Advances in Carbon Dot-Based Ratiometric Fluorescent Probes for Environmental Contaminant Detection: A Review.

Detecting environmental contaminants is crucial for protecting ecosystems and human health. While traditional carbon dot (CD) fluorescent probes are versatile, they may suffer from limitations like fluctuations in signal intensity, leading to detection inaccuracies. In contrast, ratiometric fluorescent probes, designed with internal self-calibration mechanisms, offer enhanced sensitivity and reliability. This review focuses on the design and applications of ratiometric fluorescent probes based on CDs for environmental monitoring. Our discussion covers construction strategies, ratiometric fluorescence principles, and applications in detecting various environmental contaminants, including organic pollutants, heavy metal ions, and other substances. We also explore associated advantages and challenges and provide insights into potential solutions and future research directions.

[Effect of different delivery modes on the level of protein, glucose and blood lipids in cord artery and vein blood].

OBJECTIVE: To explore whether there are differences in the levels of protein, glucose and blood lipids in umbilical vein and umbilical artery blood of newborns with different delivery modes, and to evaluate their value as indicators of fetal intrauterine nutrition and nutritional support. METHODS: A total of 89 pairs of mothers and infants who were delivered in Danyang People's Hospital of Jiangsu Province from June to September 2021 were selected as the study subjects, including 38 cases of spontaneous delivery and 51 cases of cesarean section. The basic information of pregnant women, pregnancy information, newborn delivery and physical examination information were extracted from the medical record information system of the hospital. According to the mode of delivery, HITACHI 7600 automatic biochemical analyzer was used to measure the levels of protein, glucose and blood lipids in umbilical vein and umbilical artery blood, including total protein(TP), albumin(ALB), glucose(GLU), total cholesterol(TC), triglyceride(TG), high density lipoprotein cholesterol(HDL-C), low density lipoprotein cholesterol(LDL-C). The data were statistically analyzed using IBM SPSS Statistics 26.0 statistical software. RESULTS: The levels of TP, ALB, GLU, TC, TG, HDL-C and LDL-C in the umbilical vein blood of the spontaneous delivery group were(56.40±5.83)g/L, (38.41±3.43)g/L, (4.55±1.53)mmol/L, (1.68±0.42)mmol/L, (0.25±0.11)mmol/L, (0.84±0.17)mmol/L and(0.69±0.23)mmol/L, respectively. The levels of TP, ALB, GLU, TC, TG, HDL-C and LDL-C in umbilical artery blood were(56.49±9.91)g/L, (37.72±4.77)g/L, (4.07±1.52)mmol/L, (1.60±0.42)mmol/L, (0.24±0.10)mmol/L, (0.80±0.18)mmol/L and(0.68±0.24)mmol/L, respectively. The levels of TP, ALB, GLU, TC, TG, HDL-C and LDL-C in umbilical vein blood of cesarean section group were(52.08±4.12)g/L, (36.12±2.13)g/L, (3.45±1.16)mmol/L, (1.61±0.39)mmol/L, (0.19±0.08)mmol/L, (0.82±0.18)mmol/L and(0.61±0.20)mmol/L, respectively. The levels of TP, ALB, GLU, TC, TG, HDL-C and LDL-C in umbilical artery blood were(51.49±7.59)g/L, (35.40±3.60)g/L, (3.09±1.15)mmol/L, (1.48±0.40)mmol/L, (0.19±0.08)mmol/L, (0.78±0.18)mmol/L and(0.60±0.20)mmol/L, respectively. The levels of TP, ALB, Glu and TG in cord vein blood and cord artery blood in spontaneous labor group were significantly higher than those in cesarean section group(P<0.05); The levels of Glu, TC, TG and HDL-C in cord vein blood were significantly higher in spontaneous labor group and cesarean section group than those in cord artery blood(P<0.05). CONCLUSION: The levels of protein, glucose and blood lipids in umbilical vein and umbilical artery blood were different among different delivery modes.

Correlation of serum HMGB1 and HMGB2 levels with clinical symptoms in allergic rhinitis children.

This research aimed to explore the serum high-mobility group box 1 (HMGB1) and high-mobility group box 2 (HMGB2) levels in allergic rhinitis (AR) children and its correlation with clinical results. This present prospective observational study enrolled 179 AR children and 100 healthy children who came to our hospital during October 2020 to August 2022. The serum HMGB1, HMGB2, interleukin (IL)-6, IL-1ß, interferon-γ, and C-reactive protein (CRP) levels were measured by enzyme-linked immunosorbent assay. Demographic and clinical statistics including age, body mass index (BMI), sex, diastolic blood pressure, SBP, family history of allergy, Visual Analogue Score (VAS) and Rhinoconjunctivitis Quality of Life Questionnaire were collected. All data used SPSS 18.0 to statistical analyses. The proportion of family history of allergy was obviously higher in the AR group than that in the healthy group. The serum levels of HMGB1, HMGB2 and cytokines were remarkably enhanced in the AR patients. Spearman analysis supported that positive correlation existed among the HMGB1, HMGB2, CRP, IL-6 and IL-1ß levels. Serum IL-6, CRP, HMGB2, IL-1ß, VAS score and Rhinoconjunctivitis Quality of Life Questionnaire score levels were significantly higher and serum interferon-γ levels were significantly lower in the HMGB1 high expression group. Similar results were found in in the HMGB2 high group compared to the HMGB2 low group. In addition, HMGB1 and HMGB2 could be potential diagnostic biomarkers of AR patients. Finally, we found that HMGB1, HMGB2, IL-6, IL-1ß, and family history of allergy were the risk factors for AR. This study showed that the serum HMGB1 and HMGB2 levels was remarkably enhanced in AR patients and closely associated with cytokines. This study may provide new targets and a comprehensive approach for the treatment of AR patients.

The Association between Macrosomia and Amino Acids' Levels in Maternal and Cord Sera: A Case-Control Study.

This study aims to explore the relationship between macrosomia and amino acids in maternal and cord sera. METHODS: In the case-control study, 78 pairs of mothers and newborns were recruited from December 2016 to November 2019. Participants were divided into the macrosomia group (BW ≥ 4000 g, n = 39) and the control group (BW between 2500 g and 3999 g, n = 39) according to the birth weight (BW) of newborns. Maternal vein blood samples were collected before delivery and cord vein blood samples were collected after birth. The levels of amino acids in maternal and cord sera were measured by liquid chromatography and mass spectrometry (LC-MS/MS) in the year 2021. The difference in amino acid levels in maternal and cord sera between the two groups was compared, and the contribution of each amino acid to the difference between the two groups was analyzed. Unconditional logistic regression analysis was used to test the relationship between macrosomia and amino acids. RESULTS: In maternal serum during the antepartum, the levels of asparagine, glutamine, methionine, alanine, and threonine in the macrosomia group were higher but arginine was lower than that in the control group (p < 0.05). In cord serum, the levels of lysine, histidine, phenylalanine, arginine, tryptophan, valine, isoleucine, glutamate, tyrosine, and total essential amino acid (EAA) in the macrosomia group were lower while glutamine was higher than that in the control group (p < 0.05). The ratios of EAA, valine, threonine, methionine, tryptophan, and alanine in maternal serum to those in cord serum were higher, while the ratio of glutamine was lower in the macrosomia group (p < 0.05). Arginine and threonine in maternal serum and glutamate, glutamine, and histidine in cord serum were associated with macrosomia (p < 0.05). CONCLUSION: Most of the amino acid levels in the maternal sera of the macrosomia group are higher than those in the control group, while most of the amino acids' levels in the cord sera of the macrosomia group are lower than those in the control group. The ratios of some amino acids in maternal serum to those in cord serum were different between the two groups. Arginine and threonine in maternal serum and glutamate, glutamine, and histidine in cord serum are closely related to macrosomia.

Boosting Oxygen Evolution Reaction of (Fe,Ni)OOH via Defect Engineering for Anion Exchange Membrane Water Electrolysis Under Industrial Conditions.

Developing non-precious catalysts with long-term catalytic durability and structural stability under industrial conditions is the key to practical alkaline anion exchange membrane (AEM) water electrolysis. Here, an energy-saving approach is proposed to synthesize defect-rich iron nickel oxyhydroxide for stability and efficiency toward the oxygen evolution reaction. Benefiting from in situ cation exchange, the nanosheet-nanoflake-structured catalyst is homogeneously embedded in, and tightly bonded to, its substrate, making it ultrastable at high current densities. Experimental and theoretical calculation results reveal that the introduction of Ni in FeOOH reduces the activation energy barrier for the catalytic reaction and that the purposely created oxygen defects not only ensure the exposure of active sites and maximize the effective catalyst surface but also modulate the local coordination environment and chemisorption properties of both Fe and Ni sites, thus lowering the energy barrier from *O to *OOH. Consequently, the optimized d-(Fe,Ni)OOH catalyst exhibits outstanding catalytic activity with long-term durability under both laboratory and industrial conditions. The large-area d-(Fe,Ni)OOH||NiMoN pair requires 1.795 V to reach a current density of 500 mA cm-2 at an absolute current of 12.5 A in an AEM electrolyzer for overall water electrolysis, showing great potential for industrial water electrolysis.

[Effect of different delivery modes on the level of cortical hormones in cord artery and vein blood].

OBJECTIVE: To investigate the difference of cortical hormones in cord artery and vein blood of newborns with different delivery modes. METHODS: A total of 65 pregnant women who delivered in the People's Hospital of Danyang City, Jiangsu Province from June to September 2021 were selected as the study subjects, including 26 cases of spontaneous delivery and 39 cases of cesarean section. The basic information of 65 pregnant women and newborns was collected by questionnaire survey. According to the mode of delivery, the levels of corticosteroids in umbilical vein and umbilical artery blood were determined by liquid chromatography-tandem mass spectrometry(LC-MS/MS), including corticosterone, 11-desoxycorticosterone, aldosterone, cortisol, 11-deoxycortisol and cortisone. The data were statistically analyzed using IBM SPSS Statistics 26.0 statistical software. RESULTS: The levels of cortisol, 11-deoxycortisol, aldosterone, cortisol, 11-deoxycortisol and cortisone in the umbilical vein blood of the spontaneous delivery group were(2.44±1.87), (0.64±0.29), (0.49±0.35), (54.95±40.80), (3.20±1.23) and(142.27±57.42)ng/mL, respectively. The levels of corticosterone, 11-deoxycortisol, aldosterone, cortisol, 11-deoxycortisol and cortisone in umbilical artery blood were(4.51±4.47), (0.57±0.28), (0.42±0.29), (60.79±45.53), (2.69±1.25) and(123.10±46.32)ng/mL, respectively. The levels of corticosterone, 11-deoxycortisone, aldosterone, cortisol, 11-deoxycortisone and cortisone in umbilical vein blood of cesarean section group were(0.94±1.09), (0.47±0.14), (0.26±0.14), (22.63±19.82), (2.30±0.90) and(84.51±29.49)ng/mL, respectively. The levels of corticosterone, 11-deoxycortisol, aldosterone, cortisol, 11-deoxycortisol and cortisone in umbilical artery blood were(2.22±2.24), (0.43±0.17), (0.27±0.14), (30.09±25.93), (1.87±0.76) and(75.03±24.90)ng/mL, respectively. The levels of corticosterone, 11-desoxycorticosterone, aldosterone, cortisol, 11-deoxycortisol and cortisone in cord vein blood and cord artery blood in spontaneous labor group were significantly higher than those in cesarean section group(P<0.05). The levels of corticosterone and cortisol in cord vein blood were significantly lower in spontaneous labor group and cesarean section group than those in cord artery blood(P<0.05), the levels of 11-desoxycorticosterone, 11-deoxycortisol and cortisone in cord vein blood were significantly higher in spontaneous labor group and cesarean section group than those in cord artery blood(P<0.05). CONCLUSION: There are differences in the level of cortical hormones in cord artery and vein blood in different delivery modes.

In-depth insight into the effects of intrinsic calcium compounds on the pyrolysis of hazardous petrochemical sludge.

To understand the potential effects of intrinsic calcium compounds on sludge pyrolysis, the pyrolysis behavior of petrochemical sludge (PS), calcium carbonate blend PS (CaPS), and decalcified PS (DePS) were investigated using thermogravimetric analysis (TGA) and in-situ Fourier-transform infrared spectroscopy coupled with pyrolysis-gas chromatography and mass spectrometry (Py-GC/MS). The TGA results indicated that decalcification increased and decreased the energy barriers of PS decomposition in ranges 200-350 °C and 350-600 °C, respectively. In contrast, copyrolysis with CaCO3 decreased the activation energy (E) of the pseudoreaction phase 2 (PH2) and altered the mechanism model. Meanwhile, during copyrolysis, char deposition and interaction hindered CaCO3 decomposition. The two-dimensional correlation spectroscopy results, on the other hand, showed that the reaction priority of O-containing groups and CH- vibration of methyl groups were affected by both decalcification and CaCO3 copyrolysis. The Py-GC/MS results indicated that the three sludges mainly released hydrocarbons, N-containing organics, alcohols, aldehydes, and acids. During pyrolysis, CaCO3 also played a neutralization role, which reduced the release of pyrolytic acidic products. In addition, the increase of the pyrolysis temperature increased the hydrocarbon content. This research will guide the industrial application of sludge pyrolysis.

Cyclometalated iridium-coumarin ratiometric oxygen sensors: improved signal resolution and tunable dynamic ranges.

In this work we introduce a new series of ratiometric oxygen sensors based on phosphorescent cyclometalated iridium centers partnered with organic coumarin fluorophores. Three different cyclometalating ligands and two different pyridyl-containing coumarin types were used to prepare six target complexes with tunable excited-state energies. Three of the complexes display dual emission, with fluorescence arising from the coumarin ligand, and phosphorescence from either the cyclometalated iridium center or the coumarin. These dual-emitting complexes function as ratiometric oxygen sensors, with the phosphorescence quenched under O2 while fluorescence is unaffected. The use of blue-fluorescent coumarins results in good signal resolution between fluorescence and phosphorescence. Moreover, the sensitivity and dynamic range, measured with Stern-Volmer analysis, can be tuned two orders of magnitude by virtue of our ability to synthetically control the triplet excited-state ordering. The complex with cyclometalated iridium 3MLCT phosphorescence operates under hyperoxic conditions, whereas the two complexes with coumarin-centered phosphorescence are sensitive to very low levels of O2 and function as hypoxic sensors.

Photoluminescence and Raman Spectra of One-Dimensional Lead-free Perovskite CsCu2I3 Single-Crystal Wires.

Lead-free highly luminescent CsCu2I3 perovskite has attracted much attention recently, but agreements on basic optical properties have remained unsettled. By correlating X-ray diffraction with the photoluminescence (PL) of CsCu2I3 single-crystal wires, we first show that blue PL at 420 nm originates from CuI. We then exclude defect states as a source for the broadband emission centered at 570 nm from the lack of defect absorption, PL under sub-bandgap photoexcitation, observations of a linear dependence of PL intensity on excitation laser power, and a strong spectral blueshift under mild hydrostatic pressure. Finally, using a model of the self-trapped exciton and the associated coordinate configuration diagram, we explain pressure evolutions of PL energy, intensity, and lifetime. Single-crystal wires also enable us to obtain polarization-dependent Raman spectra down to 10 cm-1 and confirm their respective ambient crystal structure of orthorhombic Cmcm and phase transition to Pbnm at ∼5 GPa.

Dwarf and High Tillering1 represses rice tillering through mediating the splicing of D14 pre-mRNA.

Strigolactones (SLs) constitute a class of plant hormones that regulate many aspects of plant development, including repressing tillering in rice (Oryza sativa). However, how SL pathways are regulated is still poorly understood. Here, we describe a rice mutant dwarf and high tillering1 (dht1), which exhibits pleiotropic phenotypes (such as dwarfism and increased tiller numbers) similar to those of mutants defective in SL signaling. We show that DHT1 encodes a monocotyledon-specific hnRNP-like protein that acts as a previously unrecognized intron splicing factor for many precursor mRNAs (pre-mRNAs), including for the SL receptor gene D14. We find that the dht1 (DHT1I232F) mutant protein is impaired in its stability and RNA binding activity, causing defective splicing of D14 pre-mRNA and reduced D14 expression, and consequently leading to the SL signaling-defective phenotypes. Overall, our findings deepen our understanding of the functional diversification of hnRNP-like proteins and establish a connection between posttranscriptional splicing and SL signaling in the regulation of plant development.

Efficient Alkaline Water/Seawater Hydrogen Evolution by a Nanorod-Nanoparticle-Structured Ni-MoN Catalyst with Fast Water-Dissociation Kinetics.

Achieving efficient and durable nonprecious hydrogen evolution reaction (HER) catalysts for scaling up alkaline water/seawater electrolysis is desirable but remains a significant challenge. Here, a heterogeneous Ni-MoN catalyst consisting of Ni and MoN nanoparticles on amorphous MoN nanorods that can sustain large-current-density HER with outstanding performance is demonstrated. The hierarchical nanorod-nanoparticle structure, along with a large surface area and multidimensional boundaries/defects endows the catalyst with abundant active sites. The hydrophilic surface helps to achieve accelerated gas-release capabilities and is effective in preventing catalyst degradation during water electrolysis. Theoretical calculations further prove that the combination of Ni and MoN effectively modulates the electron redistribution at their interface and promotes the sluggish water-dissociation kinetics at the Mo sites. Consequently, this Ni-MoN catalyst requires low overpotentials of 61 and 136 mV to drive current densities of 100 and 1000 mA cm-2 , respectively, in 1 m KOH and remains stable during operation for 200 h at a constant current density of 100 or 500 mA cm-2 . This good HER catalyst also works well in alkaline seawater electrolyte and shows outstanding performance toward overall seawater electrolysis with ultralow cell voltages.

[Meta analysis of the validity of image-based dietary assessment method based on energy and macronutrients].

OBJECTIVE: Meta-analysis was used to study the validity of image-based dietary assessment(IBDA) in evaluating energy and macronutrients intake, and compared with three traditional method: weighed food record(WFR), 24-hour dietary recall(24-HDR) and double-labeled water(DLW). METHODS: Studies were retrieved and collected from various databases including China National Knowledge Infrastructure(CNKI), WanFang Database, VIP Database, PubMed, Web of Science, Cochrane Library and Embase, screened according to the inclusion and exclusion criteria. After extracting the data, all the data were Meta-analyzed through RevMan 5.4. RESULTS: A total of 24 studies were included. Meta-analysis showed that, comparison of IBDA method and traditional method in energy intake assessment[MD=-54.71 kcal/d(95%CI-118.81-9.39), P=0.09], comparison of carbohydrate intake assessment[MD=-2.77 g(95%CI-8.86-3.31), P=0.37], comparison of protein intake assessment[MD=0.00 g(95%CI-2.09-2.09), P>0.05], comparison of fat intake assessment[MD=0.10 g(95%CI-2.06-2.25), P=0.93], these differences were not statistically significant. Subgroup analysis showed that, IBDA method compared with the 24-hour dietary review method in protein intake(P=0.01), the difference was statistically significant. IBDA method overestimated protein intake by about 7.3% on average compared with the 24-hour dietary review method. CONCLUSION: There was no significant difference between IBDA method and traditional method in the assessment of energy and macronutrient intakes.

Integration of Highly Luminescent Lead Halide Perovskite Nanocrystals on Transparent Lead Halide Nanowire Waveguides through Morphological Transformation and Spontaneous Growth in Water.

The integration of highly luminescent CsPbBr3 quantum dots on nanowire waveguides has enormous potential applications in nanophotonics, optical sensing, and quantum communications. On the other hand, CsPb2 Br5 nanowires have also attracted a lot of attention due to their unique water stability and controversial luminescent property. Here, the growth of CsPbBr3 nanocrystals on CsPb2 Br5 nanowires is reported first by simply immersing CsPbBr3 powder into pure water, CsPbBr3- γ Xγ (X = Cl, I) nanocrystals on CsPb2 Br5 -γ Xγ nanowires are then synthesized for tunable light sources. Systematic structure and morphology studies, including in situ monitoring, reveal that CsPbBr3 powder is first converted to CsPb2 Br5 microplatelets in water, followed by morphological transformation from CsPb2 Br5 microplatelets to nanowires, which is a kinetic dissolution-recrystallization process controlled by electrolytic dissociation and supersaturation of CsPb2 Br5 . CsPbBr3 nanocrystals are spontaneously formed on CsPb2 Br5 nanowires when nanowires are collected from the aqueous solution. Raman spectroscopy, combined photoluminescence, and SEM imaging confirm that the bright emission originates from CsPbBr3 -γ Xγ nanocrystals while CsPb2 Br5 -γ Xγ nanowires are transparent waveguides. The intimate integration of nanoscale light sources with a nanowire waveguide is demonstrated through the observation of the wave guiding of light from nanocrystals and Fabry-Perot interference modes of the nanowire cavity.

Enhancement of the photoluminescence efficiency of hybrid manganese halides through rational structural design.

Five new zero-dimensional hybrid manganese halides based on discrete [MnCl4]2- tetrahedrons were prepared and used as highly efficient green-light emitters. Through rational management of organic cations to tailor the MnMn separation distances between neighboring [MnCl4]2- tetrahedrons, the photoluminescence quantum yield increased significantly from 7.98% to 81.11%.

Incidence and Risk Factors for Isolated Esophageal Cancer Recurrence to the Brain.

BACKGROUND: Recurrence of esophageal cancer in the brain is rare but associated with a poor prognosis. Identification of risk factors for isolated brain metastasis of esophageal cancer (iBMEC) after surgical treatment may guide surveillance recommendations to enable early identification and intervention before widespread metastasis. METHODS: Patients with iBMEC (n = 38) were identified from a prospective database of patients with esophageal cancer who underwent esophagectomy. Risk factors for iBMEC were identified using competing risk regression analysis. RESULTS: In a cohort of 1760 patients, 39% recurred and iBMEC developed in 2% by the end of the study. Survival in patients with iBMEC was similar to survival in patients with distant recurrence (median overall survival, 0.95 years; 95% confidence interval, 0.6-1.5 years). More than half of patients with iBMEC were diagnosed within 1 year postoperatively. All 38 patients with iBMEC had received neoadjuvant therapy before surgery. Pathologic complete response (PCR) to neoadjuvant therapy was associated with improved survival after brain recurrence (median overall survival, 1.56 vs 0.66 years; P = .019). CONCLUSIONS: In patients with PCR, iBMEC may represent true isolated recurrence, whereas in those with residual nodal disease, iBMEC may actually be the first observed site of widespread metastasis. Patients who receive neoadjuvant therapy, especially with PCR, may benefit from brain imaging, both preoperatively and with routine surveillance.

A novel and sensitive ratiometric fluorescence assay for carbendazim based on N-doped carbon quantum dots and gold nanocluster nanohybrid.

A novel fluorescence "turn on" ratiometric fluorescent sensor was employed to determine carbendazim. The sensing process was achieved through the strong fluorescence resonance energy transfer (FRET) between nitrogen doped carbon quantum dots (N-CQDs) and gold nanocluster (AuNCs). The photoluminescence intensity of N-CQDs can be deactivated by AuNCs through FRET effect and recovered by the addition of carbendazim. The ratiometric detection of carbendazim is achieved by recording the photoluminescence and second-order Rayleigh scattering (SRS) signal of N-CQDs/AuNCs system. With the introduction of carbendazim to the sensing platform resulted in the photoluminescence and SRS signal of N-CQDS/AuNCs enhancing. UV-vis absorption, Zeta potential and fluorescence lifetime analyses indicate that the fluorescence turn on process can be attributed to the aggregation of AuNCs breaks the FRET process and increases SRS intensity. N-CQDs/AuNCs probe present a good sensitivity and selectivity for carbendazim detection, with two linear response ranges (1-100 µM, 150-1000 µM), low detection limit of 0.83 µM and 37.25 µM. Furthermore, real sample analyses indicate that the as-presented sensor has potentials in carbendazim determination in real sample analyses.

A Multicomponent Vaccine Provides Immunity against Local and Systemic Infections by Group A Streptococcus across Serotypes.

Group A streptococcus (GAS) species are responsible for a broad spectrum of human diseases, ranging from superficial to invasive infections, and are associated with autoimmune disorders. There is no commercial vaccine against GAS. The clinical manifestations of GAS infection may be attributable to the large repertoire of virulence factors used selectively in different types of GAS disease. Here, we selected five molecules, highly conserved among GAS serotypes, and involved in different pathogenic mechanisms, as a multicomponent vaccine, 5CP. Intranasal (i.n.) immunization with 5CP protected mice against both mucosal and systemic GAS infection across serotypes; the protection lasted at least 6 months. Immunization of mice with 5CP constrained skin lesion development and accelerated lesion recovery. Flow cytometry and enzyme-linked immunosorbent assay analyses revealed that 5CP induced Th17 and antibody responses locally and systemically; however, the Th17 response induced by 5CP resolved more quickly than that to GAS when challenge bacteria were cleared, suggesting that 5CP is less likely to cause autoimmune responses. These findings support that immunization through the i.n. route targeting multiple nonredundant virulence factors can induce immunity against different types of GAS disease and represents an alternative strategy for GAS vaccine development, with favorable efficacy, coverage, duration, and safety.IMPORTANCE GAS is among the most common human pathogens and causes a wide variety of diseases, likely more than any other microorganism. The diverse clinical manifestations of GAS may be attributable to its large repertoire of virulence factors that are selectively and synergistically involved in streptococcal pathogenesis. To date, GAS vaccines have not been successful due to multiple serotypes and postinfection sequelae associated with autoimmunity. In this study, five conserved virulence factors that are involved in GAS pathogenesis were used as a combined vaccine. Intranasal immunization with this vaccine induced humoral and cellular immune responses across GAS serotypes and protected against mucosal, systemic, and skin infections. The significance of this work is to demonstrate that the efficacy of GAS vaccines can be achieved by including multiple nonredundant critical virulence factors and inducing local and systemic immunity. The strategy also provides valuable insights for vaccine development against other pathogens.

L-Aspartic Acid Capped CdS Quantum Dots as a High Performance Fluorescence Assay for Sliver Ions (I) Detection.

A new high performance fluorescence assay for detection of Ag+ based on CdS quantum dots (QDs) using L-Aspartic acid (L-Asp) as a stabilizer was proposed in this work. The CdS quantum dots conjugation with L-Aspartic acid (L-Asp@CdS QDs) were successfully synthesized via a simple hydrothermal process. The QDs have a fluorescence emission band maximum at 595 nm with a quantum yield of 11%. The obtained CdS QDs exhibit a particle size of 1.63 ± 0.28 nm and look like quantum dot flowers. Basically, the fluorescence intensity of L-Asp@CdS QDs can be enhanced only upon addition of Ag+ and a redshift in the fluorescence spectrum was observed. Under optimum conditions, the fluorescence enhancement of L-Asp@CdS QDs appeared to exhibit a good linear relationship in between 100-7000 nM (R2 = 0.9945) with the Ag+ concentration, with a detection limit of 39 nM. The results indicated that the L-Asp@CdS QDs were well used in detection for Ag+ as fluorescence probe in aqueous solution with high sensitivity and selectivity. Moreover, the sensing system has been applied in detection Ag+ in real water samples. The recovery test results were 98.6%~113%, and relative standard deviation (n = 5) is less than 3.6%, which was satisfactory.

Intranasal Vaccination With Multiple Virulence Factors Promotes Mucosal Clearance of Streptococcus suis Across Serotypes and Protects Against Meningitis in Mice.

BACKGROUND: Streptococcus suis is an emerging zoonotic agent. Its natural habitat is the tonsils, which are the main portals of S. suis entry into the bloodstream of pigs. The remarkable variability of the bacteria and complex pathogenic mechanisms make the development of a vaccine a difficult task. METHOD: Five conserved virulence factors involved in critical events of S. suis pathogenesis were combined and used as an intranasal vaccine (V5). The effect of V5 was investigated with intranasal and systemic challenge models. RESULTS: V5 induced antibody and T-cell responses at the mucosal site and systemically. The immunity promoted clearance of S. suis from the nasopharynx independent of S. suis serotypes and reduced lethality after systemic challenge with S. suis serotype 2. Moreover, mice that survived sepsis from intravenous infection developed meningitis, whereas none of these mice showed neuropathological symptoms after V5 receipt. CONCLUSION: Intranasal immunization with multiple conserved virulence factors decreases S. suis colonization at the nasopharynx across serotypes and inhibits the dissemination of the bacteria in the host. The protective mucosal immunity effects would potentially reduce the S. suis reservoir and prevent S. suis disease in pigs.

Thioglycolic acid-capped ZnSe quantum dots as nanoprobe for cobalt(II) and iron(III) via measurement of grey level, UV-vis spectra and dynamic light scattering.

Thioglycolic acid-functionalized ZnSe quantum dots (QDs) as a colorimetric nanoprobe were prepared and applied to the determination of cobalt(II) and iron(III). Test strips were obtained by a dipping-drying process. On exposure to Co(II), they undergo a color change from white to brown, and on exposure to Fe(III) from white to pink. The limits of detection (LOD) are 2.6 mg L-1 for Co(II) and 2.2 mg L-1 for Fe(III). Test strips introduce a low-cost, portable, rapid and convenient tool for determination of Co(II) and Fe(III). In addition, two other analytical methods have been studied for detection of Co(II) and Fe(III) at low concentration. The first is UV-vis spectrometry which has a LOD as low as 0.14 mg L-1 for Co(II) (at 412 nm) and 0.12 mg L-1 for Fe(III) (at 400 nm). The second is dynamic light scattering (DLS) with a LOD of 3.0 µg L-1 for Co(II) and 2.5 µg L-1 for Fe(III). Graphical abstract Thioglycolic acid-functionalized ZnSe quantum dots (TGA-ZnSe QDs) show high sensitivity and low detection limits for Co2+ and Fe3+.