Converting waste tires into p-cymene through hydropyrolysis and selective gas-phase hydrogenation/dehydrogenation.

The resource utilization and valorization of waste tires (WT) are of significant importance in reducing environmental pollution. To produce high-value p-cymene from WT, we propose a catalytic cascade process combining hydropyrolysis and catalytic gas-phase hydrotreating in a two-stage fixed-bed reactor. The effect of catalysts prepared with three different acidic supports on the hydrogenation/dehydrogenation of limonene, a compound derived from the hydropyrolysis of WT, was investigated. The p-cymene formation could be controlled by optimizing process parameters, including hydropyrolysis temperature, hydrogenation temperature, and catalyst-to-feedstock ratio (C/F). Experimental results indicated that, in the absence of a catalyst, limonene was the main product of WT depolymerization. Under optimized conditions (hydropyrolysis temperature of 425 ℃, hydrotreating temperature of 400 ℃, C/F of 10:1, and reaction pressure of 0.15 MPa), the highest relative content of p-cymene (79.1%) was obtained over the Pd/SBA-15 catalyst. This demonstrates that our proposed catalytic cascade process of hydropyrolysis and selective gas-phase hydrogenation/dehydrogenation can convert WT into p-cymene with high added value.

Association between the infections of Trichomonas vaginalis and uterine cervical human papillomavirus: a meta-analysis.

Trichomonas vaginalis (TV) may have an impact on other reproductive tract infections. Studies on the connection between the infection of TV and human papillomavirus (HPV) have been inconsistent. We performed a systematic review of the relevant articles through keywords that satisfy the criteria and filtered the articles according to the inclusion and exclusion criteria. A total of 16 eligible studies were screened for the meta-analysis, involving a total of 150,605 women. RevMan 5.4 software was used for meta-analysis of the selected literatures. The results showed that the papers included in this study had good homogeneity and no significant publication bias was found in the current analysis. The pooled estimates using a fixed-effects model showed that TV was more prevalent in HPV-infected women than in non-infected women [odds ratio (OR): 1.51, 95% confidence interval (CI): 1.29-1.75]; In turn, HPV was more widespread in TV-infected women than in uninfected women (OR: 3.62, 95% CI: 2.71-4.85). Moreover, the interaction between TV and HPV infection was insensitive to the deletion of some studies and correlation coefficients, consequently, the results were robust and reliable. These results suggested that TV is positively associated with HPV infection, and HPV is also a risk factor for TV infection.

A comprehensive SERS, SEM and EDX study of individual atmospheric PM2.5 particles in Chengdu, China.

Characterization of atmospheric fine particulate matter (PM2.5) in large cities has important implications for the study of their sources and formation mechanisms, as well as in developing effective measures to control air pollution. Herein, we report a holistic physical and chemical characterization of PM2.5 by combining surface-enhanced Raman scattering (SERS) with scanning electron microscopy (SEM) and electron-induced X-ray spectroscopy (EDX). PM2.5 particles were collected in a suburban area of Chengdu, a large city in China with a population over 21 million. A special SERS chip composed of inverted hollow Au cone (IHAC) arrays was designed and fabricated to allow direct loading of PM2.5 particles. SERS and EDX were used to reveal the chemical composition, and particle morphologies were analyzed from SEM images. SERS data of atmospheric PM2.5 indicated qualitatively the presence of carbonaceous particulate matter, sulfate, nitrate, metal oxides and bioparticles. The EDX showed the presence of the elements C, N, O, Fe, Na, Mg, Al, Si, S, K, and Ca in the collected PM2.5. Morphology analysis showed that the particulates were mainly in the form of flocculent clusters, spherical, regular crystal shaped or irregularly shaped particles. Our chemical and physical analyses also revealed that the main sources of PM2.5 are automobile exhaust, secondary pollution caused by photochemical reactions in the air, dust, emission from nearby industrial exhaust, biological particles, other aggregated particles, and hygroscopic particles. SERS and SEM data collected during three different seasons showed that carbon-containing particles are the principal sources of PM2.5. Our study demonstrates that the SERS based technique, when combined with standard physicochemical characterization methods, is a powerful analytical tool to determine the sources of ambient PM2.5 pollution. Results obtained in this work may be valuable to the prevention and control of PM2.5 pollution in air.

The correlation between Trichomonas vaginalis infection and reproductive system cancer: a systematic review and meta-analysis.

BACKGROUND: Trichomonas vaginalis (T. vaginalis) is a microaerophilic protozoan parasite which is responsible for trichomoniasis, the most common non-viral sexually transmitted infection in the world. The infection greatly damages the reproductive system. However, whether T. vaginalis infection can cause reproductive system cancer remains controversial. METHODS: This study systematically searched PubMed, EMBASE, Ovid and Google scholar, and 144 relevant articles were retrieved and classified into three categories: epidemiological investigations (68), reviews (30) and research articles (46). These three types of articles were verified according to their respective inclusion and exclusion criteria. Stata 16 was used to conduct a meta-analysis on the articles of epidemiological investigations for analysing the correlation between T. vaginalis infection and reproductive system cancer. RESULTS: The result of meta-analysis indicated that the rate of T. vaginalis infection in the cancer group was significantly higher than that in the non-cancer group (OR = 1.87, 95% CI 1.29-2.71, I2 = 52%). Moreover, the cancer rate of the population infected with T. vaginalis was significantly higher than that of the population without T. vaginalis infection (OR = 2.77, 95% CI 2.37-3.25, I2 = 31%). The review articles and most research articles stated that the infection of T. vaginalis could lead to cancer and the pathogenic mechanisms were as follows: T. vaginalis promoting inflammatory response, T. vaginalis infection changing the internal environment around parasitic sites and signal transduction pathway, the metabolites secreted by T. vaginalis inducing carcinogenesis and T. vaginalis increasing other pathogenic microbial infection to promote the occurrence of cancer. CONCLUSIONS: Our study confirmed that there was a correlation between the infection of T. vaginalis and reproductive system cancer, and provided some possible research directions for clarifying the carcinogenic mechanisms caused by T. vaginalis infection.

Identification and classification of particle contaminants on photomasks based on individual-particle Raman scattering spectra and SEM images.

Particle contamination of photo masks is a significant issue facing the micro-nanofabrication process. It is necessary to analyze the particulate matter so that the contamination can be effectively controlled and eliminated. In this study, Raman spectroscopy was used in combination with scanning electron microscopy with energy analysis (SEM-EDX) techniques to study the contamination of individual particles on the photomask. From Raman spectroscopic analysis, the Raman bands of particles mainly contributed to the vibrational modes of the elements C, H, O, and N. Their morphology and elemental composition were determined by SEM-EDX. The sizes of the particles are mostly less than 0.8 µm according to the SEM image analysis. Hierarchical clustering analysis (HCA) of the Raman spectra of particles have shown that the particles can be classified into six clusters which are assigned to CaCO3, hydrocarbon and hydrocarbon polymers, mixture of NH4NO3 and few (NH4)2SO4, mixtures metal oxides, D and G peaks of carbon, fluorescent and (NH4)2SO4 clusters. Finally, principal component analysis (PCA) was used to verify the correctness of the classification results. The identification and classification analysis of individual particles of photomask contamination illustrate the chemical components of the particles and provide insights into mask cleaning and how to effectively avoid particle contamination.

A systematic review of the correlation between Trichomonas vaginalis infection and infertility.

BACKGROUND: Trichomonas vaginalis (T. vaginalis) is an extracellular flagellated protozoan parasitizing the human genital and urinary tracts. T. vaginalis infection impacts human reproductive function, but whether it causes infertility is still a matter of debate. METHODS: In this work, we consulted 205 relevant articles, which were classified into three categories: epidemiological investigations (100), review articles (43), and research articles (62). RevMan 5.4 was used to conduct a meta-analysis of the articles reporting epidemiological investigations comparing the incidence of T. vaginalis infection between infertile and fertile groups. Review and research articles were used to summarize the pathogenesis of infertility caused by T. vaginalis. RESULTS: The results indicated that rate of T. vaginalis infection in the infertile group was significantly higher than that in the fertile group. Moreover, the epidemiological surveys showed that the infertility rates of population infected with T. vaginalis were significantly higher than that of population without T. vaginalis infection. Nine out of ten (90%) related review articles stated that T. vaginalis infection causes infertility, and the review and research articles indicated the main pathogenic mechanisms of infertility caused by T. vaginalis were as follows: T. vaginalis impairs sperm quality, resulting in infertility; the immune response triggered by T. vaginalis infection impacts human reproductive function. CONCLUSION: Our results confirm that there is a correlation between T. vaginalis infection and infertility, and T. vaginalis infection can lead to infertility. The study provides a foundation for further investigations into its pathogenesis.

Surface-enhanced Raman Scattering of Au-Ag bimetallic nanopillars fabricated using surface-plasmon lithography.

Arrays of gold-silver (Au-Ag) bimetallic nanopillars were fabricated by a newly developed surface-plasmon lithography (SPL) and their enhancement properties as surface-enhanced Raman scattering (SERS) substrates have been studied. We demonstrated that the SPL is a low-cost and high efficiency method for the fabrication of SERS substrates with both high sensitivity and reproducibility. The nanopillars showed a good response in the detection of methylene blue molecules at a low concentration of 1.0 × 10-11mol· l-1. The SERS enhancement factors (EFs) are on the orders of 107and the relative standard deviation of SERS intensity is <8% over an area of 50µm × 50µm. The EFs increase fast with the height increasing from 200 to 530 nm, then increase slowly when further increase the height of the nanopillars to 1100 nm. In addition, the Au-Ag bimetallic coating has shown much higher SERS enhancement than the coatings of either the pure Au or Ag. The excellent SERS enhancement and reproducibility of the Au-Ag coated nanopillars indicated that the fabricated SERS substrates can be used for the detection of biochemical molecules at trace level and the SPL is a promising method for fabrication of SERS substrates.

An efficient LSPR method to quantitatively detect dimethoate: Development, characterization and evaluation.

In recent years, there has been growing concern among consumers about pesticide contamination in fruits. Therefore, rapid, reliable, and consistent detection methods for OPPs, especially dimethoate, are crucially needed. The existing quantitative methods for detecting dimethoate are not suitable for rapid measuring system such as the dimethoate samples from two channels. Hence this paper examines the utilization of a dual-channel system for utilize the absorption variations of the Localized Surface Plasmon Resonance (LSPR) bands of gold nanoparticles (AuNPs) were investigate for detection of dimethoate. Under optimized conditions, the relationship between concentrations of dimethoate and absorbance ratios (A(520)/A(640)) was linearly found in the concentration range of 10-100 nM. Result from the experiment shows that both channels exhibit a linear correlation coefficient as high as 0.97 and a limit of detection (LOD) as low as 5.5 nM. This LSPR detection system was characterized by testing the dimethoate in apple samples and the recovery rates were found to be in the range of 85.90% to 107.37%. The proposed dual-channel LSPR system for detecting dimethoate creating a new approach for detecting organophosphate insecticide in agricultural fields. It could lay the foundation for designing a high-throughput analysis of the insecticides using a wavelength division multiplexing switch (WDMS).

A multi-channel localized surface plasmon resonance system for absorptiometric determination of abscisic acid by using gold nanoparticles functionalized with a polyadenine-tailed aptamer.

A multi-channel localized surface plasmon resonance system is described for absorptiometric determination of abscisic acid (ABA). The system is making use of gold nanoparticles and consists of a broadband light source, a multi-channel alignment device, and a fiber spectrometer. The method is based on the specific interaction between an ABA-binding aptamer and ABA. This induces the growth of gold nanoparticles (AuNPs) functionalized with a polyadenine-tailed aptamer that act as optical probes. Different concentrations of ABA give rise to varied morphologies of grown AuNPs. This causes a change of absorption spectra which is recorded by the system. ABA can be quantified by measurement of the peak wavelength shifts of grown AuNPs. Under optimized conditions, this method shows a linear relationship in the 1 nM to 10 µM ABA concentration range. The detection limit is 0.51 nM. The sensitivity of the ABA assay is strongly improved compared to the method based on salt-induced AuNP aggregation. This is attributed to the use of a poly-A-tailed aptamer and the catalytic ability of AuNPs. In the actual application, the ABA concentration of ABA in fresh leaves of rice is measured with the maximum relative error of 8.03% in comparison with the ELISA method. Graphical abstractSchematic representation of an absorptiometric approach for determination of abscisic acid based on the growth of polyA-tailed aptamer-AuNPs probes and a multi-channel localized surface plasmon resonance system.

Edible Gelatin Diagnosis Using Laser-Induced Breakdown Spectroscopy and Partial Least Square Assisted Support Vector Machine.

Edible gelatin has been widely used as a food additive in the food industry, and illegal adulteration with industrial gelatin will cause serious harm to human health. The present work used laser-induced breakdown spectroscopy (LIBS) coupled with the partial least square-support vector machine (PLS-SVM) method for the fast and accurate estimation of edible gelatin adulteration. Gelatin samples with 11 different adulteration ratios were prepared by mixing pure edible gelatin with industrial gelatin, and the LIBS spectra were recorded to analyze their elemental composition differences. The PLS, SVM, and PLS-SVM models were separately built for the prediction of gelatin adulteration ratios, and the hybrid PLS-SVM model yielded a better performance than only the PLS and SVM models. Besides, four different variable selection methods, including competitive adaptive reweighted sampling (CARS), Monte Carlo uninformative variable elimination (MC-UVE), random frog (RF), and principal component analysis (PCA), were adopted to combine with the SVM model for comparative study; the results further demonstrated that the PLS-SVM model was superior to the other SVM models. This study reveals that the hybrid PLS-SVM model, with the advantages of low computational time and high prediction accuracy, can be employed as a preferred method for the accurate estimation of edible gelatin adulteration.

A simple colorimetric probe based on anti-aggregation of AuNPs for rapid and sensitive detection of malathion in environmental samples.

In this study, a simple colorimetric probe was developed for rapid and highly sensitive detection of malathion based on gold nanoparticles (AuNPs) anti-aggregation mechanism. A certain amount of NaOH can cause the aggregation of citrate-stabilized AuNPs due to the electrostatic interactions, and the color of AuNP solution changes from wine-red to gray. While in the presence of malathion, malathion is easily hydrolyzed in a strong alkali environment (pH > 9), followed by the production of a mass of negative charges, and thus the aggregated AuNPs turns to well-dispersed and the color of AuNP solution changes from gray to wine-red. This characteristic change can be visualized with the naked eye and quantitatively detected by an ultraviolet-visible (UV-Vis) spectrometer. Under optimized conditions, this probe exhibited a linear response to malathion in the concentration range of 0.05-0.8 µM with a limit of detection (LOD) down to 11.8 nM. The probe also showed good specificity for malathion detection in the presence of other interfering pesticide residues. Furthermore, the probe was successfully employed to detect malathion in environmental samples, with a recovery of 94-107% and a relative standard deviation (RSD) less than 8%. The results demonstrated that the proposed colorimetric probe based on anti-aggregation of AuNPs could be used for quantitative analysis of malathion and provided great potential for malathion determination in environmental samples.

Yellow Pigment Aurovertins Mediate Interactions between the Pathogenic Fungus Pochonia chlamydosporia and Its Nematode Host.

Nematophagous fungi are globally distributed soil fungi and well-known natural predators of soil-dwelling nematodes. Pochonia chlamydosporia can be found in diverse nematode-suppressive soils as a parasite of nematode eggs and is one of the most studied potential biological control agents of nematodes. However, little is known about the functions of small molecules in the process of infection of nematodes by this parasitic fungus or about small-molecule-mediated interactions between the pathogenic fungus and its host. Our recent study demonstrated that a P. chlamydosporia strain isolated from root knots of tobacco infected by the root-knot nematode Meloidogyne incognita produced a class of yellow pigment metabolite aurovertins, which induced the death of the free-living nematode Panagrellus redivevus. Here we report that nematicidal P. chlamydosporia strains obtained from the nematode worms tended to yield a total yellow pigment aurovertin production exceeding the inhibitory concentration shown in nematicidal bioassays. Aurovertin D was abundant in the pigment metabolites of P. chlamydosporia strains. Aurovertin D showed strong toxicity toward the root-knot nematode M. incognita and exerted profound and detrimental effects on the viability of Caenorhabditis elegans even at a subinhibitory concentration. Evaluation of the nematode mutation in the ß subunit of F1-ATPase, together with the application of RNA interference in screening each subunit of F1FO-ATPase in the nematode worms, demonstrated that the ß subunit of F1-ATPase might not be the specific target for aurovertins in nematodes. The resistance of C. elegans daf-2(e1370) and the hypersensitivity of C. elegans daf-16(mu86) to aurovertin D indicated that DAF-16/FOXO transcription factor in nematodes was triggered in response to the aurovertin attack. These findings advance our understanding of the roles of aurovertin production in the interactions between nematodes and the pathogen fungus P. chlamydosporia.

Regulation of the growth of cotton bollworms by metabolites from an entomopathogenic fungus Paecilomyces cateniobliquus.

Chemical investigation of one entomopathogenic fungus Paecilomyces cateniobliquus YMF1.01799 led to the isolation and identification of six metabolites, which include three new compounds (2-3, and 5) and three known metabolites. Their structures were established by spectroscopic studies such as 1D and 2D NMR and MS analysis. Insect growth experiments suggested that polyketide-derived compound 1 showed significant inhibitory effect on the growth of cotton bollworm Helicoverpa armigera, while terpenoid-derived metabolite 5 promoted the growth of the larvae. The findings revealed that the entomopathogenic fungus P. cateniobliquus could produce different types of metabolites to regulate growth of the insect.

Cloning and characterization of Prisilkin-39, a novel matrix protein serving a dual role in the prismatic layer formation from the oyster Pinctada fucata.

Molluscs form their shells out of CaCO(3) and a matrix of biomacromolecules. Understanding the role of matrices may shed some light on the mechanism of biomineralization. Here, a 1401-bp full-length cDNA sequence encoding a novel matrix protein was cloned from the mantle of the bivalve oyster, Pinctada fucata. The deduced protein (Prisilkin-39), which has a molecular mass of 39.3 kDa and an isoelectric point of 8.83, was fully characterized, and its role in biomineralization was demonstrated using both in vivo and in vitro crystal growth assays. Prisilkin-39 is a highly repetitive protein with an unusual composition of Gly, Tyr, and Ser residues. Expression of Prisilkin-39 was localized to columnar epithelial cells of the mantle edge, corresponding to the calcitic prismatic layer formation. Immunostaining in situ and immunodetection in vitro revealed the presence of a characteristic pattern of Prisilkin-39 in the organic sheet and in sheaths around the prisms. Prisilkin-39 binds tightly with chitin, an insoluble polysaccharide that forms the highly structured framework of the shell. Antibody injection in vivo resulted in dramatic morphological deformities in the inner shell surface structure, where large amounts of CaCO(3) were deposited in an uncontrolled manner. Moreover, Prisilkin-39 strictly prohibited the precipitation of aragonite in vitro. Taken together, Prisilkin-39 is the first protein shown to have dual function, involved both in the chitinous framework building and in crystal growth regulation during the prismatic layer mineralization. These observations may extend our view on the rare group of basic matrices and their functions during elaboration of the molluscan shell.

[Impact of patient compliance on the outcomes in hypertensive patients receiving hydrochlorothiazide based combination therapy with spironolactone or captopril].

OBJECTIVE: To explore the impact of patient compliance on the long-term outcomes in hypertensive patients receiving hydrochlorothiazide (HCTZ) based combination therapy with spironolactone or captopril. METHODS: A total of 853 patients with mild to moderate hypertension were recruited and randomly divided into HCTZ group (HCTZ 12.5 mg q.d), spironolactone group (HCTZ 12.5 mg q.d and spironolactone 20 mg q.d), and captopril group (HCTZ 12.5 mg q.d and captopril 25 mg bid) after 2-week placebo washout period and 6-week loading period for HCTZ. Since the efficacy of combination therapy was proven to be better than monotherapy 1 year after therapy beginning, patients in HCTZ group were randomly assigned to spironolactone group or captopril group. The patients were followed up for 4 years. Patients were divided to compliance (n = 424) or non-compliance group (n = 429) according test drug taking questionnaire. During the follow-up time, the blood pressure and the outcomes were recorded monthly, and blood biochemical parameters were determined once a year. RESULTS: At the end of follow up, incidence of cardio-cerebral vascular events was significantly lower in compliance group (2 fatal, 8 non-fatal) than that in noncompliance group (7 fatal, 21 non-fatal, P < 0.05). Systolic blood pressure [-(19.4 +/- 20.6) mm Hg, 1 mm Hg = 0.133 kPa] and diastolic blood pressure [-(10.7 +/- 13.5) mm Hg] were significantly reduced compared values at baseline and noncompliance group (all P < 0.001) while the reduction did not reach statistically significance in noncompliance group [-(7.3 +/- 18.2) mm Hg and -(3.5 +/- 10.2) mm Hg, all P > 0.05 vs. baseline]. The serum BUN, Cr and UA levels in the compliance group were significantly higher and the serum K(+), CHO, LDL-C level were significantly lower than baseline values. The serum BUN, UA levels in the compliance group were significantly higher while the serum K(+), cholesterol levels were significantly lower than those in the noncompliance group (all P < 0.05). CONCLUSIONS: This study indicates that patient compliance could affect the long-term outcome and antihypertensive efficacy in hypertensive patients receiving HCTZ based combination therapy with spironolactone or captopril.