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Using the solid-state method, a novel optical thermometer, RbCaLa1-x(VO4)2:xEu3+ phosphor, was synthesized. Using X-ray diffraction, the phase of the RbCaLa1-x(VO4)2:xEu3+ was confirmed. The microstructure was then observed in the SEM pattern. To estimate the temperature, the fluorescence intensity ratio (FIR) method was used. To explain the temperature-sensing properties, the absolute (Sa) and relative (Sr) sensitivities were calculated. The maximum Sa and Sr values were then determined as 2.215% and 1.125% at 473 and 423 K, respectively. After multiple heating and cooling processes, the FIR value corresponding to each temperature stabilized. This indicated the reliability of the FIR fitting formula. Subsequently, to examine the formula's accuracy, multiple temperature points ranging from 298 to 473 K were selected. The results demonstrated that the measurement error could be controlled in ±1.1 K. The difference was considerably lesser in the high-temperature region (400–430 K), and the error was in ±0.21 K. Under UV light, the colors of the RbCaLa0.82(VO4)2:0.18Eu3+ phosphor and RbCaLa(VO4)2 matrix were somewhat different, and both considerably changed with temperature. All results showed that the Eu3+-doped RbCaLa(VO4)2 phosphor is a good candidate material as an optical temperature sensor and anti-counterfeiting coating.

Two cyan-emitting phosphors with different bandwidths were successfully synthesized through the high-temperature solid-state method in a reducing atmosphere. The crystal structures, morphologies, and luminescence properties of the as-prepared phosphors were investigated. The Rietveld refinements of the powder X-ray diffraction (XRD) data demonstrated the single phase of the samples, and two crystallographic sites of La3+ were observed in the crystal structure. Under the excitation of UV light, both Ba0.45Ca2.5La6(SiO4)6: 0.05 Eu2+ and Ba1.45Ca1.5La6(SiO4)6: 0.05 Eu2+ phosphors emitted cyan light due to the 4f65 d1→4f7 transitions of the Eu2+ ion. The emission spectra could be well fitted by two component Gaussian peaks corresponding to two different coordination environments of the Eu2+ ions. The temperature-dependent photoluminescence spectra show a large difference on the thermal stability between the two phosphors. The two phosphors exhibit effective absorption of near-UV light and their internal quantum efficiencies (IQEs) were calculated as 31.5% and 42.4% under 295 nm UV-light excitation. The experimental results indicate that the novel cyan phosphors might have potential applications in white light-emitting diodes (LEDs) based on the near-UV LED chip.

Pseudocapritermes Kemner is a termite group that constructs subterranean gallery systems in topsoil. This genus is distributed in the Oriental region and contains 18 species. Dependence on the morphological measurements of soldiers makes the taxonomy of Pseudocapritermes difficult. In this study, we compared morphological characters of soldiers and adults of P. largus and P. sowerbyi. In addition, three fulllength mitochondrial genes (COI, COII, and 16S rRNA) were sequenced from a total of eight P. largus and P. sowerbyi colonies. Morphological comparison of soldiers showed that P. largus is larger than P. sowerbyi, but there was overlap in some measurements. In adults, the morphological characters of P. largus were congruent with those of P. sowerbyi. Sequence alignments of COI, COII, and 16S rRNA revealed a high pairwise genetic identity (ranging from 99.64 to 100%) between the two species, which suggested that P. largus and P. sowerbyi are the same species. Molecular phylogenetic analysis based on COII revealed that Pseudocapritermes belongs to the Termes group having soldiers with asymmetrical snapping mandibles and is more closely related to Sinocapritermes than to other Termes group genera distributed in China. Morphological similarity and genetic identity indicate that P. largus is a junior synonym of P. sowerbyi.

Disproportionate progressive collapse is a structural failure mode with low probability and high consequences. Due to this nature, progressive collapse design is usually treated as a secondary design; namely, a design check after the design for primary loadings. Various design procedures have been recommended, notably the alternate load path method through nonlinear pushdown analyses. However, most of these design procedures are iterative by nature to satisfy the design acceptable criteria. To improve the design efficiency, this study presented an innovative design technique that allows to directly determine the proper amount of reinforcement in beams and slabs of a reinforced concrete (RC) structure in order to withstand the gravitational loads under column removal scenarios. Inspired from fire-induced progressive collapse research, the proposed method employs a virtual thermal pushdown analysis, in which the temperature increase affects only the strength of reinforced steel. With carefully developed strength-temperature relationships of the rebars, the virtual thermal analysis produces a displacement-temperature curve that represents the genuine nonlinear relationship between the amount of reinforcement and structural performance (often represented by vertical displacement). This curve is then used to directly determine the amount of reinforcement at the prescribed performance target. Two beam-column sub-assemblage examples and the Alfred P. Murrah Federal Building were analyzed and redesigned to demonstrate the effectiveness of the proposed method. All three examples showed that the proposal virtual thermal pushdown method can accurately determine the appropriate amount of reinforcements to meet the performance target.

Parkinson's disease (PD) is a neurodegenerative disorder, which is characterized by microglia activation and dopaminergic neurons affected by inflammatory processes. Inflammation has been recognized to be necessary for initiation and progress of PD. Emerging evidence indicates that NLRP3 inflammasome complex is involved in the recognition and execution of host inflammatory response. Stress is acknowledged to be a predisposing and precipitating factor in some neurodegenerative diseases. However, it is unknown whether chronic unpredictable mild stress (CUMS) sensitized microglia to pro-inflammatory stimuli. In this study, in vivo experiments are used to evaluate the effects of CUMS on lipopolysaccharide (LPS)-induced microglia activation and NLRP3 inflammasome activation. The results showed that CUMS pretreatment for 14 days significantly aggravated the behavioral dysfunction of PD rats, increased the activation of microglia. Pretreatment with CUMS for 14 days increased the levels of interleukin-1β (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor-a (TNF-a) in the serum, and increased the expression of NLRP-3, ASC, Casepase-1 in the substantia nigra of PD rats. Our data showed that pretreatment with CUMS for 14 days increased the microglia activation and the DA neurons damage, and the mechanisms may be associated with the acceleration of the inflammatory response and activation of NLRP3 inflammasome.

The urban alternate water source (AWS) is of great significance to the sustainable development of the city, the pollution degree, and source of heavy metals (HMs) in AWS, and whether it will adversely affect human health has received widespread attention. In this study, the urban AWS of Xinbian River in Suzhou City, Huaibei Plain, China, was used as the research object to study the seasonal changes of HMs (As, Cr, Cu, Cd, Pb, and Zn), quantitative identification of pollution sources, and human health risks (HHR). Research results show that the contents of those HMs, except As, are less than the drinking standards limit set by the World Health Organization (WHO), and the contents of As, Cr, and Zn are the largest in summer. The multivariate statistical analysis combined with positive matrix factorization (PMF) model analysis revealed that industrial sources accounted for 44.83%, and agricultural sources accounted for 55.17%. HHR assessment based on Monte Carlo simulation shows that the noncarcinogenic risks of adults and children are in the acceptable range (hazardous ingestion (HI) 1), and the probability of carcinogenic risk values of children and adults are 95.03% and 38.96%, respectively, which are exceed the acceptable range (1 × 10

Irregular structures are known to be more prone to disproportionate collapse (DC) than structures with regular horizontal and vertical layouts. Despite this, many public, commercial and institutional buildings have to be designed with various irregularities in structural layout due to architectural and aesthetic considerations. While extensive experimental and numerical studies have been carried out to advance the basic understanding of DC behaviors of regular structures, limited research has been carried out on irregular structures. On the other hand, alternate load path method has been recommended by several design codes and standards for DC design, but the large number of potential column removal scenarios involved poses a real challenge for the wide use of the method. This paper presents a quantitative measure referred to as irregularity index, or Π , that can be used to quickly identify the worst column removal scenarios for design check of DC resistance of reinforced concrete (RC) frame structures. Based upon a solid understanding of various competing failure mechanisms and DC resistance of RC frame structures, the irregularity index was derived from the maximum load factors between the yielding load and the limit load at the end of tensile membrane action stage. For verification and validation of the proposed Π , a 3D nonlinear finite element model was developed in OpenSees and calibrated by beam-slab sub-assemblage experiments. Various numerical experiments were carried out to verify the effectiveness of the Π . The very high correlation coefficient between the calculated irregularity indices and DC resistance obtained from finite element analyses showed that the proposed irregularity index can quickly identify the worst column removal scenarios in various irregular structures including setback buildings and large-bottom-space structures. Sensitivity analysis further verified the reliability of the proposed irregularity index.

The Zn1–xAl2O4:xEu2+ phosphor powders were synthesized by the solid-state reaction method. The synthesis temperature for ZnAl2O4 was optimized, whereas the phase structure, TEM images, photoluminescence (PL) properties, the concentration quenching mechanism, the fluorescence decay curves, as well as the CIE chromaticity coordinates of the samples were investigated in details. Under the excitation at 379 nm, the phosphor exhibits an asymmetric broad-band green emission with a peak at 532 nm, which is ascribed to the 5d–4f transition of Eu2+. When the doping concentration of Eu2+ ions is 0.01, the luminescence intensity of the sample reaches the maximum value. It is further proved that the exchange interaction results in the concentration quenching of Eu2+ in the Zn1–xAl2O4:xEu2+ phosphor powders. The thermal quenching property of ZnAl2O4:Eu2+ phosphor was investigated and the quantum efficiency (QE) values of the selected Zn0.99Al2O4:0.01Eu2+ phosphor was measured and determined as 54.85%. The lifetime of the optimized sample Zn0.99Al2O4:0.01Eu2+ is 3.0852 μs and the CIE coordinate of the sample was calculated as (0.3323, 0.5538) with high-color-purity green emission. All properties indicate that the green-emitting ZnAl2O4:Eu2+ phosphor powder has potential application in white LEDs.

Modular integrated Construction (MiC) is a game changing construction approach which could significantly increase construction efficiency, quality, and sustainability. For steel MiC structures, modules are manufactured in the factories and assembled at the construction sites through inter-module connections. The concern of the vulnerability of these connections under abnormal hazards leading to disproportionate progressive collapse will impede industrial applications of MiC structures in the construction community. This study investigates the structural robustness of corner-supported modular steel buildings with the focus on different inter-module connections. A sub-structure extracted from a five-storey modular building is analysed by high fidelity finite element analysis under a corner column removal scenario. The load redistribution mechanism and failure modes are investigated thoroughly, based on which the simplified macro model is proposed where connections are modelled with rotational springs. Good consistence is found for the simplified model and the detailed FE analysis in terms of the pushdown curve. It is also found that the inter-module connection types will affect the beam-column joint properties which dominate the progressive collapse resistance of MiC structures. Therefore, attention should be paid when selecting different inter-module connections. The current rigid beam-column joint connection may lead to nonconservative evaluation.

The novel COVID-19 outbreak has affected more than 200 countries and territories as of March 2020. Given that patients with cancer are generally more vulnerable to infections, systematic analysis of diverse cohorts of patients with cancer affected by COVID-19 is needed. We performed a multicenter study including 105 patients with cancer and 536 age-matched noncancer patients confirmed with COVID-19. Our results showed COVID-19 patients with cancer had higher risks in all severe outcomes. Patients with hematologic cancer, lung cancer, or with metastatic cancer (stage IV) had the highest frequency of severe events. Patients with nonmetastatic cancer experienced similar frequencies of severe conditions to those observed in patients without cancer. Patients who received surgery had higher risks of having severe events, whereas patients who underwent only radiotherapy did not demonstrate significant differences in severe events when compared with patients without cancer. These findings indicate that patients with cancer appear more vulnerable to SARS-CoV-2 outbreak. Significance: Because this is the first large cohort study on this topic, our report will provide much-needed information that will benefit patients with cancer globally. As such, we believe it is extremely important that our study be disseminated widely to alert clinicians and patients. This article is highlighted in the In This Issue feature, p. 747

As one of the most complicated joint structures, temporomandibular joint (TMJ) is susceptible to inflammatory reaction caused by osteoarthritis, rheumatoid arthritis and so on. The treatment for TMJ inflammation is still challenging due to the rapid clearance and lack of selectivity of traditional medication. Herein, we design a novel discrete sulfonylcalix[4]arene-based magnesium(II) coordination container, MgDHIA, which features satisfactory biocompatibility, appropriate molecular size and multiple binding domains. MgDHIA is capable of selectively encapsulating rapamycin (RAPA) in the endo cavity and folic acid (FA) in the exo cavities to form the co-loaded system RAPA-FA@MgDHIA, which exhibits outstanding activated macrophages targeting, stepwise releasing and cellular uptake behaviors. For therapeutic aspect, the RAPA-FA@MgDHIA reprograms the phenotype of polarized macrophages, specifically, transforming the pro-inflammatory M1 macrophages to anti-inflammatory M2 phenotype by inhibiting NF-kB pathway. The in vivo studies also demonstrate that the RAPA-FA@MgDHIA presents higher accumulation in inflamed synovial tissues, protecting the articular cartilage and subchondral bone structures by alleviating synovial inflammation. Anyway, we first evaluate the application of coordination container-based nanomedicine in treatment of inflammatory TMJ, demonstrating that the drug and targeting agents co-loaded coordination container remarkably boosts the therapeutic efficacy of traditional medication, thus providing a promising approach for anti-inflammatory treatment in joints.

Recently, many studies show that deep neural networks (DNNs) are susceptible to adversarial examples, which are generated by adding imperceptible perturbations to the input of DNN. However, in order to convince that adversarial examples are real threats in real physical world, it is necessary to study and evaluate the adversarial examples in real-world scenarios. In this paper, we propose a natural and robust physical adversarial example attack method targeting object detectors under real-world conditions, which is more challenging than targeting image classifiers. The generated adversarial examples are robust to various physical constraints and visually look similar to the original images, thus these adversarial examples are natural to humans and will not cause any suspicions. First, to ensure the robustness of the adversarial examples in real-world conditions, the proposed method exploits different image transformation functions (Distance, Angle, Illumination and Photographing), to simulate various physical changes during the iterative optimization of the adversarial examples generation. Second, to construct natural adversarial examples, the proposed method uses an adaptive mask to constrain the area and intensities of the added perturbations, and utilizes the real-world perturbation score ( R P S ) to make the perturbations be similar to those real noises in physical world. Compared with existing studies, our generated adversarial examples can achieve a high success rate with less conspicuous perturbations. Experimental results demonstrate that, the generated adversarial examples are robust under various indoor and outdoor physical conditions, including different distances, angles, illuminations, and photographing. Specifically, the attack success rate of generated adversarial examples indoors and outdoors is high up to 73.33% and 82.22%, respectively. Meanwhile, the proposed method ensures the naturalness of the generated adversarial example, and the size of added perturbations is as low as 29361.86, which is much smaller than the perturbations in the existing works (95381.14 at the highest). Further, the proposed physical adversarial attack method can be transferred from the white-box models to other object detection models. The attack success rate of the adversarial examples (generated targeting Faster R-CNN Inception v2) is high up to 57.78% on the SSD models, while the success rate of adversarial example (generated targeting YOLO v2) on SSD models reaches 77.78%. This paper reveals that physical adversarial example attacks are real threats in the real-world conditions, and can hopefully provide guidance for designing robust object detectors and image classifiers.

Flowback water generated during shale gas extraction in Pennsylvania is mostly reused for hydraulic fracturing operation. Abandoned mine drainage (AMD), one of the most widespread threats to water quality in Pennsylvania, can potentially serve as a make-up water source to enable flowback water reuse. This study demonstrated co-treatment of flowback water and AMD produced in northeastern Pennsylvania in a pilot-scale system consisting of rapid mix reactor, flocculation tank and sedimentation tank. Sulfate concentration in the finished water can be controlled at a desired level (i.e., below 100 mg/L) by adjusting the ratio of flowback water and AMD in the influent. Fe3+ contained in the AMD can serve as a coagulant to enhance the removal of suspended solids, during which Fe2+ is co-precipitated and the total iron is reduced to a desirable level. Solid waste generated in this process (i.e., barite) will incorporate over 99% of radium present in the flowback water, which offers the possibility to control the fate of naturally occurring radioactive materials (NORM) brought to the surface by unconventional gas extraction. Sludge recirculation in the treatment process can be used to increase the size of barite particles formed by mixing flowback water and AMD to meet specifications for use as a weighting agent in drilling fluid. This alternative management approach for NORM can be used to offset the treatment cost and promote flowback water reuse, reduce environmental impacts of AMD and reduce pressure on fresh water sources.

Management of Marcellus Shale flowback water is a rising concern in Pennsylvania. Due to limited capacity for wastewater disposal by deep-well injection, flowback water reuse is the dominant management option in PA. Microfiltration is a promising technology to be used in a mobile treatment system for solids removal from Marcellus Shale flowback water prior to reuse. It was found previously that early Marcellus Shale flowback water could cause severe membrane fouling due to the presence of stable submicron colloids. Bench-scale cross-flow filtration system was used in this study to evaluate the feasibility of microfiltration for treatment of Marcellus Shale flowback water that does not contain these submicron colloids. The performance of alumina (Al 2 O 3 ) and silicon carbide (SiC) ceramic membranes that have distinct surface charge properties was evaluated in this system using a constant transmembrane pressure. The difference in the isoelectric point of these membranes suggested possible differences in fouling behavior, but extremely high salinity of the flowback water screened the electrostatic interactions and minimized these differences. For the two flowback waters tested in this study, the one with lower TDS caused more severe fouling of both SiC and Al 2 O 3 membranes during the first 15 min of filtration. The flux decline analysis revealed that intermediate pore blocking was the dominant fouling mechanism in the early filtration stage. Such behavior was due to the fact that the particulate matter in this flowback water was in the aggregate form and the flocs were prone to breakup at elevated shear stress caused by high pumping rate. Despite having much higher TSS, the other flowback water did not cause excessive membrane fouling due to stability and strength of its original particles.

In this study, the performance of catalytic ozonation in the treatment of bio-treated coking wastewater (BCW) using pilot- and full-scale systems was investigated. Additionally, the removal efficiency of organic pollutants from BCW, the deactivation mechanism of MnxCe1-xO2/γ-Al2O3, and backflushing optimization for in-situ catalyst regeneration, which have not been previously investigated, were analysed. Results of the 12-month pilot scale experiments showed that catalytic ozonation resulted in the effective removal of organic pollutants when backflushing was applied as an in-situ catalyst regeneration strategy. The effluent chemical oxygen demand (COD) content decreased from 150 to 78 mg L−1, and remained below a discharge limitation of 80 mg L−1, and the stable COD removal efficiencies (from 56.0% to 47.9%) indicated that catalyst deactivation, which primarily resulted from the deposition of inorganic salts on the surface of the catalyst that limited interaction between ozone and active sites and/or prevented electrons transfer, was primarily inhibited by backflushing. The catalyst regeneration via in-situ air- and water-backflushing was attributed to the scrubbing, collision, and/or the loosing effect. Additionally, in the full-scale experiment, the catalytic ozonation process with in-situ alternative backflushing exhibited a stable COD removal efficiency (above 45.6%) for 885 days when water- and air-flushing strengths of 10 L m−2 s−1 and 15 L m−2 s−1, respectively, were applied with a 7-day regeneration interval. Therefore, the results of this study provide new insights into catalytic ozonation and support its engineering application in BCW treatment.

Parkinson's disease (PD) is the second most common neurodegenerative disease, which is characterized by loss of dopaminergic neurons in the substantia nigra pars compacta (SNpc). Accumulated evidences have suggested that oxidative stress is closely associated with the dopaminergic neurodegeneration of PD that can be protected by antioxidants. Biochanin A that is an O-methylated isoflavone in chickpea is investigated to explore its protective mechanism on dopaminergic neurons of the unilateral lipopolysaccharide (LPS)-injected rat. The results showed that biochanin A significantly improved the animal model's behavioral symptoms, prevented the loss of dopaminergic neurons and inhibited the deleterious microglia activation in the LPS-induced rats. Moreover, biochanin A inhibited nicotinamide adenine dinucleotide phosphate oxidase (NADPH oxidase) activation and malondialdehyde (MDA) production, increased superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities in the rat brain. These results suggested that biochanin A might be a natural candidate with protective properties on dopaminergic neurons against the PD.

Gd2−xO2S:xTb3+ phosphors were prepared by the microwave solid state method, and its phase formation and morphologies were studied by the X-ray powder diffraction (XRD) and scanning electron microscope (SEM) techniques. The photoluminescence (PL) properties, cathodoluminescence (CL) properties and PL thermal stability of the samples were investigated, which indicated that better luminescence properties can be obtained via the microwave method compared to the conventional high temperature solid-state method. The composition-optimized Gd1.85O2S:15%Tb3+ exhibited strong green emission peaking at 546 nm upon excitation at 254 nm with the CIE coordinates of (0.238, 0.382). Different electric voltage and current dependent CL spectra investigations of Gd1.85O2S:15%Tb3+ phosphor shows similar green spectral profile as PL emission and it also demonstrates the good luminescence stability suggesting its potential application as green emission component in cathode ray tube (CRT).

Flowback water generated during unconventional gas extraction is of great concern due to its high total dissolved solids (TDS), radioactive elements and organic matter. Abandoned mine drainage (AMD) is a water source that is often located in the vicinity of gas wells and can be mixed with flowback water to reduce fresh water usage for hydraulic fracturing. The feasibility of microfiltration to separate solids created by mixing actual flowback water and AMD was evaluated using a bench-scale setup. Hydrophilic polyvinyldiene fluoride (PVDF) membrane with a pore size of 0.22 μm was as a model polymeric microfiltration membrane. Severe membrane fouling occurred during the first 5 min of filtration with one flowback/AMD mixture while no significant fouling was observed for a different mixture. It was found that the flowback water that caused membrane fouling contained stable iron-based colloids with an average particles size of 0.2 μm, especially in the samples collected early in the flowback period. These colloids were not formed by mixing flowback water containing high barium concentration with AMD rich in sulfate but were originally present in the flowback water. Stability of these sub-micron colloidal particles at high ionic strength of the flowback water is attributed to organic coating on the particle surface.

Rare earth aluminate phosphors are well-known for being nontoxic and environmentally friendly. In this work, Tb3+-doped SrLaAlO4 phosphors were synthesized via a facile high temperature solid-state reaction method. The Optimum reaction temperature is determined to be 1300 °C based on the results of powder X-ray diffraction (XRD). The SEM patterns and TEM images correspond with the results of Rietveld refinement and show that the SrLa1-xAlO4:xTb3+ samples present a flaky structure. The results of photoluminescence spectrums (PL) show that SrLa1-xAlO4:xTb3+ phosphors can absorb in the UV–vis spectral region of 228 nm–263 nm and exhibit several emission peaks between 450 and 650 nm, and the highest peak was at 508 nm. The luminescence properties of SrLa1-xAlO4:xTb3+ have a strict dependence on the cation substitution levels. When the doping concentration of Tb3+ was 0.05, the emission intensity of the sample is strongest. The thermal quenching result of the SrLa0.95AlO4:0.05 Tb3+ phosphors shows that these phosphors are relatively sensitive to temperature changes under an excitation of 228 nm, as the temperature increases from 25 °C to 125 °C, the emission intensity (peak at 548 nm) decayed to 55.11% of that at room temperature. However, when the temperature increases to 125 °C, the emission intensity (peak at 548 nm) decayed to 61.16% of the initial value under an excitation of 263 nm, which showed a relatively good thermal stability. The internal quantum efficiency (QE) values of the SrLa0.95AlO4:0.05 Tb3+ phosphors was measured and determined to be 48%. Under excitations of 228 nm and 263 nm, the lifetimes of the optimized sample SrLa0.95AlO4:0.05 Tb3+ were 1.3986 ms and 1.2095 ms, respectively, and the CIE coordinates of the sample were calculated as (0.2971, 0.4981), (0.3056, 0.5329), respectively. Under both excitations SrLa0.95AlO4:0.05 Tb3+ exhibited high-color-purity green emission.

The aim of this article is the partial axiomatization for 1-level universal logic. A propositional calculus formal deductive system UL−hɛ(0,1) based on 1-level universal AND operator of universal logic is built up. The corresponding algebra is introduced. The soundness and the completeness of system UL−hɛ(0,1) are proved.

Bacterial ferritin of Azotobacter vinelandii (AvBF) is directly able to pick electrons up for iron release from or transfer them for storage to a platinum electrode in the absence of mediator or other reducer. The ferritin containing the structure of heme-Co2+ in part shows weakened activity to electrode and decreases the rate of iron release greatly. A reversible reduction process of the ferritin is observed by the spectral change regularly ranging from 310 to 260 nm under mixed gases containing 98% H2 and 2% to O2. The activity of nitrogen fixation from the whole cell of A. vinelandii increases greatly by H2 reduction with potentials ranging from -397 to -425 mV vs. NHE, indicating two important roles of H2-uptake reaction of the ferritin in increasing activity of nitrogen fixation and in supplying iron to synthesize nitrogenase.