Research on fine co-focus adjustment method for segmented solar telescope.

For segmented telescopes, achieving fine co-focus adjustment is essential for realizing co-phase adjustment and maintenance, which involves adjusting the millimeter-scale piston between segments to fall within the capture range of the co-phase detection system. CGST proposes using a SHWFS for piston detection during the co-focus adjustment stage. However, the residual piston after adjustment exceeds the capture range of the broadband PSF phasing algorithm( ± 30µm), and the multi-wavelength PSF algorithm requires even higher precision in co-focus adjustment. To improve the co-focus adjustment accuracy of CGST, a fine co-focus adjustment based on cross-calibration is proposed. This method utilizes a high-precision detector to calibrate and fit the measurements from the SHWFS, thereby reducing the impact of atmospheric turbulence and systematic errors on piston measurement accuracy during co-focus adjustment. Simulation results using CGST demonstrate that the proposed method significantly enhances adjustment accuracy compared to the SHWFS detection method. Additionally, the residual piston after fine co-focus adjustment using this method falls within the capture range of the multi-wavelength PSF algorithm. To verify the feasibility of this method, experiments were conducted on an 800mm ring segmented mirror system, successfully achieving fine co-focus adjustment where the remaining piston of all segments fell within ±15µm.

Estimation of gastric cancer burden attributable to Helicobacter pylori infection in Asia.

BACKGROUND: Helicobacter pylori causes large burden of gastric cancer (GC) in Asia. We aimed to comprehensively quantify the burden of GC attributable to H. pylori infection in Asia. METHODS: We searched related articles from January 1998 to December 2020 to obtain the prevalence and relative risks (or odds ratio) of GC associated with H. pylori in Asia. The burden of GC attributable to H. pylori infection was quantified by Population Attributable Fraction (PAF) and Disability-adjusted life-years (DALYs). RESULTS: We quantified the burden of GC attributable to H. pylori infection with 415.6 thousand DALYs and 38.03% PAF through the five included Asian countries in 2019. The study found that the burden had obvious regional differences. The DALYs ranged from 298.9 thousand in China to 1.9 thousand in Malaysia, and the PAFs were between 58.00% in Japan and 30.89% in China. The average prevalence of H. pylori in the included general population was estimated to be 56.29%. CONCLUSIONS: Helicobacter pylori poses a huge disease burden of GC to the population, and its eradication should receive attention, especially in the countries with high incidence of and mortality due to GC.

Variant of SNPs at lncRNA NEAT1 contributes to gastric cancer susceptibility in Chinese Han population.

BACKGROUND: The long noncoding RNA (lncRNA) nuclear-enriched abundant transcript 1 (NEAT1) has been implicated in many tumors risk including gastric cancer. However, the association of single nucleotide polymorphisms (SNPs) at NEAT1 with gastric cancer risk has not been studied. The aim of this study was to investigate the association between SNPs in NEAT1 and gastric cancer susceptibility. METHODS: In this study, four SNPs in lncRNA NEAT1 were selected for genotyping in 484 gastric cancer patients and 484 controls in Chinese Han population. Quantitative real-time PCR (qRT-PCR) was conducted to evaluate the potential function of rs3825071. Attributable risk percentage (ARP) and population attributable risk percentage (PARP) were used to assess the epidemiological effect. RESULTS: In the dominant model (GG), the genotypes AG + AA of rs3825071 and rs7943779 were associated with an increased risk of gastric cancer (OR = 1.72, 95%CI = 1.27-2.32 and OR = 1.63, 95%CI = 1.19-2.22). Individuals harboring ≥ 3 risk alleles have higher risk of gastric cancer (OR = 1.88, 95% CI = 1.26-2.80, P = 0.002). ARP and PARP associated with gastric cancer were 42.53% and 10.88% for rs3825071, and were 33.78% and 6.26% for rs7943779, respectively. Furthermore, compared with the genotype GG of rs3825071, the genotypes AG and AA had higher expression of NEAT1. CONCLUSIONS: We found that the genetic variations in NEAT1 were significantly associated with risk of gastric cancer. The G > A variant of rs3825071 may confer gastric cancer susceptibility by changed biological effects to increase the expression of NEAT1.

Red to Near-Infrared Mechanochromism from Metal-free Polycrystals: Noncovalent Conformational Locks Facilitating Wide-Range Redshift.

Piezochromic organic materials that present a large difference in fluorescence wavelength in the near-infrared region have important potential applications; however, few such metal-free luminophores have been reported. In this study, we design and prepare π-conjugated electron acceptors whose planar conformation can be locked by the noncovalent interactions. The planar fused-ring geometry can narrow the optical band gap, enhance the molecular stability and rigidity, as well as increase the radiative rate. As expected, the polymorphs Re-phase and Ni-phase emit the high-brightness fluorescence with wavelength maxima (λem,max ) at 615 and 727 nm, respectively. Upon full grinding, the λem,max of Re-phase is bathochromically shifted to 775 nm. The ground powder of Re-phase becomes metastable as a consequence of noncovalent conformational locking and that the red to near-infrared (large colour difference) mechanochromism arises from the high degree of conformational coplanarity. This strategy is both conceptually and synthetically simple and offers a promising approach to the development of organic piezochromic materials with wide-range redshift and excellent penetrability.

4-Di-phenyl-phosphanyl-8-methyl-1,5-naphthyridine.

In the title compound, C21H17N2P, the dihedral angles between the 1,5-naphthyridine ring system (r.m.s. deviation = 0.005 Å) and the phenyl rings are 89.18 (8) and 77.39 (8)°. The phenyl rings are almost perpendicular, making a dihedral angle of 88.12 (8)°. The only possible inter-molecular inter-action is a very weak aromatic π-π stacking inter-action [centroid-centroid separation = 3.898 (2) Å].

Body Dissatisfaction and Restricted Diet in Chinese Adolescents: A Longitudinal Analysis.

Background/Objective: Body dissatisfaction and restricted diet frequently co-occur among adolescents. However, the exact temporal relationship between the two is unclear. Furthermore, most relevant studies concentrate on Western cultural backgrounds, with only a few investigations conducted in many non-Western developing countries, including China. Therefore, this study aimed to investigate the mutual relationship between body dissatisfaction and restricted diet among Chinese adolescents. Patients/Methods: We recruited a sample of 672 middle school students from China (358 females, mean age = 14.33±0.94) and collected self-reported measures of body dissatisfaction and restricted diet at three-time points (with a five-month interval between each). We used cross-lagged models to examine the bidirectional relationship between body dissatisfaction and restricted diet. Results: (1) Both cross-sectional and cross-lagged correlation analysis showed positive correlation between body dissatisfaction and restricted diet (r=0.29-0.36; r=0.25-0.35, Ps<0.001); (2) The cross-lagged effect of body dissatisfaction on restricted diet was significant (ß=0.09, 0.13, Ps<0.01), and vice versa (ß=0.20, 0.18, Ps<0.001); (3) The differences in the associations between body dissatisfaction and restricted diet across gender were found. Conclusion/Implications: There is a bidirectional relationship between adolescents' body dissatisfaction and restricted diet. Our findings enrich the existing literature on body image and dietary health, thereby contributing to the reduction of negative body image and disordered eating among adolescents.

V-doped porous CoP nanoarrays grown on carbon cloth with optimized electronic structure for the hydrogen evolution reaction.

As an efficient, renewable and clean energy, hydrogen is expected to replace traditional fossil fuel energy in the future. Currently, platinum-based materials (Pt) are excellent electrocatalysts for hydrogen evolution reaction (HER), but their high cost and low natural abundance limit their widespread application. Therefore, it is urgent to develop low-cost, highly efficient and earth-abundant electrocatalysts to replace the precious platinum-based materials. In this study, a Co-based organic framework (ZIF-67) was grown on a flexible substrate carbon cloth (CC), and a V-doped CoP nanoarray (V-CoP/CC) was prepared using a simple in situ ion exchange/phosphating method. Due to its unique porous structure, effective doping of V atoms and the in situ electrode construction, the V-CoP/CC exhibited high electrolytic hydrogen evolution reaction (HER) performance, with an overpotential of 98 mV at a current density of 10 mA cm-2. This work has important theoretical and practical significance for in situ construction of heteroatom-doped CoP electrodes.

Novel multifunctional organic semiconductor materials based on 4,8-substituted 1,5-naphthyridine: synthesis, single crystal structures, opto-electrical properties and quantum chemistry calculation.

A series of 4,8-substituted 1,5-naphthyridines (1a-1h) have been successfully synthesised by a Suzuki cross-coupling between 4,8-dibromo-1,5-naphthyridine (4) and the corresponding boronic acids (2a-2h) in the presence of catalytic palladium acetate in yields of 41.4-75.8% and have ben well characterized. They are thermally robust with high phase transition temperatures (above 186 °C). Compounds 1b, 1e and 1f crystallized in the monoclinic crystal system with the space groups P2(1)/c, P2(1)/c and P2(1)/n, respectively. All of them show the lowest energy absorption bands (λ(max)(Abs): 294-320 nm), revealing low optical band gaps (2.77-3.79 eV). These materials emit blue fluorescence with λ(max)(Em) ranging from 434-521 nm in dilute solution in dichloromethane and 400-501 nm in the solid state. 4,8-Substituted 1,5-naphthyridines 1a-1h have estimated electron affinities (EA) of (2.38-2.72 eV) suitable for electron-transport materials and ionization potentials (IP) of 4.85-5.04 eV facilitate excellent hole-injecting/hole-transport materials properties. Quantum chemical calculations using DFT B3LYP/6-31G* showed nearly identical the lowest unoccupied molecular orbitals (LUMO) of -2.39 to -2.19 eV and the highest occupied molecular orbitals (HOMO) of -5.33 to -6.84 eV. These results demonstrate the 4,8-substituted 1,5-naphthyridines 1a-1h with a simple architecture might be promising blue-emitting (or blue-green-emitting) materials, electron-transport materials and hole-injecting/hole-transport materials for applications for developing high-efficiency OLEDs.

1,5-Bis[(2-meth-oxy-eth-oxy)meth-yl]-1,5-naphthyridine-4,8(1H,5H)-dione.

The complete mol-ecule of the title compound, C(16)H(22)N(2)O(6), is generated by crystallographic inversion symmetry. The conformation of the N-C-O-C fragment of the side chain is approximately gauche [torsion angle = -74.84 (17)°]. In the crystal, weak C-H⋯O inter-actions link the mol-ecules.

Effect of Intrinsic Pore Distribution on Ion Diffusion Kinetics of Supercapacitor Electrode Surface.

The electrolyte ion diffusion kinetics have an important impact on electrochemical energy storage. Herein, we report the effect of the intrinsic porosity of NiCoP on accelerating electrolyte ion diffusion kinetics and accommodating volume expansion during the charge/discharge process. The pore distribution model of electrode/electrolyte was designed and optimized by the finite element simulation, demonstrating the visualization and quantitative analysis of the diffusion process of the electrode/electrolyte interface with intrinsic porous structure. When the pore area ratio reached 50.01%, the theoretical diffusion coefficient of 1.41 × 10-11 m2 s-1 would be conducive to the rapid diffusion of electrolytes. The electrode gained a specific capacity of 2805 F g-1 at a current density of 1 A g-1 based on the measured diffusion coefficient (1.79 × 10-10 m2 s-1), superior to 1.44-times that of the pristine electrode. The diffusion barriers of intrinsic porous NiCoP (3.19 eV) and conventional NiCoP (47.10 eV) were calculated by the density functional theory calculations, respectively. The intrinsic porous NiCoP was prepared by the hydrothermal treatment, annealing, and phosphating processes. The pore distribution was regulated by the concentration of NaHCO3 as a pore-forming additive. This work combines simulations and experiments to form a method to optimize diffusion kinetics at the electrode/electrolyte interface.

Biochar increases Panax notoginseng's survival under continuous cropping by improving soil properties and microbial diversity.

Replant problem is widespread in agricultural production and causes serious economic losses, which has limited sustainable cultivation of Panax notoginseng (PN), a well-known medicinal plant in Asia. Here we conducted a field experiment to investigate the effectiveness and possible mechanisms of biochar to improve its survival under continuous cropping. Biochar from tobacco stems was applied at 4 rates of 9.0, 12, 15, and 18 t/ha to a soil where PN has been continuously cultivated for 10 years. After 18 months, soil properties, 5 allelochemicals, including p-hydroxybenzoic acid, vanillic acid, syringic acid, p-coumaric acid, and ferulic acid, key pathogen Fusarium oxysporum, microbial community, and PN survival rate were investigated. Our results show that 10 years' continuous PN cropping led to soil acidification, accumulation of NH4+-N and F. oxysporum, and low PN survival rate. However, biochar increased its survival rate from 6.0% in the control to 69.5% under 15 t/ha treatment. Moreover, soil pH, available P and K, organic matter content, and microbial diversity were increased while NH4+-N and allelochemicals vanillic acid and syringic acid contents were decreased under biochar treatment (P<0.05). Soil available K increased from 177 to 283 mg·kg-1 while NH4+-N decreased from 6.73 to 4.79 mg·kg-1 under 15 t/ha treatment. Further, soil pH, available P and K, and microbial diversity (bacteria and fungi) were positively correlated with PN survival rate, however, NH4+-N content was negatively correlated (P<0.05). Our study indicates that biochar effectively increased the survival rate of Panax notoginseng under continuous cropping by improving soil properties and microbial diversity.

Purification and Mechanism of Microcystinase MlrC for Catalyzing Linearized Cyanobacterial Hepatotoxins Using Sphingopyxis sp. USTB-05.

Cyanobacterial hepatotoxins, including microcystins (MCs) and nodularins (NODs), are widely produced, distributed and extremely hazardous to human beings and the environment. However, the catalytic mechanism of microcystinase for biodegrading cyanobacterial hepatotoxins is not completely understood yet. The first microcystinase (MlrA) catalyzes the ring opening of cyclic hepatotoxins, while being further hydrolyzed by the third microcystinase (MlrC). Based on the homology modeling, we postulated that MlrC of Sphingopyxis sp. USTB-05 was a Zn2+-dependent metalloprotease including five active sites: Glu56, His150, Asp184, His186 and His208. Here, the active recombinant MlrC and five site-directed mutants were successfully obtained with heterologous expression and then purified for investigating the activity. The results indicated that the purified recombinant MlrC had high activity to catalyze linearized hepatotoxins. Combined with the biodegradation of linearized NOD by MlrC and its mutants, a complete enzymatic mechanism for linearized hepatotoxin biodegradation by MlrC was revealed.

Association of triglyceride-glucose index and its interaction with obesity on hypertension risk in Chinese: a population-based study.

Hypertension and triglyceride-glucose (TyG) index are both closely associated with insulin resistance, respectively, while the role of TyG index and the association between TyG index and obesity on hypertension risk remain unclear. This study aimed to examine the association and interactive effect of TyG index and obesity on hypertension risk. There was a population-based cross-sectional survey in Henan, China. Multivariate logistic regression analysis was performed to estimate the association between TyG index and the risk of prehypertension and hypertension. The area under curves (AUC) of TyG index and joint indicators (TyG index and obesity indices) was calculated to assess the predictive ability of hypertension. The additive interaction was computed to evaluate the interactive effect between TyG index and obesity. Compared with the lowest TyG quartile, participants in the highest quartile had an increased risk of prehypertension (odds ratio (OR): 1.69, 95% confidence interval (CI): 1.18-2.44) and hypertension (OR: 2.53, 95% CI: 1.80-3.57). The AUCs of joint indicators were significantly higher than TyG index in predicting hypertension (all P < 0.01). Presence of higher TyG index enhanced the ORs of waist-to-height ratio (WHtR) and percent body fat (PBF) from 3.50 (95% CI: 2.55-4.80) to 6.51 (95% CI: 4.81-8.82), and from 3.88 (95% CI: 2.78-5.42) to 7.09 (95% CI: 5.11-9.84) with significant additive interaction on hypertension, respectively. Increased TyG index was significantly associated with a higher risk of prehypertension and hypertension in Chinese adults. Besides, our results also demonstrated the interactions of TyG index and WHtR and PBF on hypertension risk.

Genetic variant of cyclooxygenase-2 in gastric cancer: More inflammation and susceptibility.

Gastric cancer accounts for the majority cancer-related deaths worldwide. Although various methods have considerably improved the screening, diagnosis, and treatment of gastric cancer, its incidence is still high in Asia, and the 5-year survival rate of advanced gastric cancer patients is only 10%-20%. Therefore, more effective drugs and better screening strategies are needed for reducing the incidence and mortality of gastric cancer. Cyclooxygenase-2 (COX-2) is considered to be the key inducible enzyme in prostaglandins (PGs) synthesis, which is involved in multiple pathways in the inflammatory response. For example, inflammatory cytokines stimulate innate immune responses via Toll-like receptors and nuclear factor-kappa B to induce COX-2/PGE2 pathway. In these processes, the production of an inflammatory microenvironment promotes the occurrence of gastric cancer. Epidemiological studies have also indicated that non-steroidal anti-inflammatory drugs can reduce the risk of malignant tumors of the digestive system by blocking the effect of COX-2. However, clinical use of COX-2 inhibitors to prevent or treat gastric cancer may be limited because of potential side effects, especially in the cardiovascular system. Given these side effects and low treatment efficacy, new therapeutic approaches and early screening strategies are urgently needed. Some studies have shown that genetic variation in COX-2 also play an important role in carcinogenesis. However, the genetic variation analysis in these studies is incomplete and isolated, pointing out only a few single nucleotide polymorphisms (SNPs) and the risk of gastric cancer, and no comprehensive study covering the whole gene region has been carried out. In addition, copy number variation (CNV) is not mentioned. In this review, we summarize the SNPs in the whole COX-2 gene sequence, including exons, introns, and both the 5' and 3' untranslated regions. Results suggest that COX-2 does not increase its expression through the CNV and the SNPs in COX-2 may serve as the potential marker to establish risk stratification in the general population. This review synthesizes emerging insights of COX-2 as a biomarker in multiple studies, summarizes the association between whole COX-2 sequence variation and susceptibility to gastric cancer, and discusses the future prospect of therapeutic intervention, which will be helpful for early screening and further research to find new approaches to gastric cancer treatment.

Which Individuals with Positive Family History of Gastric Cancer Urgently Need Intensive Screening and Eradication of Helicobacter Pylori? A Systematic Review and Meta-Analysis.

Background: Family history may inform individuals that they are at risk of gastric cancer (GC). However, it is too extensive to conduct intensive screening strategies for all individuals with family history of GC instead of average-risk screening. To establish more precise prevention strategies, accurate risk estimates are necessary for individuals with family history of GC. Methods: We searched PubMed, EMBASE and Cochrane for all relevant studies from their inception to May 21, 2020, for cohort and case-control studies investigating the association between family history of GC and its risk. Relative risk (RR) and 95% confidence interval (CI) were pooled from studies using random-effects or fixed effects. Results: The RR of GC was 2.08 (95% CI=1.86-2.34) in individuals with family history of GC according to twenty-nine case-control studies and 1.83 (95%CI=1.67-2.01) from six cohort studies. The increased risk was higher in individuals with sibling history of GC than those with parental history of GC (RR=3.18, 95% CI=2.12-4.79 vs. RR=1.66, 95% CI=1.46-1.89, P=0.021). For individuals with 2 or more first-degree relatives (FDRs) with GC, the RR was 2.81(95% CI=1.89-3.99). Subjects with both family history and Helicobacter pylori (H. pylori) infection confer a higher risk of GC (RR = 4.03, 95%CI=2.46-6.59). Conclusion: The RR of GC among FDRs is lower than in previous studies. However, the risk of GC is markedly increased in individuals having a sibling with GC, more than 2 FDRs with GC. Intensified screening and eradication therapy for H. pylori could be considered for these individuals.

Two-level analysis of risk factors for ischemic cardiovascular disease-A community-based study from Henan, China.

BACKGROUND: Ischemic cardiovascular disease (ICVD) has high incidence and high mortality worldwide. The studies of its risk factors were mostly concentrated on an individual level, and there are scarce studies on the two levels of risk factors which include individual and regional levels. METHODS: The data were obtained from a community-based study in 4 cities and 6 counties of Henan, China. Risk factors were initially screened by one-way analysis of variance or chi-square test. Then, they were re-analyzed using a two-level logistic regression model to construct a personal disease risk prediction model. RESULTS: A two-level ICVD risk prediction model comprised 11 variables: age, body mass index (BMI), family history of hypertension, marital status, salt intake, smoking, moderate recreational physical activities, alcohol intake, and education at the individual level. Among the unalterable risk factors, for each additional unit of age and family history of hypertension, the risk of ICVD increased by 1.08 and 1.07 units [ß95% confidence interval (95%CI): 0.99-1.16, 0.97-1.17, both p < 0.0001], respectively. Among the modifiable risk factors, the ICVD risk increases by 0.67, 0.27, and 0.28 units for each additional unit of BMI, marital status, and education (ß95%CI: 0.60-0.74, p < 0.0001; ß95%CI: 0.14-0.40, p = 0.0012, 0.18-0.37, p = 0.0001). CONCLUSIONS: The two-level ICVD risk model can predict that the risk of one person for ICVD will be lower if one is younger, thinner, and well-educated without a family history of hypertension. Overall, the two-level ICVD risk prediction model gets a better fitting effect than the single-level model.

The effects of extended π-conjugation in bipyridyl ligands on the tunable photophysics, triplet excited state and optical limiting properties of Pt(ii) naphthalimidyl acetylide complexes.

Pt(ii) complexes that exhibit long-lived triplet excited state lifetimes are promising for optical power limiting materials. The introduction of large π-conjugated substituents can switch the triplet excited state to a long-lived 3π,π* state. Herein, we report four Pt(ii) diimine complexes with high π-conjugation via inserting an aryl group on the diimine ligand. Their photophysical properties were investigated using spectroscopic techniques. All the complexes exhibit strong ground absorption bands in their UV-Vis absorption spectra (maximum peaks ranging from 370 to 530 nm) and long-lived emission and triplet excited states. The insertion of π-conjugated substituents induces a pronounced red-shift in the ground state absorption and longer emission lifetime. Broadband transient absorption spectra in the visible-NIR region and Z-scan properties under 532 nm were carried out on the Pt(ii) diimine complexes, resulting in a remarkably strong reverse saturable absorption at 532 nm for nanosecond laser pulses. Otherwise, the high π-conjugation in the bipyridyl ligand increases the reverse saturable absorption. Therefore, these Pt(ii) diimine complexes with high π-conjugation are excellent candidates for devices that require strong reverse saturable absorption.

Intrinsic alterations in the hydrogen desorption of Mg2NiH4 by solid dissolution of titanium.

Achieving rapid hydrogen desorption at low temperatures is one of the main challenges for Mg-based alloys in hydrogen storage. Here, we report that the dehydrogenation process of Mg2NiH4 can be intrinsically improved with the solid dissolution of titanium into its lattices. The hydrogen desorption is suggested to be promoted by shifting the rate-limiting step from proven nucleation and/or diffusion to two-dimensional phase boundary migration based on kinetic modeling studies, for which few additions have been obtained, probably due to the understanding being confounded by other impurity phases. This alteration intrinsically results in enhanced desorption properties of Mg2NiH4 when Ti is dissolved, i.e., not only does it exhibit a decreased peak desorption temperature with a reduction in the activation energy, but it also positively changes the enthalpy value in comparison with that of the pure compound. These obtained results allow for a deep understanding of how the intrinsic desorption features are enhanced by solid dissolution, and also provide insight into improving hydrogen storage in Mg-based alloys.