Effectiveness of radiation processing in elimination of Campylobacter from poultry meat

Campylobacter, a common poultry intestine commensal, is a well known cause of human gastric illnesses across the globe. Consumption of contaminated poultry meat is a major cause of Campylobacter related infections. In the present study, radiation sensitivity of indigenous strains of C. jejuni and C. coli isolated from poultry was evaluated. The decimal reduction dose (D₁₀) values of different Campylobacter isolates at 0-4 °C in saline and blood broth were in the range of 0.120-0.210 kGy and 0.170-0.234 kGy, respectively. D₁₀ values in chicken meat homogenate for Campylobacter were in the range of 0.110-0.190 kGy. Chicken meat samples were inoculated with C. jejuni and exposed to gamma radiation to study the effectiveness of radiation treatment in elimination of Campylobacter. Radiation treatment with a dose of 1 kGy could achieve complete elimination of 10⁵ CFU of Campylobacter/g in poultry meat samples. No recovery of Campylobacter was observed, even after enrichment and selective plating in 1 kGy treated chicken meat samples stored at 4 °C up to 7 days. Present study shows that irradiation of poultry meat with 1 kGy can ensure safety of poultry meat.     

An in-silico approach to study the possible interactions of miRNA between human and SARS-CoV2

BackgroundThe progressive SARS-CoV2 outbreaks worldwide have evoked global investigation. Despite the numerousin-silico approaches, the virus-host relationship remains a serious concern. MicroRNAs are the small non-coding RNAs that help in regulating gene profiling. The current study utilized miRNA prediction tools along with the PANTHER classification system to demonstrate association and sequence similarities shared between miRNAs of SARS-CoV2 and human host.MethodAn in-silico approach was carried out using Vmir analyzer to predict miRNAs from SARS-CoV2 viral genomes. Predicted miRNAs from SARS-CoV2 viral genomes were used for effective hybridization sequence identification along the nucleotide similarities with human miRNAs from miRbase database. Further, it was proceeded to analyze the gene ontology using miRDB with PANTHER classification.ResultBased on the prediction and analysis, we have identified 22 potential miRNAs from five genomes of SARS-CoV2 linked with 12 human miRNAs. Analysis of human miRNAs hsa-mir-1267, hsa-mir-1-3p, hsa-mir-5683 were found shared between all the five viral SARS-CoV2 miRNAs. Further, PANTHER classification analyzed the gene-ontology being carried by these associations showed that 44 genes were involved in biological functions that includes genes specific for signaling pathway, immune complex generation, enzyme binding with effective role in the virus-host relationship.ConclusionOur analysis concludes that the genes identified in this study can be effective in analyzing the virus-host interaction. It also provides a new direction to understand viral pathogenesis with a probable new way to link, that can be used to understand and relate the miRNAs of the virus to the host conditions.     

MiR-144-3p is associated with pathological inflammation in patients infected with Mycobacteroides abscessus

Infection with rapidly growing nontuberculous mycobacteria is emerging as a global health issue; however, key host factors remain elusive. Here, we investigated the characteristic immune profiles of peripheral blood mononuclear cells (PBMCs) from patients infected with Mycobacteroides abscessus subsp. abscessus (Mabc) and M. abscessus subsp. massiliense (Mmass). Using an integrated analysis of global mRNA and microRNA expression profiles, we found that several inflammatory cytokines/chemokines [interleukin (IL)-1β, IL-6, C-X-C motif chemokine ligand 2, and C-C motif chemokine ligand 2] and miR-144-3p were significantly upregulated in PBMCs from patients compared with those from healthy controls (HCs). Notably, there was a strong correlation between the expression levels of miR-144-3p and proinflammatory cytokines/chemokines. Similarly, upregulated expression of miR-144-3p and proinflammatory cytokines/chemokines was found in macrophages and lungs from mice after infection with Mabc and Mmass. We showed that the expression of negative regulators of inflammation (SARM1 and TNIP3) was significantly downregulated in PBMCs from the patients, although they were not putative targets of miR-144-3p. Furthermore, overexpression of miR-144-3p led to a marked increase in proinflammatory cytokines/chemokines and promoted bacterial growth in macrophages. Together, our results highlight the importance of miR-144-3p linking to pathological inflammation during M. abscessus infection.Subject terms: Bacterial infection, Bacterial infection, Chemokines, Mechanisms of disease     

On the hypothetical protein F154 of the TTV1 virus/Thermoproteus Tenax. Part II: Synthesis of the trieicosapeptide,corresponding to the protein sequence 79–101

Summary For the identification of a protein predicted by DNA sequence analysis of the TTV1 virus from the archaebacteriumThermoproteus tenax, the trieicosapeptide H-Thr-Pro-Thr-Pro-Thr-Pro-Thr-Tyr-Asp-Ile-Thr-Tyr-Val-Val-Phe-Asp-Val-Thr-Pro-Ser-Pro-Thr-Pro-OH, corresponding to the protein fragment 79–101, was prepared by conventional methods of peptide synthesis. This sequence portion may possibly represent a suitable protein specific immunepitope.

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Zur Hypothese eines TTV1 Virus/Thermoproteus tenax F154-Proteins. Teil II: Synthese des Protein-fragments 79–101

Zusammenfassung Für den Nachweis der Expression des Proteins F154 — nach einer Sequenzanalyse des Genoms des TTV1 Virus im ArchaebakteriumThermoproteus tenax postuliert — wurde das Peptid H-Thr-Pro-Thr-Pro-Thr-Pro-Thr-Tyr-Asp-Ile-Thr-Tyr-Val-Val-Phe-Asp-Val-Thr-Pro-Ser-Pro-Thr-Pro-OH (Proteinfragment 79–101) mit Hilfe konventioneller Peptidsynthese hergestellt. Diese Peptidsequenz sollte ein geeignetes proteinspezifisches Immunepitop darstellen.

     

Layered double hydroxides as supports for intercalation and sustained release of antihypertensive drugs

Zn/Al layered double hydroxides (LDHs) were intercalated with the anionic antihypertensive drugs Enalpril, Lisinopril, Captopril and Ramipril by using coprecipitation or ion-exchange technique. TG-MS analyses suggested that the thermal stability of Ena⁻, Lis⁻ (arranged with monolayer, resulted from X-ray diffraction (XRD) and Fourier transform infrared spectra (FT-IR) analysis was enhanced much more than Cap^- and Ram^- (arranged with bilayer). The release studies show that the release rate of all samples markedly decreased in both pH 4.25 and 7.45. However, the release time of Ena^-, Lis^- were much longer compared with Cap^-, Ram^- in both pH 4.25 and 7.45, it is possible that the intercalated guests, arranged with monolayer in the interlayer, show lesser repulsive force and strong affinity with the LDH layers. And the release data followed both the Higuchi-square-root law and the first-order equation well. Based on the analysis of batch release, intercalated structural models as well as the TG-DTA results, we conclude that for drug-LDH, stronger the affinity between intercalated anions and the layers is, better the thermal property and the stability to the acid attack of drug-LDH, and the intercalated anions are easier apt to monolayer arrangement within the interlayer, were presented.     

LC�CMS�CMS Determination of Gizzerosine in Poultry Feed

A new selective method for the determination of the bioactive amine gizzerosine in poultry feed is presented based on hydrophilic interaction chromatography coupled to electrospray ionisation and tandem quadrupole mass spectrometry. The protonated molecular ions were selected for fragmentation and scanning of the two major product ions using the mass analyser in the multiple reaction monitoring mode. The analytical methodology included acid hydrolysis of feed sample aliquots and desalting and crude clean-up of hydrolysates using cation-exchange chromatography on a polymeric solid-phase extraction sorbent. Mean overall recoveries (n = 9) were 68?C82% in spike-recovery experiments. The limit of detection was 0.25 mg kg^?1. The method was applied to the analysis of fish meal and fish meal-containing poultry feed samples. Although gizzerosine could not be detected in any of the samples, it was found in fish meal made from sand eel after heating to 130 °C for 24 h.     

Computational analysis revealed miRNAs produced by Chikungunya virus target genes associated with antiviral immune responses and cell cycle regulation

Chikungunya virus (CHIKV) that causes chikungunya fever, is an alphavirus that belongs to the Togaviridae family containing a single-stranded RNA genome. Mosquitoes of the Aedes species act as the vectors for this virus and can be found in the blood, which can be passed from an infected person to a mosquito through mosquito bites. CHIKV has drawn much attention recently because of its potential of causing an epidemic. As the detailed mechanism of its pathogenesis inside the host system is still lacking, in this in silico research we have hypothesized that CHIKV might create miRNAs, which would target the genes associated with host cellular regulatory pathways, thereby providing the virus with prolonged refuge. Using bioinformatics approaches we found several putative miRNAs produced by CHIKV. Then we predicted the genes of the host targeted by these miRNAs. Functional enrichment analysis of these targeted genes shows the involvement of several biological pathways regulating antiviral immune stimulation, cellular proliferation, and cell cycle, thereby provide themselves with prolonged refuge and facilitate their pathogenesis, which in turn may lead to disease conditions. Finally, we analyzed a publicly available microarray dataset (GSE49985) to determine the altered expression levels of the targeted genes and found genes associated with pathways such as cell differentiation, phagocytosis, T-cell activation, response to cytokine, autophagy, Toll-like receptor signaling, RIG-I like receptor signaling and apoptosis. Our finding presents novel miRNAs and their targeted genes, which upon experimental validation could facilitate in developing new therapeutics to combat CHIKV infection and minimize CHIKV mediated diseases.     

Assessment of the Activity of Decoquinate and Its Quinoline-O-Carbamate Derivatives against Toxoplasma gondii In Vitro and in Pregnant Mice Infected with T. gondii Oocysts

The quinolone decoquinate (DCQ) is widely used in veterinary practice for the treatment of bacterial and parasitic infections, most notably, coccidiosis in poultry and in ruminants. We have investigated the effects of treatment of Toxoplasma gondii in infected human foreskin fibroblasts (HFF) with DCQ. This induced distinct alterations in the parasite mitochondrion within 24 h, which persisted even after long-term (500 nM, 52 days) treatment, although there was no parasiticidal effect. Based on the low half-maximal effective concentration (IC₅₀) of 1.1 nM and the high selectivity index of >5000, the efficacy of oral treatment of pregnant mice experimentally infected with T. gondii oocysts with DCQ at 10 mg/kg/day for 5 days was assessed. However, the treatment had detrimental effects, induced higher neonatal mortality than T. gondii infection alone, and did not prevent vertical transmission. Thus, three quinoline-O-carbamate derivatives of DCQ, anticipated to have better physicochemical properties than DCQ, were assessed in vitro. One such compound, RMB060, displayed an exceedingly low IC₅₀ of 0.07 nM, when applied concomitantly with the infection of host cells and had no impact on HFF viability at 10 µM. As was the case for DCQ, RMB060 treatment resulted in the alteration of the mitochondrial matrix and loss of cristae, but the changes became apparent at just 6 h after the commencement of treatment. After 48 h, RMB060 induced the expression of the bradyzoite antigen BAG1, but TEM did not reveal any other features reminiscent of bradyzoites. The exposure of infected cultures to 300 nM RMB060 for 52 days did not result in the complete killing of all tachyzoites, although mitochondria remained ultrastructurally damaged and there was a slower proliferation rate. The treatment of mice infected with T. gondii oocysts with RMB060 did reduce parasite burden in non-pregnant mice and dams, but vertical transmission to pups could not be prevented.     

Extraction and Immobilization of SA-α-2,6-Gal Receptors on Magnetic Nanoparticles to Study Receptor Stability and Interaction with Sambucus nigra Lectin

The interaction between influenza virus hemagglutinins and host cell with terminal sialic acid linked receptors, SA-α-2,6-Gal for human strains is important to obtain insights into this infectious disease. Sambucus nigra lectin has high affinity for SA-α-2,6-Gal receptors. The goals of this work were: to extract the SA-α-2,6-Gal receptors from porcine airways; to perform receptors immobilization and study their storage stability; and to determine some parameters of interaction between the receptor and S. nigra lectin. The receptor isolation was monitored by means of bound sialic acid (BSAc) detection. A major band of protein at 66.7 kDa was clearly visible in SDS-PAGE assay. Eighty-one percent of isolated glycoproteins were immobilized on magnetic nanoparticles. The kinetics of BSAc storage stability at 4 °C was approximated as the first order reaction with kinetic constant and half-life estimated as 0.062 day^?1 and 11.2 days, respectively. The dissociation constant (K _d) calculated from Scatchard's plot was 2.47?×?10^?7 M, and the receptor concentration was equal to 7.92?×?10^?5 M. Procedure for N-SA-α-2,6-Gal -receptors extraction based on their affinity to S. nigra lectin with magnetic nanoparticles, and their immobilization in active form, was not described previously, and may have wide application in designing biosensors or virus removal from areas or contaminated samples.     

SnpFilt: A pipeline for reference-free assembly-based identification of SNPs in bacterial genomes

De novo assembly of bacterial genomes from next-generation sequencing (NGS) data allows a reference-free discovery of single nucleotide polymorphisms (SNP). However, substantial rates of errors in genomes assembled by this approach remain a major barrier for the reference-free analysis of genome variations in medically important bacteria. The aim of this report was to improve the quality of SNP identification in bacterial genomes without closely related references. We developed a bioinformatics pipeline (SnpFilt) that constructs an assembly using SPAdes and then removes unreliable regions based on the quality and coverage of re-aligned reads at neighbouring regions. The performance of the pipeline was compared against reference-based SNP calling for Illumina HiSeq, MiSeq and NextSeq reads from a range of bacterial pathogens including Salmonella, which is one of the most common causes of food-borne disease. The SnpFilt pipeline removed all false SNP in all test NGS datasets consisting of paired-end Illumina reads. We also showed that for reliable and complete SNP calls, at least 40-fold coverage is required. Analysis of bacterial isolates associated with epidemiologically confirmed outbreaks using the SnpFilt pipeline produced results consistent with previously published findings. The SnpFilt pipeline improves the quality of de-novo assembly and precision of SNP calling in bacterial genomes by removal of regions of the assembly that may potentially contain assembly errors. SnpFilt is available from https://github.com/LanLab/SnpFilt.     

Quantification of multi-class antibiotics by UHPLC–MS/MS analysis combined with salt-assisted acetonitrile extraction: comparative evaluation of dairy and poultry manure

ABSTRACT

A comprehensive multiresidue method for the analysis of 33 antibiotics from 7 prevalent classes was comparably investigated for both dairy and poultry manure samples, which can be important pollution sources for the release of antibiotics into the environment. Following salting-out-assisted extraction with acetonitrile, the antibiotics were quantified with ultrahigh-performance liquid chromatography tandem mass spectrometry without a clean-up step. By changing the composition of the mobile phase for chromatography, a pronounced signal enhancement was achieved not only for tetracyclines (TCs) but also for other groups of antibiotics in the manure samples. Although the physicochemical properties of selected antibiotics were quite different, the apparent recovery values from dairy and poultry manure samples by using an extraction solvent comprising McIlvaine buffer and ethylenediaminetetraacetic solution at pH 3 were 86–121% and 89–113%, respectively. Apparent recovery of the antibiotics was not remarkably affected by the extraction solvent over a wide range of pH values, with the exception of the recovery of TC antibiotics from poultry manure, which was in the 53–55% range at pH 8. Furthermore, the poor performance of the analytical method for a few of the antibiotics in poultry manure was correlated with high metal and organic contents of the complicated matrix. The high suppression effects of co-eluted matrix components were compensated by constructing matrix-matched calibration curves and by using internal standards. Simultaneous quantification of seven different antibiotic classes with low limit of detection values varying from 0.38 to 31 μg kg^?1 for dairy manure and from 0.32 to 5.85 μg kg^?1 for poultry manure facilitated their monitoring. The application of the developed analytical method to dairy, broiler and layer-hen manure samples from confined animal feeding operations showed that a wide variety of antibiotics at high concentrations were found in broiler manure.     

Cryochemical modification,activity, and toxicity of dioxidine

Dioxidine nanoparticles are prepared via cryochemical modification of the pharmacopoeial dioxidine substance. The form of the cryomodified dioxidine is characterized by data from ¹H NMR spectroscopy; X-ray diffraction analysis; such thermal analytical methods as TG and DSC; low-temperature argon adsorption; and transmission electron microscopy. It is shown that the cryomodified samples are synthesized in the form of dioxidine nanocrystals 50–300 nm in size, with a crystal structure differing from that of the initial pharmacopoeial substance. The prepared cryomodified dioxidine nanoparticles inhibit the growth of E. coli 52, S. aureus 144, M. cyaneum 98, and B. cereus 9 better than the initial pharmacopoeial substance, and have comparable chronic toxicity.     

8-Hydroxypyrene-1,3,6-trisulphonate and octanesulphonate co-assembled layered double hydroxide and its controllable solid-state luminescence by hydrothermal synthesis

8-Hydroxy-pyrene-1,3,6-trisulphonate (HPTS) and octanesulphonate (OS) have been co-intercalated into the ZnAl layered double hydroxide (LDH) host by a hydrothermal co-precipitation method, with samples denoted as HPTS (x%)-OS/Zn₂Al-LDH (x stands for the molar percentage content of HPTS with respect to total amount of HPTS and OS). The structure and chemical compositions of the as-prepared compounds were characterized by X-ray diffraction (XRD) and elemental analysis. The steady-state and time-decay fluorescent studies show that HPTS (2%)-OS/Zn₂Al-LDH has the optimal luminous emission and the longest fluorescent lifetime. Moreover, these samples exhibit controllable dual fluorescence between the blue and green regions upon changing the interlayer HPTS content, external pH values, and host–guest interaction, illustrating that these organic–inorganic samples have potential application in the field of tunable solid luminescent materials.     

Quality Evaluation of Taxilli Herba from Different Hosts Based on Simultaneous Determination of Multiple Bioactive Constituents Combined with Multivariate Statistical Analysis

Taxilli Herba (TAXH) is an important traditional Chinese medicine with a long history, dating from the Eastern Han Dynasty to the present times. However, the active constituents in it that parasitize different hosts vary, affecting its clinical efficacy. Given the complexity of the host origins, evaluating the quality of TAXH is critical to ensure the safety and effectiveness of clinical medication. In the present study, a quantitative method based on ultra-fast liquid chromatography tandem triple quadrupole mass spectrometry (UFLC-QTRAP-MS/MS) was established, which simultaneously determined the content of 33 active constituents, including 12 flavonoids, 4 organic acids, 12 amino acids, and 5 nucleosides in 45 samples. Orthogonal partial least squares discriminant analysis (OPLS-DA) was employed to classify and distinguish between TAXH and its adulterants, Tolypanthi Herba (TOLH). A hierarchical clustering analysis (HCA) was conducted combined with a heatmap to visually observe the distribution regularity of 33 constituents in each sample. Furthermore, gray relational analysis (GRA) was applied to evaluate the quality of samples to get the optimal host. The results demonstrated that TAXH excelled TOLH in quality as a whole. The quality of TAXH parasitizing Morus alba was also better, while those that were parasitic on Cinnamomum camphora and Glyptostrobus pensilis had relatively poor quality. This study may provide comprehensive information that is necessary for quality control and supply a scientific basis for further exploring the quality formation mechanism of TAXH.     

Determination of different arsenic species in food‐grade spirulina powder by ion chromatography combined with inductively coupled plasma mass spectrometry

A “two‐step” pressurized microwave‐assisted extraction method coupled with ion chromatography with inductively coupled plasma mass spectrometry for the determination of different arsenic species in spirulina samples was developed. The extraction method used H₂O₂/H₂O (1:5, v/v) as solvent to extract all arsenic species except arsenite, which was extracted by using water as solvent. The extraction method had a satisfactory recovery (>96%) and took a short time (20.0 min). With our method, all arsenic species in spirulina samples were completely separated and determined with recoveries of 84–105% and relative standard deviations of 2–4%. Food‐grade spirulina powder samples from seven provinces (Inner Mongolia, Zhejiang, Fujian, Hainan, Yunnan, Jiangsu, and Guangxi) in China were analyzed using the optimized protocol. Arsenate was detected at the concentration range of 170–394 ng/g in all the spirulina samples. Dimethylarsinic acid was detected at the concentration range of 32–839 ng/g in spirulina from above‐six provinces except Guangxi. Monomethylarsonic acid (67 ± 3 ng/g) was detected only in spirulina from Yunnan province. Arsenite was detected at the concentration range of 28–147 ng/g in spirulina from above five provinces except Hainan and Guangxi. Five unknown organic arsenic species were found in spirulina from above six provinces except Guangxi.     

Synthesis and characterization of highly conjugated side‐group‐substituted benzo[1,2‐b:4,5‐b′]dithiophene‐based copolymer for use in organic solar cells

A new donor–acceptor (D–A) conjugated copolymer based on benzo[1,2‐b:4,5‐b′]dithiophene (BDT) and thieno[3,4‐c]pyrrole‐4,6‐dione (TPD) was synthesized via a Stille cross‐coupling reaction. A highly conjugated thiophene‐based side group, tris(thienylenevinylene) (TTV), was incorporated into each BDT unit to generate the two‐dimensional D–A copolymer (PBDT‐TTV). An alkoxy‐substituted BDT‐based TPD copolymer (PBDT‐OR) was synthesized using the same polymerization method for comparison. PBDT‐TTV thin films produced two distinct absorption peaks. The shorter wavelength absorption (458 nm) was attributed to the BDT units containing the TTV group, and the longer wavelength band (567–616 nm) was attributed to intramolecular charge transfer between the BDT donor and the TPD acceptor. The highest occupied molecular orbital energy levels of PBDT‐OR and PBDT‐TTV were calculated to be −5.53 and −5.61 eV, respectively. PBDT‐TTV thin films harvested a broad solar spectrum covering the range 300–700 nm. A comparison with the PBDT‐OR films revealed stronger interchain π–π interactions in the PBDT‐TTV films and, thus, a higher hole mobility. A polymer solar cell device prepared using PBDT‐TTV as the active layer was found to exhibit a higher power conversion efficiency than a device prepared using PBDT‐OR under AM 1.5 G (100 mW/cm²) conditions. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018 , 56, 653–660     

Production of Polyhydroxyalkanoates (PHAs) by Vibrio alginolyticus Strains Isolated from Salt Fields

Vibrio alginolyticus is a halophilic organism usually found in marine environments. It has attracted attention as an opportunistic pathogen of aquatic animals and humans, but there are very few reports on polyhydroxyalkanoate (PHA) production using V. alginolyticus as the host. In this study, two V. alginolyticus strains, LHF01 and LHF02, isolated from water samples collected from salt fields were found to produce poly(3-hydroxybutyrate) (PHB) from a variety of sugars and organic acids. Glycerol was the best carbon source and yielded the highest PHB titer in both strains. Further optimization of the NaCl concentration and culture temperature improved the PHB titer from 1.87 to 5.08 g/L in V. alginolyticus LHF01. In addition, the use of propionate as a secondary carbon source resulted in the production of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV). V. alginolyticus LHF01 may be a promising host for PHA production using cheap waste glycerol from biodiesel refining.     

Analysis of 140 Veterinary Drugs and Other Contaminants in Poultry Muscle by Ultrahigh-Performance Liquid Chromatography–Tandem Mass Spectrometry

A simple, straightforward multi-class analytical method was developed for the identification of 140 veterinary drug residues and other contaminants in poultry muscle, ranging from very polar to reasonably non-polar drugs, including basic, amphoteric, and neutral compounds. The method was based on extraction with acetonitrile–aqueous ethanol aqueous, purification by n-hexane, and low temperature clean-up and analysis in a single analytical run by ultra-performance liquid chromatography coupled with electrospray ionization and tandem mass spectrometry (UHPLC–ESI–MS/MS) operating in positive multiple reaction monitoring (MRM). For most of the target analytes, the optimized pretreatment processes led to no significant interference on the analysis of the sample matrix. Limits of quantification (LOQs) varied from 0.05 to 10 µg kg^?1. Average analyte recoveries ranged from 60 to 139%, and the intra-day and inter-day precision were 2–30% and 4–29%, respectively. For over 90% of the analytes, the average recovery values ranged from 70 to 120% with the corresponding RSD below 20%, which were acceptable and in agreement with the criteria of Commission Decision 2002/657/EC. This methodology has been successfully applied for the analysis of poultry muscle samples from local markets (China). Quinolones, tetracyclines, sulfonamides, and amantadine were frequently detected in poultry samples.     

Precise thermal ionization mass spectrometric measurements of 142Nd/144Nd and 143Nd/144Nd isotopic ratios of Nd separated from geological standards by chromatographic methods

A chromatographic separation technique for ¹⁴²Nd/¹⁴⁴Nd and ¹⁴³Nd/¹⁴⁴Nd isotope ratio measurements is established and applied to the analyses of geological standards of basaltic compositions (BCR-2, BIR-1) using Isoprobe-T TIMS. The instrument was tested for reliability and reproducibility to measure Nd isotope composition using the synthetic standard JNdi-1. The techniques were also applied to a carbonatite lava sample, OL-6, Oldoinyo Lengai, to check the validity of method for carbonatite matrix. The isotope ratios of ¹⁴³Nd/¹⁴⁴Nd for synthetic Nd standard JNdi-1, geological standards BCR-2, BIR-1, and carbonatite lava sample OL-6 obtained by these methods are in good agreement with previously published data. The ¹⁴³Nd/¹⁴⁴Nd values for JNdi-1 and BCR-2 have an external precision of ±13 ppm and ±15 ppm (2σ), respectively. The JNdi-1 and BCR-2 data for ¹⁴²Nd/¹⁴⁴Nd has an external precision of ±12 ppm and ±8 ppm (2σ), respectively. The ¹⁴²Nd/¹⁴⁴Nd composition of the two geological standards BCR-2 and BIR-1 are indistinguishable from synthetic mono-element standard JNdi-1, and they all fall within the 12 ppm (2σ) envelope of external precision. The external reproducibility is sufficient to distinguish and resolve 20 ppm anomalies in ¹⁴²Nd/¹⁴⁴Nd values.     

Application of probabilistic neural networks in qualitative analysis of near infrared spectra: determination of producing area and variety of loquats

Near infrared (NIR) spectra of a sample can be treated as a signature, allowing samples to be grouped on basis of their spectral similarities. Near infrared spectroscopy (NIRS) combined with probabilistic neural networks (PNN) have been used to discriminate producing area and variety of loquats. Two varieties of loquats (‘Dahongpao’ and ‘Jiajiaozhong’) picked from two producing areas of ‘Tangxi’ and ‘Cunan’ in Zhejiang province were analyzed in this study. Principal component analysis (PCA) was applied before PNN modeling and the results indicated that the dimension of the vast spectral data can be effectively reduced. For each model, half samples were used to train the network and the remaining half were used to test the network. The results of the PCA-PNN models for discriminating the variety of samples from the same producing area or for discriminating the producing area of the same variety samples were much better than those of the PCA-PNN models for discriminating variety or producing area of all loquat samples. The results of this study show that NIRS combined with PCA-PNN is a feasible way for qualitative analysis of discriminating fruit producing areas and varieties.