Discrimination of Dioscorea species (Chinese yam) using FT-IR integrated with chemometric approach.

Dioscorea oppositifolia is an important crop and functional food. D. oppositifolia tuber is often adulterated with D. persimilis, D. alata, and D. fordii tuber in the commercial market. This study proposed an integrated Fourier transform infrared spectroscopy (FT-IR) with chemometric approach to differentiate these four Dioscorea species. A total of 107 Dioscorea spp. tuber samples were collected from different locations in China. Principal Component Analysis (PCA), PCA-Class, and Orthogonal Partial Least Square Discriminant Analysis (OPLS-DA) were utilised to classify the FT-IR spectra. In this PCA is unable to differentiate the Dioscorea spp. tuber effectively. However, PCA-Class and OPLS-DA can distinguish spp. these 4 species Dioscorea tuber with high accuracy, sensitivity, and specificity. Additionally, the RMSEE, RMSEP and RMSECV values for OPLS-DA model were low, showing that it is a good model. The combination of FT-IR with the PCA-Class and OPLS-DA is practical in discriminating Dioscorea spp. tubers.

Application of FT-IR spectroscopy and chemometric technique for the identification of three different parts of Camellia nitidissima and discrimination of its authenticated product.

Camellia nitidissima C.W. Chi is a golden camellia recognized in Chinese herbology and widely used as tea and essential oil in Chinese communities. Due to its diverse pharmacological properties, it can be used to treat various diseases. However, unethical sellers adulterated the flower with other parts of Camellia nitidissima in their product. This study used an integrated tri-step infrared spectroscopy method and a chemometric approach to distinguish C. nitidissima's flowers, leaves, and seeds. The three different parts of C. nitidissima were well distinguished using Fourier transform infrared spectroscopy (FT-IR), second-derivative infrared (SD-IR) spectra, and two-dimensional correlation infrared (2D-IR) spectra. The FT-IR and SD-IR spectra of the samples were subjected to principal component analysis (PCA), PCA-class, and orthogonal partial least square discriminant analysis (OPLS-DA) for classification and discrimination studies. The three parts of C. nitidissima were well separated and discriminated by PCA and OPLS-DA. The PCA-class model's sensitivity, accuracy, and specificity were all >94%, indicating that PCA-class is the good model. In addition, the RMSEE, RMSEP, and RMSECV values for the OPLS-DA model were low, and the model's sensitivity, accuracy, and specificity were all 100%, showing that it is the excellent one. In addition, PCA-class and OPLS-DA obtained scores of 27/32 and 26/32, respectively, for detecting adulterated and other TCM reference flower samples from C. nitidissima. Combining an infrared spectroscopic method with a chemometric approach proved that it is possible to differentiate distinct sections of C. nitidissima and discriminate adulterated samples of C.nitidissima flower.

Effect of hypoxia on epithelial growth factor receptor expression and cell apoptosis of breast cancer and cervical cancer xenografts in nude mice / 中华放射肿瘤学杂志

Objective To observe the effect of hypoxia on the expression of epithelial growth factor receptor (EGFR) and cell apoptosis of breast and cervical cancer xenografts in nude mouse models.Methods The nude mouse models with MCF-7 and HeLa xenografts were established.The degree of hypoxia and EGFR expression were observed by confocal microscopy.The influence of EGFR expression on cell apoptosis under hypoxia was observed by TUNEL assay.Results EGFR expression was either up-regulated or down-regulated in the MCF-7 and HeLa cells with high degree of hypoxia.Furthermore,the degree of apoptosis was reduced in tumor tissues with high EGFR expression compared with that in those with low expression of EGFR.Conclusion The hypoxia in MCF-7 and HeLa cells exerts heterogeneous effect on EGFR expression.Under hypoxic conditions,EGFR exoression is negatively correlated with cell apoptosis.

Nuclear EGFR:a potential target for radiosensitizer / 中华放射肿瘤学杂志

Nuclear epithelial growth factor receptor (EGFR) plays an important role in the development, metastasis, treatment, and prognosis of cancer. Radiotherapy, one of the main therapies for malignant tumor, causes EGFR transfer into the nucleus along with tumor therapy, thereby reducing radiosensitivity. Insight into the biological characteristics and functions of nuclear EGFR has an important reference value for improving radiosensitivity. Therefore, this article elaborates on EGFR transport into the nucleus,the features of nuclear EGFR,and its relationship with radiosensitivity and clinical targeted therapy.