Colorimetric sensors constructed with one dimensional PtNi nanowire and Pt nanowire nanozymes for Hg2+ detection.

BACKGROUND: In recent years, environmental pollution has attracted widespread global attention. Among them, environmental problems caused by heavy metal pollution pose a serious threat to human health and ecosystems. Mercury is a common heavy metal pollutant with high toxicity and wide distribution. Excessive intake of Hg2+ can cause permanent and severe damage to the nervous system, respiratory system, and kidneys in the human body. Therefore, developing both accurate and fast detection methods for Hg2+ is of great significance. RESULTS: A sensitive Hg2+ colorimetric sensor is designed based on PtNi nanowires (NWs) and Pt NWs with peroxidase-mimetic activity. PtNi NWs and Pt NWs catalyze the reaction of 3,3', 5,5'-tetramethylbenzidine (TMB) with hydrogen peroxide (H2O2) to produce blue oxidized TMB (oxTMB). The specific interaction of Pt-Hg significantly inhibits the peroxidase-mimetic activity of PtNi NW and Pt NW nanozymes, resulting in a lighter blue color. It is worth noting that compared with specific activity (SA) of Pt NWs (3.31 U/mg), PtNi NWs own superior SA (10.43 U/mg), which inevitably leads to a wider linear range of Hg2+ analysis (1 nM-200 µM) and a lower detection limit (0.6748 nM) for PtNi NWs-based colorimetric sensor, versus linear range (4 nM-5 µM) and LOD of 1.198 nM for Pt NWs-based colorimetric sensor, which are far below the Hg2+ threshold (10 nM) for drinking water set by the US Environmental Protection Agency. SIGNIFICANCE: The two nanozyme colorimetric sensors have been successfully used for the evaluation of Hg2+ in complex river water and tap water. Due to the advantages of simple operation, fast response, and high sensitivity, colorimetric sensors have broad application prospects in environmental monitoring.

The complete mitochondrial genome of Pontederia crassipes: using HiFi reads to investigate genome recombination and gene transfer from chloroplast genome.

Water hyacinth (Pontederia crassipes Mart.) is a monocotyledonous aquatic plant renowned for its rapid growth, extensive proliferation, biological invasiveness, and ecological resilience to variations in pH, nutrients, and temperature. The International Union for Conservation of Nature (IUCN) has listed P. crassipes among the top 100 invasive species. However, comprehensive genomic information, particularly concerning its mitochondrial genome (mitogenome), remains surprisingly limited. In this study, the complete mitogenome of P. crassipes was analyzed using bioinformatics approaches. The mitogenome is 399,263 bp long and contains 38 protein-coding genes (PCGs), 24 tRNA genes, and 3 rRNA genes. Sequence analysis revealed that the complete mitogenome of the species contains 3,289 dispersed repeats, and 765 RNA editing sites in protein-coding genes. The P. crassipes mitogenome possessed un-conserved structures, including extensive sequence transfer between its chloroplasts and mitochondria. Our study on the mitogenome of P. crassipes offers critical insights into its evolutionary patterns and phylogenetic relationships with related taxa. This research enhances our understanding of this invasive species, known for its significant biomass and rapid overgrowth in aquatic environments.

Luminescence properties and energy-transfer behavior of Y2-x-yBixEuyMgTiO6 phosphors.

In recent years, double perovskite has become a research hotspot of luminescent matrix materials due to its flexible structure, easy doping and good thermal stability. By using a high temperature solid-state technique, Bi3+ and Eu3+ co-doped Y2-x-yBixEuyMgTiO6 (0 ≤ x ≤ 0.1, 0 ≤ y ≤ 0.5) phosphors were made. X-ray diffraction (XRD) analysis shows that the crystal structure of all samples is monoclinic system, P21/n; Bi3+ and Eu3+ can be doped into the position of Y3+ in the substitution system of Y2MgTiO6. Both photoluminescence spectroscopy (PL) and X-ray excitation luminescence spectroscopy (XEL) were used to investigate the link between Bi3+ and Eu3+ doping concentrations and luminescence intensity. PL shows that: When 375 nm is used as the excitation wavelength, by varying the doping concentration of Eu3+ in the Y1.995-yBi0.005EuyMgTiO6 phosphor, it is possible to create the color-tunable emission from blue to red; The introduction of an appropriate amount of Bi3+ will increase the typical Eu3+ emission; The way that the system's Bi3+ and Eu3+ exchange energy can be observed by combining the fluorescence decay curve and photoluminescence. Fitting by concentration quenching model shows that the resonant dipole-dipole transition is the mechanism of energy transfer between Bi3+→Eu3+; X-rays may successfully stimulate the phosphor, and the spectral distribution of XEL and PL is basically the same; The introduction of an appropriate amount of Bi3+ is also beneficial to improving the sensitivity of XEL; Changes in temperature affect the sample's emission intensity; In addition, the samples remain stable for an extended period while being continuously exposed to X-rays at various environmental temperatures. The a forementioned findings suggest that the phosphor has potential use value in the lighting industry, X-ray imaging and temperature sensor.

Dosimetric and spectroscopic study of LiMgPO4 doped with Tm3+ and Er3.

Olivine-type phosphate LiMgPO4 doped with rare earth elements is considered a novel dosimetric material with excellent performance that is suitable for thermoluminescence (TL) and optically stimulated luminescence (OSL) measurements. Novel LiMgPO4:Tm,Er samples were synthesized by a high-temperature solid-state reaction method. A detailed study of the TL and OSL of the samples was performed using ß-ray irradiation and X-ray-excited optical luminescence (XEOL) spectroscopy. Density functional theory (DFT) calculations were performed to predict the preferential positions of thulium and erbium, and photoluminescence (PL) spectra and TL 3D spectra were analyzed. The DFT calculation results show that Mg is preferentially replaced by Tm/Er in the LiMgPO4 system. The PL/TL3D/XEOL spectra of the samples are dominated by the characteristic luminescence of Tm3+, and the OSL decay curve of photoluminescence has fast and slow decay components with decay constants of 5 s and 42 s, respectively. The TL and XEOL results show that LiMgPO4:Tm,Er has strong emission signals under different types of radiation rays. The PL/TL3D/XEOL spectral results show that Er3+ has no radiative excitation, but Tm3+ has strong luminescence, such that the sample still emits strong TL and PL signals. Two TL emission peaks occur at approximately 120 °C and 300 °C, where the high-temperature peak is significantly more intense than the low-temperature peak, promoting the stability of the TL and OSL signals of the samples. The TL curve consists of 6 general TL dynamic peaks. The nonlinear parameters of the TL dose response are R = 0.08 and D 0 = 479 Gy, and the OSL dose response is linear in the range of 0.2-1000 Gy. The TL and OSL signals of the LiMgPO4:Tm,Er phosphor have good repeatability. Therefore, the LiMgPO4:Tm,Er phosphor can be used for radiation dose measurement.

Study of thermoluminescence, photoluminescence and dosimetry for the YAGG:Ce (Y2.96Al3.4Ga1.6O12:0.04Ce) phosphor.

The comprehensive effect of ionizing radiation should be considered in the use and or analysis of certain electronic equipment. Fluorescent powders are widely used in electronic equipment, so they are attempted to be used as thermoluminescence (TL) dosimeter directly. Green YAGG:Ce phosphors were prepared by a high-temperature solid-state reaction method. The TL glow curves, TL dose response, TL three-dimensional (3D) spectra (80 K-800 K) and photoluminescence spectra for the phosphors were measured. The measurement results show that the luminescence peak temperature for the sample occurs at approximately 458 K and the luminescence peak temperatures in the TL 3D spectra are located at 130 K, 240 K and 458 K; there are four kinds of activation energies of traps in the material; the TL response of each component for the YAGG:Ce phosphor shows good linearity and the detection sensitivity of the phosphor is estimated to be less than 2 mGy. TL 3D spectra and PL spectra show that the luminescence from the phosphors arises from the 2D3/2 â†’ 2F5/2,7/2 transition of Ce ions, and the TL 3D spectra at 130 K, 240 K and 458 K are almost the same, which proves that the temperature can hardly change the relative probability of the 2D3/2 â†’ 2F5/2,7/2 transitions. The results show that YAGG:Ce could be used as dosimeter material.

Genomic Analysis of LEA Genes in Carica papaya and Insight into Lineage-Specific Family Evolution in Brassicales.

Late embryogenesis abundant (LEA) proteins comprise a diverse superfamily involved in plant development and stress responses. This study presents a first genome-wide analysis of LEA genes in papaya (Carica papaya L., Caricaceae), an economically important tree fruit crop widely cultivated in the tropics and subtropics. A total of 28 members were identified from the papaya genome, which belong to eight families with defined Pfam domains, i.e., LEA_1 (3), LEA_2 (4), LEA_3 (5), LEA_4 (5), LEA_5 (2), LEA_6 (2), DHN (4), and SMP (3). The family numbers are comparable to those present in Ricinus communis (Euphorbiaceae, 28) and Moringa oleifera (Moringaceae, 29), but relatively less than that found in Moringa oleifera (Cleomaceae, 39) and Arabidopsis thaliana (Brassicaceae, 51), implying lineage-specific evolution in Brassicales. Indeed, best-reciprocal-hit-based sequence comparison and synteny analysis revealed the presence of 29 orthogroups, and significant gene expansion in Tarenaya and Arabidopsis was mainly contributed by whole-genome duplications that occurred sometime after their split with the papaya. Though a role of transposed duplication was also observed, tandem duplication was shown to be a key contributor in gene expansion of most species examined. Further comparative analyses of exon-intron structures and protein motifs supported fast evolution of this special superfamily, especially in Arabidopsis. Transcriptional profiling revealed diverse expression patterns of CpLEA genes over various tissues and different stages of developmental fruit. Moreover, the transcript level of most genes appeared to be significantly regulated by drought, cold, and salt stresses, corresponding to the presence of cis-acting elements associated with stress response in their promoter regions. These findings not only improve our knowledge on lineage-specific family evolution in Brassicales, but also provide valuable information for further functional analysis of LEA genes in papaya.

Study on the Quantitative Characterization and Seepage Evolution Characteristics of Pores of Loaded Coal Based on NMR.

Quantitative characterization of the pore structure and gas seepage characteristics of loaded coal is of great significance to the study of high-efficiency gas drainage in coal seams. Aiming at the problem of imperfect characterizations of coal seepage characteristics based on nuclear magnetic resonance (NMR), a calculation method for the pore permeability of coal with different pore diameters is proposed. The pore structure and seepage characteristics of coal have been quantitatively studied using a nuclear magnetic resonance (NMR) system. The results show that with increasing external load, the proportion of the pore volume of the coal sample in the range of 0.01-0.52 µm gradually decreases, while that in the range of 5.11-352.97 µm increases. In this process, the porosity increases from 0.9967 to 1.0103%, the connectivity increases from 0.1718 to 0.2391, and the permeability increases from 2.64 × 10-6 to 8.20 × 10-6 µm2. The calculation of the coal sample connectivity and permeability using the improved NMR permeability component proves that 94.37-352.97 µm pores are the main channel of fluid flow. When the axial pressure increases, the coal body permeability in the aperture range of 94.37-352.97 µm rapidly increases. The improved permeability component calculation model can better reflect the variation law of pore permeability of the loaded coal body.

Increases in Genetic Diversity of Weedy Rice Associated with Ambient Temperatures and Limited Gene Flow.

Hypotheses regarding the association of increased species or genetic diversity with gradually warmer regions as a global pattern have been proposed, but no direct and solid experimental data are available to approve the association between plant genetic diversity and ambient temperatures. To test the diversity-temperature hypothesis, we studied genetic diversity and genetic differentiation of weedy rice (Oryza sativa f. spontanea) populations occurring naturally in early- and late-season rice fields that share nearly the same ecological conditions but with slightly different temperatures. Data collected from 10-year historical climatic records indicated a ~2 ℃ higher average air temperature in the late rice-cultivation seasons than in the early seasons. Results based on molecular fingerprints of 27 SSR (simple sequence repeat) loci showed a higher level of genetic diversity in the late-season weedy rice populations than in the early-season populations. In addition, a positive correlation was detected between the increased proportion of genetic diversity (ΔHe ) and genetic differentiation among the weedy rice populations, suggesting limited gene flow. Therefore, we conclude from this study that increased genetic diversity in the late-season weedy rice populations is probably caused by the higher ambient temperatures. This finding provides evidence for the possible association between genetic diversity and ambient temperatures.

A new isolation device for shortening gene flow distance in small-scale transgenic maize breeding.

The transmission of pollen is the main cause of maize gene flow. Under the compulsory labeling system for genetically modified (GM) products in China, isolation measures are crucial. At present, there is no effective isolation device for preventing and controlling the short-range flow of GM maize pollen. The purposes of the present experiments were to overcome the deficiencies of existing technology and to demonstrate a new isolation device for decreasing the gene flow distance of GM maize. The isolation device we invented was shown to be more robust than traditional isolation methods, and it can be disassembled and repeatedly reused. The most important point was that the frequency of gene flow could be greatly reduced using this device. When the distance from the isolation device was more than 1 m, the gene flow rate could be decreased to less than 1%, and when the distance from the isolation device was more than 10 m, the gene flow rate could be reduced to less than 0.1%. When the isolation device was adopted to isolate GM maize in conjunction with bagging the tassels of GM maize at the pollination stage, the gene flow could be controlled to less than 0.1% when the distance from the isolation device was more than 1 m. This device was, however, only applicable for small plots and can shorten the isolation distance of GM maize planting and improve the purity of seeds, all while meeting the needs of close isolation breeding. The use of this device represents a feasible method for risk prevention and control of GM crops.

THERMOLUMINESCENCE SPECTRA AND DOSE RESPONSES OF SrSO4 PHOSPHORS DOPED WITH RARE EARTHS (Eu, Dy, Tm) AND PHOSPHORUS.

The thermoluminescence (TL) spectra and dose responses of strontium sulphate doped with rare earth ions show that the SrSO4:Eu2+ phosphor might reasonably be assumed a isoelectronic trap sample which has unique TL characteristics: there is only one obvious glow peak at 385 nm, 489 K in the TL 3D emission spectra and its TL dose response is linear-sublinear. However, there are several elementary glow peaks in the TL 3D emission spectra and their TL dose responses are linear-supralinear for SrSO4:RE3+ (RE = Dy, Tm). These TL peaks occurred from low to high temperature indicate that the traps are distributed in different energy levels. When a suitable amount of other impurities co-doped into these SrSO4:RE3+, such as phosphorus, the relative intensities of these elementary glow peaks are changed significantly, especially the TL peak ~500 K is enhanced while the peaks at lower temperature are suppressed. The enhanced peak of SrSO4:RE3+,P is attributed to the deep traps. Their dose responses remain in nonlinearity when co-doped phosphorus. The above results and the luminescence properties of other sulphate doped rare earths impurities illustrate that the TL characteristics depend on the structure of defect complexes which can be assumed the basic elements in the TL multi-stage processes.

Short-term clinical effect of 3D printing techniques on the correction of complex malformations.

BACKGROUND: To explore the clinical effects of 3D printing techniques on the correction of complex malformation. METHOD: A computed tomography (CT) scan was used to collect data on malformations of patients and the orthopedic plan was made by virtual manipulation of the reality before surgery. The results of the virtual orthopedics were compared with the expected results. A guide plate for osteotomy was also utilized when necessary. The actual operation was carried out according to the plan. RESULTS: The average age of the 11 patients was 19.09 years (19.09 ± 6.93 years) and the average follow-up was 16 months (16 ± 15.11 months). The symptoms were obviously improved. The preoperative World Health Organization Disability Assessment Schedule (WHODAS 2.0) score, modified Barthel index and Functional Independence Measure (FIM) score in patients were 70.45 ± 15.75, 96.55 ± 3.78 and 121.36 ± 4.15, respectively and correspondingly 53 ± 12.75, 98.82 ± 1.66 and 123.82 ± 4.60 after surgery, respectively. There were significant differences before and after surgery (P < 0.05). CONCLUSION: The use of 3D printing technology can provide intuitive and accurate help for the correction of complex limb malformations and greatly facilitates the communication between doctors and patients. The FIM score is suitable for the evaluation of the curative effect before and after the treatment of patients with complex malformations.

Facile synthesis of ZrO2 coated BiOCl0.5I0.5 for photocatalytic oxidation-adsorption of As(III) under visible light irradiation.

ZrO2 modified BiOCl0.5I0.5 composites (ZBCI), synthesized via a facile precipitation method at room temperature, were utilized to photocatalytically oxidize and adsorb arsenite from water under visible light irradiation. The composites were well characterized by using various techniques. With visible light irradiation, 5 mg L-1 of As(III) could be completely removed by ZBCI (0.25 g L-1) in 90 min. Particularly, we found that ZBCI composites not only could oxidize As(III) into As(V) with visible light irradiation, but also could effectively capture the generated As(V), leading to the negligible residual As(III) or As(V) in aqueous solutions after 90 min treatment. In the fabricated composites, ZrO2 acted as the main adsorption sites while BiOCl0.5I0.5 served as the primary photocatalysis center. Because of the heterostructure of ZBCI, e- generated by BiOCl0.5I0.5 would be transferred to ZrO2 and inhibited e--h+ recombination rate, contributing to the improved photocatalytic efficiency. ZBCI could effectively remove As(III) over a broad range of pH from 3 to 11. Chloride and nitrate did not obviously affect the photocatalytic As(III) removal, while sulfate and phosphate yet reduced the capture of As(III). Moreover, ZBCI composites exhibited high photocatalytic As(III) removal efficiency during the fourth reused cycles. The facile synthesized ZBCI could be employed to capture and oxidize As(III) from water.

Publisher Correction: Use of RNAi technology to develop a PRSV-resistant transgenic papaya.

A correction to this article has been published and is linked from the HTML version of this paper. The error has been fixed in the paper.

Use of RNAi technology to develop a PRSV-resistant transgenic papaya.

Papaya ringspot virus (PRSV) seriously limits papaya (Carica papaya L.) production in tropical and subtropical areas throughout the world. Coat protein (CP)- transgenic papaya lines resistant to PRSV isolates in the sequence-homology-dependent manner have been developed in the U.S.A. and Taiwan. A previous investigation revealed that genetic divergence among Hainan isolates of PRSV has allowed the virus to overcome the CP-mediated transgenic resistance. In this study, we designed a comprehensive RNAi strategy targeting the conserved domain of the PRSV CP gene to develop a broader-spectrum transgenic resistance to the Hainan PRSV isolates. We used an optimized particle-bombardment transformation system to produce RNAi-CP-transgenic papaya lines. Southern blot analysis and Droplet Digital PCR revealed that line 474 contained a single transgene insert. Challenging this line with different viruses (PRSV I, II and III subgroup) under greenhouse conditions validated the transgenic resistance of line 474 to the Hainan isolates. Northern blot analysis detected the siRNAs products in virus-free transgenic papaya tissue culture seedlings. The siRNAs also accumulated in PRSV infected transgenic papaya lines. Our results indicated that this transgenic papaya line has a useful application against PRSV in the major growing area of Hainan, China.

Chondrocyte FGFR3 Regulates Bone Mass by Inhibiting Osteogenesis.

Chondrogenesis can regulate bone formation. Fibroblast growth factor receptor 3, highly expressed in chondrocytes, is a negative regulator of bone growth. To investigate whether chondrocyte FGFR3 regulates osteogenesis, thereby contributing to postnatal bone formation and bone remodeling, mice with conditional knock-out of Fgfr3 in chondrocytes (mutant (MUT)) were generated. MUT mice displayed overgrowth of bone with lengthened growth plates. Bone mass of MUT mice was significantly increased at both 1 month and 4 months of age. Histological analysis showed that osteoblast number and bone formation were remarkably enhanced after deletion of Fgfr3 in chondrocytes. Chondrocyte-osteoblast co-culture assay further revealed that Fgfr3 deficiency in chondrocytes promoted differentiation and mineralization of osteoblasts by up-regulating the expressions of Ihh, Bmp2, Bmp4, Bmp7, Wnt4, and Tgf-ß1, as well as down-regulating Nog expression. In addition, osteoclastogenesis was also impaired in MUT mice with decreased number of osteoclasts lining trabecular bone, which may be related to the reduced ratio of Rankl to Opg in Fgfr3-deficient chondrocytes. This study reveals that chondrocyte FGFR3 is involved in the regulation of bone formation and bone remodeling by a paracrine mechanism.

Gamma radiation induced darkening in barium gallo-germanate glass.

Barium gallo-germanate (BGG) glass is an important glass matrix material used for mid-infrared transmission and mid-infrared fiber laser. In this study, we investigated the γ-ray irradiation induced darkening effect of BGG glass. Optical transmittance spectra, electron paramagnetic resonance (EPR) and thermoluminescence (TL) spectra were employed to investigate the γ-ray irradiation induced defects. Two kinds of Ge-related defects in the irradiated BGG glass, named Ge-related non-bridging oxygen hole center (Ge-NBOHC) and Ge-related electron centers (GEC), were verified. In addition, the absorption bands of the two defects have been separated and the peak absorptivity of Ge-NBOHC and GEC defects is at 375 nm and 315 nm, respectively.

Deletion of FGFR3 in Osteoclast Lineage Cells Results in Increased Bone Mass in Mice by Inhibiting Osteoclastic Bone Resorption.

Fibroblast growth factor receptor 3 (FGFR3) participates in bone remodeling. Both Fgfr3 global knockout and activated mice showed decreased bone mass with increased osteoclast formation or bone resorption activity. To clarify the direct effect of FGFR3 on osteoclasts, we specifically deleted Fgfr3 in osteoclast lineage cells. Adult mice with Fgfr3 deficiency in osteoclast lineage cells (mutant [MUT]) showed increased bone mass. In a drilled-hole defect model, the bone remodeling of the holed area in cortical bone was also impaired with delayed resorption of residual woven bone in MUT mice. In vitro assay demonstrated that there was no significant difference between the number of tartrate-resistant acid phosphatase (TRAP)-positive osteoclasts derived from wild-type and Fgfr3-deficient bone marrow monocytes, suggesting that FGFR3 had no remarkable effect on osteoclast formation. The bone resorption activity of Fgfr3-deficient osteoclasts was markedly decreased accompanying with downregulated expressions of Trap, Ctsk, and Mmp 9. The upregulated activity of osteoclastic bone resorption by FGF2 in vitro was also impaired in Fgfr3-deficient osteoclasts, indicating that FGFR3 may participate in the regulation of bone resorption activity of osteoclasts by FGF2. Reduced adhesion but not migration in osteoclasts with Fgfr3 deficiency may be responsible for the impaired bone resorption activity. Our study for the first time genetically shows the direct positive regulation of FGFR3 on osteoclastic bone resorption. © 2016 American Society for Bone and Mineral Research.

[Comparation on Haversian system between human and animal bones by imaging analysis].

OBJECTIVE: To explore the differences in Haversian system between human and animal bones through imaging analysis and morphology description. METHODS: Thirty-five slices grinding from human being as well as dog, pig, cow and sheep bones were observed to compare their structure, then were analysed with the researchful microscope. RESULTS: Plexiform bone or oeston band was not found in human bones; There were significant differences in the shape, size, location, density of Haversian system, between human and animal bones. The amount of Haversian lamella and diameter of central canal in human were the biggest; Significant differences in the central canal diameter and total area percentage between human and animal bones were shown by imaging analysis. CONCLUSION: (1) Plexiform bone and osteon band could be the exclusive index in human bone; (2) There were significant differences in the structure of Haversian system between human and animal bones; (3) The percentage of central canals total area was valuable in species identification through imaging analysis.

[New improved approaches for DYS385 detection].

OBJECTIVE: To establish more sensitive methods for detection of DYS385 in routine forensic casework. METHODS: The primers recommended by Genome Database (GDB) and Schneider were used to amplify DYS385 respectively. Then, a semi-nested PCR of DYS385 was designed by using the two different primers as outer and inner primer. A series of experiments were carried out to achieve good result by adjusting the ratio of outer/inner primer and optimizing the PCR condition. RESULTS: It showed that an overall 112 bp shorter DYS385 fragments and better electrophoretic separation were obtained by using primer2B. By using the semi-nested PCR approach, the shorter specific DYS385 fragments could be amplified and detectable DNA amounted to 50 pg. CONCLUSION: This method is 20 fold more sensitive than the ordinary method.