. RESULTS: Lower CA125 (⩽ 35 u/ml, P= 0.0015) serum levels, stage IIIa (P= 0.0027), 1-3 positive lymph nodes (P= 0.0256), negative vascular invasion (P= 0.0215), lower CA199 (⩽ 27 u/ml, P= 0.0038) serum levels, and wild-type BRAF status (P= 0.0125) were significantly associated with a higher 2-year DFS rate in patients with stage III colorectal cancer. However, in multivariate COX analysis, the association remained significant only for CA125 levels (vs. ⩽ 35 u/ml group, HR 3.341; 95% CI, 1.198-9.316; P= 0.0212), vascular invasion (vs. negative vascular invasion, HR, 2.349; 95% CI, 1.227-4.499; P= 0.01), and BRAF (V600E) (vs. wild Braf, HR, 7.794; 95% CI, 1.867-32.531; P= 0.0049). CONCLUSION: Lower CA125 serum levels, negative vascular invasion, and wild-type BRAF status were significantly associated with improved 2-year DFS rates among patient with stage III disease who received adjuvant chemotherapy.

Study on the Method of Voigt Profiles Two Wings Fitting Non-Uniform Flow Field Absorbance.

In the field of the absorption spectrum, especially for direct tunable diode laser absorption spectroscopy (dTDLAS) technology, the integrated area of the absorption spectrum is needed to be measured accurately for calculating the temperature and the component concentration of the flow field. Doing single optical path absorption spectroscopic measurement in the non-uniform flow field, spectral lineshape broadening is varied with the flow changes, in previous research reports, researchers mainly use single Voigt or Lorentz profile to fit absorbance curve or use directly integral to obtain the integrated area of the absorption spectrum. There are some shortcomings in these methods, resulting in certain error between the fitting result and the actual area, which is not conducive to the accurate measurement of flow field parameters. Firstly, the error is analyzed theoretically, and then, we adopt the simulation method to obtain the error size of the method. Finally, we proposed the Voigt wings fitting absorbance method to reduce the fitting error. The operation of Voigt wings fitting method is to Select the wings of the spectral line, and then use Voigt profile fitting, The difference between the two wings was used the numerical integral method to calculate area, the integrated area is sum of Voigt profile fitting area and numerical integral area. We have used water vapor as the target gas, with eight absorption lines which have different low-level states energy from HITRAN 2012 database being selected-, building two kinds of non-uniform flow field model base on the flat flame furnace, and through the method of segmentation to equivalent processing the no uniformity of flow field. Using Voigt profile fitting method, numerical integral method and Voigt profile wings fitting method to obtain the integral area of models, the error size is obtained by comparing with the theoretical value. As the result of contrast, the fitting error of Voigt profile fitting method is large and related to the different absorption line, the error of numerical integral method is biggest but it is nothing to do with absorption line, the fitting error of Voigt profile wings fitting method is least and stable. By force of contrast, we determined the appropriate method to obtain integral area in the different non-uniform flow field, which is beneficial to obtain accurate integrated area and flow field parameters.

Exosome-Transmitted lncARSR Promotes Sunitinib Resistance in Renal Cancer by Acting as a Competing Endogenous RNA.

Sunitinib resistance is a major challenge for advanced renal cell carcinoma (RCC). Understanding the underlying mechanisms and developing effective strategies against sunitinib resistance are highly desired in the clinic. Here we identified an lncRNA, named lncARSR (lncRNA Activated in RCC with Sunitinib Resistance), which correlated with clinically poor sunitinib response. lncARSR promoted sunitinib resistance via competitively binding miR-34/miR-449 to facilitate AXL and c-MET expression in RCC cells. Furthermore, bioactive lncARSR could be incorporated into exosomes and transmitted to sensitive cells, thus disseminating sunitinib resistance. Treatment of sunitinib-resistant RCC with locked nucleic acids targeting lncARSR or an AXL/c-MET inhibitor restored sunitinib response. Therefore, lncARSR may serve as a predictor and a potential therapeutic target for sunitinib resistance.

[Laser Tuning Performance Testing and Optimization in TDLAS Oxygen Measuring Systems].

TDLAS (tunable diode laser absorption spectroscopy) technology, with its unmatched advantages such as high selectivity molecular spectra, fast response, high sensitivity, non-contact measuring, become the preferred scheme for combustion process diagnosis, and can be effectively used for oxygen measuring. DFB (distributed feedback) laser diode with its small size, low power consumption, long service life, narrow linewidth, tunable wavelength has become the main choice of the TDLAS system. Performance of laser tuning characteristics is a key factor restricting TDLAS's measuring performance. According to TDLAS oxygen measuring system's working requirements, a simple experimental method was used to test and analyze tuning characteristics such as wavelength current, power current and wavelength temperature of a 764 nm DFB laser diode in the system. Nonlinear distortion of tuning curves was obvious, which affects oxygen measuring accuracy. The laser spectra's characteristics such as narrow linewidth, high side mode suppression ratio and wide wavelength tuning range are obvious, while its wavelength-current tuning curve with a tuning rate of about 0.023 nm x mA(-1) is not strictly linear. The higher the temperature the greater the threshold current, the PI curve is not strictly linear either. Temperature tuning curve is of good linearity, temperature-wave-length tuning rate keeps constant of about 0.056 nm/DEG C. Temperature tuning nonlinearity can be improved by high temperature control accuracy, and current power nonlinearity can be improved by setting the reference light path. In order to solve the wavelength current tuning nonlinear problems, the method of DA controlling injection current was considered to compensate for non-linear wavelength current tuning according to DFB laser diode tuning mechanism and polynomial fitting of test results. In view of different type of lasers, this method needs only one polynomial fitting process before the system's initial work. The compensation scheme is reasonable and the realization is simple, what's more, it does not affect the measuring process. The experiments prove that XI curve's linear fit residuals are less than 1 µm after compensation, far less than those of before compensation 22 pm, the compensation effect is obvious, which provided a basis for various oxygen parameters' TDLAS measuring and inversion.

[Reconstruction Research for Gas Concentration and Temperature of Flame Based on Algebraic Reconstruction Technique].

We specify water vapor among combustion products as the target gas based on tunable diode absorption spectroscopy in this paper. The direct absorption signals of water vapor after being processed can be used to calculate the gas concentration distributions and temperature distributions of the combustion region of methane and air flat flame furnace via algebraic reconstruction technique (ART). In the numerical simulation, reconstruction region is a grid of five by five, we assume a temperature and water vapor concentration distribution of 25 grid, then simulate different direction laser rays which cross the combustion region, generating projection of each ray, by ART reconstruction algorithm, it turns out that the temperature and water vapor distribution reconstruction error is less than 1%. In the experiment, we chose a distributed-feedback laser to scan the target gas H2O7 153.722, 7 153.748 and 7 154.354 cm(-1) as absorbtion line pair to measure temperature of the flame, we consider the former two line as one absorbtion line. By Stages multi-directional scanning, the authors abtain 16 different regions distributin of temperature and gas concentration of furnace when we collecte 30 different angle data by spectral data processing, reconstruction algorithm, two absorbtion line ratio method for temperature sensing, finding the temperature and water concentration are higher in the center than in the edge, it turns out that the reconstruction algorithm is good enough to achieve the distributions of gas concentration and temperature of the combustion region.

[Measurements of CO2 Concentration Profile in Troposphere Based on Balloon-Borne TDLAS System].

The main source and sink of CO2 in the atmosphere are concentrated in the troposphere. It is of great significance to the study of CO2 flux and global climate change to obtain the accurate tropospheric CO2 concentration profile. For the characteristics of high resolution, high sensitivity and fast response of tunable diode laser absorption spectroscopy (TDLAS), a compact balloon-borne system based on direct absorption was developed to detect the CO2 concentration profiles by use of the 2 004. 02 nm, R(16), v1+v3 line without the interfere of H2O absorption and the CO2 density of the number of molecules below 10 km in the troposphere was obtained. Due to the balloon-borne environment, a compact design of one single board integrated with laser driver, signal conditioning, spectra acquiring and concentration retrieving was developed. Limited by the working capability and hardware resources of embedded micro-processor, the spectra processing algorithm was optimized to reduce the time-cost. Compared with the traditional TDLAS sensors with WMS technique, this system was designed based on the direct absorption technique by means of an open-path Herriott cell with 20 m optical-path, which avoided the process of standardization and enhanced the environmental adaptation. The universal design of hardware and software platform achieved diverse gas measuring by changing the laser and adjusting some key parameters in algorithm. The concept of compact design helped to reduce the system's power and volume and balanced the response speed and measure precision. The power consumes below 1.5 W in room temperature and the volume of the single board is 120 mm x 100 mm x 25 mm, and the measurement accuracy is ± 0.6 x 10(-6) at 1.5 s response time. It has been proved that the system can realize high precision detection of CO2 profile at 15 m vertical resolution in troposphere and TDLAS is an available method for balloon-borne detection.

Research on remote sensing of broadband absorbers by using near-infrared diode lasers.

This paper reports the development of an experimental technique for optical remote sensing of broadband absorbers in ambient air. Broadband absorbers have been difficult to detect due to a lack of narrow absorption features, which makes it hard to separate them from interference with other absorbing species and background. In combination with a multidimensional linear regression procedure, we have developed a further step to correct for water vapor and background influences. Various physical processes limiting the detection sensitivity were studied and solutions were developed to reduce their influences. Although the received optical signal from backscatter was very weak as no corner cube reflector was used, we have demonstrated the technique on remote sensing of broadband absorption of ethanol vapor in ambient air with a moderate detection limit of 200 ppm · m. This portable handheld system is particularly suitable for quick "point-and-measure" applications. The developed technique is also applicable for detection of other broadband absorbers.

[Study of high temperature water vapor concentration measurement method based on absorption spectroscopy].

Tunable diode laser absorption spectroscopy (TDLAS) has been developed to realize the real-time and dynamic measurement of the combustion temperature, gas component concentration, velocity and other flow parameters, owing to its high sensitivity, fast time response, non-invasive character and robust nature. In order to obtain accurate water vapor concentration at high temperature, several absorption spectra of water vapor near 1.39 µm from 773 to 1273 K under ordinary pressure were recorded in a high temperature experiment setup using a narrow band diode laser. The absorbance of high temperature absorption spectra was calculated by combined multi-line nonlinear least squares fitting method. Two water vapor absorption lines near 7154.35 and 7157.73 cm(-1) were selected for measurement of water vapor at high temperature. A model method for high temperature water vapor concentration was first proposed. Water vapor concentration from the model method at high temperature is in accordance with theoretical reasoning, concentration measurement standard error is less than 0.2%, and the relative error is less than 6%. The feasibility of this measuring method is verified by experiment.