Three-Dimensional Appearance and Physicochemical Properties of Pleurotus eryngii under Different Drying Methods.

This study investigated the effects of different drying methods on the drying characteristics, three-dimensional (3D) appearance, color, total polysaccharide content (TPC), antioxidant activity, and microstructure of Pleurotus eryngii slices. The drying methods included hot air drying (HAD), infrared drying (ID), and microwave drying (MD). The results showed that the drying method and conditions significantly influenced the drying time, with MD having a significant advantage in reducing the drying time. The 3D appearance of P. eryngii slices was evaluated based on shrinkage and roughness as quantitative indexes, and the best appearance was obtained by hot air drying at 55 and 65 °C. HAD and ID at lower drying temperatures obtained better color, TPC, and antioxidant activity, but MD significantly damaged the color and nutritional quality of P. eryngii. The microstructure of dried P. eryngii slices was observed using scanning electron microscopy, and the results showed that drying methods and conditions had an obvious effect on the microstructure of P. eryngii slices. Scattered mycelia were clearly observed in P. eryngii samples dried by HAD and ID at lower drying temperatures, while high drying temperatures led to the cross-linking and aggregation of mycelia. This study offers scientific and technical support for choosing appropriate drying methods to achieve a desirable appearance and quality of dried P. eryngii.

Comparison of contrast-enhanced ultrasound targeted biopsies versus standard systematic biopsies for prostate cancer correction in different PSA value groups in rural China.

OBJECTIVE: To investigate prostate cancer detection rate of different biopsy protocols in different PSA value groups in rural China. METHODS: A total of 186 patients underwent contrast-enhanced ultrasound (CEUS) in order to determine the puncture target prior to biopsy were enrolled in this retrospective study. All patients underwent 12-core SB combined with CEUS-TB. The biopsy results of different biopsy protocols were compared in patients with stratification by PSA value. RESULTS: Among the 186 patients underwent prostate biopsy, the histopathologic results revealed prostate cancer (PCa) in 117 cases (62.9%) and benign lesions in 69 cases (37.1%). The PCa detection rate between 8-core SB and 12-core SB showed no significant difference in PSA 4-10 ng/ml group, while the 12-core SB was significantly higher than CEUS-TB (44.9% versus 32.7%, P = 0.01). In PSA 10-20 ng/ml group, the significant difference was not seen between SB and CEUS-TB (50.0% versus 45.7%, P = 0.15). As for PSA greater than 20 ng/ml group, the PCa detection rate by SB was higher than CEUS-TB, but showed no statistically significance (79.1% versus 76.9%, P = 0.15). In the overall patients, the biopsy core positive rate of CEUS-TB was significantly higher than SB (97% versus 55.5% and 28.5%, P = 0.0001). CONCLUSION: The flexible use of SB combined with CEUS-TB can reduce the number of biopsy cores in higher PSA groups. It has clinical importance in the detection of PCa in different PSA value groups in rural China.

The value of oral contrast ultrasonography in the diagnosis of gastric cancer in elderly patients.

BACKGROUND: This study aims to investigate the value of oral contrast ultrasonography (OCUS) in the diagnosis of gastric cancer in elderly patients. METHODS: OCUS data obtained from patients ≥ 60 years old were retrospectively analyzed and compared with gastroscopy results. RESULTS: Among the 12,716 subjects examined by OCUS, 5021 subjects were ≥ 60 years old, which accounted for 39.48% (5021/12,716). Gastritis, gastric polyp, benign ulcer, and gastric cancer were detected by OCUS in 1099 patients. Among them, 196 patients underwent gastroscopy. Furthermore, ulcerative lesions were detected in 32 patients by OCUS and in 51 patients by gastroscopy, and the coincidence rate was 62.74%. Among these patients, gastric cancer was diagnosed in 18 patients by OCUS with a detection rate of 1.64% (18/1099) and detected in 19 patients by gastroscopy with a diagnostic coincidence rate of 94.73% (18/19). Furthermore, benign ulcer was detected in 14 patients by OCUS and in 32 patients by gastroscopy, and the diagnostic coincidence rate was 43.75% (14/32). CONCLUSION: OCUS helps to timely detect senile gastric cancer and can be used as a suitable technique for the detection of gastric diseases.

[Clinical value of contrast-enhanced ultrasonography in the diagnosis of prostate cancer in patients with different PSA concentrations].

OBJECTIVE: To investigate the clinical value of contrast-enhanced ultrasonography (CEUS) in the diagnosis of prostate cancer in patients with different concentrations of prostate-specific antigen (PSA). METHODS: Based on the PSA concentration, 186 patients were divided into three groups (PSA 4－10 µg/L, 11－20 µg/L, and >20 µg/L) and underwent transrectal CEUS and biopsy. We compared the pathological results with the CEUS features in different groups of patients and performed a statistical analysis on the characteristics of the CEUS manifestations of prostate cancer and benign prostatic lesions. RESULTS: Of the 186 patients, 118 (63.4%) were diagnosed by biopsy with prostate cancer and the other 68 (36.6%) with benign prostatic lesions. The positive rate of CEUS in the diagnosis of prostate cancer was above 95% in all the three groups, significantly higher than that of conventional ultrasound in the PSA 4－10 and >10－20 µg/L groups (P <0.01). CONCLUSIONS: Contrast-enhanced ultrasonography can achieve a high detection rate in the diagnosis of prostate cancer, especially for the patients with a low PSA concentration, and therefore can be used as one of the most valuable diagnostic techniques for this purpose.

Development of highly sensitive amperometric biosensor for glucose using carbon nanosphere/sodium alginate composite matrix for enzyme immobilization.

In this study, we developed a highly sensitive amperometric biosensor for glucose detection based on glucose oxidase immobilized in a novel carbon nanosphere (CNS)/sodium alginate (SA) composite matrix. This hybrid material combined the advantages of CNS and natural biopolymer SA. This composite film was characterized by scanning electron microscope, electrochemical impedance spectroscopy and UV-vis, which indicated that the hybrid material was suitable for immobilization of glucose oxidase. Various experimental conditions were investigated that influenced the performance of the biosensor, such as pH, applied potential and temperature. Under the optimum conditions, the biosensor showed excellent performance for glucose over a wide linear concentration range from 1.0 × 10(-6) to 4.6 × 10(-3) M with a detection limit of 0.5 µM based on a signal-to-noise ratio of 3. Furthermore, the biosensor exhibited excellent long-term stability and satisfactory reproducibility.

A sensitive amperometric acetylcholine biosensor based on carbon nanosphere and acetylcholinesterase modified electrode for detection of pesticide residues.

A sensitive biosensor based on acetylcholinesterase (AChE) and carbon nanosphere (CNS) immobilized on a glassy carbon electrode was developed for the detection of pesticides by the inhibition of AChE activity. The inhibition effect of the pesticides resulted in a decrease of current response of the acetylthiocholine chloride that was used as a substrate to obtain an electrochemical signal. When applied to the pesticides carbofuran and fenitrothion, the designed biosensor exhibited high sensitivity and low detection limits. The inhibition ratio of carbofuran and fenitrothion were linearly proportional to their concentrations ranging from 0.40 to 4.79 and 6.26 to 125.31 µg/L, respectively. The theoretical detection limits were found to be 0.082 µg/L for carbofuran and 2.61 µg/L for fenitrothion. Furthermore, as the biosensor offers good reproducibility and stability, it could be used for trace detection of pesticides in real samples. Compared with other AChE biosensors, the proposed biosensor was convenient and it exhibited extreme sensitivity to pesticides.

[Simplification of NIR model for citrus's sugar content based on sensory methods].

The prediction of sugar content (SC) in citrus by near-infrared spectroscopy (NIRS) and sensory test was investigated the validation whether the result of non-destructive determination methods by NIRS can meet the request of consumers' sensory or not, and the simplification of the prediction model of NIRS for citrus's SC with variables selection on the basis of meeting their demands. Result of the latter analyzed by one-way ANOVA shows that there was a significant difference influenced by individual diversity, but not by gender. After excluding the sensuous outliers, root mean standard error of deviation (RMSED) of every participator was calculated and the minimum equaled to 0.633, which was chosen as borderline of NIR model's RMSEP to meet the sensory request Then, combined with spectral preprocessing and variables selection methods, SPA-MLR model was obtained by its robustness with Rp = 0.86, as well as RMSEP = 0.567 for prediction set, furthermore, prediction time just costs 6.8 ms. The achievement that not only meets the customers' sensory, but also simplifies the prediction model can be a good reference for real time application in future.

[Investigation on dermal contamination among workers occupationally exposed to dimethylformamide].

OBJECTIVE: To establish a method for the determination of dimethylformamide (DMF) and investigate dermal contamination and absorption among workers occupationally exposed to DMF. METHOD: 37 workers exposed to DMF were divided randomly into two groups. DMF was washed down by isopropyl alcohol in A group (16 workers) and water in B group(21 workers).Gas chromatography was used for the quantification of dermal contamination and N-methylformamide(NMF) in urine, correlative study was done between them. RESULTS: DMF could be detected in all samples in A group, but could not be detected in B group. The miscellaneous peaks could be completely separated from the DMF peak in the sample spectrum, without manual inference. The highest degree of total dermal contamination was observed in wet spinning workshop [(2.84 +/- 1.31) mg], postprocessing workshop [(2.50 +/- 0.95) mg] and dry spinning workshop [(1.95 +/- 0.61) mg] were lower. The respiratory cumulative exposure dosages were 351.3, 201.3 and 135.2 mg respectively. The average DMP concentration in air of the third printing processing workshop, the dry spinning workshop and the wet spinning workshop was 60.2, 89.6, 156.4 mg/m3 respectively, and the respiratory tract contamination in the workers of the three workshops were 135.2, 201.3 and 351.3 mg respectively. There was statistical independence between the quantification of total dermal contamination and NMF in urine (r = 0.176, P > 0.05). CONCLUSION: Isopropyl alcohol is the effective washing solvent.When the concentration of DMF in workplace air is above the occupational exposure limit, respiratory tract absorption is the principal pathway of DMF absorption,but dermal contamination of DMF should not be ignored.

[Identification of egg freshness using near infrared spectroscopy and one class support vector machine algorithm].

Near infrared (NIR) spectroscopy combined with pattern recognition was attempted to discriminate the freshness of eggs. The algorithm of one-class support vector machine (OC-SVM) was employed to solve the classification problem due to imbalanced number of training samples. In this work, 86 samples of eggs (71 samples of fresh eggs and 15 samples of unfresh eggs) were surveyed by Fourier transform NIR spectroscopy. Firstly, original spectra of eggs in the wave-number range of 10 000-4 000 cm(-1) were acquired. And then, principal component analysis (PCA) was employed to extract useful information from original spectral data, and the number of PCs was optimized. Finally, OC-SVM was performed to calibrate discrimination model, and the optimal PCs were used as the input eigenvectors of model. In order to obtain a good performance, the regularization parameter v and parameter sigma of the kernel function in OC-SVM model were optimized in building model. The optimal OC-SVM model was obtained with nu = 0.5 and sigma2 = 20.3. Experimental result shows that OC-SVM got better performance than conventional two-class SVM model under the same condition. The OC-SVM model was achieved with identification rates of 80 for both fresh eggs and unfresh eggs in the independent prediction set. The identification rates of fresh eggs were 100% in two-class SVM model. However, when the two-class SVM model was used to discriminate the unfresh eggs of, the identification rates were 0% in the independent prediction set. Compared with conventional two-class SVM model, the OC-SVM model showed its superior performance in discrimination of minority unfresh eggs samples. This work shows that it is feasible to identify egg freshness using NIR spectroscopy, and OC-SVM is an excellent choice in solving the problem of imbalanced number of samples in training set.

[Study of simplification of prediction model for kiwifruit firmness using near infrared spectroscopy].

To simplify the prediction model of kiwifruit firmness, SNV was used to preprocess the near infrared (NIR) spectra (1 000-2 500 nm)of kiwifruit. PLS model simplification by optimizing spectral intervals and decreasing the number of factors through net analyte preprocessing (NAP)was carried out. Results showed that the performance of NAP/PLS model is the best. It was achieved with 5 factors in five wavenumber ranges(5 189-5 370, 4 549-4 620, 6 049-6 230, 6 999-7 730, and 6 249-6 614 cm(-1)). The optimal model was achieved with R2 = 0.819 41 and RMSECV = 0.701 77 in the calibration set and R2 = 0.780 67 and RMSEP = 0.882 71 in the prediction set. This indicates that the model not only may efficiently simplify PLS model, but also may improve precision and predictive ability.

[The determination of beef tenderness using near-infrared spectroscopy].

The prediction of beef tenderness was studied using near-infrared spectroscopy. The absorption spectra of beef samples were collected between 4,000 and 10,000 cm(-1), the maximum shear force of these samples was obtained using the Warner-Bratzler attachment, and subjective judgment for the tenderness grade of beef was studied. Beef samples with the maximum shear force less than 6 kg were regarded as tender, and their tenderness grade was defined as the value of 1. Those with the maximum shear force greater than 9 kg were regarded as tough, and their tenderness grade was defined as the value of 3. And those with the maximum shear force between 6 and 9 kg were regarded as medium, and their tenderness grade was defined as the value of 2. The study shows that the absorption value of tougher beef is generally higher than that of tender beef. Multiple linear regression was used to build the model between the absorption value and tenderness grade. The results give the correlation coefficient r is 0.806. The accuracy of the model for predicting tenderness grade of beef was 84.21% for a validation set including 19 samples. This result indicates that NIR spectroscopy is capable of predicting tenderness grade of beef.