A preliminary metabolomics study of the database for biological samples of schizophrenia among Chinese ethnic minorities.

BACKGROUND: Schizophrenia (SCZ) is a profound mental disorder with a multifactorial etiology, including genetics, environmental factors, and demographic influences such as ethnicity and geography. Among these, the studies of SCZ also shows racial and regional differences. METHODS: We first established a database of biological samples for SCZ in China's ethnic minorities, followed by a serum metabolomic analysis of SCZ patients from various ethnic groups within the same region using the LC-HRMS platform. RESULTS: Analysis identified 47 metabolites associated with SCZ, with 46 showing significant differences between Miao and Han SCZ patients. These metabolites, primarily fatty acids, amino acids, benzene, and derivatives, are involved in fatty acid metabolism pathways. Notably, L-Carnitine, L-Cystine, Aspartylphenylalanine, and Methionine sulfoxide demonstrated greater diagnostic efficacy in Miao SCZ patients compared to Han SCZ patients. CONCLUSION: Preliminary findings suggest that there are differences in metabolic levels among SCZ patients of different ethnicities in the same region, offering insights for developing objective diagnostic or therapeutic monitoring strategies that incorporate ethnic considerations of SCZ.

Effect of luminescent materials on the biochemistry, ultrastructure, and rhizobial microbiota of Spirodela polyrhiza.

Fluorescent materials and technologies have become widely used in scientific research, and due to the ability to convert light wavelengths, their application to photosynthetic organisms can affect their development by altering light quality. However, the impacts of fluorescent materials on aquatic plants and their environmental risks remain unclear. To assess the effects of luminescent materials on floating aquatic macrophytes and their rhizosphere microorganisms, 4-(di-p-tolylamino)benzaldehyde-A (DTB-A) and 4-(di-p-tolylamino)benzaldehyde-M (DTB-M) (emitting blue-green and orange-red light, respectively) were added individually and jointly to Spirodela polyrhiza cultures and set at different concentrations (1, 10, and 100 µM). Both DTB-A and DTB-M exhibited phytotoxicity, which increased with concentration under separate treatment. Moreover, the combined group exhibited obvious stress relief at 10 µM compared to the individually treated group. Fluorescence imaging showed that DTB-A and DTB-M were able to enter the cell matrix and organelles of plant leaves and roots. Peroxidation induced cellular damage, contributing to a decrease in superoxide dismutase (SOD) and peroxidase (POD) activities and malondialdehyde (MDA) accumulation. Decomposition of organelle structures, starch accumulation in chloroplasts, and plasmolysis were observed under the ultrastructure, disrupting photosynthetic pigment content and photosynthesis. DTB-A and DTB-M exposure resulted in growth inhibition, dry weight loss, and leaf yellowing in S. polyrhiza. A total of 3519 Operational Taxonomic Units (OTUs) were identified in the rhizosphere microbiome. The microbial communities were dominated by Alphaproteobacteria, Oxyphotobacteria, and Gammaproteobacteria, with the abundance and diversity varied significantly among treatment groups according to Shannon, Simpson, and Chao1 indices. This study revealed the stress defense response of S. polyrhiza to DTB-A and DTB-M exposures, which provides a broader perspective for the bioremediation of pollutants using aquatic plants and supports the further development of fluorescent materials for applications.

A Facile Strategy for Multiplex Protein Detection by a Fluorescent Microsphere-Based Digital Immunoassay.

The digital immunoassay is a highly sensitive detection technique based on single-molecule counting and is widely used in the ultrasensitive detection of biomarkers. Herein, we developed a fluorescent microsphere-based digital immunoassay (FMDIA) by employing fluorescent microspheres as both the carriers for immunoreaction and fluorescent reports for imaging. In this approach, the target protein in the sample was captured by fluorescent microspheres to form a biotin-labeled sandwich immunocomplex, and then, the fluorescent microspheres containing the target protein molecules were captured by adding streptavidin-coated magnetic beads (SA-MBs). By counting the proportion of fluorescence-positive magnetic beads, the concentration of the target protein can be precisely quantified. As a proof of concept, α fetoprotein (AFP) and human interleukin-6 (IL-6) were used to assess the analytical performance of the proposed FMDIA, and limit of detection (LOD) values of 21 pg/mL (0.30 pM) and 0.19 pg/mL (7.3 fM) were achieved, respectively. The results of AFP detection in serum samples of patients and healthy people were consistent with the reference values given by the hospital. Furthermore, by adding fluorescent microspheres of various colors for encoding, the proposed FMDIA can easily realize the simultaneous detection of multiple proteins without the need to introduce multiple modified magnetic beads. This multiplex protein detection strategy, in which the reactions are first carried out on the fluorescent microspheres and then magnetic beads are used to capture the fluorescent reporters containing the target molecules, provides a new idea for digital assays.

Amplification-free detection of Mpox virus DNA using Cas12a and multiple crRNAs.

Mpox virus (MPXV) is a zoonotic DNA virus that caused human Mpox, leading to the 2022 global outbreak. MPXV infections can cause a number of clinical syndromes, which increases public health threats. Therefore, it is necessary to develop an effective and reliable method for infection prevention and control of epidemic. Here, a Cas12a-based direct detection assay for MPXV DNA is established without the need for amplification. By targeting the envelope protein gene (B6R) of MPXV, four CRISPR RNAs (crRNAs) are designed. When MPXV DNA is introduced, every Cas12a/crRNA complex can target a different site of the same MPXV gene. Concomitantly, the trans-cleavage activity of Cas12a is triggered to cleave the DNA reporter probes, releasing a fluorescence signal. Due to the application of multiple crRNAs, the amount of active Cas12a increases. Thus, more DNA reporter probes are cleaved. As a consequence, the detection signals are accumulated, which improves the limit of detection (LOD) and the detection speed. The LOD of the multiple crRNA system can be improved to ~ 0.16 pM, which is a decrease of the LOD by approximately ~ 27 times compared with the individual crRNA reactions. Furthermore, using multiple crRNAs increases the specificity of the assay. Given the outstanding performance, this assay has great potential for Mpox diagnosis.

Nucleic Acid Amplification-Free Digital Detection Method for SARS-CoV-2 RNA Based on Droplet Microfluidics and CRISPR-Cas13a.

Most of the methods currently developed for RNA detection based on CRISPR were combined with nucleic acid amplification. As a result, such methods inevitably led to certain disadvantages such as multiple operations, expensive reagents, and amplification bias. To solve the above problems, we developed a highly sensitive and specific nucleic acid amplification-free digital detection method for SARS-CoV-2 RNA based on droplet microfluidics and CRISPR-Cas13a. In this assay, thousands of monodisperse droplets with a size of 30 µm were generated within 2 min by a negative pressure-driven microfluidic chip. By confining a single target RNA recognition event to an independent droplet, the collateral cleavage products of activated Cas13a could be accumulated in one droplet. By combining the droplet microfluidics and CRISPR-Cas13a, SARS-CoV-2 RNA could be easily detected within 30 min with a detection limit of 470 aM. The performance of this assay was verified by specificity experiments and spiking and recovery experiments with human saliva. Compared with many developed methods for SARS-CoV-2 RNA detection, our method is time- and reagent-saving and easy to operate. Taken together, this digital detection method based on droplet microfluidics and CRISPR-Cas13a provides a promising approach for RNA detection in clinical diagnostics.

Combined toxic effects of polypropylene and perfluorooctanoic acid on duckweed and periphytic microorganisms.

Microplastics and perfluorooctanoic acid coexist in the aquatic environment. Duckweed was exposed to a range of concentrations (0.1-1000 µg L-1) of solutions containing polypropylene (PP) and perfluorooctanoic acid (PFOA) for 14 days to measure their toxicity. The result showed the single and combined PP and PFOA treatments did not significantly influence the growth of duckweed. The greatest PP and PFOA concentrations of combined pollution affect plant chlorophyll. Moreover, the combined treatment of duckweed consistently resulted in increased malondialdehyde (MDA) levels, indicating oxidative damage. As an antioxidant stress response, the combination-treated plants were encouraged to produce superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT). Meanwhile, 3519 Operational Taxonomic Units (OTUs) were identified in the duckweed rhizosphere. Proteobacteria was the most predominant microbial community. Shannon, Simpson, and Chao1 discovered that microbial communities changed in response to single and combination PP and PFOA treatments, with decreased diversity and increased abundance. In addition, SEM analysis also revealed that the combined treatment significantly phyllosphere microorganisms. The findings of this investigation add to our knowledge of how PP and PFOA affect duckweed and the rhizospheric microorganisms, expanding the theoretical basis for employing duckweed in complex contamination.

Combined toxic effects of perfluorooctanoic acid and microcystin-LR on submerged macrophytes and biofilms.

Perfluorooctanoic acid (PFOA) and microcystin-LR (MCLR) are pervasive pollutants in surface waters that induce significant toxic effects on aquatic organisms. However, the combined environmental risk of PFOA and MCLR remains unclear. To assess the toxic effects of PFOA and MCLR on submerged macrophytes and biofilms, Vallisneria natans was exposed to different concentrations of PFOA and MCLR (0.01, 0.1, 1.0 and 10.0 µg L-1). Vallisneria natans was sensitive to high concentrations of MCLR (10 µg L-1): plants exposed to 10 µg L-1 of MCLR measured a biomass of 3.46 g, which was significantly lower than the 8.71 g of the control group. Additionally, antagonistic interactive effects were observed in plants exposed to combined PFOA and MCLR. Exposure to these pollutants adversely affected photosynthesis of the plants and triggered peroxidation that promoted peroxidase, superoxide dismutase and catalase activities, and increased malondialdehyde and glutathione concentrations. The total chlorophyll content was lower in the highest concentration of the combined treatment group (0.443 mg g-1) than in the control group (0.534 mg g-1). Peroxidase activity increased from 662.63 U mg-1 Pr to 1193.45 U mg-1 Pr with increasing PFOA concentrations. Metabolomics indicated that the stress tolerance of Vallisneria natans was improved via altered fatty acid metabolism, hormone metabolism and carbon metabolism. Furthermore, PFOA and MCLR influenced the abundance and structure of the microbial community in the biofilms of Vallisneria natans. The increased contents of autoinducer peptide and N-acylated homoserine lactone signaling molecules indicated that these pollutants altered the formation and function of the biofilm. These results expand our understanding of the combined effects of PFOA and MCLR in aquatic ecosystems.

Joint toxicity mechanisms of perfluorooctanoic acid and sulfadiazine on submerged macrophytes and periphytic biofilms.

Hazardous chemicals, such as perfluoroalkyl substances (PFASs) and antibiotics, coexist in aquatic environments and pose a severe threat to aquatic organisms. However, research into the toxicity of these pollutants on submerged macrophytes and their periphyton is still limited. To assess their combined toxicity, Vallisneria natans (V. natans) was exposed to perfluorooctanoic acid (PFOA) and sulfadiazine (SD) at environmental concentrations. Photosynthetic parameters such as chlorophyll a, chlorophyll b, total chlorophyll, and carotenoids were lower in the SD exposure group, indicating that SD had a significant effect on the photosynthesis of aquatic plants. Single and combined exposures effectively induced antioxidant responses, with increases in superoxide dismutase, peroxidase activities, and ribulose-1,5-bisphosphate carboxylase concentrations, as well as malondialdehyde content. Accordingly, antagonistic toxicity was assessed between PFOA and SD. Furthermore, metabolomics revealed that V. natans improved stress tolerance through changes in enoic acid, palmitic acid, and palmitoleoyloxymyristic acid related to the fatty acid metabolism pathway responding to the coexisting pollutants. Additionally, PFOA and SD in combination induced more effects on the microbial community of biofilm. The alternation of α- and ß-D-glucopyranose polysaccharides and the increased content of autoinducer peptides and N-acylated homoserine lactones indicated that PFOA and SD changed the structure and function of biofilm. These investigations provide a broader perspective and comprehensive analysis of the responses of aquatic plants and periphyton biofilms to PFAS and antibiotics in the environment.

CRISPR/Cas13a Trans-Cleavage-Triggered Catalytic Hairpin Assembly Assay for Specific and Ultrasensitive SARS-CoV-2 RNA Detection.

New coronavirus (SARS-CoV-2), which has caused the coronavirus disease 2019 (COVID-19) pandemic, has brought about a huge burden on global healthcare systems. Rapid and early detection is important to prevent the spread of the pandemic. Here, an assay based on CRISPR/Cas13a and catalytic hairpin assembly (CHA), termed as Cas-CHA, was developed for ultrasensitive and specific detection of SARS-CoV-2 RNA. Upon specific recognition of the target, the CRISPR/Cas13a collaterally cleaved a well-designed hairpin reporter and triggered the CHA reaction. Under optimized conditions, the assay detected the SARS-CoV-2 RNA with a wide range of 100 aM to 100 nM and realized a low detection limit of 84 aM. At the same time, the whole detecting process could be completed within 35 min. More importantly, the assay was able to distinguish SARS-CoV-2 RNA from common human coronaviruses and analyze in saliva samples. By the flexible design of crRNA, the assay was expanded to detect other viruses. The clinical sample analysis verified that the proposed assay held a great potential for practical testing.

Changes in the cervicovaginal microbiota composition of HPV16-infected patients after clinical treatment.

BACKGROUND: High-risk human papillomavirus (hrHPV) infection is a key factor that alters cervicovaginal microbiota patterns and causes cervical intraepithelial neoplasias (CINs) or even cervical cancer. Although local excisional treatment can clear hrHPV infection and restore the cervicovaginal microbiota, it is unclear which cervicovaginal microbiota represents recovery. Our objective was to describe the cervicovaginal microbiota before and after treatments and to assess the association between the microbiota and HPV persistence. RESULTS: A cohort of 91 participants was classified into four groups (healthy control women and HPV16-infected women with CIN I, CIN II/III, and squamous cell carcinoma [SCC]). Endocervical swabs were collected 3 months prior to treatment and at 3 months post-treatment for bacterial 16S rRNA gene pyrosequencing and for HPV DNA testing. There was an increase in the number of Lactobacillus bacterial species present after the clinical treatments, and the community state type (CST) profiles were shifted from dysbiotic CSTs II and IV to Lactobacillus-dominated CSTs I and III. Specifically, the composition of Geobacter and Prevotella before treatment and Lactobacillus secaliphilus after treatment might have been related to CIN I, the composition of Burkholderia before treatment and Lactobacillus iners after treatment might have been related to CIN II/III, and the composition of Atopobium and Aerococcus before treatment and Bacilli after treatment might have been related to SCC. Further functional predictions revealed that the composition differences were linked to infectious disease- and cancer-related genes. CONCLUSION: Our study provides an illustration of the changes in CSTs and the cervicovaginal microbiota before and after HPV16 clearance in each disease state.

A dual-signal sensing strategy based on ratiometric fluorescence and colorimetry for determination of Cu2+ and glyphosate.

Herein, a dual-signal sensing strategy based on ratiometric fluorescence and colorimetry for Cu2+ and glyphosate determination was constructed. Fluorescence silicon nanoparticles (SiNPs) were prepared by hydrothermal reaction, which has maximum fluorescence intensity under the excitation of 355 nm. o-Phenylenediamine (OPD) was oxidized through Cu2+ to generate 2,3-diaminophenazine (oxOPD). The obtained oxOPD showed a strong absorption peak at 417 nm and quenched the fluorescence of SiNPs at 446 nm due to fluorescence resonance energy transfer (FRET). Meanwhile, oxOPD produced a new fluorescence emission at 556 nm forming a ratiometric state. With increasing Cu2+, the original solution changed from colorless to yellow. When glyphosate was present, the interaction between Cu2+ and the functional groups of glyphosate could reduce the oxidation of oxOPD, resulting in the enhancement of fluorescence at 446 nm and the decrease of fluorescence at 556 nm. Furthermore, the addition of glyphosate changed yellow solution to colorless. Under the optimal conditions of OPD (1 mM), 20 mM Tris-HCl buffer (pH 7.5), and incubation time (4 h), the ratiometric fluorescence sensor had good selectivity and showed a wide linear range of 0.025-20 µM with the LOD of 0.008 µM for Cu2+ and 0.15-1.5 µg/mL with the LOD of 0.003 µg/mL for glyphosate, respectively. Besides, it is worth mentioning that this developed sensing system showed good performance in real samples, providing a simple and reliable dual-signal detection strategy.

A turn-on fluorescence sensor based on Cu2+ modulated DNA-templated silver nanoclusters for glyphosate detection and mechanism investigation.

The abuse application of glyphosate can result in a potential hazard for environment and human, however its ultrasensitive detection remains challenging. Herein, a Cu2+ modulated DNA-templated silver nanoclusters (DNA-AgNCs) sensor was constructed to sensitively determine glyphosate based on the turn-on fluorescence strategy. The fluorescence quenching of DNA-AgNCs occurred with the existence of Cu2+. Upon the presence of glyphosate, the functional groups on the surface of glyphosate could chelate with Cu2+, following the fluorescence recovery of DNA-AgNCs. Through the stoichiometric methods, we unveil that Cu2+-trigged fluorescence quenching mode is a combination of static and dynamic quenching with the static mode being predominant. In DNA-AgNCs/Cu2+ system, the carboxylate, amine, and phosphonate groups of glyphosate interact with Cu2+ through chelation, in which the carboxylate oxygen, the phosphonate oxygen atoms, and the monoprotonated secondary amine nitrogen atom and Cu2+ form chelate rings. This fluorescence sensor showed a desired linearity of glyphosate analysis under the optimum conditions, ranging from 15 to 100 µg/L with a low detection down to 5 µg/L. Moreover, the proposed sensor was successfully utilized to measure glyphosate in real samples, indicating a promising application in pesticide residues detection.

Early Diagnosis of Occult Blood of Colorectal Cancer Based on Nano-Colloidal Gold Sandwich Immunochromatography.

The development of science and technology has deepened people's understanding of cancer, changing the management of malignant tumors in the medical field. Given the common precancerous characteristics of colorectal cancer (CRC), researchers studied early CRC screening. The complexity of traditional diagnostics forced medical staff to speed up CRC innovation early screening methods. Here, we prepared nano-colloidal gold raw materials with different particle sizes (15 and 30 nm) and observed the morphological characteristics and properties of the materials. Simultaneously, the nanocolloidal gold double antibody sandwich kit was designed through the optimum pH value and protein content screening experiment. The results of clinical enteroscopy confirmed the important guiding significance of the equipment in early CRC screening.

Abnormally increased DNA methylation in chorionic tissue might play an important role in development of ectopic pregnancy.

BACKGROUND: Human Ectopic Pregnancy (hEP) is the second most common cause of pregnancy-related deaths in the first trimester. Without timely detection, EPs can lead to an increased rate of infertility and an elevated risk for future tubal EPs. In addition, most studies in the field focus on the effect of the fallopian tube (maternal factors) and ignore epigenetic changes in genes and proteins of the embryo, which may also cause EPs. Therefore, the present study hypothesized that embryos also play an important role in the development of EP. The study also speculated that DNA methylation is associated with ectopic pregnancy. Consequently, the effects of DNA methylation on the occurrence and development of ectopic pregnancy were investigated. Moreover, genome-wide DNA methylation of chorionic tissue from ectopic and intrauterine pregnancies was detected using Illumina HumanMethylation450 arrays. RESULTS: Forty-three hypermethylated genes involved in the regulation of adhesion as well as gene transcription and translation were identified. Furthermore, the PPI network showed that AMOTL1, SDR42E1, CAMTA1, PIP5K1C, KIAA1614, TSTD1 and DNER may play important roles in the occurrence and development of ectopic pregnancy. In addition, SDR42E1, CAMTA1 and TSTD1 displayed higher levels of methylation in ectopic pregnancy while PIP5K1C and DNER showed low degrees of methylation. CONCLUSIONS: The study reveals that abnormal increase in methylation may be an early indicator or an inducer of ectopic pregnancy. In addition, AMOTL1, SDR42E1, CAMTA1, PIP5K1C, KIAA1614, TSTD1 and DNER might play important roles in the occurrence and development of ectopic pregnancy. However, the specific molecular mechanisms are still unclear and require further studies.

S100B gene polymorphisms are associated with the S100B level and Alzheimer's disease risk by altering the miRNA binding capacity.

To examine the role of S100B in genetic susceptibility to Alzheimer's disease (AD), we conducted a case-control study to analyze four polymorphism loci (rs2839364, rs1051169, rs2300403, and rs9722) of the S100B gene and AD risk. We found an independent increased risk of AD in ApoE ε4(-) subjects carrying the rs9722 AA-genotype (OR = 2.622, 95% CI = 1.399-4.915, P = 0.003). Further investigation revealed the serum S100B levels to be lower in rs9722 GG carriers than in rs9722 AA carriers (P = 0.003). We identified three miRNAs (miR-340-3p, miR-593-3p, miR-6827-3p) in which the seed match region covered locus rs9722. Luciferase assays indicated that the rs9722 G allele has a higher binding affinity to miR-6827-3p than the rs9722 A allele, leading to a significantly decreased fluorescence intensity. Subsequent western blot analysis showed that the S100B protein level of SH-SY5Y cells, which carry the rs9722 G allele, decreased significantly following miR-6827-3p stimulation (P = 0.009). The present study suggests that the rs9722 polymorphism may upregulate the expression of S100B by altering the miRNA binding capacity and may thus increase the AD risk. This finding would be of great help for the early diagnosis of AD.

ART strategies in Klinefelter syndrome.

PURPOSE: Patients with Klinefelter syndrome (KS) who receive assisted reproductive technology (ART) treatment often experience poor pregnancy rates due to decreased fertilization, cleavage, and implantation rates and even an increased miscarriage rate. Mounting evidence from recent studies has shown that various technological advances and approaches could facilitate the success of ART treatment for KS patients. In this review, we summarize the methods for guiding KS patients during ART and for developing optimal strategies for preserving fertility, improving pregnancy rate and live birth rate, and avoiding the birth of KS infants. METHODS: We searched PubMed and Google Scholar publications related to KS patients on topics of controlled ovarian stimulation protocols, sperm extraction, fertility preservation, gamete artificial activation, round spermatid injection (ROSI), and non-invasive prenatal screening (PGD) methods. RESULTS: This review outlines the different ovulation-inducing treatments for female partners according to the individual sperm status in the KS patient. We further summarize the methods of retrieving sperm, storing, and freezing rare sperm. We reviewed different methods of gamete artificial activation and discussed the feasibility of ROSI for sterile KS patients who absolutely lack sperm. The activation of eggs in the process of intracytoplasmic sperm injection and non-invasive PGD are urgently needed to prevent the birth of KS infants. CONCLUSION: The integrated strategies will pave the way for the establishment of ART treatment approaches and improve the clinical outcome for KS patients.

A turn-on fluorescent nanoprobe based on N-doped silicon quantum dots for rapid determination of glyphosate.

N-Doped silicon quantum dots (N-SiQD) were synthesized using N-[3-(trimethoxysily)propyl]-ethylenediamine and citric acid as silicon source and reduction agent, respectively. The N-SiQD shows a strong blue fluorescence with a high quantum yield of about 53%. It is found that a selective static quenching process occurs between N-SiQDs and Cu2+. Glyphosate can inhibit this phenomenon and trigger the rapid fluorescence enhancement of the quenched N-SiQDs/Cu2+ system due to the specific interaction between Cu2+ and glyphosate. With such a design, a turn-on fluorescent nanoprobe based on N-SiQD/Cu2+ system was established for rapid determination of glyphosate. The determination signal of N-SiQD/Cu2+ was measured at the optimum emission wavelength of 460 nm after excitation at 360 nm. Under optimal conditions, the turn-on nanoprobe showed a linear relationship between fluorescent response and glyphosate concentrations in the range 0.1 to 1 µg mL-1. The limit of determination was calculated to 7.8 ng mL-1 (3σ/S). Satisfactory recoveries were obtained in the determination of spiked water samples, indicating the potential use for environmental monitoring. Graphical abstract Schematic representation of N-SiQD/Cu2+ system for glyphosate determination. Fluorescence quenching of N-SiQDs induced by copper ions and the succedent fluorescent "turn on" triggered by glyphosate.

Green emitting carbon dots for sensitive fluorometric determination of cartap based on its aggregation effect on gold nanoparticles.

A fluorometric method was developed for the determination of the insecticide cartap. It is based on the use of green emitting carbon dots (CDs) and gold nanoparticles (Au NPs). The CDs were prepared from phenol and ethylene diamine by a hydrothermal route. They have excitation/emission maxima at 410/513 nm) and a fluorescence quantum yield of 29%. They were characterized by TEM, Raman, XRD, XPS, FT-IR, UV and fluorescence spectroscopies. The green fluorescence of the CDs is strongly reduced by the red-colored Au NPs because of an inner filter effect. Upon addition of cartap, it will cause the aggregation of the Au NPs owing to Au-N interaction between Au NPs and cartap to form purple colored aggregates with spectra that do not overlap the green emission of the CDs. Hence, their fluorescence is restored. Under optimum conditions, the method allows for the quantitation of cartap in the 5-300 nM concentration range, and the detection limit is 3.8 nM. The method was successfully applied to the determination of cartap in spiked real samples and gave satisfactory results. Graphical abstract Schematic presentation of green emitting carbon dots for sensitive fluorometric determination of cartap based on its aggregation effect on gold nanoparticles.

Aberrant expression of oxidative stress related proteins affects the pregnancy outcome of gestational diabetes mellitus patients.

Gestational diabetemellitus (GDM) is a condition whereby a mother's glucose tolerance is impaired with onset or first recognition during pregnancy which is not either type 1 or type 2 diabetes mellitus. Oxidative stress plays an essential role in diabetes, however, whether it also includes in GDM has not been fully clarified. Therefore, we investigated the changes of oxidative stress biomarkers and their relationship with pregnancy outcomes in patients with GDM. The serum and placenta were collected for absorbance-based assay and immunohistochemistry assay (IHC). The patients' clinical information was collected and the pregnancy outcome was tracked. It was found that elder age is a risk factor to result in GDM. Moreover, GDM patients showed poor clinical factors or outcomes including higher prepregnancy weight and BMI value, premature delivery, higher rates of cesarean delivery, macrosomia, premature rupture of fetal membranes (PROM). Increasing serum MDA level and decline GSH and SOD levels were observed in GDM patients. Meanwhile, HO-1, Nrf2 and NQO1 overexpressed in GDM placental tissues. In the GDM group, MDA level was negatively associated with prepregnancy weight, while, SOD level was positively correlated with neonatal birth weight. We found an intensive relationship between SOD content and preterm birth in the GDM group. There is no significant difference between the level of MDA/GSH and neonatal birth weight as well as preterm birth. MDA, GSH and SOD levels were not associated with an increased risk of cesarean delivery or PROM. This study indicates aberrant expression of oxidative stress related proteins affects the pregnancy outcome of GDM patients.

An Ultrasensitive Electrochemical DNA Biosensor Based on Carboxylated Multi-walled Carbon Nanotube/Molybdenum Disulfide Composites for KRAS Gene Detection.

In this paper, an ultrasensitive electrochemical biosensor based on carboxylated multi-walled carbon nanotube/molybdenum disulfide composites (MWCNTs-COOH/MoS2) for the detection of KRAS gene is described. An easy, low-cost method, named one-step hydrothermal, was used for the synthesize of MWCNTs-COOH/MoS2 nanocomposites, and scanning electronic microscopy (SEM), high resolution transmission electron microscopy (HRTEM), Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) were used for characterizing the prepared composites. Furthermore, cyclic voltammetry (CV) and differential pulse voltammetry (DPV) were employed for an electrochemical performance study of this biosensor. Under optimal conditions, the detection limit of target DNA achieved down to 3 fM (S/N = 3) with high sensitivity; the linear range with the logarithm of the concentrations of target DNA varied from 1.0 × 10-14 to 1.0 × 10-7 M. Finally, the practicality of our proposed sensor was verified by a determination of the KRAS gene in human serum samples with good accuracy and high precision due to the excellent conductivity and large active surface area of the MWCNTs-COOH/MoS2 nanocomposites. This proposed biosensor thus provides a practical method for the rapid and sensitive analysis of gene detection.