[Color characterization and its correlation with quality index during ripening of Rubus chingii].

The color of Rubus chingii was characterized by digital method, and the content of water extract, alcohol extract, total flavonoids, total polysaccharides, total polyphenols, ellagic acid, linden glycoside, kaophenol-3-O-rutin were determined. Correlation regression was used to analyze the correlation between color and composition. The results showed that L~* was positively correlated with total polyphenols, kaophenol-3-O-rutin and tilide, and moderately positively correlated with total flavones, ellagic acid and aqueous extracts. The a~* value was negatively correlated with total polyphenols, kaophenol-3-O-rutin, and linden glycosides, while was moderately correlated with total flavones, aqueous extracts, and ellagic acid. The b~* value was negatively correlated with the water extract, and moderately correlated with the content of total polyphenols, total polysaccharides, alcohol extract and kaophenol-3-O-rutin, which showed that R. chingii mature color had a significant correlation with material composition in the process of dynamic change. According to the law of dynamic change in the color and quality indexes, it is determined that the appropriate harvest time is in late April to May 1, while the fruit is not turn yellow. The agronomic traits related to fruit was(12.49±0.56) mm in diameter,(14.25±1.19)mm in height,(1.20±0.14) g in weight, the chroma L~* value was 52.87±3.14,a~* value was 2.01±1.58, b~* values was 28.31±3.88. The results lay a foundation for establishing an objective quantitative evaluation model of R. chingii color from experience.

[Clinical effect of multi-oil fat emulsion for parenteral nutrition support in extremely low birth weight infants].

OBJECTIVE: To study the clinical effect of multi-oil fat emulsion for parenteral nutrition support in extremely low birth weight (ELBW) infants. METHODS: A retrospective analysis was performed for 49 ELBW infants who were admitted from January 1, 2018 to July 30, 2020, with an age of ≤14 days on admission and a duration of parenteral nutrition of > 14 days. According to the type of lipid emulsion received, the ELBW infants were divided into two groups: soybean oil, medium-chain triglycerides, olive oil, and fish oil (SMOF) (n=26) and medium-chain triglycerides/long-chain triglycerides (MCT/LCT) (n=23). The two groups were compared in terms of clinical features, complications, nutrition support therapy, and outcome. RESULTS: The 49 ELBW infants had a mean birth weight of (892±83) g and a mean gestational age of (28.2±2.3) weeks. There was no significant difference between the two groups in the incidence rates of hemodynamically significant patent ductus arteriosus, intraventricular hemorrhage, neonatal necrotizing enterocolitis, retinopathy of prematurity, bronchopulmonary dysplasia (BPD), grade Ⅲ BPD, sepsis, and pneumonia (P > 0.05). There was also no significant difference in the duration of parenteral nutrition, the age of total enteral nutrition, and head circumference/body length/body weight at discharge between the two groups (P > 0.05). Of all the infants, 22 (45%) had parenteral nutrition-associated cholestasis (PNAC), with 13 (50%) in the SMOF group and 9 (39%) in the MCT/LCT group but there was no significant difference in the incidence of PNAC between the two groups (P > 0.05); however, the infants with PNAC in the SMOF group had significantly lower peak values of direct bilirubin and alanine aminotransferase than those in the MCT/LCT group (P < 0.05). CONCLUSIONS: The application of multi-oil fat emulsion in ELBW infants does not reduce the incidence rate of complications, but compared with MCT/LCT emulsion, SMOF can reduce the severity of PNAC in ELBW infants.

[Clinical features of neonatal enterovirus infection].

OBJECTIVE: To study the clinical features of neonatal enterovirus infection, especially severe enterovirus infection. METHODS: A retrospective analysis was performed for the clinical data of 244 neonates with enterovirus infection. According to the severity of infection, they were divided into a common infection group with 231 neonates and a severe infection group with 13 neonates. Clinical features were compared between the two groups. RESULTS: Of the 244 neonates, 207 (84.8%) developed the disease in May to October, with the highest number of patients in June to July. Compared with the common infection group, the severe infection group had a significantly lower gestational age at birth and a significantly higher proportion of preterm infants (P<0.05). Compared with the common infection group, the severe infection group had a significantly earlier onset time (P<0.05) and significantly higher incidence rates of skin petechiae and ecchymosis, respiratory symptoms, sepsis-like manifestations (poor appetite, crying less, and less movement), concomitant diseases (such as pneumonia, myocarditis, necrotic hepatitis, and coagulation disorder), thrombocytopenia, prolonged prothrombin time, elevated creatine kinase-MB, and elevated alanine aminotransferase (P<0.05). The severe infection group had a significantly higher mortality rate than the common infection group (P<0.05). CONCLUSIONS: There are significant differences in onset time, common clinical manifestations, and concomitant diseases between the neonates with common and severe enterovirus infection. In the enterovirus epidemic season, if the neonates have rashes and/or sepsis-like manifestations such as poor appetite and less movement, especially if the laboratory tests suggest liver damage and coagulation dysfunction, it is necessary to pay particular attention to the possibility of severe enterovirus infection.

[Application of vacuum stretcher combined with feeding in cranial magnetic resonance imaging examination for neonates: a prospective randomized controlled study].

OBJECTIVE: To study the effect and safety of vacuum stretcher combined with feeding in cranial magnetic resonance imaging (MRI) examination for neonates. METHODS: A prospective study was performed for the neonates with hyperbilirubinemia, with a gestational age of >34 weeks and stable vital signs, who needed cranial MRI examination and did not need oxygen inhalation hospitalized in the Department of Neonatology, Children's Hospital of Zhejiang University School of Medicine, from September to November, 2019. The neonates were randomly divided into a vacuum stretcher combined with feeding group and a conventional sedation group. Vital signs were monitored before, during, and after MRI examination. The success rate of MRI procedure was recorded. RESULTS: A total of 80 neonates were enrolled in the study, with 40 neonates in the vacuum stretcher combined with feeding group and 40 in the conventional sedation group. The vacuum stretcher combined with feeding group had a significantly higher success rate of MRI procedure than the conventional sedation group (P<0.05). As for the neonates who underwent successful MRI examination, the fastest heart rate after examination in the vacuum stretcher combined with feeding group was significantly lower than that in the conventional sedation group (P<0.05), while there were no significant differences between the two groups in transcutaneous oxygen saturation, respiratory rate, and body temperature before and after MRI examination (P>0.05). No complications, such as apnea, acute allergic reactions, and malignant fever, were observed. CONCLUSIONS: Vacuum stretcher combined with feeding can improve the success rate of MRI procedure and reduce the use of sedatives, and meanwhile, it does not increase related risks.

[Effects of different application amounts of potassium fulvic acid on yield and quality of Fritillaria thunbergii].

Fritillaria thunbergii is a commonly used traditional Chinese medicine, which has the effects of clearing heat and resolving stagnation, eliminating phlegm and relieving cough. At present, it is mostly produced by cultivation, and the cultivation process requires application of base fertilizer, winter fertilizer, seedling fertilizer and late top dressing. Now farmyard manure or organic fertilizer can be used to replace the base fertilizer and winter fertilizer, but the research on the replacement of organic fertilizer has not been completed for the late top dressing. Potassium fulvate is a kind of fulvate fertilizer, which can not only regulate the growth of crops but also supplement potassium necessary for the growth of crops. In this paper, using F. thunbergii as a model plant with mature cultivation techniques, the effect of potassium fulvate on the quality and yield of rhizome traditional Chinese medicine F. thunbergii was systematically studied for the first time. HPLC-ELSD was used to determine the contents of peimine A and peimine B, hot dip method was used to determine the content of alcohol extract, and the SPAD-502 Plus chlorophyll meter was used to detect SPAD value. The results showed that applying 1.5 to 2.25 kg·hm~(-2) of potassium fulvic acid per hectare could effectively improve the yield of F. thunbergii and there was significantly difference between potassium phosphate monobasic and potassium fulvic acid in terms of quality. After the application of range 1.5 to 2.25 kg·hm~(-2) of potassium fulvic acid per hectare, the content of alcohol soluble extract of F. thunbergii was ranged 21.61% to 22.27%, the total amount of peimine A and peimine B were ranged 0.09% to 0.10%. Applying 1.5 to 2.25 kg·hm~(-2) of potassium fulvic acid per hectare could replace the conventional pure chemical fertilizer potassium phosphate monobasic, which could be used as top dressing fertilizer for the cultivation of F. thunbergii.

Management strategies of neonatal jaundice during the coronavirus disease 2019 outbreak.

The outbreak of coronavirus disease 2019 (COVID-19; formally known as 2019-nCoV) has become a most challenging health emergency. Owing to rigorous quarantine and control measures taken in China, routine neonatal health surveillance and follow-up have become challenging. Without follow-up surveillance, some rapid and progressive newborn diseases, such as bilirubin encephalopathy, may be ignored. The characteristics of onset age of kernicterus suggest that monitoring of bilirubin level at home provides a useful way to alert hospital visits and to prevent the development of extremely hyperbilirubinemia. Therefore, we developed an online follow-up program for convenient monitoring of bilirubin level of newborns that is based on our practical experiences. The aim is to make our management strategies of neonatal jaundice tailored to the infection prevention and control during the COVID-19 epidemic.

[Effect of 17% ethylenediaminetetraacetic acid irrigation on the dentin adhesion of Enterococcus faecalis].

OBJECTIVE: This work aims to uncover the promoting effect of 17% ethylenediaminetetraacetic acid (EDTA) irrigation on the dentin adhesion of Enterococcus faecalis (E. faecalis). METHODS: Forty-eight half split samples and twelve dentin slices were randomly divided into three experimental groups and one control group. The experimental groups and the control group were soaked with EDTA in different time lengths and with normal saline, respectively. E. faecalis was inoculated, and its dentin adhesion was measured via scanning electron microscopy, confocal laser scanning microscopy (CLSM), colony forming unit counts, and histological Gram staining. RESULTS: According to histological Gram staining, the depth showed no statistically significant differences between 1 min group and the control group, 1 min group and 3 min groups (P>0.05). E. faecalis intruded in the dentine tubules (measured by CLSM), and the thickness of the biofilm on the dentin surface and the colony numbers of experimental groups were greater than those of the control group (P<0.05). The differences between the three experimental groups were statistically signi-ficant (P<0.05). CONCLUSIONS: EDTA (17%) irrigation can promote E. faecalis adhesion to dentin. This adhesion would in turn prolong EDTA treatment time.

[Correlation analysis between quality and habitat phenotype of Hovenia acerba].

The contents of dihydromyricetin and total flavonoids of Hovenia acerba seeds were detected by HPLC-DAD and UV spectrophotometer. And then the correlation between the habitat, phenotype and quality of H. acerba seeds were deeply studied. There were big differences in both appearance and quality among the H. acerba seeds from different places. It showed that the content of dihydromyricetin in H. acerba seeds was 0.41-9.81 mg•g⁻¹, and the content of total flavonoids was 5.52-21.98 mg•g⁻¹. The cluster analysis showed that the quality of H. acerba seeds was related to the habitat. The samples from Jianghan Plain Area showed relatively stable and excellent quality. According to the correlation analysis, there was a significant positive correlation between 1 000-seeds weight, red-black seeds ratio and the content of dihydromyricetin, while the content of total flavonoids was not related to the 1 000-seeds weight and red-black seeds ratio. So the 1 000-seeds weight and red-black seeds ratio could be used as an initial judgment of the quality of H. acerba seeds. As dihydromyricetin and total flavonoids content was not related, both dihydromyricetin and total flavonoids should be taken into account when the quality of H. acerba seeds was studied.

[Study on combined effects of chemical components for different flowers blossoming degree of yellow medicinal Chrysanthemum morifolium from Zhejiang].

The ingredients of five kinds of Zhejiang's yellow Chrysanthemum morifolium with different flower blossoming stages were comparatively analyzed. Polysaccharides, total flavonoids, volatile oil, alcohol extract, water extract, chlorogenic acid, luteolin, 3,5-O-dicaffeoyl quinic acid and fingerprint of the ingredient were determined as indicators. During flower blossoming stages, the ingredients of Ch. morifolium showed a big difference with a certain variation. At the early opening stage, the contents of flavonoids and volatile oil were higher, the content of chlorogenic acid, luteolin, 3,5-O-dicaffeoyl quinic acid were higher in the middle of the flowers 50% -80% fowers blossoming degree is the optimal time for harvest.

Glucotoxicity and α cell dysfunction: involvement of the PI3K/Akt pathway in glucose-induced insulin resistance in rat islets and clonal αTC1-6 cells.

AIM/HYPOTHESIS: The objective of this study was to assess how long-term exposure to high glucose affects the α cell function and whether the increased glucagon secretion is mediated via insulin resistance. MATERIALS AND METHODS: We established a ß cell-depleted rat model to obtain pure primary α cells. Furthermore, isolated rat islets and TC1-6 cells (a clonal α cell line) were exposed to high glucose (25 or 30 mmol/L) and low glucose (5.5 mmol/L) for up to 5 days to evaluate the influence of chronic glucose toxicity on glucagon secretion and glucagon gene expression. Moreover, we added insulin and/or Wortmannin to examine if the inhibitory effect of insulin on glucagon secretion was impaired by high glucose via the phosphatidylinositol 3 kinase/PKB protein kinase B pathway. RESULTS: Both glucagon secretion and glucagon gene expression were increased in response to 5 days exposure to high glucose. While a moderate insulin concentration slightly inhibits glucagon secretion from rat islets and α TC1-6 cells at high glucose, a pronounced increase in glucagon secretion was observed at low glucose. We found that the insulin-mediated activity of the phosphatidylinositol 3 kinase/PKB protein kinase B pathway in the α cell was markedly impaired by chronic exposure to high glucose. CONCLUSION: The hypersecretion of glucagon induced by glucotoxicity may be secondary to insulin resistance of the α cell induced by impaired activity of the insulin signaling pathway.

[Effect of acupoint-catgut-embedment on mammary gland hyperplasia].

OBJECTIVE: To evaluate the clinical therapeutic effect of acupoint-catgut-embedment therapy in the treatment of mammary gland hyperplasia (MGH). METHODS: Eighty MGH patients were equally randomized into acupoint-catgut-embedment (ACE) group and medication (Rupixiao, a herbal patent drug for relieving MGH) group according to odd-numbered days or even-numbered days of visiting. Subcutaneous catgut-embedment was performed in Wuyi (ST 15), Rugen (ST 18), Tanzhong (CV 17), Xuehai (SP 10), Zusanli (ST 36) and Yanglingquan (GB 34), once every 15 days for 3 months. Patients of the medication group were treated by oral administration of Rupixiao (3 tablets, 3 times per day, 3 months altogether). The degree of breast pain and the size of the hyperplastic lump were observed before and after the treatment. Serum estrodiol, progesterone and prolactin contents on day 1 to day 3 of menstruation were detected by using an automation chemiluminescence immune analysator. RESULTS: After the treatment, of the two 40 MGH patients in the ACE and medication groups, 16 (40. 0%) and 5 (12. 5%) were cured basically, 8 (20. 0%) and 8 were improved markedly in their symptoms and signs, 16 (40. 0%) and 22 (55. 0%) were effective, and 0 and 5 (12. 5%) failed in the treatment, with the effective rates being 100% and 87.5%, respectively. The therapeutic effect of the ACE group was significantly better than that of the medication group (P<0. 05). In comparison with the pretreatment, the pain grades and the size of the hyperplastic lump in both ACE and medication groups decreased significantly after immediate termination of the treatment and 6 months after the treatment (P<0.01), and the therapeutic effects of the ACE group were significantly superior to those of the medication group in reducing pain grade and hyperplastic lump size (P<0. 01). After the treatment, serum estrodiol and progesterone contents were decreased evidently in both ACE and medication groups (P<0. 01, P<0. 05). Type-B ultrasonic examination showed that of the two 40 MGH patients in the ACE and medication groups, 16 and 5 cases turned to normal in their mammary glands, and the cure rate of the ACE group was evidently higher than that of the medication group (P<0. 01). CONCLUSION: Acupoint-catgut-embedment is effective in relieving MGH, and its therapeutic effect is apparently superior to that of medication (oral administration of Rupixiao).

[Factors influence volatile oil content in Ocimun basilicum introduced from Xinjiang province to south-east China].

OBJECTIVE: To obtain the information on ecological adaptation of Ocimun basilicum introduced from Xinjiang to Hangzhou and study the effect of different harvesting times, drying methods, and different organs of Ocimun basilicum on Volatile oil content METHODS: Extraction was undertaken according to The Pharmacopoeia of China, 2010 edition. RESULTS: Sun-drying was the most efficient way to obtain Volatile oil compared with other methods. The largest biomass was harvested at 3rd, September. Furthermore, Volatile oil was found to accumulate mostly in the flowers and little in the stems. CONCLUSION: Ocimun basilicum can readily inhabit in Hangzhou and its economic value can be significant improved by growing two seasons per year. Only harvest leaves and flowers can significantly reduce the cost for transport and also increase oil extract rate of Volatile oil.

Role and mechanism of uncoupling protein 2 on the fatty acid-induced dysfunction of pancreatic alpha cells in vitro.

BACKGROUND: Uncoupling protein (UCP) 2 is related to the dysfunction of beta cells induced by fatty acids. However, whether UCP2 has similar effects on alpha cell is still not clear. This study aimed to investigate the effects of UCP2 and its possible mechanisms in lipotoxicity-induced dysfunction of pancreatic alpha cells. METHODS: The alpha TC1-6 cells were used in this study to evaluate the effects of palmitate and/or UCP2 inhibit factors on the glucagon secretory function, glucagon content, the glucagon mRNA level and the nitrotyrosine level in the supernatant. Meantime, the expression levels of UCP2 and peroxisome proliferator-activated receptor-γ coactivator-1 alpha (PGC-1 alpha) were measured by real-time reverse transcription polymerase chain reaction (RT-PCR) and Western blotting. Furthermore, the possible relationship between UCP2 and insulin signal transduction pathway was analyzed. RESULTS: Palmitate stimulated alpha cell glucagon secretion and the expression of UCP2 and PGC-1 alpha, which could be partially decreased by the inhibition of UCP2. Palmitate increased nitrotyrosine level and suppressed insulin signal transduction pathway in alpha cells. Inhibition of UCP2 influenced the effects of free fatty acid on alpha cells and may relate to glucagon secretion. CONCLUSION: UCP2 played an important role on alpha cell dysfunction induced by free fatty acid in vitro, which may be related to its effects on oxidative stress and insulin signal transduction pathway.

[Comparison of clinical outcomes in very low birth weight infants with anemia by different transfusion strategies].

OBJECTIVE: To evaluate the risks and benefits of two transfusion strategies (liberal-transfusion and restrictive-transfusion), as judged by the clinical progress and outcome, in very low birth weight infants. METHODS: The clinical data of 93 hospitalized very low birth weight infants who required blood transfusions were retrospectively studied. The infants were assigned to either the liberal transfusion group (n=58), with higher hematocrit levels, or the restrictive-transfusion group (n=35), with lower hematocrit levels. RESULTS: The infants in the restrictive-transfusion group received more numbers of RBC transfusions compared with the liberal-transfusion group (2.6+/-1.8 vs 1.8+/-1.0; p<0.05). Liberal-transfusion was associated with faster weight gain and the duration to return to the birth weight averaged 10 days in the liberal-transfusion group compared with 13 days in the restrictive-transfusion group (p<0.01). The infants in the liberal-transfusion group had shorter duration of mechanical ventilation than in the restrictive-transfusion group (5.5+/-4.2 days vs 8.0+/- 5.9 days; p<0.05). There were no significant differences in the incidence of apnea and nosocomial infections between two groups. CONCLUSIONS: The study suggests the possible benefits from liberal-transfusion for clinical recovery in very low birth weight infants. The restrictive transfusion does not decrease the number of transfusions. It in fact increases the number of clinical indicated transfusions. Neonatologists should weigh the advantages and disadvantages on transfusions to make the optimal decision.

[The role of syntaxin1A/synaptosome-associated protein-25 in reversing hyperglycemia-induced alpha cell toxicity].

OBJECTIVE: To investigate the effects of reversal of hyperglycemic toxicity on the synthesis and secretion of glucagon by the alpha cells and the possible mechanisms thereof. METHODS: Mouse glucagonoma cells of the line TC1-6 were cultured in medium containing 5.5 mmol/L glucose for 10 days (low glucose group, LG), in medium containing 25 mmol/L glucose for 10 days (high glucose group, HG), in medium with 25 mmol/L glucose for 5 days and then in medium with 5.5 mmol/L glucose for 5 days (high-low glucose group, HL group), or in medium with 5.5 mmol/L glucose for 5 days and then in medium with 25 mmol/L glucose for 5 days (LH group), Radioimmunoassay was used to detect the glucagon concentration in the supernatant. RT-PCR was used to detect the mRNA expression of glucagon in the TC1-6 cells. Western blotting was used to detect the protein expression of the Snare proteins: syntaxin1A and synaptosome-associated protein (SNAP)-25. RESULTS: (1) The glucagon level of the HG/LG group was lower than that of the HG group by 29% (P < 0.05). (2) The glucagon mRNA expression level in the TC1-6 cells of the HG/HL group was significantly lower than that of the HG group by (52.6 +/- 2.8)% (P < 0.05). (3) The syntaxin1A and SNAP-25 expression levels in the TC1-6 cells of the HG group were significantly higher than those of the LG group by 36% and 69% respectively (both P < 0.05), and the syntaxin1A and SNAP-25 expression levels in the TC1-6 cells of the HG/LG group were significantly lower than those of the HG group by 49% and 56% respectively (both P < 0.05). CONCLUSION: After removing the high glucose toxicity the abnormal glucagon secretion by the alpha-cells can be ameliorated obviously, and the expression levels of syntaxin1A and SNAP-25 proteins that promote the secretion of glucagon are reduced accordingly.

[Establishment and application of AFLP fingerprinting system in Atractylodes macrocephala germplasm].

OBJECTIVE: To establish the AFLP Fingerprinting system in the germplasm of Atractylodes macrocephala Koidz. METHODS: 10 wild or cultivated Atractylodes macrocephala were used for AFLP fingerprinting analysis by EcoRI and MseI restriction enzymes with silver staining. RESULTS: Using 2X CTAB buffer extraction method can obtain the best genomic DNA samples. According to the AFLP polymorphism, sixteen out of forty primer pairs were selected to be suitable for AFLP analysis. Total 3003 polymorphic bands were obtained from the 16 sets of primer. Based on the AFLP results, the 10 samples of Atractylodes macrocephala germplasm were classified into four types. CONCLUSION: The establishment of the AFLP fingerprinting system in Atractylodes macrocephala will be used in the identification of germplasms and breeding of the species.

[Study on correlation between Atractylodes macrocephala viability and germination rate].

OBJECTIVE: To screen the optimized methods for detection seed viability and germination rate determination of Atractylodes macrocephala, and determine the relationship between seed viability and germination rate. METHOD: There were four methods, which including 2,3,5-triphynel tetrazolilum chloride (TTC) staining, red ink staining, BTB staining and Nongjia method, to evaluate the 12 A. macrocephala local varieties'seed viability and measure their germination rate. RESULT: Seed viability of A. macrocephala using TTC staining ranked the first compared to that of other three methods. Seed viability was significantly related with germination rate using TTC method. Their correlation coefficient reached 0.915 and regression equation was also found out between seed viability (X) and germination rate (Y), which was Y = -0.083 4 + 0.995 4X. CONCLUSION: TTC staining was the optimal method to determine A. macrocephala seed vitality. Furthermore, seed viability was significant related with germination rate of A. macrocephala.

[Mutagenic effects of gamma-rays on Coix lacryma-jobi var. ma-yuen].

OBJECTIVE: To study the mutagenic effect of gamma-rays on Coix lacryma-jobi var. ma-yuen. METHOD: Physiological and mutagenic effects of gamma-rays on C. lacryma-jobi var. ma-yuen dormant seeds were studied. The germination percentage, seeding survival, seeding height and root length of M1 plants and the frequency of chlorophyll mutation in M2 generation were selected as criteria. RESULT: The gamma-rays showed obvious inhibitory action to the seedling growth, and a strong ability in inducing the chlorophyll mutation. CONCLUSION: The gamma-rays is one kind of C. lacryma-jobi var. ma-yuen effective mutagen. The appropriate dose of gamma-rays is 450 Gy for C. lacryma-jobi var. ma-yuen dormant seeds.

Digital color image watermarking based on phase-shifting interferometry and neighboring pixel value subtraction algorithm in the discrete-cosine-transform domain.

A novel single-channel color-image watermarking with digital-optics means based on phase-shifting interferometry (PSI) and a neighboring pixel value subtraction algorithm in the discrete-cosine-transform (DCT) domain is proposed. The converted two-dimensional indexed image matrix from an original color image is encrypted to four interferograms by a PSI and double random-phase encoding technique. Then the interferograms are embedded in one chosen channel of an enlarged color host image in the DCT domain. The hidden color image can be retrieved by DCT, the improved neighboring pixel value subtraction algorithm, an inverse encryption process, and color image format conversion. The feasibility of this method and its robustness against some types of distortion and attacks from the superposed image with different weighting factors are verified and analyzed by computer simulations. This approach can avoid the cross-talk noise due to direct information superposition, enhance the imperceptibility of hidden data, and improve the efficiency of data transmission.

Information security system by iterative multiple-phase retrieval and pixel random permutation.

A novel information security system based on multiple-phase retrieval by an iterative Fresnel-transform algorithm and pixel random permutation (PRP) technique is proposed. In this method a series of phase masks cascaded in free space are employed and the phase distributions of all the masks are adjusted simultaneously in each iteration. It can achieve faster convergence and better quality of the recovered image compared with double-phase encoding and a similar approach in the spatial-frequency domain with the same number of phase masks and can provide a higher degree of freedom in key space with more geometric parameters as supplementary keys. Furthermore, the security level of this method is greatly improved by the introduction of the PRP technique. The feasibility of this method and its robustness against occlusion and additional noise attacks are verified by computer simulations. The performance of this technique for different numbers of phase masks and quantized phase levels is investigated systematically with the correlation coefficient and mean square error as convergence criterions.