Multichannel highly secure wireless communication system with information camouflage capability.

Information metasurface has shown great potential in wireless communications owing to its ability to flexibly control electromagnetic waves. However, it is still a big challenge to achieve high-security and large-channel capacity wireless communications by a simple system. Here, we propose a space-polarization-division multiplexing secure wireless communication system with information camouflage capability based on the information metasurface, which can realize multichannel encrypted wireless communications with different polarization coding strategies independently and simultaneously. A polarization mask key is introduced to encrypt the target message, and the cipher message is further concealed behind a cover image with steganography and sent to the user by using the polarization modulation strategy. Different polarization mask keys can be adopted in each individual communication by changing the polarization coding strategy to enhance the system security. The proposed scheme integrates computational algorithm encryption and physical layer security together and thus has the advantages of high security, large channel capacity, and strong camouflage ability.

Computer-Vision Based Gesture-Metasurface Interaction System for Beam Manipulation and Wireless Communication.

Hand gesture plays an important role in many circumstances, which is one of the most common interactive methods in daily life, especially for disabled people. Human-machine interaction is another popular research topic to realize direct and efficient control, making machines intelligent and maneuverable. Here, a special human-machine interaction system is proposed and namedas computer-vision (CV) based gesture-metasurface interaction (GMI) system, which can be used for both direct beam manipulations and real-time wireless communications. The GMI system first needs to select its working mode according to the gesture command to determine whether to perform beam manipulations or wireless communications, and then validate the permission for further operation by recognizing unlocking gesture to ensure security. Both beam manipulation and wireless communication functions are validated experimentally, which show that the GMI system can not only realize real-time switching and remote control of different beams through gesture command, but also communicate with a remote computer in real time by translating the gesture language to text message. The proposed non-contact GMI system has the advantages of good interactivity, high flexibility, and multiple functions, which can find potential applications in community security, gesture-command smart home, barrier-free communications, and so on.

Biological activity of EXf, a peptide analogue of exendin-4.

Exendin-4 is an incretin mimetic that has been developed for the treatment of patients with type 2 diabetes. EXf is an available carboxy-terminal truncated fragment of exendin-4 with two amino acid substitutions. The purpose of these studies was to evaluate the biological activity of EXf. After a single subcutaneous injection, EXf significantly decreased plasma glucose concentration and glucose excursion following the administration of an oral glucose challenge both in non-diabetic (ICR), monosodium l-glutamate induced insulin resistance (MSG-IR) and diabetic KK-ay mice. Meanwhile, EXf resulted in an increase of first-phase insulin secretion in normal mice and KK-ay mice following the glucose challenge. EXf was also shown to inhibit small intestinal transit in rodent models. EXf activated the cAMP response element (CRE) of the rat insulin I gene promoter (RIP1) GFP-construct in a dose-dependent manner in the cultured mouse insulinoma cell line, termed NIT-1, and this agonist activity was blocked by the glucagon-like peptide 1 (GLP-1) receptor antagonist exendin(9-39). In summary, EXf, an analogue of exendin-4, has agonist activity to GLP-1 receptor in vitro and glucoregulatory activities in vivo, thus it can be considered as a new candidate for the treatment of type 2 diabetes.

The PPARalpha/gamma dual agonist chiglitazar improves insulin resistance and dyslipidemia in MSG obese rats.

1. The aim of this study was to investigate the capacity of chiglitazar to improve insulin resistance and dyslipidemia in monosodium L-glutamate (MSG) obese rats and to determine whether its lipid-lowering effect is mediated through its activation of PPARalpha. 2. Chiglitazar is a PPARalpha/gamma dual agonist. 3. The compound improved impaired insulin and glucose tolerance; decreased plasma insulin level and increased the insulin sensitivity index and decreased HOMA index. Euglycemic hyperinsulinemic clamp studies showed chiglitazar increased the glucose infusion rate in MSG obese rats. 4. Chiglitazar inhibited alanine gluconeogenesis, lowered the hepatic glycogen level in MSG obese rats. Like rosiglitazone, chiglitazar promoted the differentiation of adipocytes and decreased the maximal diameter of adipocytes. In addition, chiglitazar decreased the fibrosis and lipid accumulation in the islets and increased the size of islets. 5. Chiglitazar reduced plasma triglyceride, total cholesterol (TCHO), nonesterified fatty acids (NEFA) and low density lipoprotein-cholesterol levels; lowered hepatic triglyceride and TCHO contents; decreased muscular NEFA level. Unlike rosiglitazone, chiglitazar showed significant increase of mRNA expression of PPARalpha, CPT1, BIFEZ, ACO and CYP4A10 in the liver of MSG obese rats. 6. These data suggest that PPARalpha/gamma coagonist, such as chiglitazar, affect lipid homeostasis with different mechanisms from rosiglitazone, chiglitazar may have better effects on lipid homeostasis in diabetic patients than selective PPARgamma agonists.

Pioglitazone can ameliorate insulin resistance in low-dose streptozotocin and high sucrose-fat diet induced obese rats.

AIM: To investigate the effect of the peroxisome proliferator-activator receptor (PPAR)-gamma agonist, pioglitazone, on insulin resistance in low-dose streptozotocin and high sucrose-fat diet induced obese rats. METHODS: Normal female Wistar rats were injected intraperitoneally with low-dose streptozotocin (STZ, 30 mg/kg) and fed with a high sucrose-fat diet for 8 weeks. Pioglitazone (20 mg/kg) was administered orally to the obese and insulin-resistant rats for 28 d. Intraperitoneal glucose tolerance tests, insulin tolerance tests and gluconeogenesis tests were carried out over the last 14 d. At the end of d 28 of the treatment, serums were collected for biochemical analysis. Glucose transporter 4 (GLUT4) and insulin receptor substrate-1 (IRS-1) protein expression in the liver and skeletal muscle were detected using Western blotting. RESULTS: Significant insulin resistance and obesity were observed in low-dose STZ and high sucrose-fat diet induced obese rats. Pioglitazone (20 mg/kg) treatment significantly decreased serum insulin, triglyceride and free fatty acid levels, and elevated high density lipoprotein-cholesterol (HDL-C) levels. Pioglitazone also lowered the lipid contents in the liver and muscles of rats undergoing treatment. Gluconeogenesis was inhibited and insulin sensitivity was improved markedly. The IRS-1 protein contents in the liver and skeletal muscles and the GLUT4 contents in skeletal muscle were elevated significantly. CONCLUSION: The data suggest that treatment with pioglitazone improves insulin sensitivity in low-dose STZ and high sucrose-fat diet induced obese rats. The insulin sensitizing effect may be associated with ameliorating lipid metabolism, reducing hyperinsulinemia, inhibiting gluconeogenesis, and increasing IRS-1 and GLUT4 protein expression in insulin-sensitive tissues.

[Ameliorations of pioglitazone on insulin resistance in spontaneous IGT-OLETF rats].

AIM: To investigate the ameliorations of pioglitazone, a member of the thiazolidinedione group of antidiabetic agents, on insulin resistance in spontaneous OLETF rats with impaired glucose tolerance (IGT-OLETF). METHODS: One group of IGT-OLETF rats was orally administered pioglitazone at the dose of 20 mg x kg(-1) (qd) for 2 weeks. Another group was given the same volume of solvent as control. Glucose tolerance and insulin tolerance were tested, and blood glucose concentrations, insulin levels and lipids in serum, liver and muscle were determined. Insulin sensitive index (ISI) was calculated by the reciprocal of fasting blood glucose times fasting insulin. RESULTS: Pioglitazone was shown to markedly enhance the glycemic response to exogenous insulin (0. 4 x kg(-1), sc) in the model. The falls of blood glucose at 40 and 90 min in the insulin tolerance test were augmented by 70% and 158% in the treated group than the control. The serum insulin levels were significantly decreased and the ISI nearly normalized after treatment. Pioglitazone also lowered the serum TG and FFA levels and the lipids in liver and muscle. No effect was found on the expression of leptin in epididymal adipose tissues and on the activity of GFAT, a key enzyme in hexosamine biosynthesis pathway (data were not shown). CONCLUSION: Pioglitazone can improve the insulin resistance state in IGT-OLETF rats. Correction of lipid disorder may be associated with it.

[Effects of conjugated linoleic acid on obese MSG mice with insulin resistance].

AIM: To study the effect of conjugated linoleic acid (CLA) on obese MSG mice with insulin resistance. METHODS: About four months old, obese MSG mice with insulin resistance were divided into control, CLA and rosiglitazone groups and drugs were administrated ig once a day. Body weights were recorded regularly, insulin and glucose tolerance were tested. In addition, serum insulin and TNF-alpha concentrations in serum and fat tissues were determined. RESULTS: CLA was shown to reduce the body weight and fat weight in MSG mice, but can not improve the abnormal insulin and glucose tolerance in these mice. Indeed, the serum insulin and TNF-alpha concentrations in the fat tissues of the group treated with CLA were higher than those in the models and the insulin sensitivity index was significantly lower than that in the model mice. CONCLUSION: CLA can reduce the body weight of MSG mice, but can not improve the insulin resistance in these mice.