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Solar driven nitrogen (N2) fixation to synthesize ammonia is a potential alternative for the traditional Haber-Bosch approach to meeting industrial demand, but is largely hampered by the difficulties in the harvesting of solar energy and activating inert N2. In this work, hollow CeF3 nanospheres co-doped with activator Tm3+ and sensitizer Yb3+ (Yb3+:Tm3+:CeF3) were prepared by microwave hydrothermal method. The product was employed as a catalyst for photo-driven N2 fixation by adjusting the molar ratio of Ce3+:Yb3+:Tm3+. Results show that the porous hollow structure enhances the light-harvesting by physical scattering and reflection. In addition, heteroatom doping generates abundant fluorine vacancies (FV) which provide abundant active sites for adsorption and activation of N2. The sample with molar ratio of CeF3:Yb3+:Tm3+ at 178:20:2 demonstrates the highest utilization of solar energy attributed to the strongest upconversion capability of near-infrared (NIR) light to visible and ultraviolet (UV) light, and the NH4+ concentration achieves the highest value of 15.06 μmol/(gcat∙h) under simulated sunlight while nearly 6.22 μmol/(gcat∙h) under NIR light. Current study offers a promising and sustainable strategy for the fixation of atmospheric N2 using full-spectrum solar energy.

Calorie-dense starchy thickeners (CDSTs) are preferable for dysphagic individuals while in terms of both sufficient moisture and energy intake. In the present study, we evaluated the thickening and anti-sedimentation effects of five commercial CDSTs and pre-screened the best candidate of germ rice (GR) powder for further formulation with xanthan and guar gums (XG and GG). The formulated model food matrices (MFMs) with different concentrations of CDST were prepared: nectar-like, honey-like, and pudding-like defined as 200 ± 50 mPa·s, 1050 ± 50 mPa·s, and 1800 ± 50 mPa·s, respectively. These CDST-MFMs were also subjected to evaluations of their physicochemical properties and stability. The solubility of MFMs containing GR could be as high as 60.95%; whereas the oil binding capabilities ranged between 3.77 and 4.22%, which were significantly higher (p

Photocatalytic fixation of nitrogen has been recognized as a green and promising strategy for ammonia synthesis under ambient conditions. However, the efficient reduction of nitrogen remains a challenge due to high activation energy of nitrogen and low utilization of solar energy. Herein, lanthanum oxyfluoride with different doping content of Pr3+ (LaOF:xPr3+) upconversion nanorods were synthesized by microwave hydrothermal method. Results indicated that the doping of Pr3+ generated considerable defects on the surface of LaOF which acted as the adsorption and activation center for nitrogen. Meanwhile, the Pr3+ ion narrowed the band gap and broadened the light response range of LaOF because LaOF:Pr3+ can upconvert visible light into ultraviolet light, which excite LaOF nanorods and improve the utilization of solar light. The doping amount of Pr3+ had critical effect on the photocatalytic nitrogen fixation performance which reached as high as 180 μmol·L−1·ho1 when the molar ratio of Pr3+ to LaOF was optimized to be 2%.

Developing cost-effective photocatalyst which converts nitrogen to ammonia under mild conditions remains a great challenge from both academic and industrial perspective. In this work, we synthesize one dimensional attapulgite (ATP) mineral supported Pr3+:CeF3 nanocomposite by a microwave hydrothermal method. Results indicate that adequate doping of Pr3+ facilitates the conversion of visible light into ultraviolet light which expands the adsorption range of solar energy. The abundant fluorine vacancies which generate from the incorporation of partial metal ions of ATP into the crystal lattice of CeF3 act as active sites promoting the adsorption of N2 as well as weakening the N ≡ N triple bond in the photocatalysis reaction. The 40 wt% loading of Pr3+:CeF3 exhibits the highest photocatalytic nitrogen fixation performance attributed to the formation of Z-scheme structure which not only improves the separation of photoexcited charge carriers, but also preserve the high redox potential to reduce nitrogen. This work provides a sustainable way for nitrogen fixation using solar energy based on natural mineral and beyond.

Gouty arthritis (GA) is a multifactorial disease whose pathogenesis is utterly complex, and the current clinical treatment methods cannot wholly prevent GA development. Western medicine is the primary treatment strategy for gouty arthritis, but it owns an unfavorable prognosis. Therefore, the prevention and treatment of GA are essential. In China, traditional Chinese medicine (TCM) has been adopted for GA prevention and treatment for thousands of years. Gout patients are usually treated with TCM according to their different conditions, and long-term results can be achieved by improving their physical condition. And TCM has been proved to be an effective method to treat gout in modern China. Nevertheless, the pharmacological mechanism of TCM for gout is still unclear, which limits its spread. The theory of prevention and treatment of gout with TCM is more well acknowledged in China than in abroad. In this article, Chinese herbs and ancient formula for gout were summarized first. A total of more than 570 studies published from 2004 to June 2021 in PubMed, Medline, CNKI, VIP, Web of Science databases and Chinese Pharmacopoeia and traditional Chinese books were searched; the current status of TCM in the treatment of GA was summarized from the following aspects: articular chondrocyte apoptosis inhibition, antioxidative stress response, inflammatory cytokine levels regulation, uric acid excretion promotion, immune function regulation, uric acid reduction, and intestinal flora improvement in subjects with gout. The literature review concluded that TCM has a specific curative effect on the prevention and treatment of GA, particularly when combined with modern medical approaches. However, lacking a uniform definition of GA syndrome differentiation and the support of evidence-based medicine in clinical practice have provoked considerable concern in previous studies, which needs to be addressed in future research.

Explosive welding is an efficient method for metals welding. However, in explosive welding, the shock wave generated by the explosion can not only damage the sensitive structure in the area of the process, but also can actually destroy a welded joint immediately after its creation. By placing an additional structure (anvil) can reduce the influence of shock waves. The influence of different anvil on the explosive welding of aluminum and magnesium plates has been investigated by using AUTODYN Software in this paper. The results show that the steel anvil is much more appropriate than sand and magnesium.

In this paper, the measurement conditions of heavy metal enriched on the filter membrane using X-ray fluorescence were talked about. According to the heavy metal enriched on the film, the specific parameters were analysed. Through many experiments, the suitable parameters were decided. In order to excite mainly heavy metal in air, the excitation voltage should be not less than 30kV. The excitation current should be between 20μA and 60μA. The measured distance should be between 4mm and 15mm. The best choice of pulse shaping time is around 6.4μs. These parameters setting should have very good application value in air heavy metal measurement.

Larvae homozygous for the recessive lethal allele without children(rgl) (woc(rgl)) fail to pupariate. Application of exogenous 20-hydroxyecdysone elicits puparium formation and pupation. Ecdysteroid titer measurements on mutant larvae show an endocrine deficiency in the brain-ring gland complex, which normally synthesizes ecdysone, resulting in a failure of the larvae to achieve a threshold whole body hormone titer necessary for molting. Ultrastructural investigation revealed extensive degeneration of the prothoracic cells of the ring gland in older larvae. The woc gene, located in polytene chromosomal region 97F, consists of 11 exons. A 6.8-kb transcript is expressed throughout development but is absent in the mutant woc(rgl) larvae. The woc gene encodes a protein of 187 kDa. Eight zinc fingers of the C2-C2 type point to a possible function as a transcription factor. The woc protein shows considerable homology to human proteins which have been implicated in both mental retardation and a leukemia/lymphoma syndrome.

Summary Ecdysteroid localization in target tissues of Drosophila melanogaster was demonstrated by the utilization of low temperature autoradiography and immunohistochemistry. Autoradiographic studies utilized high specific activity [3H]ponasterone A, an ecdysteroid with exceptional molting hormone activity in Drosophila. The data revealed a selective nuclear concentration of the labelled ligand in cells of the salivary gland, corpus allatum (source of juvenile hormone), prothoracic gland (source of ecdysone) and the central nervous system. Nuclear localization was also observed in epithelial cells of the esophagus and muscle cells of the pharynx and mandibles, etc. The specific labelling of cell nuclei was prevented by incubation of the tissue with [3H]ponasterone A in the presence of excess unlabelled ponasterone A. Nuclear localization of ponasterone A in the salivary gland was also observed when using an antiserum against ecdysteroids and an avidin-biotin-complex (ABC) detection system. The staining sh...

The prothoracic glands of the tobacco hornworm, Manduca sexta, secrete the precursor of the insect molting hormone and normally undergo programmed cell death (PCD) during pupal-adult metamorphosis, between days 5 and 6 after pupation. This phenomenon can be elicited prematurely in vitro by the addition of 20-hydroxyecdysone (20E) to the gland cultures. To induce nuclear condensation in vitro in the glands from day-1 pupae, the effective dose range of 20E is 0.7-7 micrograms/ml and the minimum exposure period is 24 h. Prothoracic glands from different stages of pupal-adult development express different responsiveness to exogenous ecdysteroids. By utilizing terminal deoxynucleotidyl-transferase-mediated dUTP nick-end-labeling (TUNEL) and the apoptotic DNA laddering method together with transmission electron microscopy, it has been demonstrated that the ecdysteroid-induced cell death of the prothoracic glands occurs via not only apoptosis but also autophagy, i.e., the induced dying cells show both severe nuclear fragmentation and autophagic vacuole formation, characteristics typical of apoptotic and autophagic cell death. The composite data indicate that ecdysteroids regulate directly both apoptotic and autophagic mechanisms of PCD of the prothoracic glands.

The term “neurosteroid” refers to both classic and unique steroid molecules that are synthesized from cholesterol (C) by the central and peripheral nervous systems of higher vertebrates. Therein, they accumulate and modulate nervous activity by a variety of mechanisms other than the classic steroid receptor-mediated modulation of genomic activity, although such may also be involved. Since the insect nervous system expresses ecdysteroid receptors and responds both directly and developmentally to ecdysteroids, the possibility of ecdysteroidogenesis in the pupal and adult central and peripheral nervous system of Manduca sexta and the nervous system of Drosophila melanogaster larvae was investigated. The endogenous concentrations of the critical, dietary-derived Δ 5,7 -sterols ergosterol and 7-dehydrocholesterol (7dC) remained 10 to 20-fold higher in the Manduca pupal and adult nervous tissues than was found in the larval hemolymph at the cessation of feeding. In addition, it was determined that the Manduca pupal nervous system, but not that of the adult, could synthesize 3 H/ 14 C-7dC or 3 H-7-dehydro-25-hydroxycholesterol ( 3 H-7d25C) from 3 H/ 14 C-cholesterol ( 3 H/ 14 C-C) or the polar sterol substrate 3 H-25-hydroxycholesterol ( 3 H-25C), respectively. However, none of the nervous system samples from the two species and the several stages analyzed, a small window of neural development in these insects, were capable of incorporating any of the above tracer precursor sterols into a radiolabelled ecdysteroid, i.e. less than 0.0005%. Thus, the absence of neurosteroidogenesis by the insect nervous system stands in sharp contrast to previously described nervous system steroid hormone biosynthesis by the mammalian nervous system.

Studies in vitro revealed that intact ring glands of Drosophila melanogaster convert tritiated cholesterol (C) and 25-hydroxycholesterol (25C) via 7-dehydrocholesterol (7dC) and 7-dehydro-25-hydroxycholesterol (7d25C), respectively, to ecdysone (E) and 2-deoxyecdysone (2dE), while both intact and homogenized ovaries synthesize only 2dE from these precursors. Emulsified 7d25C was incorporated directly into ecdysteroids by these tissue preparations at a much greater rate than was 7d25C made in situ from 25C. To probe the basis of the biochemical defect in the ecdysteroid deficient conditional mutant ecdysoneless (ecd1), the differential incorporation into ecdysteroids of C (via 7dC), and particularly of 25C (via 7d25C), was measured relative to that observed after the incubation of 7d25C directly with both wild type and mutant tissues in vitro at 30 degrees C, the restrictive temperature. Both C and 25C were equally 7,8-dehydrogenated in situ to 7dC or 7d25C, respectively, by both wild type and mutant tissues at 30 degrees C. However, the rate of subsequent conversion of either of these delta 5,7-sterol intermediates synthesized in situ to ecdysteroids was reduced an average of 50% in the mutant tissues relative to the wild type. Yet, when emulsified 7d25C was incubated directly with either the wild type or mutant tissues at the restrictive temperature, the amplified rate of conversion of the freely available 7d25C to ecdysteroid by these tissues was identical. These data suggest that the defect in ecd1 tissue-mediated ecdysteroidogenesis does not involve a "hit" on any of the enzymes involved in either the 7,8-dehydrogenation of C or 25C or in the subsequent oxidation of 7d25C or 7dC to ecdysteroid. Rather, the mutation appears to affect the expression of a gene governing the translocation of delta 5,7-sterol intermediates from the subcellular compartment where they are synthesized and/or stored to the site of subsequent oxidation to ecdysteroid.

The insect brain neuropeptide, prothoracicotropic hormone (PTTH), elicits the molting process by stimulating ecdysteroidogenesis in the prothoracic glands. Changes in the subcellular distribution of PTTH during the fifth larval instar and larval-pupal metamorphosis of Bombyx were investigated using immunogold electron microscopy and computerized image analysis. A time-resolved fluoroimmunoassay was employed to quantify the hemolymph PTTH titer and the hemolymph ecdysteroid titer was determined by radioimmunoassay. Immunoreactivity was apparent only in the cytoplasm of two pairs of dorsal-lateral neurosecretory cells (La) in the brain, the prothoracicotropes, and their axons that traverse the peripheral area of the brain neuropil and then enter the neurohemal lobes of the corpora cardiaca and end in the corpora allata. Immunospecificity was evident as noted by the restriction of the 5-nm gold particles to the neurosecretory granules. Synaptic contacts were noted frequently between the dendritic collaterals of the prothoracicotropes and neighboring collaterals from other neurons. The morphological data suggest that PTTH is synthesized and released throughout the fifth larval instar. The concentration of gold particles in the neurosecretory granules and the number of neurosecretory granules increased five times during the fifth instar, and these increases were correlated with surges in the hemolymph PTTH and ecdysteroid titers. The data suggest that PTTH biosynthesis, secretory granule formation, and secretion are three continuous and almost synchronized events.

In the late third larval instar of Drosophila melanogaster, the prothoracic gland, an endocrine portion of the ring gland, synthesizes ecdysteroids at an accelerated rate. The resultant ecdysteroid titer peak initiates the events associated with metamorphosis. The normal prothoracic gland displays several ultrastructural features at this developmental stage that reflect increased steroidogenic activity, including extensive infoldings of the plasma membrane (membrane invaginations) and an increase in both the concentration of smooth endoplasmic reticulum (SER) (or transitional ER) and elongated mitochondria. By contrast, the prothoracic glands of larvae homozygous for a conditional larval lethal mutation, l(3)ecd1ts, not only fail to produce ecdysteroids at normal levels at the restrictive temperature (29 degrees C), but also acquire abnormal morphological features that reflect the disruptive effects of the mutation. These abnormalities include an accumulation of lipid droplets presumed to contain sterol precursors of ecdysteroids, a disappearance of SER and a drastic reduction of membrane invaginations in the peripheral area of the cell. These morphological defects are observed in prothoracic glands dissected from larvae transferred from 18 degrees C to 29 degrees C approximately 24 h before observation and also within 4 h of an in vitro transfer to 29 degrees C following dissection from wandering third instar larvae reared at 18 degrees C. No ultrastructural abnormalities were noted in the corpus allatum portion of mutant ring glands. These observations further indicate the direct involvement of the ecd gene product in ecdysteroid synthesis and suggest a role for the gene in the proper transport of precursors to the site where they can be utilized in ecdysteroid biosynthesis.