Near-infrared Plasmonic Far-field Nanofocusing Effects with Elongated Depth of Focus based on Hybrid Au–Dielectric–Ag Subwavelength Structures

In this paper, we propose a new far-field nanofocusing lens with elongated depth of focus (DOF) under near-infrared (NIR) wavelength. The surface plasmons can be excited by using the hybrid metal–insulator–metal (MIM) subwavelength structure under the NIR wavelength. The constructive interference of surface plasmons launched by the subwavelength MIM structure can form a nanoscale focus that is modulated by the novel metal grating from the near field to the far field. The numerical simulations demonstrated that a nanoscale focal spot (in plane focal area 0.177λ ²) with elongated DOF (3.358λ) and long focal length (5.084λ) can be realized with reasonably designing parameters of the lens. By controlling the positions of the inner radii of each slit ring and the grating width, the focal length, focal spot, and DOF can be tuned easily. This design method, which can obtain the nanoscale focal spot and micron DOF in far field under NIR illumination, paved the road for utilizing the NIR plasmonic lens in superresolution optical microscopic imaging, optical trapping, biosensing, and complex wavefront/beam shaper.     

Modulation of Visible and Near-Infrared Surface Plasmon Resonance of Au Nanoparticles Based on Highly Doped Graphene

We study an active modulation of surface plasmon resonance (SPR) of Au nanoparticles based on highly doped graphene in visible and near-infrared regions. We find that compared to the traditional metal SPR, the SPR of Au nanoparticles based on graphene causes a remarkable blue shift. The field intensity in the gap is redistributed to standing wave. The field intensity of standing wave is about one order of magnitude higher than the traditional model. Moreover, the SPR of Au nanoparticles can be actively modulated by varying the graphene Fermi energy. We find the maximum modulation of field intensity of absorption spectra is more than 21.6 % at λ?=?822?nm and the amount of blue shift is 17.4 nm, which is about 2.14 % of the initial wavelength λ ₀?=?813.4?nm, with increasing monolayer graphene Fermi energy from 1.0 to 1.5 ev. We find that the SPR sensitivity to the refractive index n of the environment is about 642 nm per refractive index unit (RIU). The SPR wavelengths have a big blue shift, which is about 33 nm, with increasing number of graphene layers from 1 to 3, and some shoulders on the absorption spectra are observed in the models with multilayer graphene. Finally, we study the Au nanorod array based on monolayer graphene. We find that the blue shift caused by the graphene increases from 14 to 24 nm, with increasing gap g _y from 10 to 20 nm. Then, it decreases from 24 to 14 nm, with increasing gap g _y from 20 to 50 nm. This study provides a new way for actively modulating the optical and optoelectronic devices.     

Shrub cover expressed as an ‘arthropod island’ in xeric environments

Based on the vague importance of shrub cover, an attempt was made to create a theoretical concept framework known as an ‘arthropod-island’ analytical model. These models were based on the multi-bond correlation between shrubs, soil properties, and above- and below-ground biotic communities. By utilizing published datasets on (i.e., above- and below-ground) arthropod communities related to shrub species and age, the proposed models for an ‘arthropod island’ were applied in order to determine their fitness for xeric ecosystems. It was found that the ‘arthropod-island’ concept could be the result of statistical differences in ecologically adaptive (i.e., preferable) redistribution of arthropods among the microhabitats beneath the shrub canopy and in the open spaces. Taxon density, relative to the richness and Shannon indices, was found to be more sensitive to the selected models. The relative interaction intensity index [RII = (A ? B)/(A + B), A = shrub canopy value, B = intershrub value] was found to be more suitable for the ‘arthropod island’ at the community level. The relative neighbor effect [RNE = (B ? A)/max(A, B)] and RII were found to be suitable at the population level, while the fitted model heavily depended on the variety of arthropod taxon. It was suggested that there were consistent ‘arthropod island’–shrub relationships between shrub species and between shrub ages in terms of arthropod density at the community level. The arthropod taxon was found to indicate an inconsistent ‘arthropod island’–shrub relationship between shrub species that differed from shrub ages at the population level.     

Hydrogen sulphide-related thiol metabolism and nutrigenetics in relation to hypertension in an elderly population

Hydrogen sulphide (H₂S) is a gaseous signalling molecule that regulates blood flow and pressure. It is synthesised from cysteine via cystathionine β-synthase and cystathionine γ-lyase. We examined whether thiol precursors of H₂S, transsulphuration pathway gene variants (CBS-844ins68 and CTH-G1364T) and key B-vitamin cofactors might be critical determinants of hypertension in an elderly Australian population. An elderly Australian retirement village population (n = 228; age 65–96 years, 91 males and 137 females) was assessed for the prevalence of two transsulphuration pathway–related variant genes associated with cysteine synthesis and hence H₂S production. Thiols were determined by HPLC, genotypes by PCR and dietary intake by food frequency questionnaire. Homocysteine levels were statistically higher in the hypertensive phenotype (p = 0.0399), but there was no difference for cysteine or glutathione. Using nominal logistic regression, cysteine, CTH-G1364T genotype, dietary synthetic folate and vitamin B₆ predicted clinical phenotype (determined as above/below 140/90 mm Hg) and then only in female subjects (p = 0.0239, 0.0178, 0.0249 and 0.0371, respectively). Least-squares regression supports cysteine being highly inversely predictive of diastolic blood pressure: p and r ² values <0.0001 and 0.082; 0.0409 and 0.046; and <0.0001 and 0.113 for all subjects, males and females, respectively. Additionally, CTH-G1364T genotype predicts diastolic blood pressure in males (p = 0.0217; r ² = 0.083), but contrasts with observations for females. Overall, analyses, including stepwise regression, suggest cysteine, dietary natural and synthetic folate, vitamins B₆ and B₁₂, and both genetic variants (CTH-C1364T and CBS-844ins68) are all aetiologically relevant in the regulation of blood pressure. Hydrogen sulphide is a vasorelaxant gasotransmitter with characteristics similar to nitric oxide. Cysteine and the G1364T and 844ins68 variants of the cystathionine γ-lyase and cystathionine β-synthase genes, respectively, are the biological determinants of H₂S synthesis, and all three are shown here to influence the hypertensive phenotype. Additionally, B-vitamin cofactors for these three enzymes may also be important determinants of blood pressure.     

Milk and Dairy Products Intake Is Associated with Low Levels of Lead (Pb) in Workers highly Exposed to the Metal

Lead (Pb) is a toxic metal, frequently associated with occupational exposure, due to its widespread use in industry and several studies have shown high Pb levels in workers occupationally exposed to the metal. The aim of this study was to evaluate the influence of milk and dairy products (MDP) on Pb levels in blood (B-Pb), plasma (P-Pb), and urine (U-Pb), in workers from automotive battery industries in Brazil. The study included 237 male workers; information concerning diet and lifestyle were gathered through a questionnaire, and B-Pb, P-Pb, and U-Pb were determined by ICP-MS. Mean B-Pb, P-Pb, and U-Pb were 21 ± 12, 0.62 ± 0.73 μg/dL, and 39 ± 47 μg/g creatinine, respectively. Forty three percent of participants declared consuming ≤3 portions/week of MDP (classified as low-MDP intake), while 57% of individuals had >3portions/week of MDP (high-MDP intake). B-Pb and P-Pb were correlated with working time (r _s  = 0.21; r _s  = 0.20; p < 0.010). Multivariable linear regressions showed a significant influence of MDP intake on B-Pb (β = ?0.10; p = 0.012) and P-Pb (β = ?0.16; p < 0.010), while no significance was seen on U-Pb. Our results suggest that MDP consumption may modulate Pb levels in individuals highly exposed to the metal; these findings may be due to the Pb-Ca interactions, since the adverse effects of Pb are partially based on its interference with Ca metabolism and proper Ca supplementation may help to reduce the adverse health effects induced by Pb exposure.     

Genetic Polymorphism of <Emphasis Type="Italic">GABRR2</Emphasis> Modulates Individuals’ General Cognitive Ability in Healthy Chinese Han People

Previous studies have indicated that the cognitive impairment or deficit is associated with GABAergic signaling in central nervous system. Inspired by the finding that receptor GABRR2 modulates concentration of GABA and phasic inhibitory GABAergic transmission in brain. This study investigated to what extent a genetic variant (c.1423C>T, rs282129) of GABRR2 gene modulates individuals’ general cognitive ability in 987 Chinese Han people. Results showed a significant influence of GABRR2 gene polymorphism on individuals’ Raven’s Standard Progressive Matrices (RSPM) performance (F = 3.58, P = .028 by ANOVA and χ ² = 9.35, P = .009 by K–W test, respectively), even if non-genetic factors were partialed out (gender, major, types of birthplace, and socioeconomic index) (B = ?.67, SE = .26, t = 2.63, P = .009). The finding provided a strong evidence, to our knowledge, for the view that genetic variant of GABRR2 gene may contribute to the difference of individuals’ general cognitive ability, independently.     

Enhancement of Second Harmonic Generation in Metal-Insulator-Metal Plasmonic Waveguides

Nonlinear effects such as second harmonic generation (SHG) are important for applications such as switching and wavelength conversion. In this study, the generation of second harmonic in metal-insulator-metal (MIM) plasmonic waveguides was investigated for both symmetric and asymmetric structures. This study considered two different structures as plasmonic waveguides for the generation of second harmonic, and analysis was performed using the finite-difference time-domain method. Besides, the structure has grating on both sides for more coupling between photons and plasmons. The wavelength duration of grating per unit length (number of grooves) was optimized to reach the highest second harmonic generation. To perform this optimization, the wavelength of operation (λ = 458 nm) was considered. It was shown that field enhancement in symmetric MIM waveguides can result in the enhancement of SHG magnitude when compared to literature values. Also, asymmetric devices result in more than two orders of magnitude enhancement in SHG, as compared to the symmetric structure. It has been shown that the electric field of the second harmonic depends on the thickness of the crystal (insulator). Hence, its thickness was optimized to achieve the highest electric field.     

Nutrients Other than Selenium Are Important for Promoting Children’s Health in Kashin-Beck Disease Areas

Overall nutritional status has been proved associated with people’s health. The overall nutritional status of children in Kashin-Beck disease (KBD) areas has been overlooked for decades. Therefore, it is worth investigating in the current generation to gather evidence and make suggestions for improvement. A cross-sectional study with three 24-h dietary recalls was conducted to collect raw data on the daily food intake of children. Recorded food was converted into daily nutrient intakes using CDGSS 3.0 software. WHO AnthroPlus software was used to analyse the BMI-for-age z-score (BAZ) for estimating the overall nutrition status of children. All the comparisons and regression analyses were conducted with SPSS 18.0 software. Multiple nutrient intakes among children from the Se-supplemented KBD-endemic were under the estimated average requirement. The protein-to-carbohydrate ratio (P/C ratio) was significantly higher in children from the non-Se-supplemented KBD-endemic area than the other areas (P < 0.001). The children’s BAZ was negatively associated with age (B = ?0.095, P < 0.001) and the number of KBD relatives (B = ?0.277, P = 0.04), and it was positively associated with better housing conditions, receiving colostrum, and daily intakes of niacin and zinc by multivariate regression analysis (F = 10.337, R = 0.609, P < 0.001).Compared to non-Se-supplemented KBD-endemic area and non-endemic areas, children in Se-supplemented KBD-endemic areas have an insufficient intake of multiple nutrients. School breakfast and lunch programmes are recommended, and strict implementation is the key to ensuring a positive effect.     

Cross-talk between macrophages,smooth muscle cells,and endothelial cells in response to cigarette smoke: the effects on MMP2 and 9

The aim of the present study was to analyze the expression of sex-determining region Y-related high mobility group box 4 (SOX4) in non-small cell lung cancer (NSCLC) and its correlation with clinicopathologic characteristics, including the survival of NSCLC patients. To observe initially the expression status of SOX4 in lung squamous cell carcinoma and adenocarcinoma at gene expression omnibus. The expression of SOX4 mRNA and protein was examined in NSCLC tissues and normal lung tissues through real-time PCR and immunohistochemistry. Meanwhile, the relationship of SOX4 expression levels with clinical characteristics of 168 NSCLC patients was analyzed by immunohistochemistry. Univariate and multivariate analyses were performed to determine the association between SOX4 expression and prognosis of NSCLC patients. In our results, SOX4 expression was increased in NSCLC tissues compared with paired normal lung tissues in microarray data (GSE3268). SOX4 mRNA and protein expression were markedly higher in NSCLC tissues than in normal lung tissues (P = 0.001 and P = 0.001, respectively). Using immunohistochemistry, high levels of SOX4 protein were positively correlated with status of differentiated degree (high vs. middle, P = 0.004; high vs. low, P < 0.001), clinical stage (I–II vs. III–IV, P < 0.001), T classification (T1–T2 vs. T3–T4, P = 0.004), N classification (N0–N1 vs. N2–N3, P = 0.002), and M classification (M0 vs. M1, P = 0.011) in NSCLC. Moreover, the higher level of SOX4 expression was markedly correlated with poor overall survival in NSCLC patients (P < 0.001). Multivariate analysis suggested that increased SOX4 expression was a poor independent prognostic predictor for NSCLC patients (P = 0.002). In conclusion, SOX4 plays an important role on NSCLC progression and prognosis and may serve as a convictive prognostic biomarker for NSCLC patients.     

Nonlinear dynamics of beam–plasma instability in a finite magnetic field

The nonlinear dynamics of beam–plasma instability in a finite magnetic field is investigated numerically. In particular, it is shown that decay instability can develop. Special attention is paid to the influence of the beam?plasma coupling factor on the spectral characteristics of a plasma relativistic microwave accelerator (PRMA) at different values of the magnetic field. It is shown that two qualitatively different physical regimes take place at two values of the external magnetic field: B ₀ = 4.5 kG (Ω ~ ωB _p ) and 20 kG (Ω _B ? ω_p). For B ₀ = 4.5 kG, close to the actual experimental value, there exists an optimal value of the gap length between the relativistic electron beam and the plasma (and, accordingly, an optimal value of the coupling factor) at which the PRMA output power increases appreciably, while the noise level decreases.     

A novel haplotype within C-reactive protein gene influences CRP levels and coronary heart disease risk in Northwest Indians

According to several epidemiological and clinical studies, the concentration of C-reactive protein (CRP) in blood is associated with the risk of coronary heart disease (CHD). However, these studies are limited in high incidence and prevalence area of North-West India. The present case control study investigated the contribution of three relevant CRP single nucleotide polymorphisms: ?717A>G located in the promoter region (rs2794521), +1059G>C on exon2 (rs1800947) and +1444C>T in the 3′ UTR (rs1130864) in 180 angiographically verified CHD cases and 175 control subjects. Minor allele frequencies (G, C and T) of rs2794521, rs1800947 and rs1130864 are observed to be 21.1, 11.7, 29.4 and 11.4, 10.0, 19.7 % in CHD cases and controls respectively. AA genotype of ?717A>G and TT genotype of +1444C>T were significantly associated (P = 0.02 & 0.03 respectively) with the risk of CHD whereas, +1059G and +1444T were found to be strongly related (P = 0.023 & P = 0.008 respectively) with multivariable adjusted CRP levels. AGT Haplotype was significantly associated with the adjusted CRP levels (P < 0.05). Disease association analysis revealed that haplotype AGT influences CHD risk (OR 2.4, 95 % CI 1.23–4.84, P = 0.006) which exacerbates after correcting the confounding effects of risk variables (OR 2.5, 95 % CI 1.27–4.99, P = 0.004). With the global index of Akaike information criterion, it has been observed that the carrying each single unit of this susceptibility haplotype increases CHD risk by a value of 2.41 ± 0.439 (β ± SE) in the recessive mode.     

Molecular Epidemiology of Trypanosomatids and <Emphasis Type="Italic">Trypanosoma cruzi</Emphasis> in Primates from Peru

We determined the prevalence rate and risk of infection of Trypanosoma cruzi and other trypanosomatids in Peruvian non-human primates (NHPs) in the wild (n = 126) and in different captive conditions (n = 183). Blood samples were collected on filter paper, FTA cards, or EDTA tubes and tested using a nested PCR protocol targeting the 24Sα rRNA gene. Main risk factors associated with trypanosomatid and T. cruzi infection were genus and the human–animal context (wild vs captive animals). Wild NHPs had higher prevalence of both trypanosomatids (64.3 vs 27.9%, P < 0.001) and T. cruzi (8.7 vs 3.3%, P = 0.057), compared to captive NHPs, suggesting that parasite transmission in NHPs occurs more actively in the sylvatic cycle. In terms of primate family, Pitheciidae had the highest trypanosomatid prevalence (20/22, 90.9%) and Cebidae had the highest T. cruzi prevalence (15/117, 12.8%). T. cruzi and trypanosomatids are common in Peruvian NHPs and could pose a health risk to human and animals that has not been properly studied.     

Congruence and the Biomonitoring of Aquatic Ecosystems: Are Odonate Larvae or Adults the Most Effective for the Evaluation of Impacts

Odonata have been widely used as indicators for the biomonitoring of terrestrial and aquatic habitats due to their sensitivity to environmental impacts. We aimed to determine whether the larval or adult phases of these insects were the best predictors of variation in habitat parameters and the loss of environmental integrity. Specimens were collected during three seasons (dry, rainy, and ebb) from 12 points in the Suiá-missu River basin, at the headwaters of the Xingu River in Mato Grosso, Brazil. The Protest analysis indicated a high degree of congruence between the assemblages of larvae and adults in streams with varying degrees of habitat integrity (R = 0.832, p < 0.001, m ² = 0.307). When the congruence with environmental factors was analyzed, a significant association was found only for the larval phase (R = 0.318, p = 0.03, m ² = 0.888). When the suborders were analyzed separately, congruence was confirmed for anisopteran adults (R = 0.338, p = 0.031, m ² = 0.885) and larvae (R = 0.417, p = 0.003, m ² = 0.826) and for the zygopteran adults (R = 0.345, p = 0.027, m ² = 0.881) and larvae (R = 0.405, p = 0.011, m ² = 0.836). These results indicate that both larvae and adults respond systematically to environmental impacts. We suggest that either life phase can be used for biomonitoring, given their effectiveness for the interpretation of disturbance in terrestrial and aquatic habitats. These findings further reinforce the effectiveness of this insect order for the detection of modifications to the environment, showing that they are good indicators of environmental conditions.     

Cellulases immobilization on chitosan-coated magnetic nanoparticles: application for <Emphasis Type="Italic">Agave Atrovirens</Emphasis> lignocellulosic biomass hydrolysis

In the present study, Trichoderma reesei cellulase was covalently immobilized on chitosan-coated magnetic nanoparticles using glutaraldehyde as a coupling agent. The average diameter of magnetic nanoparticles before and after enzyme immobilization was about 8 and 10 nm, respectively. The immobilized enzyme retained about 37 % of its initial activity, and also showed better thermal and storage stability than free enzyme. Immobilized cellulase retained about 80 % of its activity after 15 cycles of carboxymethylcellulose hydrolysis and was easily separated with the application of an external magnetic field. However, in this reaction, K _m was increased eight times. The immobilized enzyme was able to hydrolyze lignocellulosic material from Agave atrovirens leaves with yield close to the amount detected with free enzyme and it was re-used in vegetal material conversion up to four cycles with 50 % of activity decrease. This provides an opportunity to reduce the enzyme consumption during lignocellulosic material saccharification for bioethanol production.     

Simulation of Some Plasmonic Biosensors for Detection of Hemoglobin Concentration in Human Blood

Three recently published plasmonic biosensors based on a birefringent solid-core or a partial-solid-core microstructured optical fiber are simulated for detection of hemoglobin concentration in human blood. For a larger value of the number of holes n _h but for the same value of the gold radius, the resonance spectral width and the difference between maximal amplitude sensitivity and resonant wavelengths are decreased, when the refractive index of the analyte is n _a = 1.357. Also, the loss and maximum of the amplitude sensitivity are increased in the same conditions. At the resonant wavelength λ = 0.6496 μm for the devices with n _h = 14, 17, and 35 holes and n _a = 1.357, the hemoglobin concentration is close to the mean value (157.5 g/l) of a man.     

Simultaneous estimation of saponin contents from soybean seed using Fourier transform infrared spectroscopy and high-performance liquid chromatography analysis

The aim of this study is to determine the feasibility of Fourier transform infrared (FT-IR) spectroscopy for simultaneous determination of saponin contents in different soybean cultivars. In cross validation between predicted content of saponin by PLS regression modeling from FT-IR spectra and measured content by HPLC, total saponin contents were predicted with good accuracy (R ² ≥ 0.71). In external validation, saponin group Ab (R ² = 0.88), saponin DDMP-group βg (R ² = 0.85), total saponin group B (R ² = 0.88), and total saponin content (R ² = 0.87) were predicted with good accuracy, while prediction for saponin group Aa (R ² = 0.58), saponin group Bb′ (R ² = 0.58), and total saponin group A (R ² = 0.25) had relatively lower accuracy. Considering these results, we suggest that the PLS prediction system for saponin contents using FT-IR analysis could be applied as a novel screening tool for high yielding lines in soybean breeding.     

Associations of MMP-2 −1306 C/T and MMP-9 −1562 C/T polymorphisms with breast cancer risk among different populations: a meta-analysis

The meta-analysis aims to investigate association between two matrix metalloproteinases (MMPs) polymorphisms (MMP-2 ?1306 C/T and MMP-9 ?1562 C/T) and breast cancer risk. Eligible studies were retrieved from relevant databases, based on predefined criteria. Quality assessment was evaluated by Newcastle–Ottawa Scale. Odds ratio (OR) with its 95% confidence interval (CI) was selected as the effect size for the meta-analysis. As a result, 13 studies were included. MMP-2 ?1306 C/T polymorphism was not significantly associated with breast cancer risk under all genetic models (P > 0.05). However, subgroup analysis stratified by ethnicity showed a significant association between MMP-2 ?1306 C/T polymorphism and reduced breast cancer risk in Asian populations under allelic model (OR 0.60, 95% CI 0.39–0.90, P = 0.02) and dominant model (OR 0.55, 95% CI 0.34–0.89, P = 0.02). MMP-9 ?1562 C/T polymorphism was significantly related to increased breast cancer risk under allelic model (OR 1.50, 95% CI 1.06–2.12, P = 0.02), additive model (OR 1.45, 95% CI 1.02–2.05, P = 0.04) and recessive model (OR 1.54, 95% CI 1.13–2.12, OR 0.007). A significant association between MMP-9 ?1562 C/T polymorphism and increased breast cancer risk in Caucasian was detected under most of the genetic models (P < 0.05). MMP-2 ?1306 C/T polymorphism might be significantly associated with reduced breast cancer risk in Asian, while MMP-9 ?1562 C/T might be closely related to increased breast cancer risk, especially in Caucasian.     

Plasmon-Assisted Enhancement and Tuning of Optical Properties in <Emphasis Type="Italic">β-</Emphasis>In<Subscript>2</Subscript>S<Subscript>3</Subscript> Quantum Dots

Exciton-plasmon coupling can significantly modify the spectral response of semiconductor quantum dots in a metal nanoparticle-semiconductor complex system. β-In₂S₃ quantum dots of size ～3 nm and Ag nanospheres of size ～100 nm were synthesized by chemical route and coated over glass substrates. In the strong coupling regime, the plasmons are shown to mediate indirect Coulomb interaction between the quantum dots. In the proximity of Ag plasmons, the excitonic binding energy of the β-In₂S₃ quantum dots increases by ～500 meV, indicating that the interaction potential between the quantum dots is positive and repulsive in nature. This interaction also leads to strong coupling of the defect levels in the SQD complex. The defect emission wavelength can be enhanced by an order of 10² or shifted from red region (～650 nm) to green (～550 nm) by controlling the plasmon-induced defect level coupling. The experimental observation demonstrates one of the theoretically predicted consequences of exciton-plasmon interaction. This work demonstrates the possibility of harnessing the potential of the two complimentary systems (semiconductor quantum dots and metal nanoparticles) to achieve controllable emission and absorption properties for fabrication of nano plasmonic devices.     

Use of yeast (<Emphasis Type="Italic">Pichia kudriavzevii</Emphasis>) as a novel feed additive to ameliorate the effects of aflatoxin B<Subscript>1</Subscript> on broiler chicken performance

The aim of this study was to evaluate the efficacy of autochthonous Pichia kudriavzevii as a novel bioadsorbent for aflatoxin B₁ (AFB₁). The selection of this yeast was based on the AFB₁ adsorption capacity previously demonstrated in vitro (Magnoli et al. 2016). One-day-old Cobb broilers (n = 160) were randomly assigned to four dietary treatments (T1: basal diet (B); T2: B + 0.1% yeast; T3: B + AFB₁, 100 μg/kg; T4: B + 0.1% yeast + AFB₁, 100 μg/kg). Performance parameters (average daily weight gain body, average daily consumption, feed conversion ratio, carcass weight, and dead weight), biochemical parameters (albumin, globulin, and albumin/globulin), liver pathological changes, and AFB₁ residual levels in the liver and excreta were evaluated. Significant differences (P < 0.05) in performance parameters were observed among treatments and controls: T3 group showed the lowest average daily body weight gain value while in T4 group, the value of this parameter increased significantly (P < 0.05). T3 and T4 groups showed the lowest and highest values for average daily feed consumption, respectively. The feed conversion ratio (FC) showed no significant differences among treatments. T3 group showed the lowest dead weight and carcass weight compared with T1 group. The biochemical parameters showed no significant differences among treatments. T3 group showed macroscopic and microscopic liver changes compared to the control. Aflatoxin B₁ levels (μg/g) were detected in broiler livers and showed significant differences among treatments (P < 0.05). In conclusion, native P. kudriavzevii incorporation (0.1%) in broiler diets containing AFB₁ was shown to be effective in ameliorating the adverse effects of AFB₁ on production.     

Spectroscopic evidence for an all-ferrous [4Fe–4S]<Superscript>0</Superscript> cluster in the superreduced activator of 2-hydroxyglutaryl-CoA dehydratase from <Emphasis Type="Italic">Acidaminococcus </Emphasis><Emphasis Type="Italic">fermentans</Emphasis>

The key enzyme of the fermentation of glutamate by Acidaminococcus fermentans, 2-hydroxyglutarylcoenzyme A dehydratase, catalyzes the reversible syn-elimination of water from (R)-2-hydroxyglutaryl-coenzyme A, resulting in (E)-glutaconylcoenzyme A. The dehydratase system consists of two oxygen-sensitive protein components, the activator (HgdC) and the actual dehydratase (HgdAB). Previous biochemical and spectroscopic studies revealed that the reduced [4Fe–4S]⁺ cluster containing activator transfers one electron to the dehydratase driven by ATP hydrolysis, which activates the enzyme. With a tenfold excess of titanium(III) citrate at pH 8.0 the activator can be further reduced, yielding about 50% of a superreduced [4Fe–4S]⁰ cluster in the all-ferrous state. This is inferred from the appearance of a new Mössbauer spectrum with parameters δ = 0.65 mm/s and ΔE _Q = 1.51–2.19 mm/s at 140 K, which are typical of Fe(II)S₄ sites. Parallel-mode electron paramagnetic resonance (EPR) spectroscopy performed at temperatures between 3 and 20 K showed two sharp signals at g = 16 and 12, indicating an integer-spin system. The X-band EPR spectra and magnetic Mössbauer spectra could be consistently simulated by adopting a total spin S _t = 4 for the all-ferrous cluster with weak zero-field splitting parameters D = ?0.66 cm^?1 and E/D = 0.17. The superreduced cluster has apparent spectroscopic similarities with the corresponding [4Fe–4S]⁰ cluster described for the nitrogenase Fe-protein, but in detail their properties differ. While the all-ferrous Fe-protein is capable of transferring electrons to the MoFe-protein for dinitrogen reduction, a similar physiological role is elusive for the superreduced activator. This finding supports our model that only one-electron transfer steps are involved in dehydratase catalysis. Nevertheless we discuss a common basic mechanism of the two diverse systems, which are so far the only described examples of the all-ferrous [4Fe–4S]⁰ cluster found in biology.