Volatile-compound fingerprinting and discrimination of positional isomers in stamp-pad ink tracing using HS-GC-IMS combined with multivariate statistical analysis.

The rising crime rate associated with document forgery has a significant impact on public safety and social stability. In document fraud cases, determining the origin of a particular stamp-pad ink is the most important objective. In this study, a comprehensive analysis of the volatile compounds in quick-drying stamp-pad inks from six commonly used brands were performed for the first time, utilizing a combination of headspace-gas chromatography-ion mobility spectrometry (HS-GC-IMS) and multivariate statistical analysis methods. Visual and comparative analysis of the differential volatile components among different stamp-pad ink samples was conducted using fingerprints and volcano plots. A total of 127 volatile compounds were accurately identified, with ketones, esters, alcohols, and aldehydes being the most abundant compounds in the stamp-pad inks. Hierarchical clustering analysis (HCA), including dendrograms and clustering heatmaps, was utilized to explore the correlations between these compounds and the samples. Additionally, the precise identification of positional isomers and functional group isomers of aliphatic compounds was achieved. To achieve accurate discrimination of various stamp-pad ink samples, a multivariate statistical analysis method was utilized to establish a classification model for them. Based on the results obtained from HS-GC-IMS, effective discrimination among different brands of stamp-pad ink samples was achieved through principal component analysis (PCA) and orthogonal partial least squares discriminant analysis (OPLS-DA). The model exhibited excellent performance, with the fit index of dependent variables (R2Y) and the predictive index of the model (Q2) values of 0.99 and 0.984, respectively. These results provided significant theoretical evidence for the application of HS-GC-IMS as an efficient technique in the analysis of volatile compounds, identification of positional isomers and functional group isomers, as well as tracing the origin of stamp-pad ink and analyzing the formation time of documents.

Associations among Body Mass Index, Waist-to-Hip Ratio, and Cognitive Impairment Tend to Follow an Opposite Trend and Are Sex Specific: A Population-Based Cross-Sectional Study in a Rural Area of Xi'an, China.

INTRODUCTION: The relationship between obesity and cognitive impairment (CI) is highly heterogeneous in previous studies, which may be due to insufficient consideration of anthropometric indicators and sex. This study compared the cross-sectional relationships among body mass index (BMI), waist-to-hip ratio (WHR), and CI among people aged ≥40 years, and sex-specific relationships were also considered. METHODS: This was a population-based cross-sectional study with a cluster sampling design. CI was defined as a Mini-Mental State Examination score lower than the cutoff value. Multivariate logistic regression was used. BMI and WHR were fitted as both restricted cubic splines and categorical data. Stratified analysis and interaction analysis were performed to explore the sex-specific relationship. RESULTS: A total of 1,792 subjects (40.5% male) were analyzed, and 230 were confirmed to have CI. The relationships among BMI, WHR, and CI were significant (poverall = 0.023, pnonlinear = 0.097; poverall = 0.017, pnonlinear = 0.078, respectively) but exhibited an opposite trend in the total population in the analyses with BMI and WHR as restricted cubic splines. Further categorical analyses showed that subjects with a BMI <23 kg/m2 tended to have a higher risk of CI than those with BMI ≥23 kg/m2 (16.2% vs. 11.8%, p = 0.017; OR = 1.366 [0.969-1.926], p = 0.075), and subjects with a WHR >0.92 had a significantly higher risk of CI than those with a WHR ≤0.92 (11.7% vs. 16.2%, p = 0.011; OR = 1.619 [1.161-2.258], p = 0.005). In addition, the relationship between a low BMI and CI was more significant in males (p = 0.034), while the relationship between a high WHR and CI was more significant in females (p = 0.002). Further studies are needed to confirm the sex differences because of the marginal significance result in the interaction analysis (p = 0.051 for interaction term BMI × sex; p = 0.056 for interaction term WHR × sex). CONCLUSION: The relationships among BMI, WHR, and CI exhibit an opposite trend. A low BMI or high WHR was positively associated with CI, which was more prominent in males for a low BMI and females for a high WHR.

Protocol of End-PSCI trial: a multicenter, randomized controlled trial to evaluate the effects of DL-3-n-butylphthalide on delayed-onset post stroke cognitive impairment.

BACKGROUND: Delayed-onset post stroke cognitive impairment (PSCI) results from secondary neurodegeneration induced by stroke. Whereas targeted prevention or treatment strategies are still missing due to lack of evidences. This trial aims to evaluate the preventive effects of DL-3-n-butylphthalide (NBP) on delayed-onset PSCI. METHODS: Effects of NBP on Delayed-onset Post Stroke Cognitive Impairment (End-PSCI) is a prospective, parallel-group, open-label, multicenter, randomized controlled trial with blinded outcome assessment. Hospital patients with acute cerebral infarction (within 2 weeks of onset) will be randomized into either standard medical therapy group or standard medical therapy combined NBP treatment group (NBP 200 mg, three times per day for 24 weeks). The primary outcome is the difference of incidence of delayed-onset PSCI between two groups. The secondary outcomes include difference of white matter degeneration, cognitive scores and prevalence of early-onset PSCI between two groups. DISCUSSION: End-PSCI trial will provide evidences for NBP preventing delayed-onset PSCI. The secondary outcomes will also provide valuable insights into the pathogenesis of delayed-onset PSCI and mechanism of NBP's actions. TRIAL REGISTRATION: Trialsearch.who.int , ChiCTR2000032555, 2020/5/2, prospectively registered.

Acute nitrous oxide-induced neuropathy mimicking Guillain-Barré syndrome.

The early clinical features of nitrous oxide (N2 O)-induced neuropathy were mimicking that of Guillain-Barré syndrome (GBS). We aimed to explore clinical and laboratory characteristics of N2 O-induced neuropathy in comparison with GBS. We retrospectively reviewed data of 15 patients with N2 O-induced neuropathy and compared them with 15 GBS patients. The age of the N2 O-induced neuropathy group was significantly younger than that in the GBS group (22 ± 5 vs 45 ± 17). Paresthesia was more common in N2 O-induced neuropathy group (100% vs 53.3%). The proportion of distal upper limbs weakness was lower than that in GBS group (20.0% vs 93.3%). There was no significant difference in the distal weakness of the lower limbs (100% vs 80.0%). The incidence of motor conduction block and compound muscle action potential amplitude reduction in upper limbs was lower than that in GBS group (6.7% vs 60.0%; 26.7% vs 80.0%). The sensory nerve action potential amplitude drop in the lower limbs was more severe than that in GBS group (53.3% vs 0). The increase of Mean corpuscular volume (MCV) was more pronounced compared to GBS group (96.97 ± 6.00 vs 88.55 ± 5.41). High homocysteine levels were more common in N2 O-related group [29.80(11.60, 70.50) vs 14.35(9.22, 19.30)]. Typical clinical features of the acute N2 O neuropathy appears to be a myeloneuropathy, affecting the lower limbs more than the upper limbs, mixed axonal-demyelinating electrophysiological performance, higher homocysteine level, and larger MCV and common posterior spinal cord involvement in cervical segment.

Magnetic solid-phase extraction using polydopamine-coated magnetic multiwalled carbon nanotube composites coupled with high performance liquid chromatography for the determination of chlorophenols.

Polydopamine (PDA)-coated magnetic multiwalled carbon nanotube (M-MWCNT) composites were synthesized in two facile preparation steps, and were used as adsorbents for magnetic solid-phase extraction (MSPE) coupled with high-performance liquid chromatography (HPLC) for simultaneous extraction, enrichment and determination of five kinds of typical chlorophenols (CPs) in water samples. The as-prepared magnetic composites showed excellent magnetic properties and high thermal stability. Various main parameters influencing the extraction efficiency of MSPE were systematically investigated. Under the optimized MSPE-HPLC conditions, a high enrichment factor (EF) was obtained in the range of 85-112 for 2-chlorophenol (2-CP), 4-chlorophenol (4-CP), 2,6-dichlorophenol (2,6-DCP), 2,4-dichlorophenol (2,4-DCP) and 2,4,6-trichlorophenol (2,4,6-TCP). Good linearity was obtained in the range of 2.0-200 µg L-1 for 2-CP and 4-CP and 1.0-200 µg L-1 for 2,6-DCP, 2,4-DCP and 2,4,6-TCP, with a correlation coefficient (R2) higher than 0.9964. The limits of detection (LODs) and the limits of quantification (LOQs) were in the range of 0.10-0.31 µg L-1 and 0.35-1.03 µg L-1, respectively. The intraday and interday precisions evaluated using relative standard deviation (RSD) values were in the range of 1.05-2.25% and 1.88-2.83%, respectively. The validated MSPE-HPLC method was also successfully applied to analyze five kinds of CPs in tap water, lake water, river water and seawater samples, and satisfactory recoveries were obtained in the range of 76.87-106.5% with RSDs of 1.64-6.78%.

The increased activity of a transcription factor inhibits autophagy in diabetic embryopathy.

BACKGROUND: Maternal diabetes induces neural tube defects and stimulates the activity of the forkhead box O3 (Fox)O3a in the embryonic neuroepithelium. We previously demonstrated that deleting the FOXO3a gene ameliorates maternal diabetes-induced neural tube defects. Macroautophagy (hereafter referred to as "autophagy") is essential for neurulation. Rescuing autophagy suppressed by maternal diabetes in the developing neuroepithelium inhibits neural tube defect formation in diabetic pregnancy. This evidence suggests a possible link between FoxO3a and impaired autophagy in diabetic embryopathy. OBJECTIVE: We aimed to determine whether maternal diabetes suppresses autophagy through FoxO3a, and if the transcriptional activity of FoxO3a is required for the induction of diabetic embryopathy. STUDY DESIGN: We used a well-established type 1 diabetic embryopathy mouse model, in which diabetes was induced by streptozotocin, for our in vivo studies. To determine if FoxO3a mediates the inhibitory effect of maternal diabetes on autophagy in the developing neuroepithelium, we induced diabetic embryopathy in FOXO3a gene knockout mice and FoxO3a dominant negative transgenic mice. Embryos were harvested at embryonic day 8.5 to determine FoxO3a and autophagy activity and at embryonic day 10.5 for the presence of neural tube defects. We also examined the expression of autophagy-related genes. C17.2 neural stem cells were used for in vitro examination of the potential effects of FoxO3a on autophagy. RESULTS: Deletion of the FOXO3a gene restored the autophagy markers, lipidation of microtubule-associated protein 1A/1B-light chain 3I to light chain 3II, in neurulation stage embryos. Maternal diabetes decreased light chain 3I-positive puncta number in the neuroepithelium, which was restored by deleting FoxO3a. Maternal diabetes also decreased the expression of positive regulators of autophagy (Unc-51 like autophagy activating kinase 1, Coiled-coil myosin-like BCL2-interacting protein, and autophagy-related gene 5) and the negative regulator of autophagy, p62. FOXO3a gene deletion abrogated the dysregulation of autophagy genes. In vitro data showed that the constitutively active form of FoxO3a mimicked high glucose in repressing autophagy. In cells cultured under high-glucose conditions, overexpression of the dominant negative FoxO3a mutant blocked autophagy impairment. Dominant negative FoxO3a overexpression in the developing neuroepithelium restored autophagy and significantly reduced maternal diabetes-induced apoptosis and neural tube defects. CONCLUSION: Our study revealed that diabetes-induced FoxO3a activation inhibited autophagy in the embryonic neuroepithelium. We also observed that FoxO3a transcriptional activity mediated the teratogenic effect of maternal diabetes because dominant negative FoxO3a prevents maternal diabetes-induced autophagy impairment and neural tube defect formation. Our findings suggest that autophagy activators could be therapeutically effective in treating maternal diabetes-induced neural tube defects.

Dual-template molecularly imprinted polymers for dispersive solid-phase extraction of fluoroquinolones in water samples coupled with high performance liquid chromatography.

Novel dual-template molecularly imprinted polymers (dt-MIPs) were prepared by simple and facile precipitation polymerization using norfloxacin (NOR) and enrofloxacin (ENR) as templates for simultaneous selective recognition and extraction of the two fluoroquinolones (FQs). The as-prepared dt-MIPs exhibited high adsorption capacity and excellent selectivity towards NOR and ENR. Several main parameters affecting the efficiency of dt-MIP based dispersive solid-phase extraction (DSPE) were systematically investigated, coupled with high performance liquid chromatography determination. Consequently, high enrichment factors of 71 and 61 were obtained for NOR and ENR respectively, and good linearity in the range of 1-200 µg L-1 was observed, with correlation coefficients (r) above 0.9977. The limits of detection and quantification for NOR were 0.22 and 0.67 µg L-1, respectively, and 0.36 and 0.98 µg L-1 for ENR. Satisfactory recoveries of the two FQs from spiked lake, sea and tap water samples at three concentration levels were attained in the range of 80.9-101.0% with relative standard deviations of 0.9-6.9%. The present study not only has great potential for applications in FQ determination, but will also enrich research into dual/multi-template imprinting.

Dispersive liquid-liquid microextraction coupled with pressure-assisted electrokinetic injection for simultaneous enrichment of seven phenolic compounds in water samples followed by determination using capillary electrophoresis.

Offline dispersive liquid-liquid microextraction combined with online pressure-assisted electrokinetic injection was developed to simultaneously enrich seven phenolic compounds in water samples, followed by determination using capillary electrophoresis, namely phenol, 4-chlorophenol, pentachlorophenol, 2,4,6-trichlorophenol, 2,4-dichlorophenol, 2-chlorophenol, and 2,6-dichlorophenol. Several parameters affecting separation performance of capillary electrophoresis and the enrichment efficiency of pressure-assisted electrokinetic injection and dispersive liquid-liquid microextraction were systematically investigated. Under the optimal conditions, seven phenolic compounds were completely separated within 14 min and good enrichment factors were obtained of 61, 236, 3705, 3288, 920, 86, and 1807 for phenol, 4-chlorophenol, pentachlorophenol, 2,4,6-trichlorophenol, 2,4-dichlorophenol, 2-chlorophenol, and 2,6-dichlorophenol, respectively. Good linearity was attained in the range of 0.1-200 µg/L for 2,4-dichlorophenol, 0.5-200 µg/L for 4-chlorophenol, pentachlorophenol, 2,4,6-trichlorophenol, 2-chlorophenol, and 2,6-dichlorophenol, as well as 1-200 µg/L for phenol, with correlation coefficients (r) over 0.9905. The limits of detection and quantification ranging from 0.03-0.28 and 0.07-0.94 µg/L were attained. This two step enrichment method was potentially applicable for the rapid and simultaneous determination of phenolic compounds in water samples.

OsYSL16 is Required for Preferential Cu Distribution to Floral Organs in Rice.

Deficiency of copper (Cu) causes low fertility in many plant species, but the molecular mechanisms underlying distribution of Cu to the floral organs are poorly understood. Here, we found that a member of yellow-stripe like (YSL) family, YSL16 encoding the Cu-nicotianamine (Cu-NA) transporter, was highly expressed in the rachilla, with less expression in the palea and lemma of rice (Oryza sativa). ß-Glucuronidase (GUS) staining of transgenic rice carrying the OsYSL16 promoter-GUS showed that OsYSL16 was mainly expressed in vascular bundles of the rachilla as well as the palea and lemma. Knockout of OsYSL16 resulted in decreased Cu distribution to the stamens, but increased distribution to the palea and lemma. A short-term (24 h) 65Cu labeling experiment confirmed increased Cu concentration of palea and lemma in the mutant. Furthermore, we found that redistribution of Cu from the palea and lemma was impaired in the osysl16 mutant after exposure to Cu-free solution. The osysl16 mutant showed low pollen germination, but this was rescued by addition of Cu in the medium. Our results indicate that OsYSL16 expressed in the vascular bundles of the rachilla is important for preferential distribution of Cu to the stamens, while OsYSL16 in vascular bundles of the palea and lemma is involved in Cu redistribution under Cu-limited conditions in rice.

Dispersive liquid-liquid microextraction of five chlorophenols in water samples followed by determination using capillary electrophoresis.

Dispersive liquid-liquid microextraction (DLLME) coupled with CE was developed for simultaneous determination of five types of chlorophenols (CPs), namely 2-chlorophenol (2-CP), 4-chlorophenol (4-CP), 2,4-dichlorophenol (2,4-DCP), 2,6-dichlorophenol (2,6-DCP), and 2,4,6-trichlorophenol (2,4,6-TCP) in water samples. Several parameters affecting DLLME and CE conditions were systematically investigated. Under the optimized DLLME-CE conditions, the five CPs were separated completely within 7.5 min and good enrichment factors were obtained of 40, 193, 102, 15, and 107 for 4-CP, 2,4,6-TCP, 2,4-DCP, 2-CP, and 2,6-DCP, respectively. Good linearity was attained in the range of 1-200 µg/L for 2,4,6-TCP, 2,4-DCP, 2-300 µg/L for 4-CP and 2-CP, and 1-300 µg/L for 2,6-DCP, with correlation coefficients (r) over 0.99. The LOD (S/N = 3) and the LOQ (S/N = 10) were 0.31-0.75 µg/L and 1.01-2.43 µg/L, respectively. Recoveries ranging from 60.85 to 112.36% were obtained with tap, lake, and river water spiked at three concentration levels and the RSDs (for n = 3) were 1.31-11.38%. With the characteristics of simplicity, cost-saving, and environmental friendliness, the developed DLLME-CE method proved to be potentially applicable for the rapid, sensitive, and simultaneous determination of trace CPs in complicated water samples.

Speciation analysis of mercury by dispersive solid-phase extraction coupled with capillary electrophoresis.

A pretreatment method of dispersive solid-phase extraction (DSPE) along with back-extraction followed by CE-UV detector was developed for the determination of mercury species in water samples. Sulfhydryl-functionalized SiO2 microspheres (SiO2 -SH) were synthesized and used as DSPE adsorbents for selective extraction and enrichment of three organic mercury species namely ethylmercury (EtHg), methylmercury (MeHg), and phenylmercury (PhHg), along with L-cysteine (L-cys) containing hydrochloric acid as back-extraction solvent. Several main extraction parameters were systematically investigated including sample pH, amount of adsorbent, extraction and back-extraction time, volume of eluent, and concentration of hydrochloric acid. Under optimal conditions, good linearity was achieved with correlation coefficients over 0.9990, in the range of 4-200 µg/L for EtHg, and 2-200 µg/L for MeHg and PhHg. The LODs were obtained of 1.07, 0.34, and 0.24 µg/L for EtHg, MeHg, and PhHg, respectively, as well as the LOQs were 3.57, 1.13, and 0.79 µg/L, respectively, with enrichment factors ranging from 109 to 184. Recoveries were attained with tap and lake water samples in a range of 62.3-107.2%, with relative standard deviations of 3.5-10.1%. The results proved that the method of SiO2 -SH based DSPE coupled with CE-UV was a simple, rapid, cost-effective, and eco-friendly alternative for the determination of mercury species in water samples.

Alterted SLIT2/ROBO1 signalling is linked to impaired placentation of missed and threatened miscarriage in early pregnancy.

AIMS: Two-thirds of early pregnancy failures present with reduced trophoblast invasion, and SLIT2/ROBO1 signalling is considered to play an important role in trophoblast function during pregnancy. We investigated SLIT2/ROBO1 signalling associated with missed and threatened miscarriage during early gestation. METHODS AND RESULTS: Human placenta samples were collected from women with missed miscarriage (n = 25), threatened miscarriage (n = 22) and termination of pregnancy controls (n = 32). Corresponding decreases in beta human chorionic gonadotrophin (ß-hCG) levels and shallow trophoblast invasion were observed in patients with missed and threatened miscarriage, immunohistological staining revealed abnormal Slit2 and Robo1, as well as E-cadherin and activating protein-2 alpha (AP-2α) expression in villi and extravillous trophoblasts, and the expression of these proteins were confirmed in villi and decidua of miscarriage material by Western blotting. Using HTR8/SVneo cells, blocking SLIT2/ROBO1 signalling promoted cell migration, proliferation and suppressed differentiation. Moreover, blocking SLIT2/ROBO1 signalling in HTR8/SVneo cells altered trophoblast differentiation-related and angiogenesis-related gene mRNA expression, which also occurred in the tissues of missed and threatened miscarriage. CONCLUSIONS: SLIT2/ROBO1 signalling may regulate trophoblast differentiation and invasion causing restricting ß-hCG production, shallow trophoblast invasion and inhibiting placental angiogenesis in missed and threatened miscarriage during the first trimester.

Molecular imprinting: perspectives and applications.

Molecular imprinting technology (MIT), often described as a method of making a molecular lock to match a molecular key, is a technique for the creation of molecularly imprinted polymers (MIPs) with tailor-made binding sites complementary to the template molecules in shape, size and functional groups. Owing to their unique features of structure predictability, recognition specificity and application universality, MIPs have found a wide range of applications in various fields. Herein, we propose to comprehensively review the recent advances in molecular imprinting including versatile perspectives and applications, concerning novel preparation technologies and strategies of MIT, and highlight the applications of MIPs. The fundamentals of MIPs involving essential elements, preparation procedures and characterization methods are briefly outlined. Smart MIT for MIPs is especially highlighted including ingenious MIT (surface imprinting, nanoimprinting, etc.), special strategies of MIT (dummy imprinting, segment imprinting, etc.) and stimuli-responsive MIT (single/dual/multi-responsive technology). By virtue of smart MIT, new formatted MIPs gain popularity for versatile applications, including sample pretreatment/chromatographic separation (solid phase extraction, monolithic column chromatography, etc.) and chemical/biological sensing (electrochemical sensing, fluorescence sensing, etc.). Finally, we propose the remaining challenges and future perspectives to accelerate the development of MIT, and to utilize it for further developing versatile MIPs with a wide range of applications (650 references).

Molecularly imprinted polymers for dispersive solid-phase extraction of phenolic compounds in aqueous samples coupled with capillary electrophoresis.

A simple and sensitive method for the simultaneous determination of seven phenolic compounds in aqueous samples was developed by dispersive solid-phase extraction (DSPE) coupled with capillary electrophoresis (CE), namely phenol, 4-chlorophenol (4-CP), pentachlorophenol (PCP), 2,4,6-trichlorophenol (2,4,6-TCP), 2,4-dichlorophenol (2,4-DCP), 2-chlorophenol (2-CP) and 2,6-dichlorophenol (2,6-DCP). Molecularly imprinted polymers (MIPs) prepared by precipitation polymerization with 2,4,6-trichlorophenol (2,4,6-TCP) as template were used as DSPE sorbents to selectively adsorb the phenols. Various parameters affecting the extraction efficiency were evaluated and excellent CE separation was achieved within 13.5 min by using 15 mmol/L borate buffer containing 15% (v/v) methanol at pH = 9.8. Under the optimized conditions, good linearity was obtained in the range of 2-200 µg/L for phenol, 2,4-DCP and 2,6-DCP, 2-300 µg/L for 4-CP and 2-CP, 1.5-150 µg/L for PCP, and 2-400 µg/L for 2,4,6-TCP, with the correlation coefficient (R2 ) higher than 0.9938. Limits of detection and limits of quantification were in the range of 0.18-0.44 µg/L and 0.59-1.45 µg/L, respectively. The developed MIPs-DSPE-CE method was also successfully applied to determine the seven phenolic compounds in lake, tap, seawater and tannery wastewater. The average recoveries at three different spiked levels ranged from 70.75 to 106.7% with the relative standard deviations of 1.15-6.28%.

Dispersive liquid-liquid microextraction for four phenolic environmental estrogens in water samples followed by determination using capillary electrophoresis.

Dispersive liquid-liquid microextraction (DLLME) coupled with CE was successfully developed for simultaneous determination of four types of phenolic environmental estrogens (PEEs), namely hexestrol (HS), bisphenol A (BPA), diethylstilbestrol (DES) and dienestrol (DS). Several parameters affecting DLLME and CE conditions were systematically investigated including the type and volume of extraction solvent and dispersive solvent, extraction time, salt, pH value, surfactant, buffer solution and so on. Under the optimal conditions, DLLME-CE exhibited strong enrichment ability, presenting high enrichment factors of 467, 241, 367 and 362 for HS, BPA, DES and DS, respectively, as well as low detection limits of 0.3, 0.6, 0.6 and 0.3 µg/L, respectively. Excellent linearity was achieved in the range of 2.0-150 µg/L for HS and DS, and 4.0-300 µg/L for BPA and DES, with correlation coefficients R>0.9983. Recoveries ranging from 70.4 to 108.1% were obtained with tap water, lake water and seawater samples spiked at three concentration levels and the relative standard deviations (RSDs, for n = 5) were 2.1-9.7%. This DLLME-CE method with high selectivity and sensitivity, high stability, simplicity, cost-effectiveness, eco-friendliness was proved potentially applicable for the rapid and simultaneous determination of PEEs in complicated water samples.

Investigating the effect of excess caffeine exposure on placental angiogenesis using chicken 'functional' placental blood vessel network.

It is now known that over-consumption of caffeine by pregnant mothers could have detrimental effects on normal fetal development. However, it remains obscure how caffeine's harmful effect impacts directly or indirectly on the developing embryo/fetus through damaging placenta development. In this study, we demonstrated the morphological similarities between the yolk sac and chorioallantoic membranes (CAM) of chick embryos and the villi of the mammalian placenta. Using the chick yolk sac and the CAM as a model, we found that 5-15 µmol per egg of caffeine exposure inhibited angiogenesis. Under the same condition, cell proliferation in extraembryonic mesoderm was reduced while apoptosis was enhanced. Semi-quantitative RT-PCR analysis revealed that caffeine treatment down-regulated VEGF, VEGFR2, PIGF, IGF2 and NRP1 expression, but up-regulated Ang1 and Ang2 expression. We performed in situ hybridization to show VE-cadherin expression and as to demonstrate the blood vessels in the CAM and yolk sac membranes. This distribution of the VE-cadherin(+) blood vessels was determined to be reduced after caffeine treatment. Furthermore, MDA activity was induced after caffeine exposure, but GSH-PX activity was inhibited after caffeine exposure; SOD activity was unchanged as compared with the control. In summary, our results suggest that caffeine exposure could negatively impact on angiogenesis in the chick yolk sac and CAM by targeting angiogenesis-related genes. Some of these genes are also involved in regulating excess ROS generation. The results implied that the negative impact of caffeine on fetal development was partly attributed to impaired placental angiogenesis.

Angiogenesis is repressed by ethanol exposure during chick embryonic development.

It is now known that excess alcohol consumption during pregnancy can cause fetal alcohol syndrome to develop. However, it is not known whether excess ethanol exposure could directly affect angiogenesis in the embryo or angiogenesis being indirectly affected because of ethanol-induced fetal alcohol syndrome. Using the chick yolk sac membrane (YSM) model, we demonstrated that ethanol exposure dramatically inhibited angiogenesis in the YSM of 9-day-old chick embryos, in a dose-dependent manner. Likewise, the anti-angiogenesis effect of ethanol could be seen in the developing vessel plexus (at the same extra-embryonic regions) during earlier stages of embryo development. The anti-angiogenic effect of ethanol was found associated with excess reactive oxygen species (ROS) production; as glutathione peroxidase activity increased while superoxide dismutase 1 and 2 activities decreased in the YSMs. We further validated this observation by exposing chick embryos to 2,2'-azobis-amidinopropane dihydrochloride (a ROS inducer) and obtained a similar anti-angiogenesis effect as ethanol treatment. Semiquantitative reverse transcription-polymerase chain reaction analysis of the experimental YSMs revealed that expression of angiogenesis-related genes, vascular endothelial growth factor and its receptor, fibroblast growth factor 2 and hypoxia-inducible factor, were all repressed following ethanol and 2,2'-azobis-amidinopropane dihydrochloride treatment. In summary, our results suggest that excess ethanol exposure inhibits embryonic angiogenesis through promoting superfluous ROS production during embryo development.

Gender specific effect of LIPC C-514T polymorphism on obesity and relationship with plasma lipid levels in Chinese children.

Hepatic lipase (LIPC) is a key rate-limiting enzyme in lipoprotein catabolism pathways involved in the development of obesity. The C-514T polymorphism in the promoter region is associated with decreased LIPC activity. We performed a case-controlled study (850 obese children and 2119 controls) and evaluated the association between LIPC C-514T polymorphism, obesity and plasma lipid profile in Chinese children and adolescents. Additionally, we conducted a meta-analysis of all results from published studies as well as our own data. A significant association between the polymorphism and obesity is observed in boys (P = 0.042), but not in girls. And we observed a significant relationship of the polymorphism with total cholesterol (TC) and high density lipoprotein cholesterol (HDL-C) independent of obesity in boys. The T allele carriers have higher levels of low density lipoprotein cholesterol (LDL-C) in obese boys, and triglyceride (TG), TC and LDL-C in non-obese girls (all P < 0.05). In the meta-analysis, under dominant model the T allele increased body mass index (BMI) level in boys, while it decreased BMI in girls, and increased the levels of TC both in the overall and subgroups, TG and HDL-C in the overall and boys, and LDL-C in the overall (all P < 0.05). Our results suggest that the T allele might carry an increased risk of obesity in Chinese boys. The meta-analysis suggests that T allele acts as a risk allele for higher BMI levels in male childhood, while it is a protective allele in female childhood. And the polymorphism is associated with the levels of plasma lipids, which may be modulated by obesity and gender.

Speciation analysis of mercury in water samples by dispersive liquid-liquid microextraction coupled to capillary electrophoresis.

In this study, a method of pretreatment and speciation analysis of mercury by dispersive liquid-liquid microextraction along with CE was developed. The method was based on the fact that mercury species including methylmercury (MeHg), ethylmercury (EtHg), phenylmercury (PhHg), and Hg(II) were complexed with 1-(2-pyridylazo)-2-naphthol to form hydrophobic chelates and l-cysteine could displace 1-(2-pyridylazo)-2-naphthol to form hydrophilic chelates with the four mercury species. Factors affecting complex formation and extraction efficiency, such as pH value, type, and volume of extractive solvent and disperser solvent, concentration of the chelating agent, ultrasonic time, and buffer solution were investigated. Under the optimal conditions, the enrichment factors were 102, 118, 547, and 46, and the LODs were 1.79, 1.62, 0.23, and 1.50 µg/L for MeHg, EtHg, PhHg, and Hg(II), respectively. Method precisions (RSD, n = 5) were in the range of 0.29-0.54% for migration time, and 3.08-7.80% for peak area. Satisfactory recoveries ranging from 82.38 to 98.76% were obtained with seawater, lake, and tap water samples spiked at three concentration levels, respectively, with RSD (n = 5) of 1.98-7.18%. This method was demonstrated to be simple, convenient, rapid, cost-effective, and environmentally benign, and could be used as an ideal alternative to existing methods for analyzing trace residues of mercury species in water samples.

Mechanically Tough and Conductive Hydrogels Based on Gelatin and Z-Gln-Gly Generated by Microbial Transglutaminase.

Gelatin-based hydrogels with excellent mechanical properties and conductivities are desirable, but their fabrication is challenging. In this work, an innovative approach for the preparation of gelatin-based conductive hydrogels is presented that improves the mechanical and conductive properties of hydrogels by integrating Z-Gln-Gly into gelatin polymers via enzymatic crosslinking. In these hydrogels (Gel-TG-ZQG), dynamic π-π stacking interactions are created by the introduction of carbobenzoxy groups, which can increase the elasticity and toughness of the hydrogel and improve the conductivity sensitivity by forming effective electronic pathways. Moreover, the mechanical properties and conductivity of the obtained hydrogel can be controlled by tuning the molar ratio of Z-Gln-Gly to the primary amino groups in gelatin. The hydrogel with the optimal mechanical properties (Gel-TG-ZQG (0.25)) exhibits a high storage modulus, compressive strength, tensile strength, and elongation at break of 7.8 MPa at 10 °C, 0.15 MPa at 80% strain, 0.343 MPa, and 218.30%, respectively. The obtained Gel-TG-ZQG (0.25) strain sensor exhibits a short response/recovery time (260.37 ms/130.02 ms) and high sensitivity (0.138 kPa-1) in small pressure ranges (0-2.3 kPa). The Gel-TG-ZQG (0.25) hydrogel-based sensors can detect full-range human activities, such as swallowing, fist clenching, knee bending and finger pressing, with high sensitivity and stability, yielding highly reproducible and repeatable sensor responses. Additionally, the Gel-TG-ZQG hydrogels are noncytotoxic. All the results demonstrate that the Gel-TG-ZQG hydrogel has potential as a biosensor for wearable devices and health-monitoring systems.