Fast and Ultrasensitive Detection of a Nerve Agent Simulant Using Carbazole-Based Nanofibers with Amplified Ratiometric Fluorescence Responses

In this work, we report the fast and ultrasensitive detection of a nerve agent simulant in the gas phase, diethyl chlorophosphate (DCP), by using carbazole-based nanofibers from 1. When exposed to trace DCP, the formed pyridine-phosphorylated product in 1 nanofibers can cause amplified ratiometric fluorescence responses, i.e., amplified fluorescence quenching via quenching excitons within the diffusion length of 1 nanofibers and simultaneously amplified turn-on fluorescence responses via harvesting excitons within the diffusion length to give the intramolecular charge transfer (ICT) emission at a longer wavelength. On the basis of these amplified ratiometric fluorescence responses, detection of DCP with fast response (ca. 3 s), ultrasensitivity (4 ppb), and improved selectivity is achieved.

Allogeneic stem-cell transplantation for multiple myeloma: a systematic review and meta-analysis from 2007 to 2017

Background

Despite recent advances, multiple myeloma (MM) remains incurable. However, the appearance of allogeneic stem cell transplantation (allo-SCT) through graft-versus-myeloma effect provides a potential way to cure MM to some degree. This systematic review aimed to evaluate the outcome of patients receiving allo-SCT and identified a series of prognostic factors that may affect the outcome of allo-SCT.

Patients/methods

We systematically searched PubMed, Embase, and the Cochrane Library from 2007.01.01 to 2017.05.03 using the keywords ‘allogeneic’ and ‘myeloma’.

Results

A total of 61 clinical trials involving 8698 adult patients were included. The pooled estimates (95% CI) for overall survival (OS) at 1, 2, 3 and 5 years were 70 (95% CI 56–84%), 62 (95% CI 53–71%), 52 (95% CI 44–61%), and 46 (95% CI 40–52%), respectively; for progression-free survival were 51 (95% CI 38–64%), 40 (95% CI 32–48%), 34 (95% CI 27–41%), and 27 (95% CI 23–31%), respectively; and for treatment-related mortality (TRM) were 18 (95% CI 14–21%), 21 (95% CI 17–25%), 20 (95% CI 13–26%), and 27 (95% CI 21–33%), respectively. Additionally, the pooled 100-day TRM was 12 (95% CI 5–18%). The incidences of grades II–IV acute graft-versus-host disease (GVHD) and chronic GVHD were 34 (95% CI 30–37%) and 51 (95% CI 46–56%), respectively. The incidences of relapse rate (RR) and death rate were 50 (95% CI 45–55%) and 51 (95% CI 45–57%), respectively. Importantly, disease progression was the most major cause of death (48%), followed by TRM (44%). The results failed to show an apparent benefit of allo-SCT for standard risk patients, compared with tandem auto-SCT. In contrast, all 14 trials in our study showed that patients with high cytogenetic risk after allo-SCT had similar OS and PFS compared to those with standard risk, suggesting that allo-SCT may overcome the adverse prognosis of high cytogenetic risk.

Conclusion

Due to the lack of consistent survival benefit, allo-SCT should not be considered as a standard of care for newly diagnosed and relapsed standard-risk MM patients. However, for patients with high-risk MM who have a poor long-term prognosis, allo-SCT may be a strong consideration in their initial course of therapy or in first relapse after chemotherapy, when the risk of disease progression may outweigh the transplant-related risks. A large number of prospective randomized controlled trials were needed to prove the benefits of these therapeutic options.

Electronic supplementary material

The online version of this article (10.1186/s12935-018-0553-8) contains supplementary material, which is available to authorized users.

Aptamers-Based Sensing Strategy for 17β-Estradiol Through Fluorescence Resonance Energy Transfer Between Oppositely Charged CdTe Quantum Dots and Gold Nanoparticles

A novel aptamers-based fluorescence resonance energy transfer (FRET) assay was developed employing the oppositely charged thioglycolic acid-capped CdTe quantum dots (TGA-CdTe QDs) and cysteamine-stabilized gold nanoparticles (cysteamine-AuNPs). The fluorescence of TGA-CdTe QDs was significantly quenched with addition of cysteamine-AuNPs via the FRET. The FRET process can be modulated by 17β-estradiol in that the specific recognition between 17β-estradiol and aptamers could show different effects on the aptamers-mediated aggregation of cysteamine-AuNPs, and correspondingly adjust the FRET process. The feasibility of the method has been demonstrated by carrying out the detection of 17β-estradiol with the wide linear range from 0.5·ng mL-1 to 150 ng·mL-1 and the low detection limit of 0.057 ng·mL-1. The established assay exhibited favorable selectivity towards 17β-estradiol over other endocrine disrupting compounds and probably coexisting chemicals in real samples. Furthermore, the assay has been successfully applied to detect 17β-estradiol in real tap water samples and feeds samples with good performance. The results were in full consistence with those from HPLC method, indicating the reliability of the detection system. The aptamers-based FRET assay is expected to offer a new opportunity for the rapid analysis of 17β-estradiol in real samples.

Prognostic role of neutrophil-lymphocyte ratio in multiple myeloma: a dose-response meta-analysis

Background

The neutrophil–lymphocyte ratio (NLR), a biomarker for systematic inflammation, has been recently identified as a prognostic factor for various types of both solid and hematologic malignancies. Our study presented here was the first meta-analysis assessing the prognostic role of NLR in multiple myeloma (MM).

Methods

We systematically searched PubMed, Embase, and ISI Web of Science for relevant studies. Odds ratios (ORs) or hazards ratios (HRs) with corresponding 95% CIs are pooled to estimate the association between NLR and clinicopathological parameters or survival of MM patients.

Results

Seven trials with 1,971 MM patients were enrolled in the meta-analysis, and the results indicated that elevated pretreatment NLR was significantly associated with advanced tumor stages (International Staging System [ISS] III vs ISS I–II: OR 2.427, 95% CI: 1.268–4.467; and Durie–Salmon III vs Durie–Salmon I–II: OR 1.738, 95% CI: 1.133–2.665). Moreover, increased NLR also predicted poorer overall survival (HR 2.084, 95% CI: 1.341–3.238) and progression-free survival (HR 1.029, 95% CI: 1.016–1.042). And two-stage dose–response meta-analysis revealed linear association between increased NLR and risk of mortality in MM patients.

Conclusion

We can conclude that MM patients with higher NLR are more likely to have poorer prognosis than those with lower NLR.

Prognostic and clinicopathological significance of long noncoding RNA HOXA11-AS expression in human solid tumors: a meta-analysis

Background

Recent studies have emphasized the important prognostic role of long noncoding RNAs (lncRNAs) in various types of cancers. Here we conducted a meta-analysis to investigate whether lncRNA HOXA11-AS can be served as a prognostic biomarker in human cancers.

Patients/methods

We systematically searched PubMed, Embase, ISI Web of Science, and SCOPUS for relevant studies, to investigate the prognostic significance of HOXA11-AS expression in cancer patients. Odds ratios (ORs) or hazards ratios (HRs) with corresponding 95% confidence intervals (CIs) are pooled to estimate the association between HOXA11-AS expression and clinicopathological parameters or survival of cancer patients.

Results

A total of eight eligible studies with 1320 cancer patients were enrolled in our meta-analysis. The results revealed that increased expression level of HOXA11-AS was significantly associated with clinicopathological parameters including more lymph node metastasis (OR = 2.06, 95% CI 1.31–3.25), advanced tumor stage (OR = 4.22, 95% CI 2.60–6.85), as well as poor tumor differentiation (OR = 2.49, 95 CI 1.47–4.20), but not correlated with age (p = 0.101) or gender (p = 0.845). In addition, cancer patients with high HOXA11-AS are prognosed to have shorter OS (pooled HR = 1.86, 95% CI 1.39–2.48) and PFS (pooled HR = 2.47, 95% CI 1.29–4.75).

Conclusions

HOXA11-AS overexpression might be a convinced unfavorable prognostic factor that helps the clinical decision-making process.

The response analysis of fractional-order stochastic system via generalized cell mapping method

This paper is concerned with the response of a fractional-order stochastic system. The short memory principle is introduced to ensure that the response of the system is a Markov process. The generalized cell mapping method is applied to display the global dynamics of the noise-free system, such as attractors, basins of attraction, basin boundary, saddle, and invariant manifolds. The stochastic generalized cell mapping method is employed to obtain the evolutionary process of probability density functions of the response. The fractional-order ϕ⁶ oscillator and the fractional-order smooth and discontinuous oscillator are taken as examples to give the implementations of our strategies. Studies have shown that the evolutionary direction of the probability density function of the fractional-order stochastic system is consistent with the unstable manifold. The effectiveness of the method is confirmed using Monte Carlo results.

Atmospheric ammonia alters lipid metabolism-related genes in the livers of broilers (Gallus gallus)

Atmospheric ammonia in animal housing is reported to have adverse effects on livestock performance and animal health. Previous experiments have found that 75 ppm ammonia reduced the production performance and altered body fat distribution quality of broilers. In this study, we examined the body fat distribution, serum metabolites and lipid metabolism gene expression of broiler exposed to ammonia. A total of 400 chickens were randomly allocated to four groups with four replicates and received ammonia treatments at 0, 25, 50 and 75 ppm, respectively, for 3 weeks. The average daily feed intake and weight gain were decreased when broiler was exposed to ammonia concentration exceeding 50 ppm (p < .05). The increased abdominal fat and reduced thickness of subcutaneous adipose were found in broilers of 75 ppm group (p < .05). When ammonia exceeded 50 ppm, the content of fat in breast muscle of broiler was increased, and when ammonia was higher than 25 ppm, the fat in liver was increased (p < .05). It showed that the fat content in liver was a sensitive index for broilers exposed to ammonia. Furthermore, ammonia exposure had no significant effect on total cholesterol and triglyceride in serum, but significantly increased the relative mRNA expression of acetyl-CoA carboxylase (p = .046) and malic enzyme in liver (p = .038), which indicated that ammonia exposure may increase the de novo fat synthesis in liver. In addition, ammonia increased the high-density lipoprotein cholesterol (p = .02) and activity of hepatic lipase in serum (p < .001), which indicated that ammonia exposure may improve the transportation of cholesterol to liver. To conclude, our results indicated that ammonia exposure might increase the de novo fat synthesis in liver and increased the transportation of cholesterol to liver. In addition, the concentration of ammonia in poultry house should be limited lower than 25 ppm based on the variation of hepatic fat content.

[Atypical computed tomography manifestations of thoracic sarcoidosis]

Objective: This study evaluated the atypical computed tomography (CT) manifestations of thoracic sarcoidosis. Methods: Medical data of 190 patients with thoracic sarcoidosis were retrospectively reviewed. Results: The atypical CT manifestations of thoracic sarcoidosis observed were unilateral hilar lymphadenopathy with or without mediastinal lymphadenopathy(n=12, 6.3%), mediastinal lymphadenopathy without hilar lymphadenopathy(n=9, 4.7%), patchy consolidation (n=23, 12.1%), sarcoid galaxy sign (n=22, 11.6%), reversed halo sign (n=1, 0.5%), and ground-glass opacities (n=52, 27.4%). Air trapping was found in 8 of 10 patients who underwent both inspiratory and expiratory CT. Post-treatment CT scans showed improvements in most patients. Of the 12 patients with unilateral hilar lymphadenopathy with or without mediastinal lymphadenopathy, 10(83.3%) improved. Of the 9 patients with mediastinal lymphadenopathy without hilar lymphadenopathy, 8(88.9%) improved. Of the 23 patients with patchy consolidation, 15(65.2%) improved. Of the 22 patients with the sarcoid galaxy sign, 16(72.7%) improved. The patient with the reversed halo sign improved completely. Of the 52 patients with ground-glass opacities, 31(59.6%) improved. Of the 8 patients with air trapping, 7(87.5%) improved. Conclusions: The atypical imaging manifestations of thoracic sarcoidosis included unilateral hilar lymphadenopathy with or without mediastinal lymphadenopathy, mediastinal lymphadenopathy without hilar lymphadenopathy, patchy consolidation, the sarcoid galaxy sign, the reversed halo sign, ground-glass opacity, and air trapping. These lesions mostly improved after treatment. Familiarity with these atypical signs will help increase the diagnostic accuracy of imaging studies for thoracic sarcoidosis.

Design, Synthesis, and Evaluation of Tetrahydropyrrolo[1,2-c]pyrimidines as Capsid Assembly Inhibitors for HBV Treatment

The discovery of novel tetrahydropyrrolo[1,2-c]pyrimidines derivatives from Bay41_4109 as hepatitis B virus (HBV) inhibitors is herein reported. The structure-activity relationship optimization led to one highly efficacious compound 28a (IC₅₀ = 10 nM) with good PK profiles and the favorite L/P ratio. The hydrodynamic injection model in mice clearly demonstrated the efficacy of 28a against HBV replication.

Investigating and analyzing three cohorts of mushroom poisoning caused by Amanita exitialis in Yunnan, China

Amanita exitialis is a lethal mushroom found in China. Knowledge regarding taxonomic characterization, toxin detection, general poisoning conditions, clinical manifestations, laboratory examinations, and clinical treatments for this species is currently lacking. We investigated three A. exitialis mushroom poisoning cohorts in Yunnan Province in 2014 and 2015, involving 10 patients. Mushroom samples were identified by morphological and molecular studies. Ultra performance liquid chromatography-electrospray ionization tandem mass spectrometry was used to detect the peptide toxins in the mushroom samples. Epidemiological information, clinical data, and results of laboratory examinations were collected and analyzed. The mushroom samples were all identified as A. exitialis. The average toxin concentration decreased from the cap to the stipe to the volva, and the average concentration of the peptide toxins decreased in the order of α-amanitin > phallacidin > β-amanitin > γ-amanitin. The latency period between ingestion and the onset of symptoms was 13.9 ± 2.1 h, and the time from ingestion to hospitalization was 49.6 ± 8.5 h. The most common symptoms were nausea and vomiting (100%). Four patients died from fulminant hepatic failure. Laboratory examinations showed that the alanine transaminase, aspartate transaminase, prothrombin time, and activated partial thromboplastin time levels peaked on the third day post-ingestion. Total bilirubin and direct bilirubin values peaked on day 7. The death group and the survival group had a similar variation trend of serological indexes, but the death group had a greater change. A. exitialis is an extremely dangerous mushroom and there is a need to educate the public to avoid picking and eating wild mushrooms that have not been definitively identified.

Comparative clinical characteristics and natural history of three variants of sclerosing cholangitis: IgG4-related SC, PSC/AIH and PSC alone

There is increased interest and recognition of the clinical variants of Sclerosing Cholangitis (SC) namely IgG4-SC, PSC/AIH overlap and PSC. For most Centers, the characteristic of IgG4-SC has not been thoroughly clinically compared with other sclerosing cholangitis variants. Further there are relatively few PSC/AIH overlap patients and the clinical outcome is not well characterized, especially for the PSC/AIH overlap syndrome. Our objective herein is to clarify the differences and similarities of the natural history of IgG4-SC, the PSC/AIH overlap and PSC alone. We also place in perspective the diagnostic value of serum IgG4 for IgG4-SC and investigate biomarkers for predicting the prognosis of sclerosing cholangitis. In this study, we took advantage of our large and well-defined patient cohort to perform a retrospective cohort study including 57 IgG4-SC, 36 PSC/AIH overlap patients, and 55 PSC patients. Firstly, as expected, we noted significant differences among immunoglobulin profiles and all patients exhibited similar cholestatic profiles at presentation. Cirrhotic events were found in 20 of total 57 IgG4-SC, 15 of 36 PSC/AIH overlap, and 18 of 55 PSC patients. Serum IgG4 was elevated in 92.65% of IgG4-SC patients with an 86% sensitivity and 98% specificity for diagnosis. IgG4-SC patients had a better treatment response at 6-month and 1-year than PSC/AIH patients, while the latter responded better with steroids than PSC patients. Importantly the adverse outcome-free survival of IgG4-SC patients was reduced, unlike earlier reports, and therefore similar to the PSC/AIH overlap syndrome. Serum IgG and total bilirubin were useful to predict long-term survival of IgG4-SC and PSC/AIH, respectively. In conclusion, serum IgG4≧1.25 ULN shows an excellent predictability to distinguish IgG4-SC among SC patients. IgG4-SC appears to be immune-mediated inflammatory process, while PSC/AIH overlap more tends to be cholestatic disease.

Altered Functional Connectivity of Striatal Subregions in Patients with Multiple Sclerosis

Abnormal corticostriatal resting-state functional connectivity (rsFC) has been implicated in the neuropathology of multiple sclerosis. The striatum, a component of the basal ganglia, is involved in diverse functions including movement, cognition, emotion, and limbic information processing. However, the brain circuits of the striatal subregions contributing to the changes in rsFC in relapsing–remitting multiple sclerosis (RRMS) patients remain unknown. We used six subdivisions of the striatum in each hemisphere as seeds to investigate the rsFC of striatal subregions between RRMS patients and matched healthy controls (HCs). In addition, we also scanned a subcohort of RRMS patients after an average of 7 months to test the reliability of our findings. Compared to HCs, we found significantly increased dorsal caudal putamen (DCP) connectivity with the premotor area, dorsal lateral prefrontal cortex (DLPFC), insula, precuneus, and superior parietal lobule, and significantly increased connectivity between the superior ventral striatum and posterior cingulate cortex (PCC) in RRMS patients following both scans. Furthermore, we found significant associations between the Expanded Disability Status Scale and the rsFC of the left DCP with the DLPFC and parietal areas in RRMS patients. Our results suggest that the DCP may be a critical striatal subregion in the pathophysiology of RRMS.

Highly Enhanced Photoreductive Degradation of Polybromodiphenyl Ethers with g-C3N4/TiO2 under Visible Light Irradiation

A series of high activity photocatalysts g-C₃N₄-TiO₂ were synthesized by simple one-pot thermal transformation method and characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy, Brunauer–Emmett–Teller (BET) surface area, and ultraviolet–visible diffuse reflectance spectroscopy (UV-Vis-DRS). The g-C₃N₄-TiO₂ samples show highly improved photoreductive capability for the degradation of polybromodiphenyl ethers compared with g-C₃N₄ under visible light irradiation. Among all the hybrids, 0.02-C₃N₄-TiO₂ with 2 wt % g-C₃N₄ loaded shows the highest reaction rate, which is 15 times as high as that in bare g-C₃N₄. The well_-matched band gaps in heterojunction g-C₃N₄-TiO₂ not only strengthen the absorption intensity, but also show more effective charge carrier separation, which results in the highly enhanced photoreductive performance under visible light irradiation. The trapping experiments show that holetrapping agents largely affect the reaction rate. The rate of electron accumulation in the conductive band is the rate-determining step in the degradation reaction. A possible photoreductive mechanism has been proposed.

Highly Sensitive Aptamer-Based Colorimetric Detection of Melamine in Raw Milk with Cysteamine-Stabilized Gold Nanoparticles

In this paper, a rapid and facile visual method for detecting melamine in raw milk was developed by using T-rich single-stranded DNA (ssDNA) aptamers as the recognition element and cysteamine-stabilized gold nanoparticles (CS-AuNPs) as the color indicator. The electrostatic interaction between the negatively-charged melamine-binding aptamers and the positively-charged CS-AuNPs induced the aggregation of the CS-AuNPs and a remarkable change in color from wine red to blue. The specific recognition between melamine and T-rich aptamers could cause the formation of melamine-aptamer complex through hydrogen bonding. Compared with the electrostatic interaction between CS-AuNPs and aptamers, the strongly specific recognition between melamine and aptamers played a dominant role, thus the presence of melamine could prevent the aptamers-induced aggregation and color change of CS-AuNPs. As a result of this, using CS-AuNPs as the colorimetric probe, a simple and sensitive aptasensor for melamine determination is developed. Under the optimum conditions, the absorbance change (ΔA 526) of CS-AuNPs was linearly proportional to melamine concentration in the range of 1–24 nM, with the detection limit of 0.389 nM. The application of the proposed method for the determination of melamine in raw milk samples spiked with different amounts of melamine suggested satisfactory recoveries between 92.8% and 112.2%, which are in full accordance with the results from HPLC. Due to the advantages of low cost, high sensitivity, simple operation procedure, reduced detection time, and practical application, this method would be expected for on-site and real-time screening of melamine in raw milk.

Aptamer contained triple-helix molecular switch for rapid fluorescent sensing of acetamiprid

In this study, an aptamer-based fluorescent sensing platform using triple-helix molecular switch (THMS) was developed for the pesticide screening represented by acetamiprid. The THMS was composed of two tailored DNA probes: a label-free central target specific aptamer sequence flanked by two arm segments acting as a recognition probe; a hairpin-shaped structure oligonucleotide serving as a signal transduction probe (STP), labeled with a fluorophore and a quencher at the 3' and 5'-end, respectively. In the absence of acetamiprid, complementary bindings of two arm segments of the aptamers with the loop sequence of STP enforce the formation of THMS with the "open" configuration of STP, and the fluorescence of THMS is on. In the presence of target acetamiprid, the aptamer-target binding results in the formation of a structured aptamer/target complex, which disassembles the THMS and releases the STP. The free STP is folded to a stem loop structure, and the fluorescence is quenched. The quenched fluorescence intensity was proportional to the concentration of acetamiprid in the range from 100 to 1200nM, with the limit of detection (LOD) as low as 9.12nM. In addition, this THMS-based method has been successfully used to test and quantify acetamiprid in Chinese cabbage with satisfactory recoveries, and the results were in full agreement with those from LC-MS. The aptamer-based THMS presents distinct advantages, including high stability, remarkable sensitivity, and preservation of the affinity and specificity of the original aptamer. Most importantly, this strategy is convenient and generalizable by virtue of altering the aptamer sequence without changing the triple-helix structure. So, it is expected that this aptamer-based fluorescent assay could be extensively applied in the field of food safety inspection.

Supramolecular Controlled Cargo Release via Near Infrared Tunable Cucurbit[7]uril-Gold Nanostars

The near infrared (NIR) absorption and average particle size of gold nanostars (GNSs) can be precisely controlled by varying the molar ratios of cucurbit[7]urils (CB[7]) and GNSs in aqueous solution. GNSs modified with CB[7] achieved high cargo loading with thermally activated release upon the NIR laser irradiation.

Visual Screening and Colorimetric Determination of Clenbuterol and Ractopamine Using Unmodified Gold Nanoparticles as Probe

In this paper, a sensitive method for the colorimetric detection of clenbuterol and ractopamine using citrate-stabilized gold nanoparticles (AuNPs) as probe was developed. The concentration of clenbuterol and ractopamine could be determined with naked eyes or a UV-vis spectrometer. By optimizing the influence of NaHSO₄ and incubation time, clenbuterol could be detected in the linear range of 0.1-4 µg/mL with the detection limit of 0.0158 µg/mL, and ractopamine could be detected in the linear range of 1-9 µg/mL with the detection limit of 0.0229 µg/mL. The proposed method could be successfully applied to detect clenbuterol and ractopamine in pig urines by a simple pre-treatment with excellent recoveries. The proposed colorimetric assay exhibits good reproducibility and accuracy, providing a simple and rapid method for the analysis of clenbuterol and ractopamine.

Surface modification of pure titanium to improve its anti-inflammatory function

Objective:

Surface-modified titanium material was prepared to explore its corrosion resistance and microbial adhesion.

Methods:

Atmospheric pressure plasma was used to modify the surface of pure titanium. The surface morphology and adhesion morphology of P. gingivalis (Porphyromonas gingivalis) were observed through morphology scanning electron microscopy. Reactive oxygen species (ROS) formation was detected using a fluorescence spectrophotometer. Electrochemical corrosion properties of the material were detected using simulated fluids and SAGF artificial saliva as electrolyte. Bacteria suspension absorbance was tested using an enzyme standard.

Results:

After plasma modification, the material surface exhibited numerous ROS formations and improved wettability. Compared with the control group, corrosion potential was higher but corrosion current was lower in simulated body fluids and artificial saliva. Bacterial-suspension absorbance was significantly lower than that in the control group on days 3 and 5 ( P <0.05).

Conclusion:

The electrochemical and microbial corrosion performance of titanium can be improved by atmospheric pressure plasma. Therefore, this method can thus be used for the surface modification of oral and bone implant materials.

Aptamer-based fluorescent screening assay for acetamiprid via inner filter effect of gold nanoparticles on the fluorescence of CdTe quantum dots

This paper reports a novel aptamer-based fluorescent detection method for small molecules represented by acetamiprid based on the specific binding of aptamers with acetamiprid, and the inner filter effect (IFE) of gold nanoparticles (AuNPs) on the fluorescence of CdTe quantum dots (CdTe QDs). When CdTe QDs were mixed with AuNPs, the fluorescence of CdTe QDs was significantly quenched via IFE. The IFE efficiency could be readily modulated by the absorption and the aggregation state of AuNPs. The presence of salt could easily induce the aggregation of AuNPs, resulting in the fluorescence recovery of the quenched QDs. Acetamiprid-binding aptamer (ABA) could adsorb on the negatively charged AuNPs through the coordination interaction to protect AuNPs from salt-induced aggregation, so the fluorescence of CdTe QDs would be quenched by the IFE of AuNPs. However, the specific binding of ABA with acetamiprid could release the ABA from the surfaces of AuNPs and decrease the salt tolerance of AuNPs, so the IFE-decreased fluorescence of CdTe QDs was regained with the presence of acetamiprid, and the fluorescence enhancement efficiency was driven by the concentration of acetamiprid. Based on this principle, the aptamer-based fluorescent method for acetamiprid has been established and optimized. The assay exhibited excellent selectivity towards acetamiprid over its analogues and other pesticides which may coexist with acetamiprid. Under the optimum experiment conditions, the established method could be applied for the determination of acetamiprid with a wide linear range from 0.05 to 1.0 μM, and a low detection limit of 7.29 nM (3σ). Furthermore, this IFE-based method has been successfully utilized to detect acetamiprid in six types of vegetables, and the results were in full agreement with those from HPLC and LC-MS. The proposed method displays remarkable advantages of high sensitivity, rapid analysis, excellent selectivity, and would be suitable for the practical application of target screening in real samples.

In vivo determination of muscle-derived stem cells in rat corpus cavernosum

The aim of this in vivo study was to determine the existence of muscle-derived stem cells (MDSCs) in rat corpus cavernosum. Immunohistochemical and RT-PCR analyses were performed to determine the expression of the stem cell markers (Sca-1, Oct4, and desmin) in Sprague-Dawley (SD) rats in different age groups (10 rats in each group). Sca-1 was mainly expressed in blood vessels and cavernous sinus and demonstrated primarily cytoplasmic staining. Desmin was expressed mainly in muscle tissues and staining occurred mainly in the cytoplasm but also partially in the nucleus. An extremely small amount of double-positive stained cells (Sca-1/desmin) were detected near the cavernous sinus. Expression of the markers was significantly and negatively correlated with the age of the rats (P < 0.05). The RT-PCR results showed that the expression levels of Sca-1 and desmin significantly decreased with age (P < 0.05). Correlation analysis indicated that the expression of Sca-1 and desmin were significantly and negatively correlated with the age of rats (r = -0.929, P < 0.05). The present study provides evidence for the existence of MDSCs in rat corpus cavernosum. MDSCs may have therapeutic potential in the treatment of organic erectile dysfunction.