Revealing synergetic structural activation of a CuAu surface during water-gas shift reaction.

Bimetallic alloy catalysts show strong structural and compositional dependence on their activity, selectivity, and stability. Often referred to as the "synergetic effect" of two metal elements in the alloys, their detailed dynamic information, structurally and chemically, of catalyst surface under reaction conditions remains largely elusive. Here, using aberration-corrected environmental transmission electron microscopy, we visualize the atomic-scale synergetic surface activation of CuAu under a water­gas shift reaction condition. The unique "periodic" structural activation largely determines the dominating reaction pathway, which is related to a possible "carboxyl" reaction route corroborated by density functional theory­based calculation and ab initio molecular dynamics simulation. These results demonstrate how the alloy surface is activated and catalyzes the chemical reaction, which provides insights into catalyst design with atom precision.

Deciphering the Metal-Support Interaction of Au/ZnO Catalyst Induced by H2 and O2 Pretreatment.

Metal-support interaction (MSI) provides great possibilities to tune the activity, selectivity, and stability of heterogeneous catalysts. Herein, the Au/ZnO catalyst is prepared by commercial ZnO and chloroauric acid, and the structure evolution of the catalyst pretreated by H2 and O2 gas at varied temperature is investigated to provide mechanistic insights of MSI. It is found that the H2 treatment at 300 °C and above can induce the formation of both the ZnOx overlayer and bulk Au-Zn alloy. In contrast, the O2 treatment can form the ZnOx overlayer at 500 °C and above without the formation of Au-Zn alloy. It is also revealed that the ZnOx overlayer is dynamically stable (permeable), which can provide access for reactant molecules during the reaction process. And, the Au-Zn alloy can recover to Au and ZnO under the CO oxidation reaction condition, which can be deemed as a re-activation process that endows H2 -treated samples with the superior activity and stability.

Mn(II) Coordination Complex Loaded Hydrogel: Synthesis, Characterization, Fluorescence Properties, and Application in Treating Knee Arthritis.

Using a mixed-ligand approach, we successfully obtained two Mn(II)-based coordination compounds, namely [Mn2(L1)(TBIP)·H2O]n (1) and [Mn2(L2)(NPTA)·H2O]n (2) (where L1 and L2 are 1,4-bis(thiabenzimidazol-1-ylmethyl)benzene and 1,2-bis(thiabenzimidazol-1-ylmethyl)benzene, H2NPTA is 2-nitroterephthalic acid, and H2TBIP is 5-tert-butylisophthalic acid). Fluorescence performance testing of complexes 1 and 2 showed excellent green and blue fluorescence properties. Based on this, we further prepared HA/CMCS hydrogels using natural polysaccharides hyaluronic acid (HA) and carboxymethyl chitosan (CMCS) as raw materials and studied their internal structural characteristics using scanning electron microscopy. Using "Duhuo Jisheng Decoction" as a drug model, two metal gel scaffolds loaded with "Duhuo Jisheng Decoction" were prepared, and their potential for treating knee osteoarthritis was evaluated.

17ß-estradiol activates SOX6 to balance the anabolism and catabolism via estrogen receptor 2 in chondrocyte.

We investigated the influence of 17ß-estradiol (17ß-E2) on cartilage extracellular matrix (ECM) homeostasis in postmenopausal women. We focused on the roles of estrogen receptors (ESR) and SOX6 in 17ß-E2-mediated stimulation of ECM metabolism during chondrocyte (CH) degeneration. We compared the expression of anabolic genes (collagen II and aggrecan) and catabolic genes (MMPs and TIMPs) in IL-1ß-induced CH degeneration in vitro, with and without 17ß-E2 supplementation. We separately silenced the SOX6, ESR1, and ESR2 genes in CHs to determine their impact on 17ß-E2 treatment. Additionally, we used Chromatin immunoprecipitation followed by DNA sequencing (ChIP-seq) and luciferase assays to investigate protein-DNA interactions within ESR2 and SOX6-promoter complexes. After three days of IL-1ß treatment, ESR1/2, SOX6, collagen II, aggrecan, and TIMP1/3 were decreased, while MMP3/9/13 were increased. The addition of 17ß-E2 partially reversed these effects, but silencing SOX6, ESR1, or ESR2 weakened the protective effects of 17ß-E2. Silencing ESR2, but not ESR1, abolished the upregulation of SOX6 induced by 17ß-E2. ESR2 was found to bind the SOX6 promoter and regulate SOX6 expression. 17ß-E2 upregulates SOX6 through ESR2 mediation, and the synergistic effect of 17ß-E2 and ESR2 on SOX6 balances ECM metabolism in CHs.

Temperature effects on axial dispersion in a photopolymer-based holographic lens.

This study aims to discover whether temperature has an effect on axial dispersion in a photopolymer-based holographic lens. A typical coaxial holographic lens is recorded in the acrylamide polymer system. The axial dispersion spectrum is read and collected by using a supercontinuum source and spectrometer. The temperature effects on axial dispersion in a photopolymer-based holographic lens are investigated experimentally. With increasing temperature from 23°C to 70°C, the diffraction spectrum shifts, and the axial dispersion is shortened evidently. The peak wavelength of the dispersion spectrum shifts from 629.05 to 612.50 nm with an obvious blueshift of 16.55 nm. The spatial position of the peak wavelength also decreases from around 40 to 22 mm from the material surface. Simultaneously, the position sensitivity of the device reduces from 2.53 to 1.50 nm/mm. The shortening of the effective focal length and reduction of the diffraction intensity indicate that the high temperature above 40°C is a disadvantageous factor for actual use of a holographic lens-based spectral confocal measuring device. In practical application, a constant temperature is a significant means to ensure the measurement accuracy and range.

Shear deformation response of a holographic sensor based on elastic poly(MMA-co-LMA) photopolymer.

A holographic sensor based on camphorquinon doped poly (methyl methacrylate-co-lauryl methacrylate) (poly (MMA-co-LMA)) elastic photopolymer is developed for characterizing the shear deformation of material. A shear angle and its transverse displacement, which are induced by a couple of shear stresses, are analyzed using a diffraction spectrum of a transmission holographic sensor. The dependence of the peak wavelength shift on the shear deformation presents a good linear relationship which provides a quantitative characterization means. The detectable maximum of the shear angle exceeds 26.1 deg, and the peak wavelength shift closes to 4.0 nm. The available sensitivity is better than 3.33 deg/0.5 nm (shear angle/wavelength shift) using a commercial spectrometer with 0.5 nm of resolution. Finally, the reversibility response of shear deformation further confirmed the practical applicability of the elastic polymer-based shear deformation sensor. The spectrum measurement of shear deformation provides a novel measurement means for the mechanical deformation of materials and expands the application of a holographic sensor.

Characterizing spatial uniformity of tensile deformation with an elastic polymer based holographic sensor.

Tensile deformation uniformity of material has been studied with a stretchable polymer based holographic sensor. The diffraction spectrum distribution of a holographic grating with a large area as a main response parameter is scanned. A linear spatial distribution of peak wavelength provides an important foundation for exploring the tensile uniformity. The same ratio of wavelength to position confirms that the tensile deformation of the material is uniform in a small spot size. Over the entire length of the materials, gradually increasing deformation accumulation is the main uniformity feature of tensile deformation. The uniformity response is expected to apply in sensing the deformation and stress fluctuation distribution in the middle of the thin surface. The non-uniform distribution of stress can be expressed by the nonlinear distribution of the grating diffraction spectrum. The optical measurement of tensile deformation uniformity further validates the applicability of a stretchable polymer based holographic sensor.

In CH3 NH3 PbI3 Perovskite Film, the Surface Termination Layer Dominates the Moisture Degradation Pathway.

Theoretical studies have shown that surface terminations, such as MAI or PbI layers, greatly affect the environmental stability of organic-inorganic perovskite. However, until now, there has been little effort to experimentally detect the existence of MAI or PbI terminations on MAPbI3 grains, let alone disclose their effects on the humidity degradation pathway of perovskite solar cell. Here, we successfully modified and detected the surface terminations of MAI and PbI species on polycrystalline MAPbI3 films. MAI-terminated perovskite film followed the moisture degradation process from MAPbI3 to hydrate MAPbI3 ⋅H2 O and then into PbI2 , with penetration of water molecules being the main driving force leading to the degradation of MAPbI3 layer by layer. In contrast, for the PbI-terminated perovskite film in a humid atmosphere, a deprotonation degradation pathway was confirmed, in which the film preferentially degraded directly from MAPbI3 into PbI2 , here the iodine defects played a key role in promoting the dissociation of water molecules into OH- and further catalyzing the decomposition of perovskite.

An early predictive model of frailty for older inpatients according to nutritional risk: protocol for a cohort study in China.

BACKGROUND: Previous reports suggest that the attributes of frailty are multidimensional and include nutrition, cognition, mentality, and other aspects. We aim to develop an early warning model of frailty based on nutritional risk screening and apply the frailty early warning model in the clinic to screen high-risk patients and provide corresponding intervention target information. METHODS: The proposed study includes two stages. In the first stage, we aim to develop a prediction model of frailty among older inpatients with nutritional risk. Study data were collected from a population-based aging cohort study in China. A prospective cohort study design will be used in the second stage of the study. We will recruit 266 older inpatients (age 65 years or older) with nutritional risk, and we will apply the frailty model in the clinic to explore the predictive ability of the model in participants, assess patients' health outcomes with implementation of the frailty model, and compare the model with existing frailty assessment tools. Patients' health outcomes will be measured at admission and at 30-day follow-up. DISCUSSION: This project is the first to develop an early prediction model of frailty for older inpatients according to nutritional risk in a nationally representative sample of Chinese older inpatients of tertiary hospitals. The results will hopefully help to promote the development of more detailed frailty assessment tools according to nutritional risk, which may ultimately lead to reduced health care costs and improvement in independence and quality of life among geriatric patients. TRIAL REGISTRATION: Chinese Clinical Trial Registry, ChiCTR1800017682 , registered August 9, 2018; and ChiCTR2100044148 , registered March 11, 2021.

Nurses' turnover intention and associated factors in general hospitals in China: A cross-sectional study.

AIM: To measure nurses' turnover intention and identify associated factors in general hospitals in China. BACKGROUND: Understanding nurses' turnover intention is important to retain nurses, but factors associated with turnover intention require elucidation. METHOD: A cross-sectional survey was conducted across 23 hospitals in China to investigate nurses' (N = 12,291) turnover intention and its associated factors. Associated factors were explored by univariate and multilevel multiple logistic regression analysis. RESULTS: The mean total score for nurses' turnover intention was 13.97 ± 3.63. High proactive personality score, a seriously ill family member, experience of negative workplace events, high work pressure and high work-family conflict increased the risk for turnover intention. A low turnover intention was associated with being a non-local resident nurse, position title, high salary level, good person-organisation fit and person-group fit, and high family-work facilitation. CONCLUSION: Nurses with a proactive personality, heavy family care burden, experience of negative workplace events, no position title and a low salary may merit special consideration. IMPLICATIONS FOR NURSING MANAGEMENT: Nurses' personality traits should be further focused on, and it is important to build a nurse-oriented organisation atmosphere, including protecting nurses from workplace violence, establishing friendly relationships with their families and expanding career paths.

Expansion of axial dispersion in a photopolymer-based holographic lens and its improvement for measuring displacement.

Coaxial multiple holographic lenses as high-dispersion elements are developed for a spectral confocal displacement measurement device. Wavelength and coaxial spatial multiplexing methods are used to record the holographic lens with two coaxial foci. The expansion of axial spatial dispersion in photopolymer-based multiple holographic lenses has been demonstrated and studied experimentally. The multiple holographic lenses provide a larger spatial dispersion to improve the characteristic parameters for measuring the displacement. Compared to single holographic lenses, the maximum of axial dispersion wavelength difference of the multiple lenses increases from 134.63 to 162.81 nm, and the corresponding measurable range increases from 203 to 385 mm. The axial spatial dispersion conforms to a typical exponential function. The overall spatial position sensitivity of multiple holographic lenses reaches 2.36 mm/nm. In addition, the multiple lenses also decrease the lateral dispersion compared to the single lenses. The multiple lenses can efficiently reduce the transverse measurement error. Finally, the displacement measurement result confirms the improvement of measureable spatial range. The multiple holographic lenses can accelerate the practical application of holographic lens-based optical elements.

Potential associated factors of functional disability in Chinese older inpatients: a multicenter cross-sectional study.

BACKGROUND: There is still controversy about the relationship between aging and changes in functional ability. This study aims to describe the level of basic activities of daily living (ADL) and higher-level instrumental activities of daily living (IADL) in different age groups and explore the factors associated with functional disability in Chinese older inpatients. METHODS: This cross-sectional study surveyed 9996 older inpatients aged 65 years and older from six tertiary hospitals in China from October 2018 to February 2019. The levels of ADL and IADL were measured by scores of the Barthel index and Instrumental Activities of Daily Living Scale. A mixed-effect generalized linear model was used to examine the association between functional disability and covariates. RESULTS: The average ADL score was 89.51 ± 19.29 and the mean IADL score 6.76 ± 2.01 for all participants. There was a trend of decreasing scores along with aging, and significant differences between age groups were also observed (P < 0.001). The most affected ADL and IADL was stair climbing and shopping, respectively. Sociodemographic characteristics (such as age), physical health variables (frailty, emaciation, hearing dysfunction, urinary dysfunction, defecation dysfunction, falling accidents in the past 12 months), and mental health variables (cognitive dysfunction, depression) were associated with functional disability. Patients from the emergency department or transferred from other hospitals and former alcohol drinkers are at risk of ADL disability. Former smoking is a risk factor for IADL disability, whereas current drinking, higher-level education, and residing in a building without elevators were likely to maintain a better IADL performance. CONCLUSIONS: Functional ability declines with aging, older inpatients are low dependency upon ADL and IADL. There are several associated factors among the participants derived from this investigation of a large-scale, multicenter, nationally representative Chinese older inpatient population. These findings potentially have major importance for the planning of hospital services, discharge planning, and post-discharge care. TRIAL REGISTRATION: Chinese Clinical Trial Registry, ChiCTR1800017682 , registered August 9, 2018.

Hospitalization costs among immobile patients with hemorrhagic or ischemic stroke in China: a multicenter cross-sectional study.

BACKGROUND: In this study, we aimed to analyze the hospitalization costs for immobile patients with hemorrhagic stroke (IHS) or ischemic stroke (IIS) in China and to determine the factors associated with hospitalization costs. METHODS: We evaluated patients with IHS and IIS hospitalized between November 2015 and July 2016 in six provinces or municipality cities of China. Linear regression analysis was used to examine the association with hospitalization costs and predictors. RESULTS: In total, 1573 patients with IHS and 3143 with IIS were enrolled and analyzed. For IHS and IIS, the average length of stay (LoS) was 17.40 ± 12.3 and 14.47 ± 11.55 days. The duration of immobility was 12.11 ± 9.98 and 7.36 ± 9.77 days, respectively. Median hospitalization costs were RMB 47000.68 (interquartile range 19,827.37, 91,877.09) for IHS and RMB 16578.44 (IQR 7020.13, 36,357.65) for IIS. In both IHS and IIS groups, medicine fees accounted for more than one-third of hospitalization costs. Materials fees and medical service fees accounted for the second and third largest proportions of hospital charges in both groups. Linear regression analysis showed that LoS, hospital level, and previous surgery were key determinants of hospitalization costs in all immobile patients with stroke. Subgroup analysis indicated that hospital level was highly correlated with hospitalization costs for IHS whereas pneumonia and deep vein thrombosis were key factors associated with hospitalization costs for IIS. CONCLUSIONS: We found that hospitalization costs were notably higher in IHS than IIS, and medicine fees accounted for the largest proportion of hospitalization costs in both patient groups, perhaps because most patients ended up with complications such as pneumonia thereby requiring more medications. LoS and hospital level may greatly affect hospitalization costs. Increasing the reimbursement ratio of medical insurance for patients with IHS is recommended. Decreasing medicine fees and LoS, preventing complications, and improving treatment capability may help to reduce the economic burden of stroke in China.

Photopolymer-based coaxial holographic lens for spectral confocal displacement and morphology measurement.

A spectral confocal displacement and morphology measurement device with a photopolymer-based coaxial holographic lens as a high dispersion element is developed. The linear dependence of the axial spatial position on the peak wavelength of dispersion spectrum provides a high accuracy and large range for measuring displacement and morphology. In the linear dispersion region, accompanied with a 120 nm shift of peak wavelength, the measure position range exceeds 20 mm. The available experimental accuracy of displacement and morphology can reach 47.5 µm/0.5 nm using a commercial optical fiber spectrum with a resolution of 0.5 nm. Utilizing thin polymer-based holographic lens with high dispersion can effectively compact the device size. Simultaneously, it can provide a large axial dispersion for measuring the spatial position characterization compared with the traditional glass-based dispersion lens group. A holographic optical lens based on a photopolymer is expected to apply in high-precision surface morphology measurement of large-scale macroscopic objects. It will improve the measurement accuracy and accelerate the development of holographic optical elements.

Pressure-dependent diffraction spectrum response in photopolymer-based holographic sensor.

A volume grating-based holographic pressure sensor in acrylamide photopolymer has been studied. The pressure sensing response is analyzed using a diffraction spectrum in two kinds of sensor construction methods, i.e., transmission and reflection. In a transmission sensor, the maximum of peak wavelength shifts up to 25 nm under ${1.58} \times {{10}^5}\,\,{\rm Pa}$1.58×105Pa pressure. The linear pressure response range exceeds ${2.0} \times {{10}^5}\,\,{\rm Pa}$2.0×105Pa and the optimized sensitivity is ${4.9} \times {{10}^3}\,\,{\rm Pa}/{\rm nm}$4.9×103Pa/nm. Compared to the reflection sensor, the transmission sensor with large slanted angle can provide a more excellent sensing performance. The linear and reversible peak wavelength shifts confirm the applicability of the holographic pressure sensor. A photopolymer-based holographic pressure sensor is expected to apply in a cheap and visual pressure sensing field. The transmission grating is a significant candidate for developing the holographic sensor. These experimental results can accelerate the development and practicality of holographic optical elements.

Sensing response characterization of a micro-holographic sensor and its kinetics simulation.

A photopolymer-based micro-holographic sensor was developed to improve the sensitivity in sensing environmental factors. The micro-holographic grating can be formed by interference of two counter-propagating beams. The response rate and sensitivity of the micro-grating based sensor were measured. The response rate reached 0.171 nm/s in sensing relative humidity and 0.03 nm/s in sensing ethanol vapor. The corresponding maximum of the peak wavelength shifted up to 51.2 nm and 8.9 nm, respectively, for 5 min of sensing. The minimum detectable ethanol vapor concentration was as low as 10 ppm, while the sensitivity approached up to 0.179 nm/ppm. Theoretically, relating the absorption and modulation along the thickness direction, a diffusion model with nonlocal response was proposed to describe the micro-grating formation and its sensing characterization. The numerical simulation provides a significant foundation for understanding the grating formation and sensing the physical mechanism inside the materials. These results can accelerate the development and practicality of novel holographic sensing elements.

Reversibility and repeatability of the tensile deformation response in holographic sensors.

Reversibility and repeatability of the tensile deformation response in holographic sensors formed by highly stretchable acrylamide polymers have been investigated. The diffraction spectrum of the volume grating was used to characterize the deformation. Two-way shifts of peak wavelengths, i.e., redshift in transmission and blueshift in reflection, were observed in stretching. The reduction of the average refractive index provided experimental evidence for the physical mechanism. To achieve a linear response and high repeatability, the limitation of tensile displacement was determined as 5.0 mm, and the relevant deformation is 6.6%. This value can be considered as a boundary between the elastic and plastic deformations in samples with thicknesses less than 120 µm. There was a totally linear relation between peak wavelength and deformation within the elastic range. The reversible and repeatable deformation response validated the practical applicability of a holographic sensor.

Micro-deformation response of a holographic sensor in highly stretchable polymer hydrogel.

A volume grating-based holographic sensor in highly stretchable PVA/AA polymer for sensing its micro-deformation and, hence, the displacement has been studied. One-dimensional micro-displacement induced by tensile stress is analyzed using a diffraction spectrum in two kinds of sensor construction methods, i.e., transmission and reflection. The dependence of the peak wavelength on the displacement presents a good linear relationship which provides a quantitative sensing strategy for hydrogel micro-deformation. The available sensitivity is better than 4 µm/0.5 nm (displacement/wavelength shift) using a commercial spectrometer with a resolution of 0.5 nm. Finally, the reversible deformation response further validates the practical applicability of a holographic sensor constructed by photosensitive hydrogel. The optical measurement of micro-displacement as a novel sensing strategy can accelerate the development of the holographic optical element.

Improvement of temperature-induced spectrum characterization in a holographic sensor based on N-isopropylacrylamide photopolymer hydrogel: publisher's note.

This publisher's note amends the funding section in Appl. Opt.56, 9006 (2017)APOPAI0003-693510.1364/AO.56.009006.

Immunologic properties and therapeutic efficacy of a multivalent epitope-based vaccine against four Helicobacter pylori adhesins (urease, Lpp20, HpaA, and CagL) in Mongolian gerbils.

BACKGROUND: Therapeutic vaccination is a desirable alternative for controlling Helicobacter pylori (H. pylori) infection. Attachment to the gastric mucosa is the first step in establishing bacterial colonization, and adhesins, which are on the surface of H. pylori, play a pivotal role in binding to human gastric mucosa. MATERIALS AND METHODS: In the present study, we constructed a multivalent epitope-based vaccine named CFAdE with seven carefully selected antigenic fragments from four H. pylori adhesins (urease, Lpp20, HpaA and CagL). The specificity, immunogenicity and ability to produce neutralizing antibodies of CFAdE were evaluated in BALB/c mice. After that, its therapeutic efficacy and protective immune mechanisms were explored in H. pylori-infected Mongolian gerbils. RESULTS: The results indicated that CFAdE could induce comparatively high levels of specific antibodies against urease, Lpp20, HpaA and CagL. Additionally, oral therapeutic immunization with CFAdE plus polysaccharide adjuvant (PA) significantly decreased H. pylori colonization compared with oral immunization with urease plus PA, and the protection was correlated with IgG and sIgA antibody and antigen-specific CD4+ T cells. CONCLUSIONS: This study indicated that the multivalent epitope-based vaccine, which targeted multiple adhesins in adherence of H. pylori to the gastric mucosa, is more effective than the univalent vaccine targeting urease only. This multivalent epitope-based vaccine may be a promising therapeutic candidate vaccine against H. pylori infection.