Neuronal activity in the anterior paraventricular nucleus of thalamus positively correlated with sweetener consumption in mice.

Although the brain can discriminate between various sweet substances, the underlying neural mechanisms of this complex behavior remain elusive. This study examines the role of the anterior paraventricular nucleus of the thalamus (aPVT) in governing sweet preference in mice. We fed the mice six different diets with equal sweetness for six weeks: control diet (CD), high sucrose diet (HSD), high stevioside diet (HSSD), high xylitol diet (HXD), high glycyrrhizin diet (HGD), and high mogroside diet (HMD). The mice exhibited a marked preference specifically for the HSD and HSSD. Following consumption of these diets, c-Fos expression levels in the aPVT were significantly higher in these two groups compared to the others. Utilizing fiber photometry calcium imaging, we observed rapid activation of aPVT neurons in response to sucrose and stevioside intake, but not to xylitol or water. Our findings suggest that aPVT activity aligns with sweet preference in mice, and notably, stevioside is the sole plant-based sweetener that elicits an aPVT response comparable to that of sucrose.

A circuit from lateral septum neurotensin neurons to tuberal nucleus controls hedonic feeding.

Feeding behavior is regulated by both the homeostatic needs of the body and hedonic values of the food. Easy access to palatable energy-dense foods and the consequent obesity epidemic stress the urgent need for a better understanding of neural circuits that regulate hedonic feeding. Here, we report that neurotensin-positive neurons in the lateral septum (LSNts) play a crucial role in regulating hedonic feeding. Silencing LSNts specifically promotes feeding of palatable food, whereas activation of LSNts suppresses overall feeding. LSNts neurons project to the tuberal nucleus (TU) via GABA signaling to regulate hedonic feeding, while the neurotensin signal from LSNts→the supramammillary nucleus (SUM) is sufficient to suppress overall feeding. In vivo calcium imaging and optogenetic manipulation reveal two populations of LSNts neurons that are activated and inhibited during feeding, which contribute to food seeking and consumption, respectively. Chronic activation of LSNts or LSNts→TU is sufficient to reduce high-fat diet-induced obesity. Our findings suggest that LSNts→TU is a key pathway in regulating hedonic feeding.

Label-free study on the effect of a bioactive constituent on glioma cells in vitro using terahertz ATR spectroscopy.

In this work, we report that the effect of bioactive constituent on living glioma cells can be evaluated using terahertz time-domain attenuated total reflection (THz TD-ATR) spectroscopy in a label-free, non-invasive, and fast manner. The measured THz absorption coefficient of human glioma cells (U87) in cell culture media increases with ginsenoside Rg3 (G-Rg3) concentration in the range from 0 to 50 µM, which can be interpreted as that G-Rg3 deteriorated the cellular state. This is supported either by the cell growth inhibition rate measured using a conventional cell viability test kit or by the cellular morphological changes observed with fluorescence microscopy. These results verify the effectiveness of using the THz TD-ATR spectroscopy to detect the action of G-Rg3 on glioma cells in vitro. The demonstrated technique thus opens a new route to assessing the efficacy of bioactive constituents on cells or helping screen cell-targeted drugs.

Novel Fe3O4@metal-organic framework@polymer core-shell-shell nanospheres for fast extraction and specific preconcentration of nine organophosphorus pesticides from complex matrices.

Herein, a novel core-shell-shell magnetic nanosphere denoted as Fe3O4@ZIF-8@polymer was fabricated by sequential in situ self-assembly and precipitation polymerization for effective magnetic solid-phase extraction of nine organophosphorus pesticides (OPPs) from river water, pear, and cabbage samples. The integrated Fe3O4@ZIF-8@polymer featured convenient magnetic separation property and excellent multi-target binding ability. More importantly, the functional polymer coating greatly improved the extraction performance of Fe3O4@ZIF-8 for OPPs, thus facilitating the simultaneous determination of trace OPP residues in real samples. The developed MPSE-LC-MS/MS method exhibited good linearity (R2 ≥ 0.9991) over the concentration range of 0.2-200 µg L-1, low limits of detection of 0.0002-0.005 µg L-1 for river water and 0.006-0.185 µg kg-1 for pear and cabbage, satisfactory precision with relative standard deviations ≤ 9.7% and accuracy with recoveries of 69.5-94.3%. These results highlight that the combination of polymers with MOFs has great potential to fabricate excellent adsorbents for high-throughput analysis of various contaminants in complex matrices.

Characterization of Plasmid Co-Harboring NDM-1 and SHV-12 from a Multidrug-Resistant Citrobacter freundii Strain ZT01-0079 in China.

BACKGROUND: The emergence of multidrug-resistant Citrobacter freundii poses daunting challenges to the treatment of clinical infections. The purpose of this study was to characterize the genome of a C. freundii strain with an IncX3 plasmid encoding both the bla NDM-1 and bla SHV-12 genes. METHODS: Strain ZT01-0079 was isolated from a clinical urine sample. The Vitek2 system was used for identification and antimicrobial susceptibility testing. The presence of bla NDM-1 was detected by PCR and sequencing. Conjugation experiments and Southern blotting were performed to determine the transferability of the bla NDM-1- carrying plasmid. Nanopore and Illumina sequencing were performed to better understand the genomic characteristics of the strain. RESULTS: Strain ZT01-0079 was identified as C. freundii, and the coexistence of bla NDM-1 and multiple drug resistance genes was confirmed. Electrophoresis and Southern blotting showed that bla NDM-1 was located on a ~53kb IncX3 plasmid. The NDM-1-encoding plasmid was successfully transferred at a frequency of 1.68×10-3. Both the bla NDM-1 and bla SHV-12 genes were located on the self-transferable IncX3 plasmid. CONCLUSION: The rapid spread of the IncX3 plasmid highlights the importance of continuous monitoring of the prevalence of NDM-1-encoding Enterobacteriaceae. Mutations of existing carbapenem resistance genes will bring formidable challenges to clinical treatment.

Suppressing the Radiation-Induced Corrosion of Bismuth Nanoparticles for Enhanced Synergistic Cancer Radiophototherapy.

The level of tumor killing by bismuth nanoparticles (BiNPs) as radiosensitizers depends strongly on the powerful particle-matter interaction. However, this same radiation leads to the structural damage in BiNPs, consequently weakening their specific physicochemical properties for radiosensitization. Herein, we studied the radiation-induced corrosion behavior of BiNPs and demonstrated that these damages were manifested by the change in their morphology and crystal structure as well as self-oxidation at their surface. Furthermore, artificial heterostructures were created with graphene nanosheets to greatly suppress the radiation-induced corrosion in BiNPs and enhance their radiocatalytic activity for radiotherapy enhancement. Such a nanocomposite allows the accumulation of overexpressed glutathione, a natural hole scavenger, at the reaction interfaces. This enables the rapid removal of radiogenerated holes from the surface of BiNPs and minimizes the self-radiooxidation, therefore resulting in an efficient suppression of radiation corrosion and a decrease of the depletion of reactive oxygen species (ROS). Meanwhile, the radioexcited conduction band electrons react with the high-level H2O2 within cancer cells to yield more ROS, and the secondary electrons are trapped by H2O molecules to produce hydrated electrons capable of reducing a highly oxidized species such as cytochrome c. These radiochemical reactions together with hyperthermia can regulate the tumor microenvironment and accelerate the onset of cellular redox disequilibrium, mitochondrial dysfunction, and DNA damage, finally triggering tumor apoptosis and death. The current work will shed light on radiosensitizers with an enhanced corrosion resistance for controllable and synergistic radio-phototherapeutics.

Retrospective analysis of the development history of the Chinese food additive standards system based on the CODEX principles.

In 1984, China joined the Codex Alimentarius Commission (CAC), which was established by the United Nations' World Health Organization (WHO) and the Food and Agriculture Organization (FAO), which consists of 188 member states and one member organization. Since then, China has taken an active role in various initiatives organized by the Codex Committee on Food Additives (CCFA) and has shared resources and experience with its Codex member states, thus effectively promoting the development of the Chinese food additive standards system. Instead of a country where almost no systematic food additive standard were available, China has become the host country of the CCFA's sessions. China's food additive industry is the only one that is supported by international standards, out of the industries of the International Standard Industrial Classification and China's national economy. Based on this case, four strategic milestones are summarized by retrospectively analyzing the history of the development of Chinese food additive standards from 1978 to the present. China is expected to share its valuable experience and provide references for the improvement of food additive standards systems in multiple developing countries, so promoting food safety and trade harmonization. With the advances in core technologies in the food industry, the future development of food additive standardization is also forecast in this review.

Influence of design probe and sequence mismatches on the efficiency of fluorescent RPA.

Recombinase polymerase amplification (RPA) is an isothermal amplification technique. Because of its short detection cycle and high specificity, it has been applied in various fields. However, the design of probe on the efficiency of RPA is not well understood and the effect of sequence mismatches of oligonucleotides on the performance of RPA is rarely discussed. In this study, we found that different primers with the same probe have a slight effect on the efficiency of fluorescent RPA, and different probes with the same amplified region have a great influence on the efficiency of fluorescent RPA. We summarized the design rules of probes suitable for fluorescent RPA by analyzing the experimental data. The rule is that the best distance between fluorescent groups in the probe is 1-2 bases, and the G content should be reduced as far as possible. In addition, we verified this rule by designing a series of probes. Furthermore, we found the base mismatches of the probe had a significant effect on RPA, which can lead to false positives and can change the amplification efficiency. However, 1-3 mismatches covering the center of the primer sequence only affect the amplification efficiency of RPA, not its specificity. And with an increase in the number of primer mismatches, the efficiency of RPA will decrease accordingly. This study suggests that the efficiency of fluorescent RPA is closely related to the probe. We recommend that when designing a fluorescent probe, one must consider the presence of closely related non-targets and specific bases.

A novel ultrasensitive surface plasmon resonance-based nanosensor for nitrite detection.

Nitrite is a common food additive, however, its reduction product, nitrosamine, is a strong carcinogen, and hence the ultra-sensitive detection of nitrite is an effective means to prevent related cancers. In this study, different sized gold nanoparticles (AuNPs) were modified with P-aminothiophenol (ATP) and naphthylethylenediamine (NED). In the presence of nitrite, satellite-like AuNPs aggregates formed via the diazotization coupling reaction and the color of the system was changed by the functionalized AuNPs aggregates. The carcinogenic nitrite content could be detected by colorimetry according to the change in the system color. The linear concentration range of sodium nitrite was 0-1.0 µg mL-1 and the detection limit was determined to be 3.0 ng mL-1. Compared with the traditional method, this method has the advantages of high sensitivity, low detection limit, good selectivity and can significantly lower the naked-eye detection limit to 3.0 ng mL-1. In addition, this method is suitable for the determination of nitrite in various foods. We think this novel designed highly sensitive nitrate nanosensor holds great market potential.

Development of propidium monoazide-recombinase polymerase amplification (PMA-RPA) assay for rapid detection of Streptococcus pyogenes and Streptococcus agalactiae.

Streptococcus pyogenes (Group A Streptococcus, GAS) and Streptococcus agalactiae (Group B Streptococcus, GBS) are common pathogens that threaten public health. In this study, a double recombinase polymerase (RPA) amplification assay was developed to rapidly detect these pathogens. Specificity tests revealed that the GAS and GBS strains were positive for speB and SIP genes, respectively. In clinical samples, the double assay performed similarly to the traditional biochemical method. The limits of detection were both ≤100 copies per reaction. In tests for simulant-contaminated samples, bacterial-culture media containing 103 CFU/mL original concentrations of S. pyogenes and S. agalactiae were positive in RPA assays after incubating for 4 h. Results can be obtained at 37 °C in 20 min. To determine whether propidium monoazide (PMA) can eliminate the influence of DNA extracted from dead cells, a bacterial suspension was treated with PMA before DNA extraction. Findings of RPA assay showed that DNA extracted from dead cells had no fluorescence signal. Therefore, the PMA-RPA assay is a promising technology for field tests and rapid point-of-care diagnosis.

Residue behavior and risk assessment of thifluzamide in the maize field ecosystem.

In the present work, the dissipation kinetics and final residue levels of thifluzamide in the maize field ecosystem were investigated. Using a modified quick, easy, cheap, effective, rugged, and safe (QuEChERS) extraction combined with liquid chromatography-tandem mass spectrometric detection (LC-MS/MS), a rapid, sensitive, efficient, and reliable method for extraction and quantitative analysis of thifluzamide residues in maize grain, maize plant, and soil was developed. Satisfactory recoveries of 78.7-97.0% were achieved with relative standard deviations (RSDs) in the range of 1.6 to 8.2%. The limits of detection (LODs) and the limit of quantification (LOQ) were 0.002-0.005 and 0.010 mg kg-1, respectively. The dissipation kinetics of thifluzamide in maize plant was well fitted by the first-order kinetic model with short half-lives of 0.19-0.22 days, while thifluzamide degraded slowly in soil with half-lives of 4.56-15.85 days. The final residues in maize grain, maize plant, and soil samples collected at the milk stage and the physiological maturity stage were no more than 0.010, 0.807, and 0.278 mg kg-1, respectively. Given that no maximum residue limit (MRL) for thifluzamide in maize has been established, the safety of this fungicide application was estimated by a dietary risk assessment. The hazard quotient was 0.03%, which was substantially less than 1, indicating that the long-term risk induced by the thifluzamide application on maize at the recommended dose is negligible. These results help governments to develop regulations for the safe use of thifluzamide.

Characterization of the Thermal Degradation of Vinegar and the Construction of an Identification Model for Chinese Geographical Indication Vinegars by the Py-GC-MS Technique.

The pyrolysis (Py)-GC-MS technique was first introduced for the identification of two kinds of Chinese geographical indication vinegars because its advantages are that it is a simple and convenient sample pretreatment and inlet method. Abundant Py information about vinegars was obtained using Py-GC-MS; 21 common peaks were selected. With the help of the classical partial least-squares (PLS) modeling method for data analysis, two identification models for Shanxi extra-aged (SX) and Zhenjiang (ZJ) vinegars were established, respectively. An N-reducing method was used to select the variables. The variables were reduced one at a time to build the PLS models with the lowest number of misjudgments. Both models had good recognition rates, identifying over 90% of samples correctly. Thus, combining Py-GC-MS and PLS could be regarded as an effective method for the identification of SX and ZJ vinegars.

Liraglutide reduces the body weight and waist circumference in Chinese overweight and obese type 2 diabetic patients.

AIM: To investigate the effects of liraglutide, a glucagon-like peptide-1 (GLP-1) receptor activator, on body weight and waist circumference in Chinese overweight and obese type 2 diabetic patients. METHODS: A total of 328 Chinese overweight and obese type 2 diabetic patients were included in this multi-center, open-labeled and self-controlled clinical study. The patients were subcutaneously injected with liraglutide once daily for 24 weeks as add-on therapy to their previous hypoglycemic treatments. Statistical analyses were performed using SPSS software package version 11.5 for Windows. RESULTS: Liraglutide treatment caused significant reduction of the mean body weight (from 86.61±14.09 to 79.10±13.55 kg) and waist circumference (from 101.81±13.96 to 94.29±14.17 cm), resulting in body weight lose of 5%-10% in 43.67% patients, and body weight loss above 10% in 34.06% patients, who had significant lower plasma creatinine levels. Baseline waist circumference, BMI and HOMA-IR were independently correlated with the body weight loss. Furthermore, liraglutide treatment significantly decreased HbA1c levels (from 8.66%±2.17% to 6.92%±0.95%) with HbA1c<7.0% in 35.37% patients, who had a significantly lower baseline level of HbA1c, but higher baseline levels of C peptide and glucagon. Moreover, liraglutide treatment resulted in greater body weight loss in patients with a long duration of diabetes, and better glycemic control in patients with a short duration of diabetes. CONCLUSION: Liraglutide significantly reduces body weight and waist circumference in Chinese overweight and obese type 2 diabetic patients. Patients with apparent visceral obesity, insulin resistance and a long duration of diabetes may have greater body weight loss; whereas patients with high insulin-secreting ability, hyperglucagonemia, and short-duration diabetes may obtain better glycemic control with liraglutide.

Probing starch-iodine interaction by atomic force microscopy.

We explored the interaction of iodine with three crystalline type starches, corn, potato, and sweet potato starches using atomic force microscopy. Results revealed that starch molecules aggregated through interaction with iodine solution as well as iodine vapor. Detailed fine structures such as networks, chains, and super-helical structures were found in iodide solution tests. The nanostructures formed due to iodine adsorption could help to understand the formation and properties of the starch-iodine complex.

Scanning probe acoustic microscopy of extruded starch materials: direct visual evidence of starch crystal.

Scanning probe acoustic microscopy (SPAM) has been successfully used to study inorganic and keratin biomaterials. However, few studies have attempted to apply SPAM to structural study of non-keratin organic materials such as starch based materials. This study investigated hardness and surface finish to establish sample preparation method suitable for SPAM imaging and acquired clear acoustic images of extruded starch materials. Acquired acoustic images directly exhibited certain structure of starch materials and provided visual evidence of starch material components and aggregates. In addition, through correlating acoustic images with X-ray diffraction data, crystal-structural information in nano-scale was obtained and acoustic image contrast showed a linear relationship with starch amylose content in extruded starch materials.

Chemical constituents and bioactivities of the plants of genus Flemingia Roxb. et Ait. (Leguminosae).

The genus Flemingia Roxb. et Ait. (Leguminosae) has been used for disease prevention and therapy in China since ancient times. So the material basis of the pharmacological activity in the genus Flemingia should be clear for how to use this kind of traditional Chinese medicines more reasonably in pharmacology. Therefore, this review gives an account of the current knowledge on the chemical constituents, biological activities and pharmacological properties of the plants of the genus. Several different classes of compounds were previously isolated, which the main groups are flavones, particularly prenylated flavones, and triterpenes accompanied with sterols, anthraquinones, and others. The names and structures of the chemical constituents are given in this review. In addition, the pharmacological effects of the extracts and individual compounds (mainly for flavones) derived from the genus plants have been found, including neuroprotection, anti-inflammation, anti-oxidation, cytotoxicity, hormone-like effects, antimicrobial activities, and so on.

Nano-structures of debranched potato starch obtained by isoamylolysis.

Starch debranching is fundamental for understanding the structure-function relationships of starch. In this paper, atomic force microscopy (AFM) was used to investigate potato starch by isoamylase [EC 3.2.1.68] debranching at nanometer scale. The hydrolysates were separated by gel-permeation chromatography and the fractions were imaged. In addition to linear structures and branches, coiled structures were revealed in the intermediate hydrolysates. It is concluded that isoamylolysis is very useful for a better understanding of starch structure-property relationships.

Application of the molecular combing technique to starch granules.

The molecular combing technique was used to dissociate the nanostructural units of starch granules from the starch fragments after a gelatinization process. With the help of atomic force microscopy (AFM), we observed that some nanostructural chains were just flowing out of the granules. It proves that there are substantive nanostructural units in the starch granules, a phenomenon not previously observed, so these nanostructural units were defined as suspected intermediates. Furthermore, we conclude that blocklets of starch granules are formed through twisting or distortion of nanochains.