Modeling of soluble solid content of PE-packaged blueberries based on near-infrared spectroscopy with back propagation neural network and partial least squares (BP-PLS) algorithm.

Blueberries are a nutritious and popular berry worldwide. The physical and chemical properties of blueberries constantly change through the cycle of the supply chain (from harvest to sale). The purpose of this study was to develop a rapid method for detecting the properties of packaged blueberries based on near-infrared (NIR) spectroscopy. NIR was applied to quantitatively determine the soluble solid content (SSC) of polyethylene (PE)-packaged blueberries. An orthogonal partial least squares discriminant analysis model was established to show the correlation between spectral data and the measured SSC. Multiplicative scattering correction, standard normal variable, Savitzky-Golay convolution first derivative, and normalization (Normalize) were used for spectra preprocessing. Uninformative variables elimination, competitive adaptive reweighted sampling, and iteratively retaining informative variables were jointly used for wavelength optimization. NIR-based SSC prediction models for unpacked blueberries and PE-packaged blueberries were developed using partial least squares (PLS). The prediction model for PE-packaged samples (RP 2 = 0.876, root mean square error of prediction [RMSEP] = 0.632) had less precision than the model for unpacked samples (RP 2 = 0.953, RMSEP = 0.611). To reduce the effect of PE, the back propagation (BP) neural network and PLS were combined into the BP-PLS algorithm based on the residual learning algorithm. The model of BP-PLS (RP 2 = 0.947, RMSEP = 0.414) was successfully developed to improve the prediction accuracy of SSC for PE-packaged blueberries. The results suggested a promising way of using the BP-PLS method in tandem with NIR for the rapid detection of the SSC of PE-packaged blueberries. PRACTICAL APPLICATION: Most of the NIR-based research used unpacked blueberries as samples, while the use of packaged blueberries would provide researchers with a better understanding of the crucial factors at different phases of the blueberry supply chain (from harvest to sale). To meet market demands and minimize losses, NIR spectroscopy has been proven to be a rapid and nondestructive method for the determination of the SSC of PE-packaged blueberries. This study provides an effective method for monitoring the properties of blueberries in the entire supply chain.

Physical therapy alone compared with core decompression and physical therapy for femoral head osteonecrosis in sickle cell disease. Results of a multicenter study at a mean of three years after treatment.

BACKGROUND: Osteonecrosis of the femoral head is a common complication in patients with sickle cell disease, and collapse of the femoral head occurs in 90% of patients within five years after the diagnosis of the osteonecrosis. However, the efficacy of hip core decompression to prevent the progression of osteonecrosis in these patients is still controversial. METHODS: In a prospective multicenter study, we evaluated the safety of hip core decompression and compared the results of decompression and physical therapy with those of physical therapy alone for the treatment of osteonecrosis of the femoral head in patients with sickle cell disease. Forty-six patients (forty-six hips) with sickle cell disease and Steinberg Stage-I, II, or III osteonecrosis of the femoral head were randomized to one of two treatment arms: (1) hip core decompression followed by a physical therapy program or (2) a physical therapy program alone. Eight patients withdrew from the study, leaving thirty-eight who participated. RESULTS: Seventeen patients (seventeen hips) underwent decompression combined with physical therapy, and no intraoperative or immediate postoperative complications occurred. Twenty-one patients (twenty-one hips) were treated with physical therapy alone. After a mean of three years, the hip survival rate was 82% in the group treated with decompression and physical therapy and 86% in the group treated with physical therapy alone. According to a modification of the Harris hip score, the mean clinical improvement was 18.1 points for the patients treated with hip core decompression and physical therapy compared with 15.7 points for those treated with physical therapy alone. With the numbers studied, the differences were not significant. CONCLUSIONS: In this randomized prospective study, physical therapy alone appeared to be as effective as hip core decompression followed by physical therapy in improving hip function and postponing the need for additional surgical intervention at a mean of three years after treatment.