Manganese(III) porphyrin oligomers as high-relaxivity MRI contrast agents.

Manganese(III) porphyrins (MnIIIPs) as MRI contrast agents (CAs) have drawn particular attention due to their high longitudinal relaxivity (r1) and unique biodistribution. In this work, two MnIIIP-based oligomers, MnPD and MnPT, were designed to further improve the relaxivity with ease of synthesis. The two compounds were fully characterized and their nuclear magnetic relaxation dispersion (NMRD) profiles were acquired with a fast field cycling NMR relaxometer. Both of the compounds exhibited extended high molar r1 at high fields, higher than that of Gd-DTPA, the first clinical gadolinium(III)-based MRI CA. The r1 value of per manganese atom increased with the increasing number of MnIIIP building blocks, suggesting rotational correlation time (τR) played dominant role in the r1 dispersion. The toxicity of the two MnIIIPs and the imaging effectiveness were estimated in vitro and in vivo. With good biocompatibility, significant contrast enhancement, and complete excretion in 24 h, MnPD and MnPT are both promising for high field clinical applications. The applied strategy also potentially provided a facile approach for creation of more MnIIIP oligomer as efficient T1 MRI CAs.

[Research on preprocessing method of near-infrared spectroscopy detection of coal ash calorific value].

The calorific value of coal ash is an important indicator to evaluate the coal quality. In the experiment, the effect of spectrum and processing methods such as smoothing, differential processing, multiplicative scatter correction (MSC) and standard normal variate (SNV) in improving the near-infrared diffuse reflection spectrum signal-noise ratio was analyzed first, then partial least squares (PLS) and principal component analysis (PCR) were used to establish the calorific value model of coal ash for the spectrums processed with each preprocessing method respectively. It was found that the model performance can be obviously improved with 5-point smoothing processing, MSC and SNV, in which 5-point smoothing processing has the best effect, the coefficient of association, correction standard deviation and forecast standard deviation are respectively 0.9899, 0.00049 and 0.00052, and when 25-point smoothing processing is adopted, over-smoothing occurs, which worsens the model performance, while the model established with the spectrum after differential preprocessing has no obvious change and the influence on the model is not large.

Rosai-Dorfman disease mimicking craniopharyngioma: a challenging differential diagnosis. Illustrative case.

BACKGROUND: Rosai-Dorfman disease (RDD) is a rare non-Langerhans histiocytic disorder with less than 5% central nervous system involvement and is often mistaken for meningioma given the similarity in imaging features. The authors present the unique case of a 44-year-old female who presented with ongoing visual impairment. OBSERVATIONS: A purely suprasellar mass was noted on magnetic resonance imaging and was initially diagnosed as craniopharyngioma. Unexpectedly, the pathology report revealed RDD. LESSONS: To date, only six cases of sellar RDD have been reported, and our case is the first reported with a purely suprasellar presentation. No standard treatment has been established for RDD, and next-generation sequencing may be a promising therapeutic option.

Continuous intrathecal saline infusion for treating refractory spontaneous intracranial hypotension: A case report.

Spontaneous intracranial hypotension (SIH) is a poorly understood condition that presents with a wide variety of symptoms, ranging from mild headaches to coma. It is typically caused by continuous spontaneous leakage of spinal cerebrospinal fluid (CSF), resulting in orthostatic headaches. However, the appropriate management of refractory SIH remains unclear. A 50-year-old man presented with orthostatic headache followed by a rapid decline in mental status. The imaging findings were consistent with the diagnosis of SIH, with bilateral cerebral subdural hematomas and abnormal fluid collection in the posterior epidural space from the T2 to T12 levels. Computed tomography myelography of the whole spine revealed multiple high-flow CSF leakages at the T6 to T8 levels. Despite treatment with bilateral burr hole drainage for subdural hematomas and repeated lumbar epidural blood patch (EBP) three times, the patient's condition worsened and he developed stupor. A lumbar intrathecal saline bolus (90 ml) was administered to restore CSF depletion. The patient's verbal function improved immediately, and continuous intrathecal saline infusion was administered at a rate of 10 ml/h for two days. The patient's stupor gradually resolved, and after his symptoms improved, the EBP injection was repeated at the T8 level. The patient recovered completely, and during the six-year follow-up, there were no signs of recurrence. SIH may cause a refractory decline in mental status, and lumbar intrathecal saline infusion may help arrest or reverse an impending central (transtentorial) herniation. This case demonstrates an appropriate bolus and continuous infusion of normal saline, and documents the resolution of SIH. This maneuver may change the CSF flow pattern and aims to seal the CSF fistula. Further studies are needed to better understand the mechanism of intrathecal saline infusion and establish effective treatment strategies for refractory cases of SIH.

Adjuvant imatinib treatment after R0 resection for patients with high-risk gastrointestinal stromal tumors: a median follow-up of 44 months.

BACKGROUND: The optimal duration of Imatinib adjuvant treatment for patients with high-risk gastrointestinal stromal tumors (GISTs) is uncertain. PATIENTS AND METHODS: A total of 90 patients with high-risk GISTs after curative resection were recruited into this non-randomized case-control study, including 35 having Imatinib adjuvant therapy and 55 having follow-up alone. The recurrence-free survival (RFS) was compared. RESULTS: After a median follow-up of 44.0 months, a significantly reduced recurrence rate was observed in the treatment group than the control group (17.1% vs. 78.2%, P = 0.000). One-year, 2-year, and 3-year RFS rates were 100% vs. 70.9%, 88.0% vs. 37.8%, and 88.0% vs. 27.5%, respectively; with a significant advantage for Imatinib adjuvant therapy versus the surgery only (P = 0.000, HR 0.122, 95% CI 0.041-0.363). Continuation Imatinib treatment further improved RFS by comparison with the interruption treatment (both 2-year and 3-year RFS were 95.8% vs. 63.6%, P = 0.011, HR 0.103, 95% CI 0.012-0.883). There were no serious adverse events in the adjuvant therapy group. CONCLUSIONS: Imatinib Adjuvant therapy could significantly prolong the RFS of patients with high-risk GISTs. Extended Imatinib adjuvant treatment strategy may further reduce the risk of relapse with a low drug resistance rate and toxicity profile.

[Effect of number of resected lymph nodes on the prognosis of gastric cancer patients without lymphatic metastasis].

OBJECTIVE: To investigate the long-term correlation between the number of resected lymph nodes (LNs) and the prognosis of patients with node-negative gastric cancer. METHODS: From January 1995 to December 2004, 221 patients with gastric cancer underwent D2 radical resection and were proved with no nodal involvement. The clinical records of the patients were analyzed retrospectively. The relationships of the dissected LNs number to 5-year survival rate and post-operative complication rate were analyzed respectively. RESULTS: The overall 5-year survival rate of this group was 83.5%. The total number of dissected LNs was one independent prognostic factors in this group. Among patients with the same depth of tumor invasion, the more the number of dissected LNs, the better the survival would be (P < 0.05). The patients had better long-term survival outcomes with dissected LNs counts of more than 15 for cases with pT1-2 tumor, and more than 20 for cases with pT3 tumor. The post-operative complication rate was 10.8% and it was not significantly correlated with the number of dissected lymph nodes (P > 0.05). CONCLUSIONS: The number of dissected LNs is an independent prognostic predicting factor for lymph node-negative gastric cancer. Sufficient dissection of LNs is recommended to improve the patients' long-term survival. Suitable increment of dissected LNs count would not increase the post-operative complication rate.

[Efficiency of laparoscopic D2 radical gastrectomy in gastric cancer: experiences of 218 patients].

OBJECTIVE: To explore the feasibility and efficacy of laparoscopic D2 radical gastrectomy in patients with gastric cancer. METHODS: The clinical data of 529 patients with gastric cancer underwent D2 radical resection from January 2007 to March 2009 were analyzed retrospectively. Among the patients, 218 cases underwent laparoscopic D2 gastrectomy (LAG group) and 311 cases received open gastrectomy (OG group). The patients' operation, number of retrieved lymph nodes, recovery, postoperative morbidity and mortality were compared between the two groups. RESULTS: The operative time in LAG group was (237 +/- 42) min, and was significantly longer than that in OG group [(229 +/- 42) min, P < 0.05]. However, the mean blood loss [(81 +/- 100) ml vs. (171 +/- 211) ml], number of patients needed blood transfusion (7 vs. 44 cases), first flatus time [(4.1 +/- 2.3) d vs. (5.0 +/- 1.4) d], time to resume soft diet [(4.5 +/- 2.2) d vs. (5.5 +/- 1.4) d] and postoperative hospital stay [(12 +/- 4) d vs. (14 +/- 4) d] in the two groups were all different statistically (P < 0.05), and all were better in LAG group. In LAG group, the operative time of patients with total gastrectomy was (250 +/- 46) min, and was significantly longer than that with distal gastrectomy (228 +/- 37) min (P < 0.05), but there was no significant differences in other aspects of patients' recovery between the two operation types. The postoperative morbidity of LAG group and OG group were 11.9% and 19.0%, respectively (P < 0.05). For all patients, the mean number of retrieved lymph nodes was (29 +/- 10) and the median number was 28. The mean number of retrieved lymph nodes was not significantly different between the two groups [(28 +/- 10) in LAG group vs. (29 +/- 9) in OG group, P > 0.05]. Thirteen patients (6.0%) converted to open surgery in LAG group. CONCLUSION: Laparoscopic D2 radical gastrectomy is a safe and feasible procedure with quick recovery, and it is comparable with open gastrectomy in lymph node dissection.

[Prognostic analysis of splenectomy in patients with advanced proximal gastric cancer.].

OBJECTIVE: To evaluated the prognostic impact of splenectomy on patients with advanced proximal gastric cancer. METHODS: The clinical records of 237 patients with advanced proximal gastric cancer who underwent D2 curative resection combined with splenectomy from January 1980 to June 2003 were analyzed retrospectively. Seventy-five patients presented with No.10 lymph nodes metastasis, while 162 patients did not. Potential patient prognostic factors were evaluated by univariate and multivariate analysis. The independent prognostic factors of patients were performed subgroup analysis. RESULTS: The 5-year survival rate was 27.7% for patients with No.10 lymph nodes metastasis and 35.4% for patients without, the difference was statistically significant between the two groups (P < 0.05). On univariate analysis, lymph node metastasis, macroscopic appearance, depth of invasion, type of gastrectomy and No.10 lymph nodes metastasis were predictive factors of survival. The depth of invasion, type of gastrectomy and No.10 lymph nodes metastasis were independent prognostic factors. In the subgroup analysis, the survival rates of T3 patients with and without No.10 lymph nodes metastasis was 34.5% and 39.7%, respectively (P > 0.05). For patients undergoing total gastrectomy, survival rates were 31.2% and 36.7%, respectively (P > 0.05). CONCLUSIONS: To improve patient prognosis, total gastrectomy with splenectomy should be recommended for patients with T3 proximal gastric cancer with No.10 lymph node metastasis.

[Study on classification of ethylene treated and non-ethylene treated watermelons by visible/near infrared spectroscopy].

According to the fact that farmers often picked unripe watermelon and treated them with high concentration ethylene to quicken ripeness, classification experiments on the two classes of watermelon mentioned above were conducted based on the Vis/NIR spectroscopy diffuse transmittance technique. In the discriminant analysis, a method to classify them by diffuse transmittance ration at two wavelengths was adopted to discriminate them. Result of mistake ratio 32.5% for samples without ethylene treatment and 20% for ethylene treatment samples indicated that this method could discriminate the two classes of watermelons roughly. Mahalanobis distance and partial least square methods were also used here for discriminant analysis and satisfied results were obtained. The first derivative spectra with Norris derivative filtering of samples without being ethylene-treated using Mahalanobis distance discriminant analysis got the result of mistake ratio 1.67% for calibration set, no mistake for prediction set and no mistake for samples being ethylene treated. No mistake took place for the second derivative spectra using partial least square method. In discriminant analysis, spectral data pretreatment methods influence the discriminant results and it should be selected according to the analysis methods.

[Study on Vis/NIR spectra detecting system for watermelons and quality predicting in motion].

To make Vis/NIR diffuse transmittance technique applied to quality prediction for watermelon in motion, the dynamic spectra detecting system was rebuilt. Spectra detecting experiments were conducted and the effects of noises caused by motion on spectra were analyzed. Then the least--square filtering method and Norris differential filtering method were adopted to eliminate the effects of noise on spectra smoothing, and statistical models between the spectra and soluble solids content were developed using partial least square method. The performance of different models was assessed in terms of correlation coefficients (r) of validation set of samples, root mean square errors of calibration (RMSEC) and root mean square errors of prediction (RMSEP). Calibration and prediction results indicated that Norris differential method was an effective method to smooth spectra and improve calibration and prediction results, especially, with r of 0.895, RMSEC of 0.549, and RMSEP of 0.760 for the calibration and prediction result of the first derivative spectra.

[Analysis of the pattern of solitary lymph node metastasis in gastric cancer and its prognosis].

OBJECTIVE: To explore the pattern of solitary lymph node(LN) metastasis in gastric cancer and its prognosis. METHODS: The clinical records of 83 patients with gastric cancer presenting solitary LN metastasis who underwent D2 radical resection from January 1995 to December 2003 were analyzed retrospectively. The precise stations of the metastasis of LN and their correlation with the location of primary tumor were studied. The 5-year survival rates were compared between patients with and without skipping LN metastasis. The prognostic factors were evaluated by using univariate and multivariate analyses. RESULTS: Among the 83 patients with pathologically proven solitary LN metastasis, 64 cases (77%) presented with the perigastric nodes metastasis (N1 area), and 19 cases (23%) in N2 area without N1 involvement (skipping LN metastasis). For tumors in the upper and middle third stomach, the No. 3 station was the most common first metastasized LN station (40% and 42%, respectively). While for tumors in the lower third stomach, the No.6 station was the mostly affected LN (33%). Of the patients, 77 cases were followed up for 5-14 years, the median survival time was 77.0 months, and the overall 5-year survival rate was 63%. The 5-year survival rates of the patients with and without skipping LN metastasis was 52% and 67% respectively, there was no significant difference between the two groups (P>0.05). The serosal invasion and pathological types were influencing factors of the 5-year survival rate on univariate analysis. But with multivariate analysis, only the serosal invasion was an independent factor affecting the survival. CONCLUSIONS: Perigastric nodes are the most common first sites of tumor metastasis, making them the main targets of operative sentinel lymphatic mapping procedures. The patients with serosal invasion have poorer prognosis.

Effect of lymphadenectomy extent on advanced gastric cancer located in the cardia and fundus.

AIM: To analyze the prognostic impact of lymphade-nectomy extent in advanced gastric cancer located in the cardia and fundus. METHODS: Two hundred and thirty-six patients with advanced gastric cancer located in the cardia and fundus who underwent D2 curative resection were analyzed retrospectively. Relationships between the numbers of lymph nodes (LNs) dissected and survival was analyzed among different clinical stage subgroups. RESULTS: The 5-year overall survival rate of the entire cohort was 37.5%. Multivariate prognostic variables were total LNs dissected (P < 0.0001; or number of negative LNs examined, P < 0.0001), number of positive LNs (P < 0.0001), T category (P < 0.0001) and tumor size (P = 0.015). The greatest survival differences were observed at cutoff values of 20 LNs resected for stage II (P = 0.0136), 25 for stage III(P < 0.0001), 30 for stage IV (P = 0.0002), and 15 for all patients (P = 0.0024). Based on the statistically assumed linearity as best fit, linear regression showed a significant survival enhancement based on increasing negative LNs for patients of stages III (P = 0.013) and IV (P = 0.035). CONCLUSION: To improve the long-term survival of patients with advanced gastric cancer located in the cardia and fundus, removing at least 20 LNs for stage II, 25 LNs for stage III, and 30 LNs for stage IV patients during D2 radical dissection is recommended.

Prognostic impact of metastatic lymph node ratio in advanced gastric cancer from cardia and fundus.

AIM: To investigate the prognostic impact of the metastatic lymph node ratio (MLR) in advanced gastric cancer from the cardia and fundus. METHODS: Two hundred and thirty-six patients with gastric cancer from the cardia and fundus who underwent D2 curative resection were analyzed retrospectively. The correlations between MLR and the total lymph nodes, positive nodes and the total lymph nodes were analyzed respectively. The influence of MLR on the survival time of patients was determined with univariate Kaplan-Meier survival analysis and multivariate Cox proportional hazard model analysis. And the multiple linear regression was used to identify the relation between MLR and the 5-year survival rate of the patients. RESULTS: The MLR did not correlate with the total lymph nodes resected (r = -0.093, P = 0.057). The 5-year overall survival rate of the whole cohort was 37.5%. Kaplan-Meier survival analysis identified that the following eight factors influenced the survival time of the patients postoperatively: gender (c2 = 4.26, P = 0.0389), tumor size (c2 = 18.48, P < 0.001), Borrmann type (c2 = 7.41, P = 0.0065), histological grade (c2 = 5.07, P = 0.0243), pT category (c2 = 49.42, P < 0.001), pN category (c2 = 87.7, P < 0.001), total number of retrieved lymph nodes (c2 = 8.22, P = 0.0042) and MLR (c2 = 34.3, P < 0.001). Cox proportional hazard model showed that tumor size (c2 = 7.985, P = 0.018), pT category (c2 = 30.82, P < 0.001) and MLR (c2 = 69.39, P < 0.001) independently influenced the prognosis. A linear correlation between MLR and the 5-year survival was statistically significant based on the multiple linear regression (beta = -0.63, P < 0.001). Hypothetically, the 5-year survival would surpass 50% when MLR was lower than 10%. CONCLUSION: The MLR is an independent prognostic factor for patients with advanced gastric cancer from the cardia and fundus. The decrease of MLR due to adequate number of total resected lymph nodes can improve the survival.

[Impact of negative lymph node number on prognosis advanced cancer of cardiac and stomach fundus].

OBJECTIVE: To analyze the impact of negative lymph node number on the prognosis of advanced cancer of the cardia and stomach fundus. METHODS: 236 patients with advanced cancer of the cardia and stomach fundus underwent D2 radical resection. 5-year survival rate and recurrence rate were followed up and the relationships of lymph node (LN) number to 5-year survival rate and recurrence rate were analyzed respectively, according to LN count subgroups. RESULTS: The 5-year survival rate of the entire cohort was 37.5%. The number of metastasis negative LNs was positively correlated with the LNs examined (P < 0.05). For the cancer at the same stage, the higher the number of metastasis negative LNs the higher the 5-year survival rate (P < 0.05). Linear correlation analysis showed that along with the increase of the number of negative LNs the post-operative survival rate increased. In the cancers at the stages III and IV, the 5-year survival rate increased by 6.09% and 7.65% respectively compared to the predicted values (P = 0.013 and P = 0.035). The overall recurrence rate was 61.0% within 5 years after surgery. For the cancers at the stages III and IV, the more the number of negative LNs the higher the 5-year survival rates (P < 0.05). In the cancers at the stages II and IV there were significant differences in the recurrence rates among the subgroups with different numbers of negative LNs (all P < 0.002). CONCLUSION: Number of negative LNs has a close relation with stage-based survival prediction. Dissection of sufficient lymph nodes in the procedure of D2 dissection should be recommended so as to improve the long-term therapeutic effects and reduce the recurrence rate.

[Curative effects of FTQ combined with cisplatin in treatment of advanced gastric cancer: a multicenter study].

OBJECTIVE: To determine the clinical toxicities and antitumor effects of a chemotherapy regimen of FTQ, a compound preparation of tegafur, the drug prototype of 5-furacil (5-FU), gimeracil (CDHP), a decomposition inhibitor of 5-FU, oteracil potassium, phosphorylation inhibitor of 5-FU, and combined with cisplatin in patients with inoperable locally or metastatic advanced gastric cancer. METHODS: 119 patients with inoperable locally or metastatic advanced gastric cancer admitted in 10 hospitals in China were divided into 2 groups: FTQ group (n = 59), undergoing a 3-week regime, i.e. oral use of 80 mg x m(-2) x d(-1) for 14 d and then discontinuance for 1 week and intravenous drip cisplatin 75 mg/m2 on days 1-3; and control group (n = 60) undergoing a 3-week regimen including oral use of tegafur 800 mg x m(-2) x d(-1) tid for 14 d and then discontinuance for 1 week and intravenous drip of cisplatin 75 mg/m2 on days 1-3. The curative was evaluated after at least after 2 regimens. RESULTS: There were 102 patients in the per-protocol population. The overall response rate of the FTQ group was 28. 3% (15/53), significantly higher than that of the control group (4.1%, 2/49, P = 0.004). The clinical improvement of the FTQ group was 50.9%, significantly higher than that of the control group (24.5%, P = 0.006). The main toxicities occurred in bone marrow and the digestive tract. The leucopenia and thrombocytopenia rates of the FTQ group were 47.45% and 32.22% respectively, both similar to those of the control group. There were no differences in the incidence rate of digestive canal side reaction between these 2 groups . CONCLUSION: The regimen of FTQ combined with cisplatin is generally well-tolerated and has substantial antitumor activity.

[Efficiency of D2 radical resection combined with splenectomy in T3 cancer of upper stomach].

OBJECTIVE: To analyze the efficacy and influence of D2 radical resection combined with splenectomy in T3 cancer of upper stomach. METHODS: From January 1980 to June 2002, 613 patients with T3 cancer of upper stomach received D2 radical resection. Of these cases, 102 underwent simultaneous splenectomy (splenectomy group), while 511 did not (spleen-preserved group). The metastatic rate of lymph nodes in splenic hilum and along the splenic artery (No. 10, No. 11), 5-year survival rates, recurrence rate, the postoperative complication rate and mortality rate were followed up and compared in the two groups. RESULTS: The metastasis rate of No. 10 was 23.5% for splenectomy group and 14.9% for spleen-preserved group (P < 0.05). No significant difference was found in No. 11 metastasis between the two groups. The 5-year survival rate of splenectomy group was 39.8%, and was 32.3% in spleen-preserved group (P > 0.05). The recurrence rate of splenectomy group was 55.9%, and was 60.3% in spleen-preserved group (P > 0.05). In the splenectomy group, the 5-year survival rates were similar between patients with and without No. 10 metastasis (P > 0.05). The postoperative complication rate and mortality rate of the splenectomy group were 19.6% and 4.9%, and were 13.7% and 3.1% in the spleen-preserved group, respectively; and no significant difference was found between the two groups (P > 0.05). CONCLUSIONS: D2 radical excision combined splenectomy should be recommended for stage T3 cancer of upper stomach when suspected with No. 10, No. 11 lymph nodes metastasis. Simultaneous splenectomy would not increase the postoperative complication rate and mortality rate.

Measurement of soluble solids content in watermelon by Vis/NIR diffuse transmittance technique.

Watermelon is a popular fruit in the world with soluble solids content (SSC) being one of the major characteristics used for assessing its quality. This study was aimed at obtaining a method for nondestructive SSC detection of watermelons by means of visible/near infrared (Vis/NIR) diffuse transmittance technique. Vis/NIR transmittance spectra of intact watermelons were acquired using a low-cost commercially available spectrometer operating over the range 350~1000 nm. Spectra data were analyzed by two multivariate calibration techniques: partial least squares (PLS) and principal component regression (PCR) methods. Two experiments were designed for two varieties of watermelons [Qilin (QL), Zaochunhongyu (ZC)], which have different skin thickness range and shape dimensions. The influences of different data preprocessing and spectra treatments were also investigated. Performance of different models was assessed in terms of root mean square errors of calibration (RMSEC), root mean square errors of prediction (RMSEP) and correlation coefficient (r) between the predicted and measured parameter values. Results showed that spectra data preprocessing influenced the performance of the calibration models. The first derivative spectra showed the best results with high correlation coefficient of determination [r=0.918 (QL); r=0.954 (ZC)], low RMSEP [0.65 degrees Brix (QL); 0.58 degrees Brix (ZC)], low RMSEC [0.48 degrees Brix (QL); 0.34 degrees Brix (ZC)] and small difference between the RMSEP and the RMSEC by PLS method. The nondestructive Vis/NIR measurements provided good estimates of SSC index of watermelon, and the predicted values were highly correlated with destructively measured values for SSC. The models based on smoothing spectra (Savitzky-Golay filter smoothing method) did not enhance the performance of calibration models obviously. The results indicated the feasibility of Vis/NIR diffuse transmittance spectral analysis for predicting watermelon SSC in a nondestructive way.

[Estimation of soluble solids content of intact citrus fruit by Vis/NIR spectroscopy].

Visible/Near-infrared (Vis/NIR) spectroscopy has become a very popular technique for the non-invasive assessment of intact fruit. The feasibility of using Vis/NIR spectroscopic technology for rapid quantifying soluble solids content (SSC) of citrus fruit was investigated by means of spectral transmittance mode. A total of 110 citrus fruit samples were used to develop the calibration and prediction models. The relationship between actual SSC and Vis/NIRS spectra of citrus fruit samples was analyzed via pricipal component regression (PCR) and partial least squares (PLS) regression method using TQ 6.2 spectral analysis software. Models based on the different spectral pre-processing methods were compared in the present research. Performance of different models was assessed in terms of root mean square errors of prediction (RMSEP) and correlation coefficients (r2) of prediction set of samples. The best predictive models feature a RMSEP of 0.538% and correlation coefficient (r2) of 0.801 for SSC. The results show that the Vis/NIR transmittance technique is a feasible, accurate and fast method for non-invasive estimation of citrus fruit SSC.

[Estimation of soluble solids content of apple fresh juice by FTNIR spectroscopy].

The feasibility of Fourier transform near infrared (FTNIR) spectroscopic technology for rapid quantifying the soluble solids content (SSC) of apple fresh juice was investigated by means of spectral transmittance technique. A total of 60 juice samples were used to develop the calibration models. The relationship between laboratory SSC and FTNIR spectra of apple fresh juices was analyzed via principal component regression (PCR) and partial least squares (PLS) regression method using TQ 6.2.1 quantitative software. Models based on different spectral ranges were compared. Performance of different models was assessed in terms of root mean square errors of prediction (RMSEP) and correlation coefficients (r2) of validation set of samples. The best prediction models had a RMSEP of 0.603 degree Brix and correlation coefficient (r2) of 0.997 for SSC. The results show that FTNIR transmittance technique is a feasible, accurate and fast method for non-invasive estimation of fruit fresh juice soluble solids content.

[Application of some different modeling algorithms to pear MT-firmness detection using NIR spectra].

Near infrared (NIR) spectroscopy is an instrumental method, which was widely studied and used for rapid and nondestructive detection of internal qualities of agricultural products. Statistical modeling is a very important and difficult process in NIR detection to establish the relationship between nondestructive NIR spectral data and interested quality index of the products. Classical multivariate calibration methods such as partial least square regression (PLSR), principle component regression (PCR), stepwise multilinear regression (SMLR) were often used for modeling. In the present study, besides these algorithms, another mixed algorithm was adopted for establishing a nonlinear model of NIR spectra and Magness Taylor(MT) firmness of "Xueqing" pears. The mixed algorithm was combined with SMLR and artificial neural network (ANN). NIR diffuse reflectance spectra of intact pears were measured in the spectral range of 800-2630 nm using InGaAs detector. However, only spectral information between 800 and 2500 nm was used for modeling because of the low signal to noise ratio beyond 2500 nm. Comparing the classical multivariate calibration methods of PLSR, PCR and SMLR, the modeling results using PLSR method were much better than the other two methods. Moreover, models based on original spectra turned out better results than models based on derivative spectra for all the three methods. The best results were r = 0.87, RMSEC = 3.88 N of calibration and r = 0.84, and RMSEP = 4.26 N of validation by using PLSR method based on original spectra. The mixed algorithm also performed better than SMLR and PCR, but was a bit worse than PLSR: r = 0.85, RMSEC = 4.15 N of calibration and r = 0.82, and RMSEP = 4.67 N of validation. The results indicated that fruit NIR spectra could be used for MT-firmness prediction when a proper algorithm was chosen, however, further study on statistic modeling is still necessary to improve the predicting performance.