Plumbogaidonnayite, ideally PbZrSi3O9⋅2H2O, is a new gaidonnayite-group mineral discovered as a secondary product derived from the alteration of eudialyte from the Saima alkaline complex, China. It occurs as aggregates (up to 1 mm) composed of subhedral to anhedral or platy crystals (individually 5–50 μm), associated closely with microcline, natrolite, aegirine, gaidonnayite, georgechaoite, zircon, bobtraillite and britholite-(Ce) in eudialyte pseudomorphs. The crystals are transparent, colourless or light brown with a vitreous lustre. Plumbogaidonnayite is brittle with conchoidal fracture, and it has a Mohs hardness of ~5 and a calculated density of 3.264 g/cm3. It is optically biaxial (+) with α = 1.61(3), β = 1.63(3) and γ = 1.66(4). The calculated 2V is 80°, with the optical orientations X, Y and Z parallel to the crystallographic a, b and c axes, respectively. The empirical formula is (Pb0.70Ca0.17Ba0.01K0.11Na0.01Y0.01)Σ1.01(Zr1.00Hf0.01Ti0.01)Σ1.02Si3.01O9⋅2H2O calculated on the basis of nine oxygen atoms per formula unit and assuming the occurrence of two H2O groups. Plumbogaidonnayite is orthorhombic, P21nb, a = 11.7690(4) Å, b = 12.9867(3) Å, c = 6.66165(16) Å, V = 1018.17(5) Å3 and Z = 4. The nine strongest lines of its powder XRD pattern [d in Å (I, %) (hkl)] are: 6.489 (36) (020), 5.803 (100) (101), 4.661 (27) (021), 4.336 (29) (121), 3.640 (30) (221), 3.114 (79) (112), 2.947 (27) (400), 2.622 (27) (241) and 2.493 (27) (312). Plumbogaidonnayite has a similar spiral chain framework structure with gaidonnayite and georgechaoite, which is composed of SiO4 tetrahedra and ZrO6 octahedra, but with disordered extra-framework sites (cations and H2O groups) characterised by the substitution of 2Na+ (K+)→Pb2+ (Ca2+) + □ (vacancy). The discovery of plumbogaidonnayite adds a new perspective on the cation ordering and heterovalent substitution mechanism in gaidonnayite-group minerals.

Accurately predicting neurosyphilis prior to a lumbar puncture (LP) is critical for the prompt management of neurosyphilis. However, a valid and reliable model for this purpose is still lacking. This study aimed to develop a nomogram for the accurate identification of neurosyphilis in patients with syphilis. The training cohort included 9,504 syphilis patients who underwent initial neurosyphilis evaluation between 2009 and 2020, while the validation cohort comprised 526 patients whose data were prospectively collected from January 2021 to September 2021. Neurosyphilis was observed in 35.8% (3,400/9,504) of the training cohort and 37.6% (198/526) of the validation cohort. The nomogram incorporated factors such as age, male gender, neurological and psychiatric symptoms, serum RPR, a mucous plaque of the larynx and nose, a history of other STD infections, and co-diabetes. The model exhibited good performance with concordance indexes of 0.84 (95% CI, 0.83–0.85) and 0.82 (95% CI, 0.78–0.86) in the training and validation cohorts, respectively, along with well-fitted calibration curves. This study developed a precise nomogram to predict neurosyphilis risk in syphilis patients, with potential implications for early detection prior to an LP.

Polycarboxylate superplasticizer (PCE) is a widely used water-reducing agent that can reduce significantly the water demand of concrete, which reduces the porosity and enhances the strength and durability of the concrete. (The PCE consists of a single backbone with many long PEO side chains.) Generally, aggregate occupies >70 wt.% of concrete; clay minerals are ubiquitous in nature and are difficult to avoid in mined aggregates. Clay minerals in aggregate often render the PCE ineffective and give rise to rapid loss of the fluidity of the concrete; this phenomenon is referred to as ‘poor clay tolerance of PCE.’ Though the poor clay tolerance of PCE is known widely, the relationship between the clay tolerance and the molecular structure of the PCE, in particular the effect of the side-chain structures, on clay tolerance is not understood completely. The objective of the present study was to determine the effect of different grafting densities of polyethylene oxide (PEO) side chains on the clay tolerance of PCE. The raw materials included mainly PCE, which was synthesized using acrylic acid and isopentenol polyoxyethylene ether, and a natural montmorillonite (Mnt), one of the most common clay minerals. The loss of fluidity of the cement paste was tested to assess the clay tolerance; total organic carbon was used to measure the amount of PCE adsorbed; X-ray diffraction, transmission electron microscopy, Fourier-transform infrared spectroscopy, and thermogravimetric analysis were used to investigate the microstructure of the intercalated Mnt. The results showed that preventing the superficially adsorbed PCE from being intercalated into Mnt was of great importance in terms of the improvement in clay tolerance of PCE, which increased with greater grafting density of PEO in the side chain of the PCE. The results also suggested the possibility that polymers which intercalate preferentially into the Mnt could improve significantly the clay tolerance of the PCE system.

High temperature and a large salt content weaken the surface hydration ability of clay particles in drilling fluid, reduce zeta potential, agglomerate clay particles, increase particle size, and destroy the stability of drilling mud. A filtrate reducer is required, therefore, to maintain the zeta potential of the clay, prevent the agglomeration of clay particles, and maintain good performance of the drilling mud at high temperature and high salt content. To prepare temperature- and salt-resistant polymer filtrate reducer, a betaine monomer was synthesized and copolymerized with a conventional monomer. A betaine monomer 3-(dimethyl (4-vinyl benzyl) ammonia) propyl sulfonate (DVBAPS) was synthesized and then used to create a copolymer filtrate reducer. The copolymer filtrate reducer, referred to as PAAAND, was prepared by free radical copolymerization with 2-acrylamide-2-methylpropane sulfonic acid, acrylic acid, N-vinyl pyrrolidone, acrylamide, and DVBAPS. The optimum synthesis conditions were determined by single factor evaluation, and the chemical structure of the PAAAND was confirmed by Fourier-transform infrared spectroscopy and 1H nuclear magnetic resonance spectroscopy. Results from particle-size distribution and zeta-potential measurements showed that PAAAND increased the zeta potential of clay particles and the distribution width of particles size, which served to maintain the stability of the drilling mud under high-temperature and high-salt conditions. The results of scanning electron microscopy showed that PAAAND made the filter cake formed by clay particles smoother and denser, which reduced filtration loss. The reduction in filtrate loss continued even after aging at high temperature, and, thus, PAAAND performed better than commercial products.

This study aimed to assess how Bacillus subtilis and Enterococcus faecium co-fermented feed (FF) affects the antioxidant capacity, muscle fibre types and muscle lipid profiles of finishing pigs. In this study, a total of 144 Duroc × Berkshire × Jiaxing Black finishing pigs were randomly assigned into three groups with four replicates (twelve pigs per replication). The three treatments were a basal diet (0 % FF), basal diet + 5 % FF and basal diet + 10 % FF, respectively. The experiment lasted 38 d after 4 d of acclimation. The study revealed that 10 % FF significantly increased the activity of superoxide dismutase (SOD) and catalase (CAT) compared with 0 % FF group, with mRNA levels of up-regulated antioxidant-related genes (GPX1, SOD1, SOD2 and CAT) in 10 % FF group. 10 % FF also significantly up-regulated the percentage of slow-twitch fibre and the mRNA expression of MyHC I, MyHC IIa and MyHC IIx, and slow MyHC protein expression while reducing MyHC IIb mRNA expression. Lipidomics analysis showed that 5 % FF and 10 % FF altered lipid profiles in longissimus thoracis. 10 % FF particularly led to an increase in the percentage of TAG. The Pearson correlation analysis indicated that certain molecular markers such as phosphatidic acid (PA) (49:4), Hex2Cer (d50:6), cardiolipin (CL) (72:8) and phosphatidylcholine (PC) (33:0e) could be used to indicate the characteristics of muscle fibres and were closely related to meat quality. Together, our findings suggest that 10 % FF improved antioxidant capacity, enhanced slow-twitch fibre percentage and altered muscle lipid profiles in finishing pigs.

Rapid changes in economic, environmental and social conditions generate both problems and opportunities in agriculture. The cycle from problem identification through discovery of potential solutions is lengthy. The objective of this study was to use collaborative methods to speed the cycle of discovery in sustainable organic strawberry (Fragaria × ananassa) production systems in the southeastern USA. This method, stakeholder-driven adaptive research (SDAR), combines farmers' experiential knowledge with scientists' experimental knowledge to develop rigorous research design collectively. Farmers evaluated our biological research and co-designed research experiments with scientists. Farmers and other stakeholders (1) evaluated on-station experiments individually and then made recommendations as a group, (2) served as advisory council members to direct our goals and objectives, and (3) conducted farmer field trials where they implemented aspects of our on-station experiments under their management regimes. The results eliminated potential solutions that were not feasible, ineffective or too costly for farmers to adopt. Key results included eliminating treatments using high tunnel systems altogether on one field trial on a University of Florida (UF) research facility, adding a leguminous cover crop mix treatment, adding companion planting, and eliminating strawberry cultivars Strawberry Festival and Florida Beauty from our research trials. Our proposed methodology allows farmers and other stakeholders to inform the biological research from design through dissemination to reduce the time needed to create research products in an era of rapid bio-physical, social and economic change. Accelerating the discovery cycle could significantly improve our ability to identify and address threats to the USA and global food and fiber production system.

A non-local, ordinary state-based, peridynamic elastoplastic model is formulated to numerically simulate the fracture of reinforced concrete materials. Several basic definitions are first discussed to avoid confusion; and then, a detailed derivation of the force vector state is presented, leading to a unified expression of force state for one-, two- and three-dimensional elasticity problems. Furthermore, an ordinary state-based peridynamic (OSB PD) elastoplastic analysis approach is developed for both plastic compressible and incompressible materials, including the constitutive relationship, the yield function, the consistency condition and the plasticity flow rule. The peridynamic predictions of a quasi-static deformation of the steel rods are in good agreement with the analytical solution. Moreover, the OSB PD plasticity is verified by analyzing a square plate with or without a central hole suffering different loading-unloading paths. Finally, a two dimensional reinforced concrete clamped beam subjected to impact loading is simulated with the proposed OSB PD elastoplasticity, demonstrating its capability in capturing the damage characteristics and structural failure behavior. Simulation results show good accuracy of the peridynamics in simulating elastoplastic problems.

Coral microatolls have been long used as precise indicators of past sea level, but their use for precise definition of detailed sea-level fluctuations is still rare. Here we report twelve high-precision thermal ionization mass spectrometric 230Th ages for twelve rims of five mid-Holocene microatolls from an emerged reef terrace at Leizhou Peninsula, northern South China Sea. This is a tectonically stable area, enabling us to reconstruct both the timing and trajectory of local sea-level fluctuations accurately. The elevations of these microatoll rims and cores were accurately determined relative to the surface of modern living microatolls at the same site. The results indicate that the sea level during the period of 7050–6600 yr bp (years before AD 1950) was about 171 to 219 cm above the present, with at least four cycles of fluctuations. Over this 450 yr interval, sea level fluctuated by 20–40 cm on century scales.

Recent evidence shows that excess nicotinamide can cause epigenetic changes in developing rats. The aim of the present study was to investigate the effects of maternal nicotinamide supplementation on the fetus. Female rats were randomised into four groups fed a standard chow diet (control group) or diets supplemented with 1 g/kg of nicotinamide (low-dose group), 4 g/kg of nicotinamide (high-dose group) or 4 g/kg of nicotinamide plus 2 g/kg of betaine (betaine group) for 14–16 d before mating and throughout the study. Fetal tissue samples were collected on the 20th day of pregnancy. Compared with the control group, the high-dose group had a higher fetal death rate, and the average fetal body weight was higher in the low-dose group but lower in the high-dose group. Nicotinamide supplementation led to a decrease in placental and fetal hepatic genomic DNA methylation and genomic uracil contents (a factor modifying DNA for diversity) in the placenta and fetal liver and brain, which could be completely or partially prevented by betaine. Moreover, nicotinamide supplementation induced tissue-specific alterations in the mRNA expression of the genes encoding nicotinamide N-methyltransferase, DNA methyltransferase 1, catalase and tumour protein p53 in the placenta and fetal liver. High-dose nicotinamide supplementation increased fetal hepatic α-fetoprotein mRNA level, which was prevented by betaine supplementation. It is concluded that maternal nicotinamide supplementation can induce changes in fetal epigenetic modification and DNA base composition. The present study raises the concern that maternal nicotinamide supplementation may play a role in the development of epigenetic-related diseases in the offspring.

In this paper, the plasma-filling model was extrapolated to the case of a hohlraum driven by a shaped laser pulse, and this extended model was used to obtain an initial design of the hohlraum size. A density criterion of ne = 0.1 was used for designing hohlraums which have low plasma filling with maximum achievable radiation. The method was successfully used to design a half hohlraum size with a three-step laser pulse on SGIII prototype and a U hohlraum size with shaped laser pulse for ignition. It was shown that the extended model with the criterion can provide reasonable initial design of a hohlraum size for optimal designing with a two-dimensional code.

An experiment on Al-Cu impedance-match targets, carried out at the Shenguang highpower laser facility, is described. The shock adiabat of Cu in the pressure region 0.4- 0.8 TPa, measured experimentally, is close to the extrapolated results of the data at lower pressure obtained with a high-explosive loading facility and also is in agreement with the data at high pressure measured in the underground nuclear test environment.

Hyper-Rayleigh scattering (HRS) or incoherent second-order light scattering technique has been used to investigate the second-order optical nonlinearities of nanoparticles and seems sensitive to nanoparticle aggregation. In the present work, CdS and ZnS nanoparticle colloids are prepared by the method of colloidal chemistry. From absorption spectra their average diameters are determined to be 5.0 nm for CdS and 2.5 nm for ZnS. Composite CdS-ZnS colloids are obtained by mixing the two colloids at different concentration ratio. The formation of the composites is confirmed by fluorescence measurement. The reduction of emission intensity of the ZnS colloid at 428 nm is observed with increasing CdS concentration, due to fluorescence quenching of the ZnS colloid after forming CdS-ZnS composites. The apparent combining constant of the two nanoparticles is determined to be 8.1×104 mol−1.L by fitting the relative fluorescence intensity of F0/F vs. the added CdS concentration. Upon 1064 nm laser pulse excitation, HRS signal is determined at frequency-doubling wavelength (532 nm) using photomultiplier tube (PMT). HRS experiments show that the composite CdS-ZnS colloids exhibit stronger HRS signal than both CdS and ZnS colloids, and a maximum of HRS signal appears at concentration ratio of [CdS]/[ZnS]=1. This is attributed to that the composite CdS-ZnS nanoparticles have lower symmetry which contributes substantially to the second-order optical nonlinearity of nanoparticles in the electric dipole approximation.

The design of Gallium Nitride based Metal-Semiconductor-Metal Ultra-Violet detector is discussed. We introduce a simulation model using Medici to describe the performances of such detectors. Structure parameters, such as the inter-digitated electrode dimension and the GaN layer thickness, are optimized for response current and time using this model. The simulation results can be explained by the variation of depletion region. We introduce the “effective electric field intensity” to describe the depletion region. The relationship between the “effective electric field intensity” and structure parameters are simulated and discussed.