Associations of perceived stress with loneliness and depressive symptoms: the mediating role of sleep quality.

BACKGROUND: Whether perceived stress is associated with loneliness and depressive symptoms in general adults, and to what extent sleep quality mediates the associations, remains unknown. The aim of this study was to estimate the associations of perceived stress with loneliness and depressive symptoms, and the mediating role of sleep quality in these associations. METHODS: Cross-sectional data on 734 participants (aged 18-87 years) were analyzed. Perceived stress was assessed using the 10-item Perceived Stress Scale (PSS-10; range 0-40). Sleep quality was assessed using the Pittsburgh Sleep Quality Index (PSQI; range 0-21). Loneliness was assessed using the three-item short form of the Revised University of California, Los Angeles (UCLA) loneliness scale (range 3-9). Depressive symptoms were assessed using the 10-item Center for Epidemiologic Studies Depression (CESD-10) Scale (range 0-30). General linear regression models, multivariable logistic regression models, and formal mediation analysis were performed. RESULTS: After adjustment for age and sex, we found that with each 1-point increment in the perceived stress score, both the loneliness score (ß = 0.07; 95% confidence interval [CI]: 0.06, 0.08) and depression score (ß = 0.45; 95% CI: 0.40, 0.49) increased significantly. Robust results were observed when adjusting for more confounders. Furthermore, sleep quality mediated 5.3% (95% CI: 1.3%, 10.0%; P = 0.014) and 9.7% (95% CI: 6.2%, 14.0%; P < 0.001) of the associations of perceived stress score with loneliness score and depression score, respectively. CONCLUSIONS: In general Chinese adults, perceived stress was positively associated with loneliness and depressive symptoms, and sleep quality partially mediated these associations. The findings reveal a potential pathway from perceived stress to mental health through sleep behaviors, and highlight the importance of implementing sleep intervention programs for promoting mental health among those who feel highly stressed.

Temporal and spatial analysis of vegetation cover change in the Yellow River Delta based on Landsat and MODIS time series data.

Based on the Landsat normalized difference vegetation index (NDVI) and the NDVI product of MODIS, this study synthesized two kinds of time-series images. The features were selected according to the characteristics of the time series, and the random forest algorithm was used for classification. Based on the classification results and GIS spatial analysis, the temporal and spatial changes in vegetation cover in the Yellow River Delta from 2000 to 2020 were studied. The results showed that from 2000 to 2020, the vegetation first increased and then decreased, and the dynamic degree of land cover change was generally low. The monthly average minimum NDVI values during the vegetation growth period mostly occurred before 2010, and the maximum values occurred after 2010. From the spatial perspective, the average vegetation area of the Yellow River Delta accounted for 31.54% of the total study area; specifically, the spatial pattern of vegetation distribution was relatively fixed, and the fixed vegetation area accounted for 63.90% of the total vegetation area. The spatial distribution had significant differences, and the vegetation was distributed radially from the center of the Yellow River to the periphery, with significant fragmentation found outside the watershed. The Yellow River had a strong interference with vegetation growth, and the stable vegetation distribution areas were concentrated near the Yellow River. The correlation coefficient between vegetation distribution and the location of the Yellow River was - 0.9964.

De Novo Transcriptome Sequencing Analysis of Goose (Anser anser) Embryonic Skin and the Identification of Genes Related to Feather Follicle Morphogenesis at Three Stages of Development.

The objective of this study was to evaluate the changes in the goose embryo transcriptome during feather development. RNA-Sequencing (RNA-Seq) was used to find the transcriptome profiles of feather follicles from three stages of embryonic dorsal skin at embryonic day 13, 18, and 28 (E13, E18, E28). The results showed that 3001, 6634, and 13,780 genes were differently expressed in three stages. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis revealed that differentially expressed genes (DEGs) in E13 vs. E18 were significantly mapped into the GO term of extracellular structure organization and the pathway of extracellular matrix (ECM)-receptor interaction. In E18 vs. E28, the top significantly mapped into GO term was the single-organism developmental process; the pathway was also the ECM-receptor interaction. DEGs in E13 vs. E28 were significantly mapped into the GO term of the multicellular organismal process and the pathway of cell adhesion molecules. Subsequently, the union of DEGs was categorized by succession cluster into eight profiles, which were then grouped into four ideal profiles. Lastly, the seven genes spatio-temporal expression pattern was confirmed by real-time PCR. Our findings advocate that interleukin 20 receptor subunit alpha (IL20RA), interleukin 6 receptor (IL6R), interleukin 1 receptor type 1 (IL-1R1), Wnt family member 3A (WNT3A), insulin-like growth factor binding protein 3 (IGFBP3), bone morphogenetic protein 7 (BMP7), and secreted-frizzled related protein 2 (SFRP2) might possibly play vital roles in skin and feather follicle development and growth processes.

Optimization technique for rolled edge control process based on the acentric tool influence functions.

In the process of computer controlled optical surfacing (CCOS), the uncontrollable rolled edge restricts further improvements of the machining accuracy and efficiency. Two reasons are responsible for the rolled edge problem during small tool polishing. One is that the edge areas cannot be processed because of the orbit movement. The other is that changing the tool influence function (TIF) is difficult to compensate for in algorithms, since pressure step appears in the local pressure distribution at the surface edge. In this paper, an acentric tool influence function (A-TIF) is designed to remove the rolled edge after CCOS polishing. The model of A-TIF is analyzed theoretically, and a control point translation dwell time algorithm is used to verify that the full aperture of the workpiece can be covered by the peak removal point of the tool influence functions. Thus, surface residual error in the full aperture can be effectively corrected. Finally, the experiments are carried out. Two fused silica glass samples of 100 mm×100 mm are polished by traditional CCOS and the A-TIF method, respectively. The rolled edge was clearly produced in the sample polished by the traditional CCOS, while residual errors do not show this problem the sample polished by the A-TIF method. Therefore, the rolled edge caused by the traditional CCOS process is successfully suppressed during the A-TIF process. The ability to suppress the rolled edge of the designed A-TIF has been confirmed.

One-dimensional ion-beam figuring for grazing-incidence reflective optics.

One-dimensional ion-beam figuring (1D-IBF) can improve grazing-incidence reflective optics, such as Kirkpatrick-Baez mirrors. 1D-IBF requires only one motion degree of freedom, which reduces equipment complexity, resulting in compact and low-cost IBF instrumentation. Furthermore, 1D-IBF is easy to integrate into a single vacuum system with other fabrication processes, such as a thin-film deposition. The NSLS-II Optical Metrology and Fabrication Group has recently integrated the 1D-IBF function into an existing thin-film deposition system by adding an RF ion source to the system. Using a rectangular grid, a 1D removal function needed to perform 1D-IBF has been produced. In this paper, demonstration experiments of the 1D-IBF process are presented on one spherical and two plane samples. The final residual errors on both plane samples are less than 1 nm r.m.s. The surface error on the spherical sample has been successfully reduced by a factor of 12. The results show that the 1D-IBF method is an effective method to process high-precision 1D synchrotron optics.

New figuring model based on surface slope profile for grazing-incidence reflective optics.

Surface slope profile is widely used in the metrology of grazing-incidence reflective optics instead of surface height profile. Nevertheless, the theoretical and experimental model currently used in deterministic optical figuring processes is based on surface height, not on surface slope. This means that the raw slope profile data from metrology need to be converted to height profile to perform the current height-based figuring processes. The inevitable measurement noise in the raw slope data will introduce significant cumulative error in the resultant height profiles. As a consequence, this conversion will degrade the determinism of the figuring processes, and will have an impact on the ultimate surface figuring results. To overcome this problem, an innovative figuring model is proposed, which directly uses the raw slope profile data instead of the usual height data as input for the deterministic process. In this paper, first the influence of the measurement noise on the resultant height profile is analyzed, and then a new model is presented; finally a demonstration experiment is carried out using a one-dimensional ion beam figuring process to demonstrate the validity of our approach.

Subaperture stitching test of large steep convex spheres.

Limited by the aperture and f/number of the transmission sphere (TS), large convex spheres with very small R/number (ratio of the radius of curvature to the aperture) cannot be tested in a single measurement with a standard interferometer. We present the algorithm and troubleshooting for subaperture stitching test of a half meter-class convex sphere with R/0.61. Totally 90 off-axis subapertures are arranged on 5 rings around the central one. Since the subaperture is so small, its surface error is comparable with that of the TS reference error. Hence a self-calibrated stitching algorithm is proposed to separate the reference error from the measurements. Another serious problem is the nonlinear mapping between the subaperture's local coordinates and the full aperture's global coordinates. The nonlinearity increases remarkably with the off-axis angle. As a result, we cannot directly remove power from the full aperture error map as we usually do. Otherwise incorrect spherical aberration will be generated. We therefore propose the sphericity assessment algorithm to match the stitched surface error with a best-fit sphere. The residual is true surface error which can be used for corrective figuring or for tolerance assessment. The self-calibrated stitching and troubleshooting are demonstrated experimentally.

Translation-reduced ion beam figuring.

A translation-reduced ion beam figuring (TRIBF) technique for five-axis ion beam figuring (IBF) plants is proposed to process large size components which cannot be processed in the traditional way. This novel technique enhances the capability of five-axis IBF plants by taking advantage of their rotation axes. The IBF kinematic model is described and the TRIBF processing technique is established by solving the motion parameters. Verification experiments are conducted on a 150 mm diameter planar mirror. This mirror was processed by TRIBF technique with only a 100 mm translation stage. The surface error was reduced from initial 10.7 nm rms to 1.3 nm rms within 97 minute processing time. The result indicates that the TRIBF processing technique is feasible and effective.

Research of polishing process to control the iron contamination on the magnetorheological finished KDP crystal surface.

A new nonaqueous and abrasive-free magnetorheological finishing (MRF) method is adopted for processing a KDP crystal. MRF polishing is easy to result in the embedding of carbonyl iron (CI) powders; meanwhile, Fe contamination on the KDP crystal surface will affect the laser induced damage threshold seriously. This paper puts forward an appropriate MRF polishing process to avoid the embedding. Polishing results show that the embedding of CI powders can be avoided by controlling the polishing parameters. Furthermore, on the KDP crystal surface, magnetorheological fluids residua inevitably exist after polishing and in which the Fe contamination cannot be removed completely by initial ultrasonic cleaning. To solve this problem, a kind of ion beam figuring (IBF) polishing is introduced to remove the impurity layer. Then the content of Fe element contamination and the depth of impurity elements are measured by time of flight secondary ion mass spectrometry. The measurement results show that there are no CI powders embedding in the MRF polished surface and no Fe contamination after the IBF polishing process, respectively. That verifies the feasibility of MRF polishing-IBF polishing (cleaning) for processing a KDP crystal.

Efficient fabrication of ultrasmooth and defect-free quartz glass surface by hydrodynamic effect polishing combined with ion beam figuring.

Material removal rate has greatly relied on the distribution of shear stress and dynamic pressure on the workpiece surface in hydrodynamic effect polishing (HEP). Fluid dynamic simulation results demonstrate that the higher rotation speed and smaller clearance will cause the larger material removal rate. Molecular dynamic (MD) calculations show the bonding energy of Si-O in the silicon-oxide nanoparticle is stronger than that in the quartz glass, and therefore the atoms can be dragged away from the quartz glass surface by the adsorbed silicon-oxide nanoparticle. The deep subsurface damage cannot be efficiently removed by HEP due to its extremely low removal rate. However, the subsurface damaged layer can be quickly removed by ion beam figuring (IBF), and a thinner layer containing the passivated scratches and pits will be left on the surface. The passivated layer is so thin that can be easily removed by HEP process with a low material rate under the large wheel-workpiece clearance. Combined with the IBF process, the subsurface damage and surface scratches have been efficiently removed after the HEP process. Meanwhile there are not obvious duplicated marks on the processed surface and the surface roughness has been improved to 0.130nm rms, 0.103nm Ra.

Reconfigurable optical null based on counter-rotating Zernike plates for test of aspheres.

In off-axis subapertures of most aspheres, astigmatism and coma dominate the aberrations with approximately quadratic and linear increase as the off-axis distance increases. A pair of counter-rotating Zernike plates is proposed to generate variable amount of Zernike terms Z4 and Z6, correcting most of the astigmatism and coma for subapertures located at different positions on surfaces of various aspheric shapes. The residual subaperture aberrations are then reduced within the vertical dynamic range of measurement of the interferometer. The plates are fabricated with computer generated holograms and the experimental results show the variable aberration correction effect without ghost fringes. The same plates are reconfigurable by counter-rotating to enable near-null test of various aspheres flexibly.

Surface evaluation and evolution during hydrodynamic effect polishing for quartz glass.

Hydrodynamic effect polishing (HEP), a noncontact machining process, can realize the processed surface roughness as small as atomic level. To investigate the subsurface structure, the HEP processed quartz glass surface was etched by the hydrofluoric acid solution. It has been proved that HEP is a polishing method with the ability to process the surface with atomic-level flatness and damage-free surface/subsurface. It has been found that the microplastic scratches on the lap prepolished glass were obviously exposed when the thin redeposition layer was removed. Then the scratches were gradually removed and surface roughness decreased quickly as the removal depth increased. The surface becomes very smooth and the surface roughness maintains at an atomic level when the subsurface damage is removed clearly. The experimental results demonstrated that the defects such as the scratches parallel to the rotational axis of the wheel were firstly removed during the polishing process, and then the defects vertical to the wheel rotational axis were removed.

Control of mid-spatial frequency errors considering the pad groove feature in smoothing polishing process.

Mid-spatial frequency error (MSFR) should be strictly controlled in modern optical systems. As an effective approach to suppress MSFR, the smoothing polishing (SP) process is not easy to handle because it can be affected by many factors. This paper mainly focuses on the influence of the pad groove, which has not been researched yet. The SP process is introduced, and the important role of the pad groove is explained in detail. The relationship between the contact pressure distribution and the groove feature including groove section type, groove width, and groove depth is established, and the optimized result is achieved with the finite element method. The different kinds of groove patterns are compared utilizing the numerical superposition method established scrupulously. The optimal groove is applied in the verification experiment conducted on a self-developed SP machine. The root mean square value of the MSFR after the SP process is diminished from 2.38 to 0.68 nm, which reveals that the selected pad can smooth out the MSFR to a great extent with proper SP parameters, while the newly generated MSFR due to the groove can be suppressed to a very low magnitude.

Generalized numerical pressure distribution model for smoothing polishing of irregular midspatial frequency errors.

The smoothing effect of the rigid lap plays an important role in controlling midspatial frequency errors (MSFRs). At present, the pressure distribution between the polishing pad and processed surface is mainly calculated by Mehta's bridging model. However, this classic model does not work for the irregular MSFR. In this paper, a generalized numerical model based on the finite element method (FEM) is proposed to solve this problem. First, the smoothing polishing (SP) process is transformed to a 3D elastic structural FEM model, and the governing matrix equation is gained. By virtue of the boundary conditions applied to the governing matrix equation, the nodal displacement vector and nodal force vector of the pad can be attained, from which the pressure distribution can be extracted. In the partial contact condition, the iterative method is needed. The algorithmic routine is shown, and the applicability of the generalized numerical model is discussed. The detailed simulation is given when the lap is in contact with the irregular surface of different morphologies. A well-designed SP experiment is conducted in our lab to verify the model. A small difference between the experimental data and simulated result shows that the model is totally practicable. The generalized numerical model is applied on a Φ500 mm parabolic surface. The calculated result and measured data after the SP process have been compared, which indicates that the model established in this paper is an effective method to predict the SP process.

Influence law of structural characteristics on the surface roughness of a magnetorheological-finished KDP crystal.

A new nonaqueous and abrasive-free magnetorheological finishing (MRF) method is adopted for processing potassium dihydrogen phosphate (KDP) crystal due to its low hardness, high brittleness, temperature sensitivity, and water solubility. This paper researches the influence of structural characteristics on the surface roughness of MRF-finished KDP crystal. The material removal by dissolution is uniform layer by layer when the polishing parameters are stable. The angle between the direction of the polishing wheel's linear velocity and the initial turning lines will affect the surface roughness. If the direction is perpendicular to the initial turning lines, the polishing can remove the lines. If the direction is parallel to the initial turning lines, the polishing can achieve better surface roughness. The structural characteristic of KDP crystal is related to its internal chemical bonds due to its anisotropy. During the MRF finishing process, surface roughness will be improved if the structural characteristics of the KDP crystal are the same on both sides of the wheel. The processing results of (001) plane crystal show we can get the best surface roughness (RMS of 0.809 nm) if the directions of cutting and MRF polishing are along the (110) direction.

FKBP3, a poor prognostic indicator, promotes the progression of LUAD via regulating ferroptosis and immune infiltration.

BACKGROUND: Ferroptosis was reported to possess the therapeutic potentials in various human cancers. In the present study, we explored the expression, clinical significance and the molecular mechanism of FK506 binding protein 3 (FKBP3) in the progression of lung adenocarcinoma (LUAD). MATERIAL AND METHOD: Cox regression was performed to obtain the prognosis related to differentially expressed genes (DEGs) in LUAD datasets from TCGA. We also downloaded the ferroptosis-related gene datasets from GeneCards. Venn diagram was performed to find the intersecting genes and FKBP3 was selected as the targeted gene by analyzing the diagnostic and prognostic values of Top10 intersecting genes. Moreover, univariate and multivariate analyses were performed to evaluate the association between clinicopathological factors and survival rates. GO/KEGG and GSEA analysis was performed to explore the function of FKBP3 in LUAD progression. Protein-protein interaction (PPI) network was performed via STRING database and the top10 hub genes were selected. Finally, the relationship between FKBP3 and immune infiltration was explored by ssGSEA analysis. RESULTS: Firstly, 184 genes associated with the prognosis of LUAD and ferroptosis were obtained. FKBP3 was found to be significantly associated with a poor overall survival rate of LUAD patients. Immunohistochemical staining results showed that FKBP3 was highly located in cytoplasm and membrane of cells in LUAD tissues. PPI network analysis results showed that HDAC1, YY1, HDAC2, MTOR, PSMA3, PIN1, NCL, C14orf166, PIN4, and LARP6 were the top10 hub genes. Furthermore, spearman analysis results showed that the expression of FKBP3 was positively correlated with the abundance of Th2 cells and T helper cells. CONCLUSION: High level of FKBP3 was associated with poor prognostic outcomes of LUAD patients, which also inhibited immune infiltration in LUAD tissues. Additionally, FKBP3 was involved in regulating the ferroptosis process in LUAD patients. Thus, FKBP3 possessed the tumor promotion role might be involving in regulating ferroptosis and immune infiltration in LUAD progression.

Effects of combined nitrogen and phosphorus application on soil phosphorus fractions in alfalfa (Medicago sativa L.) production in China.

Nitrogen (N) and phosphorus (P) fertilizers change the morphological structure and effectiveness of P in the soil, which in turn affects crop growth, yield, and quality. However, the effects and mechanism of combined N and P application on the content of P fractions and the transformation of effective forms in alfalfa (Medicago sativa L.) production is unclear. This experiment was conducted with four levels of N: 0 (N0), 60 (N1), 120 (N2) and 180 kg·ha-1 (N3); and two levels of P (P2O5): 0 (P0) and 100 kg·ha-1 (P1). The results indicated that, under the same N level, P application significantly increased soil total N, and total P, available P, and content of various forms of inorganic P when compared to no P application, while decreasing the content of various forms of organic P and pH value. In general, under P0 conditions, soil total N content tended to increase with increasing N application, while total P, available P content, pH, inorganic P content in all forms, and organic P content in all forms showed a decreasing trend. When compared to no N application, insoluble P (Fe-P, O-P, Ca10-P) of the N application treatments was reduced 2.80 - 22.72, 2.96 - 20.42, and 5.54 - 20.11%, respectively. Under P1 conditions, soil total N and O-P tended to increase with increasing N application, while, pH, Ca2-P, Al-P, Fe-P, Ca10-P, and organic P content of each form tended to decrease. Total P, available P, and labile organic P (LOP) of N application reduced 0.34 - 8.58, 4.76 - 19.38, and 6.27 - 14.93%, respectively, when compared to no application. Nitrogen fertilization reduced the soil Ca2-P ratio, while P fertilization reduced soil Fe-P, moderately resistant organic P (MROP), and highly resistant P (HROP) ratios, and combined N and P elevated the Ca8-P to LOP ratio. The results of redundancy analysis showed that soil total N content, available P content, and pH were the key factors affecting the conversion of P fractions in the soil. Nitrogen and P reduced the proportion of soil insoluble P, promoted the activation of soil organic P, resulting in accumulation of slow-acting P in the soil, thereby improving the efficiency of soil P in alfalfa production.

Ultrasmooth surface polishing based on the hydrodynamic effect.

This study will examine the feasibility of applying the hydrodynamic effect to ultrasmooth surface polishing. Differing from conventional pad polishing, hydrodynamic effect polishing is noncontact, as the polishing wheel is floated on the workpiece under the hydrodynamic effect. The material removal mechanism and the removal contour are analyzed in detail. Dynamic pressure and shear stress distribution on the workpiece are numerically simulated in three dimensions under different clearances between the polishing wheel and the workpiece, showing that the dynamic pressure distribution and the magnitude of shear stress on the workpiece are greatly influenced by the clearance. It is clearly demonstrated from fixed-point polishing experiments that material removal rates and contours are determined by the combined action of dynamic pressure and shear stress. A material removal analytic model is presented with the hydrodynamic effect polishing method. Finally, a polishing experiment is conducted on a quartz glass and the plastic scratches, cracks, and bumpy structures on the initial surface are clearly removed. Moreover, the processed surface roughness is improved to 0.145 nm rms, 0.116 nm Ra.

Material removal mode affected by the particle size in fluid jet polishing.

As a newly developed ultrasmooth polishing technique, fluid jet polishing (FJP) has been widely used for optical glass polishing. The size of the particle in the polishing slurry has a great influence on the material removal rate and quality of the processed surface. The material removal mode affected by the particle size is investigated in detail. Particle trajectories with different size are calculated by numerical simulations in the FJP process. Simulation results demonstrate that the particle with large size will seriously deviate from the fluid streamline and almost impact on the workpiece along a straight line in the initial incident direction. The larger is the particle size, the more deviation will occur. Impact models are established based on different particle trajectories. A polishing experiment was conducted to verify the feasibility of the mode. Experiment results show that the particle size has a great influence on the material removal mode in FJP with the same process parameters. Material is removed in the plastic mode with higher removal rate and worse surface roughness for a larger-sized particle, while the material removal occurring in the elastic mode has a much lower removal rate and smoother surface for the smaller-sized particle. Material is removed by chemical impact reaction between the particle and the surface within the elastic mode, and a smooth surface with no damage is obtained after the FJP process.

Low-content SnO2 nanodots on N-doped graphene: lattice-confinement preparation and high-performance lithium/sodium storage.

Rational construction of nanosized anode nanomaterials is crucial to enhance the electrochemical performance of lithium-/sodium-ion batteries (LIBs/SIBs). Various anode nanoparticles are created mainly via templating surface confinement, or encapsulation within precursors (such as metal-organic frameworks). Herein, low-content SnO2 nanodots on N-doped reduced graphene oxide (SnO2@N-rGO) were prepared as anode nanomaterials for LIBs and SIBs, via a distinctive lattice confinement of a CoAlSn-layered double hydroxide (CoAlSn-LDH) precursor. The SnO2@N-rGO composite exhibits the advantagous features of low-content (17.9 wt%) and uniform SnO2 nanodots (3.0 ± 0.5 nm) resulting from the lattice confinement of the Co and Al species to the surrounded Sn within the same crystalline layer, and high-content conductive rGO. The SnO2@N-rGO composite delivers a highly reversible capacity of 1146.2 mA h g-1 after 100 cycles at 0.1 A g-1 for LIBs, and 387 mA h g-1 after 100 cycles at 0.1 A g-1 for SIBs, outperforming N-rGO. Furthermore, the dominant capacitive contribution and the rapid electronic and ionic transfer, as well as small volume variation, all give rise to the enhancement. Precursor-based lattice confinement could thus be an effective strategy for designing and preparing uniform nanodots as anode nanomaterials for electrochemical energy storage.