Surface modification of zinc oxide and its application in polypropylene with excellent fire performance and ultra-violet resistance

Despite the advantages of easy moulding and excellent mechanical properties, there are still some shortcomings with polypropylene (PP) such as high flammability and poor ultra-violet (UV) resistance. In this work, modified zinc oxide (mZnO) was prepared by reacting zinc oxide nanoparticles (ZnO) with polysiloxanes, and the effect of mZnO on the effectiveness of intumescent flame-retardant and on the UV aging resistance of polypropylene were investigated. By introducing 16 wt% (intumescent flame-retardant /mZnO) and 0.3 wt% maleic anhydride-grafted PP (MAH-g-PP), the limiting oxygen index increased to 32.7 %, and passed UL-94V-0 rating. In comparison to the controls, the peak heat release rate and the peak smoke release rate were 88.5 % and 80 % lower, respectively. In addition, PP samples showed improved mechanical properties, with a 5 % increase in tensile properties compared to the pure PP sample. After 100 h of UV irradiation, the surface of the samples was relatively flat and smooth, and the carbonyl index decreased from 81.1 of neat PP to 26.7. PP composites with 100 h aging treatment still had excellent flame retardancy and mechanical properties. The results showed that mZnO was effective in improving the flame retardancy, mechanical properties and light aging tolerance of PP. This study provides a novel approach to fabricate long-life flame-retardant PP composites with low additive content.

An innovative near-infrared fluorescent probe with FRET effect for the continuous detection of Zn2+ and PPi with high sensitivity and selectivity, and its application in bioimaging

As the second most abundant transition metal element in the human body, zinc ions play an important role in the normal growth and development of the human body. We have successfully synthesized a near-infrared fluorescent probe with FRET effect for the detection of Zn2+. Probe DR6G has good selectivity and anti-interference ability for Zn2+. When Zn2+ is added to the probe DR6G solution, it responds completely within seconds, releasing red fluorescence with a detection limit of 2.02 × 10-8 M. As the main product of ATP hydrolysis, PPi is indispensable in various metabolic activities in cells and the human body. Due to the strong binding ability of Zn2+ and PPi, it is easy to form ZnPPi precipitation, so we added PPi to the solution to complete the Zn2+ detection, and realized the continuous detection of PPi, and the detection limit was 2.06 × 10-8 M. Since Zn2+ and PPi play an important role in vivo, it is of great practical significance to design and synthesize a fluorescent probe that can continuously detect Zn2+ and PPi. Biological experiments have shown that the probe DR6G has low cytotoxicity and can complete the detection of exogenous Zn2+ and PPi in cells and living mice in vitro. Bacterial experiments have shown that the DR6G probe also has certain research value in the field of environmental monitoring and microbiology. Due to the constant variation of the fluorescence signals of Zn2+ and PPi during detection, we designed the logic gate program. In practical applications, the probe DR6G can quantitatively detect Zn2+ in zinc-containing oral liquids and qualitatively detect PPi in toothpaste.

An ultrasensitive electrochemical immunosensor based on meso-PdN NCs and Au NPs/N-CNTs for quantitative cTnI detection

Electrochemical immunosensors have gained considerable attention in detecting human disease markers due to their excellent specificity, high sensitivity, and facile operation. Herein, a rational-designed sandwich-type electrochemical immunosensor is constructed for the sensitive detection of cardiac troponin I (cTnI) using nitrogen-doped carbon nanotubes loaded with gold nanoparticles (Au NPs/N-CNTs) as substrate and highly active mesoporous palladium-nitrogen nanocubes (meso-PdN NCs) as secondary antibody markers. Benefitting from its large specific surface area (638.04 m2 g-1) and high nitrogen content, novel polydopamine (PDA)/ halloysite nanotubes (HNTs) hybrid derived one-dimensional (1D) N-CNTs can provide more binding sites for the in-situ growth of Au NPs to connect Ab1. Furthermore, as an ideal substrate material, Au NPs/N-CNTs exhibit finely tuned mesoporous structures and outstanding conductivity, which facilitate the mass and electron transfer during the electrocatalysis process. Besides, highly concave surfaces and crystalline mesopores of meso-PdN NCs expose more surfaces and crevices, providing abundant reactive sites for H2O2 reduction. Remarkably, the as-obtained immunosensor presented a wide linear range (from 10 fg mL-1 to 100 ng mL-1) and an excellent low detection limit (9.85 fg mL-1). This study may offer new insights into the precise fabrication of efficient electrochemical immunosensors for various clinical diagnosis applications.

An innovative fluorescent probe based on dicyanoisoflurone derivatives for differential detection of Hg2+ and Cu2+ and its applications in bacteria, cell imaging and food analysis

BACKGROUND

Heavy metal pollution has become one of the world's most important environmental pollution, especially Hg2+ is enriched, it is easy to enter the human body through the food chain, bind to the sulfhydryl group in the protein, cause mercury poisoning. Traditional methods for detecting Hg2+ have obvious drawbacks, such as poor selectivity and long detection time. Fluorescence detection has attracted attention because of its good sensitivity and specificity detection ability. In previously reported probes for detecting Hg2+, Cu2+ often interferes. Therefore, it is of great practical significance to synthesize a fluorescent probe that can distinguish between Hg2+ and Cu2+.

RESULTS

We have successfully synthesized the probe DFS, a fluorescent probe that can differentially detect Hg2+ and Cu2+, and the probe DFS has good selectivity and anti-interference ability for Hg2+ and Cu2+. The fluorescence intensity at 530 nm increased rapidly when Hg2+ was detected; during the Cu2+ detection, the fluorescence intensity at 636 nm gradually decreased, fluorescence quenching occurred, and the detection limits of Hg2+ and Cu2+ were 7.29 × 10-9 M and 2.13 × 10-9 M, respectively. Through biological experiments, it was found that probe DFS can complete the fluorescence imaging of Hg2+ and Cu2+ in Staphylococcus aureus and HUVEC cells, which has certain research value in the field of environmental monitoring and microbiology, and the probe DFS has low cytotoxicity, so it also has broad application prospects in the field of biological imaging. In addition, the probe DFS also has good applicability for Hg2+ and Cu2+ detection in actual samples.

SIGNIFICANCE AND NOVELTY

This is a fluorescent probe that can distinguish between Hg2+ and Cu2+, the fluorescence emission peak appears at 530 nm when Hg2+ is detected; when detecting Cu2+, fluorescence quenching occurs at 636 nm, the fluorescence emission peak distance between Hg2+ and Cu2+ differs by 106 nm. This reduces mutual interference between Hg2+ and Cu2+ during detection, it provides a new idea for the detection of Hg2+ and Cu2+.

Sorption behaviour of neptunium in marine and fresh water bottom sediments in Far East area of Russia (Lake Khanka and Amur Bay)

The concentration and sorption behavior of 237Np on the bottom sediments of water bodies in the Far East region of Russia (Lake Khanka and Peter the Great Bay) were studied for the first time. The 237Np concentrations vary from 1.06 × 10-6 to 4.43 × 10-5 mBq g-1 in the bottom sediments of Lake Khanka and from 1.05 × 10-4 to 2.52 × 10-3 mBq g-1 for Amur Bay. The experiment on the adsorption of Np on marine and lake sediment showed that it is sorbed through complexation with silicates (albite, leucite). The Np sorption isotherm on marine sediments is described by the Langmuir equation; the distribution coefficients (Kd) of Np vary from 57 to 588 mL g-1. For lake sediments, the isotherm is described by the Henry equation; the Kd value reaches 935 mL g-1.

A novel "on-off-on" near-infrared fluorescent probe for Cu2+ and S2- continuous detection based on dicyanoisoflurone derivatives, and its application in bacterial imaging

We have successfully synthesized a near-infrared fluorescent probe for the continuous detection of copper and sulfur ions. The probe has good selectivity and anti-interference ability against Cu2+ and S2-. The results show that after adding Cu2+ to the DL solution of the near-infrared fluorescent probe, Cu2+ forms a [DL + Cu2+] complex with the probe, which leads to fluorescence quenching due to the paramagnetism of Cu2+. The probe can be used for the quantitative detection of Cu2+ with a detection limit of 1.26 × 10-9 M. According to the Job's plot curve the binding stoichiometry between DL and Cu2+ is 1 : 1. Subsequently, S2- was added to the [DL + Cu2+] solution, because the precipitation dissolution equilibrium constant of CuS was Ksp = 1.27 × 10-36, so the binding capacity between Cu2+ and S2- was stronger, CuS precipitation was formed, and red fluorescence was re-released, and the quantitative detection of S2- was realized, and the detection limit was 3.50 × 10-8 M. Through bacterial imaging experiments, we found that the probe can accomplish the fluorescence imaging experiments of Staphylococcus aureus, indicating that the probe has good biopenetration and biocompatibility, and has application prospects in bioimaging and environmental monitoring. In addition, the probe DL has good suitability for Cu2+ and S2- detection in real samples.

Breathers in lattices with alternating strain-hardening and strain-softening interactions

This work focuses on the study of time-periodic solutions, including breathers, in a nonlinear lattice consisting of elements whose contacts alternate between strain hardening and strain softening. The existence, stability, and bifurcation structure of such solutions, as well as the system dynamics in the presence of damping and driving, are studied systematically. It is found that the linear resonant peaks in the system bend toward the frequency gap in the presence of nonlinearity. The time-periodic solutions that lie within the frequency gap compare well to Hamiltonian breathers if the damping and driving are small. In the Hamiltonian limit of the problem, we use a multiple scale analysis to derive a nonlinear Schrödinger equation to construct both acoustic and optical breathers. The latter compare very well with the numerically obtained breathers in the Hamiltonian limit.

Differential responses and mechanistic controls of soil phosphorus transformation in Eucalyptus plantations with N fertilization and introduced N2 -fixing tree species

Introducing N₂ -fixing tree species into Eucalyptus plantations could replace nitrogen (N) fertilization to maintain high levels of N consumption and productivity. However, N enrichment may exacerbate phosphorus (P) limitation as Eucalyptus robusta Smith is extensively planted in P-poor tropical and subtropical soils. We conducted a field experiment in a pure plantation of Eucalyptus urophylla × grandis to investigate the impacts of N fertilization and introduced an N₂ -fixing tree of Dalbergia odorifera T. Chen on soil P transformation. Nitrogen fertilization significantly enhanced soil occluded P pool and reduced the other P pools due to acidification-induced pH-sensitive geochemical processes, lowering Eucalyptus leaf P concentration with higher N : P ratio. By contrast, introduced N₂ -fixing tree species did not change soil pH, labile inorganic P pool, and Eucalyptus leaf N : P ratio, even enhanced organic P pools and reduced occluded P pool probably due to altering microbial community composition particularly stimulating arbuscular mycorrhiza fungal abundance. Our results revealed differential responses and mechanistic controls of soil P transformation in Eucalyptus plantations with N fertilization and introduced N₂ -fixing tree species. The dissolution of occluded P pool along with organic P accumulation observed in the mixed plantations may represent a promising future to better manage soil P availability.

[Clinical characteristics and risk factors of periventricular-intraventricular hemorrhage in extremely low birth weight infants]

Objective: To analyze the clinical characteristics and risk factors of periventricular-intraventricular hemorrhage (PIVH) in extremely low birth weight infants (ELBWI). Methods: From January 2019 to January 2022, the clinical data of 238 ELBWI admitted to the intensive care unit of Henan Provincial Children's Hospital within 1 week after birth and regular head color ultrasound examination were retrospective reviewed. The infants were divided into PIVH group and non-PIVH group according to whether PIVH occurred. The incidence and time of PIVH were described, and the differences in basic clinical features, perinatal conditions, postnatal treatment and complications between the two groups were compared. The risk factors of PIVH in ELBWI were further explored by multivariate binary logistic regression analysis. Results: Among 238 ELBWI (146 males and 92 females), 82 cases (34.5%) developed PIVH, including 28 cases (11.8%) of severe PIVH and 54 cases (22.7%) of mild PIVH. Among the 82 cases of PIVH, 68 cases occurred within 3 days after birth. Gestational age [(27.4±1.5) weeks vs (27.8±1.5) weeks, P=0.012], gestational diabetes mellitus [0 vs 9.0%(14/156), P=0.005], fibrinogen (FIB) [(1.8±0.5) g/L vs (2.7±0.9) g/L, P=0.012] were lower in PIVH group than in non-PIVH group. However, intrauterine distress [46.3%(38/82) vs 11.5%(18/156), P<0.001], birth asphyxia [85.4%(70/82) vs 62.8%(98/156), P<0.001], patent ductus arteriosus (PDA) [65.9%(54/82) vs 51.3%(80/156）, P=0.017], failure to withdraw invasive ventilator within 1 week [82.9%(14/82) vs 67.3%(105/156), P=0.010], use of vasoactive drugs within 1 week [28.0%(23/82) vs 15.4%(24/156), P=0.020], acidosis [28.0%(23/82) vs 12.2%(19/156), P=0.002], and hemorrhagic disease [18.3%(15/82) vs 7.1%(11/156), P=0.008] were higher in PIVH group than in non-PIVH group. Multivariate binary logistic regression analysis found that the risk factors for PIVH in ELBWI were acidosis (OR=2.257, 95%CI: 1.104-4.614, P=0.026), use of vasoactive drugs within 1 week (OR=2.274, 95%CI: 1.148-4.504, P=0.018), bleeding disorders (OR=2.583, 95%CI: 1.075-6.206, P=0.034) use of vasoactive drugs within 1 week (OR=2.301, 95%CI: 1.153-4.591, P<0.001). Conclusions: The incidence of PIVH in ELBWI is high, which mostly occurs within 3 days after birth. Acidosis, hemorrhagic disease, use of vasoactive agents within 1 week and failure to evacuate invasive ventilators within 1 week may increase the risk of PIVH in ELBWI.

Ethical Conflict and Knowledge Hiding in Teams: Moderating Role of Workplace Friendship in Education Sector

Ethical conflicts arise when there is no unity between the team members and shared ethical priorities. This study aimed to identify the relationship between ethical value unity, team knowledge hiding, the relationship between the lack of shared ethical priorities and the team knowledge hiding. Workplace friendship was taken as a moderating variable to check its regulating role between the ethical conflicts and the team knowledge hiding. Data of this study were collected from the staff working in different colleges and universities. There are a total of 480 responses collected through convenience sampling technique and analyzed under a five-point Likert scale. The partial least squares-structural equation modeling (PLS-SEM) technique is used in this study. The key reason was that this approach has the fewest requirements for data normality and is a better tool for evaluating exploratory connections empirically. The output of the measurement model assessment confirms that all measurement scales are reliable. The result indicates that there was a significant and positive relationship between ethical value congruence and knowledge hiding. It was also established that there was a relationship between lack of shared ethical priorities and knowledge hiding. Workplace friendship moderated the relationship between ethical conflicts and team knowledge hiding. This study extends the literature on ethical conflict and knowledge hiding behavior. This study highlights that one of the main reasons for knowledge hiding behavior at the team level in the organization is which helps the business practicians for a design of an effective strategy to mitigate the knowledge hiding behavior in the organization.

Advances in electrospun nanofibrous membrane sensors for ion detection

Harmful metal ions and toxic anions produced in industrial processes cause serious damage to the environment and human health.

Fringe harmonics elimination in multi-frequency phase-shifting fringe projection profilometry

In fringe projection profilometry, the purpose of using two- or multi-frequency fringe patterns is to unwrap the measured phase maps temporally. Using the same patterns, this paper presents a least squares algorithm for, simultaneously with phase-unwrapping, eliminating the influences of fringe harmonics induced by various adverse factors. It is demonstrated that, for most of the points over the measured surface, projecting two sequences of phase-shifting fringe patterns having different frequencies enables providing sufficiently many equations for determining the coefficient of a high order fringe harmonic. As a result, solving these equations in the least squares sense results in a phase map having higher accuracy than that depending only on the fringe patterns of a single frequency. For the other few points which have special phases related to the two frequencies, this system of equations becomes under-determined. For coping with this case, this paper suggests an interpolation-based solution which has a low sensitivity to the variations of reflectivity and slope of the measured surface. Simulation and experimental results verify that the proposed method significantly suppresses the ripple-like artifacts in phase maps induced by fringe harmonics without capturing extra many fringe patterns or correcting the non-sinusoidal profiles of fringes. In addition, this method involves a quasi-pointwise operation, enabling correcting position-dependent phase errors and being helpful for protecting the edges and details of the measurement results from being blurred.

Efficient depth recovering method free from projector errors by use of pixel cross-ratio invariance in fringe projection profilometry

In fringe projection profilometry, errors related to projectors are not easy to compensate for, as a projector is much more difficult to calibrate than a camera. Immune to projector errors, the depth recovering method based on pixel cross-ratio invariance enables circumventing this issue by calculating the depth of a point from the shift of its camera pixel instead of from its fringe phase. With this existing technique, however, one has to search three reference phase maps along epipolar lines for pixels having the same phases. Doing so increases the measurement time significantly. To improve measurement efficiency, this paper derives, from the pixel cross-ratio invariance, a generic function representing the relationship between the depths and the corresponding pixel shifts and suggests a calibration method for determining its coefficient matrices. Using this function allows us to recover object depths just by searching a single reference phase map, thus reducing the time duration for data processing to about one-third. Besides, different from the previous method, which depends on exactly three reference phase maps, the proposed method calculates the function coefficients from more reference phase maps in the least-squares sense and denoises the benchmark reference phases by use of averaging technique, thus improving measurement accuracy. Experimental results demonstrate this method to be effective in improving measurement accuracy and efficiency.

Iterative calibration method for measurement system having lens distortions in fringe projection profilometry

In fringe projection profilometry, system calibration is crucial for guaranteeing the measurement accuracies. Its difficulty lies in calibrating projector parameters, especially when the projector lens has distortions, since the projector, unlike a camera, cannot capture images, leading to an obstacle to knowing the correspondences between its pixels and object points. For solving this issue, this paper, exploiting the fact that the fringe phases on a plane board theoretically have a distribution of rational function, proposes an iterative calibration method based on phase measuring. Projecting fringes onto the calibration board and fitting the measured phases with a rational function allow us to determine projector pixels corresponding to the featured points on the calibration board. Using these correspondences, the projector parameters are easy to estimate. Noting that the projector lens distortions may deform the fitted phase map thus inducing errors in the estimates of the projector parameters, this paper suggests an iterative strategy to overcome this problem. By implementing the phase fitting and the parameter estimating alternately, the intrinsic and extrinsic parameters of the projector, as well as its lens distortion coefficients, are determined accurately. For compensating for the effects of the lens distortions on measurement, this paper gives two solutions. The pre-compensation actively curves the fringes in computer when generating them; whereas when using the post-compensation, the lens distortion correction is performed in the data processing stage. Both methods are experimentally verified to be effective in improving the measurement accuracies.

An empirical study of the impact of goal orientation on individual ambidexterity – moderating roles of goal interdependence and constructive controversy

Purpose

Ambidexterity is the source of organizational sustainable development and long-term success. However, understanding the role of individual ambidexterity in organizations remains underdeveloped. Recently, scholars have increasingly emphasized the importance of individual ambidexterity, calling for more research on the topic. This study aims to explore the factors influencing individual ambidexterity. It proposed that goal orientation would be related to individual ambidexterity, and perceived cooperative goal interdependence and constructive controversy would play moderating roles in this relationship.

Design/methodology/approach

The paper opted for a survey study. Questionnaires were distributed to enterprise managers from a part-time MBA program at a university located in Beijing, China. They were also asked to bring copies to their colleagues, so they could fill them out. The authors obtained 229 valid questionnaires and used hierarchical regression analysis to test the relationships.

Findings

The results revealed that both learning goal orientation and performance goal orientation were significantly and positively related to individual ambidexterity. Perceived cooperative goal interdependence and constructive controversy positively moderated the relationship between learning goal orientation/ performance goal orientation and individual ambidexterity.

Practical implications

The paper provides beneficial suggestions for both managers and employees. It offers a reference for managers regarding how to promote employee ambidexterity. It also provides suggestions for employee career development.

Originality/value

The paper explored the factors influencing ambidextrous activities at the individual level, a very scare approach in extant studies. It also constructed a systematic process mechanism of individual ambidexterity, integrating both internal and external factors.

The effect of oral polyethylene glycol combined with simethicone for colonoscopy on cecal intubation rate, tolerability and acceptability : a systematic review and meta-analysis

OBJECTIVE

To assess the efficacy adjunction of oral simethicone to polyethylene glycol as bowel preparation agent on cecal intubation rate.

METHODS

We searched EMBASE, PubMed and Cochrane library for randomized controlled trials regarding simeticone plus polyethylene glycol as oral drinking agents before gastroscopy,we used the soft RevMan5.3 to perform statistical analysis and stata12.0 for publication bias.

RESULTS

12 randomized trials that met the inclusion criteria were therefore pooled into a meta-analysis, which included a total of 5,112 patients. There were no significant differences on cecal intubation rate in two groups(RR=1.0,95%CI : 0.99-1.01, P=0.93) with moderate level of evidence;Subgroups analysis of 2LPEG+ Simethicone VS 2LPEG(RR =1.0, 95% CI : 0.98,1.01), 2LPEG+ Simethicone VS 4L PEG (RR=1.00, 95% CI : 0.98,1.02), PEG+ Simethicone with bisacodyl vs PEG (RR =1.00, 95% CI : 0.99,1.02), PEG+Simethicone without bisacodyl vs PEG (RR =1.00, 95% CI : 0.98,1.02) showed no difference on cecal intubation rate.There was aslo no significant difference on cecal intubation time.Abdominal bloating incidence was lower in PEG+Simethicone group than that in PEG group (RR=0.53, 95%CI : 0.31, 0.91, P=0.02). The meta-analysis result also showed a better acceptability in PEG+Simethicone group (RR=1.28, 95% CI : 1.01, 1.49, P=0.001).

CONCLUSION

Adjunction of oral simethicone to polyethylene glycol as bowel preparation agent dose not improve cecal intubation rate on colonoscopy,but with better gastrointestinal tolerability and acceptability.

Expression of orphan GPR56 correlates with tumor progression in human epithelial ovarian cancer

G protein-coupled receptor 56 (GPR56) has been demonstrated to be a significant prognostic predictor in several types of malignances, including melanoma, glioblastoma, breast cancer, colon cancer, and pancreatic cancer. GPR56 has a putative mucin-like extracellular domain, indicating functions for this receptor in the cell-cell interactions and triggering different downstream signaling pathways responsible for regulating cell survival, proliferation, adhesion, and migration. But the expression and clinical significance of GPR56 has not been elucidated in epithelial ovarian cancer (EOC). We detected GPR56 expression by immunohistochemistry in 110 samples of ovarian serous carcinoma to explore the correlation between its expression and clinicopathologic characteristics and overall survival. As the result, we found that GPR56 expression is significantly associated with advanced FIGO stage (P = 0.01) and positive lymph node invasion (P = 0.016), and it serves as an independent unfavorable prognostic factor through univariate and multivariate analysis. GPR56 knockdown could dramatically decrease the proliferation and invasion of epithelial ovarian cancer cells through down-regulating the RhoA-GTP level and up-regulating the E-cadherin level, which indicates GPR56 could promote the progression and invasion of EOC. In conclusion, GPR56 expression was demonstrated as an independent prognostic factor in EOC, suggesting that GPR56 may play an oncogenic role through the Rho and E-cadherin pathway and GPR56 could be a novel potential drug target in EOC.

Host MyD88 signaling protects against acute graft-versus-host disease after allogeneic bone marrow transplantation

Recent experimental strategies to reduce graft-versus-host disease (GVHD) have focused largely on modifying innate immunity. Toll-like receptor (TLR)-driven myeloid differentiation primary response 88 (MyD88)-dependent signalling pathways that initiate adaptive immune function are also critical for the pathogenesis of GVHD. This study aimed to delineate the role of host MyD88 in the development of acute GVHD following fully major histocompatibility complex-mismatched allogeneic bone marrow transplantation (BMT). When myeloablated BALB/c MyD88 knock-out recipients were transplanted with C57BL/6 (B6) donor cells, they developed significantly more severe GVHD than wild-type (WT) BALB/c hosts. The increased morbidity and mortality in MyD88^-/- mice correlated with increased serum levels of lipopolysaccharide and elevated inflammatory cytokines in GVHD target organs. Additionally, MyD88 deficiency in BMT recipients led to increased donor T cell expansion and more donor CD11c⁺ cell intestinal infiltration with apoptotic cells but reduced proliferation of intestinal epithelial cells compared with that in WT BMT recipients. Decreased expression of tight junction mRNA in epithelial cells of MyD88^-/- mice suggested that MyD88 contributes to intestinal integrity. Cox-2 expression in the GVHD-targeted organs of WT mice is increased upon GVHD induction, but this enhanced expression was obviously inhibited by MyD88 deficiency. The present findings demonstrate an unexpected role for host MyD88 in preventing GVHD after allogeneic BMT.

Correction of projector nonlinearity in multi-frequency phase-shifting fringe projection profilometry

In fringe projection profilometry, the original purpose of projecting multi-frequency fringe patterns is to determine fringe orders automatically, thus unwrapping the measured phase maps. This paper presents that using the same patterns, simultaneously, allows us to correct the effects of projector nonlinearity on the measured results. As is well known, the projector nonlinearity decreases the measurement accuracies by inducing ripple-like artifacts on the measured phase maps; and, theoretical analysis reveals that these artifacts, depending on the number of phase shifts, have multiplied frequencies higher than the fringe frequencies. Based on this fact, we deduce an error function for modeling the phase artifacts and then suggest an algorithm estimating the function coefficients from a couple of phase maps of fringe patterns having different frequencies. As a result, subtracting out the estimated phase errors yields the accurate phase maps with the effects of the projector nonlinearity on them being suppressed significantly. Experiment results demonstrated that this proposed method offers some advantages over others, such as working without a photometric calibration, being applicable when the projector nonlinearity varies over time, and having satisfied efficiency in implementation.

Numerical Simulation Research on the Performance of SCWR Fuel Rod

Because of the high temperature and high pressure characteristics of supercritical water-cooled reactor (SCWR), the thermal hydraulic performance of SCWR is greatly different from pressurized water reactor (PWR), which makes the current PWR fuel rod performance analysis codes are no longer applicable to SCWR. In this research, the irradiation swelling, irradiation densification, thermal expansion, thermal creep, plastic deformation, irradiation creep and irradiation hardening of UO2 pellet, and stainless steel cladding were considered; the gas conductance and radiant conductance of gap heat transfer were considered, the forced convective heat transfer on the outer surface of cladding was considered. Meanwhile, the irradiation effects and the thermal effects on the materials parameters such as thermal conductivity, specific heat, and young’s modulus were also considered in this research. With the help of abaqus software, the related user-defined subroutines were developed, and the irradiation effects and thermal effects of SCWR fuel were introduced into the numerical simulation, and then completed the analysis of SCWR fuel rods’ performance under steady power conditions. Some reference suggestions for the design and development of SCWR fuel could be provided by the establishment of this numerical simulation method.

Eco-friendly seeded Fe3O4-Ag nanocrystals: a new type of highly efficient and low cost catalyst for methylene blue reduction

Hybrid Fe₃O₄-Ag nanocrystals, a new type of highly efficient and reusable catalyst for methylene blue (MB) reduction, are fabricated by a novel seed deposition process. X-ray diffraction and Mössbauer spectroscopy results show that the developed iron oxides are in a pure magnetite Fe₃O₄ phase. Upon manipulating the amount of Ag seeds capsuled on the modified surfaces of Fe₃O₄ nanocrystals, the catalytic capacities on the reduction of MB can be precisely adjusted with a tunable fabrication cost control. The linear correlation of the reduced MB concentration versus reaction time catalyzed by our developed hybrid Fe₃O₄-Ag nanocrystals is coherent with pseudo first order kinetics. Importantly, with remarkable recyclability features, the hybrid Fe₃O₄-Ag nanocrystals can be easily separated by applying an external magnetic field. The tailored catalytic performances of the hybrid Fe₃O₄-Ag nanocrystals during MB reduction are attributed to the optimized dynamic electron transfer process, which dominates the electrochemical mechanism wherein the nucleophilic BH₄⁻ ions donate electrons to electrophilic organic MB through Ag seeds in a regulated amount. Such developed hybrid Fe₃O₄-Ag nanocrystals pave the way towards the mass production of highly efficient and low cost catalysts for methylene blue reduction.

Hybrid Fe₃O₄-Ag nanocrystals, a new type of highly efficient and reusable catalyst for methylene blue (MB) reduction, are fabricated by a novel seed deposition process.

Self-correction of projector nonlinearity in phase-shifting fringe projection profilometry

In phase-shifting fringe projection profilometry, the luminance nonlinearity of the used projector has been recognized as one of the most crucial factors decreasing the measurement accuracy. To solve this problem, this paper presents a self-correcting technique that allows us to suppress the effect of the projector nonlinearity in the absence of any calibration data regarding the projector intensities or regarding the phase errors. In its first step, the standard phase-shifting algorithm is used to recover the phases, as well as the background intensities and the modulations. Using these results enables normalizing the fringe patterns, for ridding them of the effects of the background and modulations. Second, we smooth the calculated phase map by use of a low-pass filter in order to remove the ripple-like phase errors induced by the projector nonlinearity. Third, we determine a polynomial representing the projector nonlinearity by fitting the curve of the normalized fringe intensities against the cosine values of the smoothed phases. Finally, we correct the phase errors using the curve just obtained. Doing these steps in an iterative way eventually results in a phase map and, further, a 3D shape with their artifacts induced by the projector nonlinearity suppressed significantly. Experimental results demonstrate that this technique offers some advantages over others. It does not require a prior calibration of the projector, thus being suitable for dealing with a time-variant nonlinearity; its pointwise operation protects the edges and details of the measurement results from being blurred; and it works well with very few fringe patterns and is efficient in image capturing.

Weight loss drugs and lifestyle modification: Perceptions among a diverse adult sample

OBJECTIVES

Explore how adults from diverse racial and socioeconomic backgrounds perceive the use of weight loss drugs (prescription, over-the counter, herbals and supplements) and lifestyle modification.

METHODS

Individual, face-to-face, semi-structured interviews were conducted with persons presenting to an academic hospital-affiliated outpatient pharmacy serving ethnic minorities and low income individuals.

RESULTS

Fifty persons were interviewed, including 21 African Americans, 11 Hispanics and 17 low-income individuals (annual income <$20,000), of whom 33 self-reported as overweight or obese. Ever-users (14/50) and nonusers (36/50) of weight loss drugs expressed a belief in the importance of diet and exercise, but were not necessarily doing so themselves. Fear of side effects and skepticism towards efficacy of drugs deterred use. Some expressed concern over herbal product safety; others perceived herbals as natural and safe. Drugs were often viewed as a short-cut and not a long-term weight management solution.

CONCLUSION

A range of concerns related to the safety and efficacy of weight loss drugs were expressed by this lower income, ethnically diverse population of underweight to obese adults.

PRACTICE IMPLICATIONS

There is need and opportunity for healthcare providers to provide weight loss advice and accurate information regarding the safety and efficacy of various types of weight loss approaches.

Temporal phase unwrapping for fringe projection profilometry aided by recursion of Chebyshev polynomials

This paper presents a temporal phase-unwrapping method for fringe projection profilometry. With it, a sequence of phase-shifting fringe patterns is projected onto the measured object for getting the wrapped phase map and achieving a high measurement resolution, and an additional sequence corresponding to Chebyshev polynomials is used for determining their fringe orders. For effectuating this method, we deduce an algorithm by use of the recursive property of Chebyshev polynomials. This algorithm, combined with a correction operation in the least-squares sense, allows us to accurately estimate the fringe orders in the presence of noise. Experimental results demonstrate the proposed method to be effective in restoring the absolute phase maps of fringe patterns.

[Posterior debridement combined with atlantoaxial fusion to upper cervical tuberculosis]

Objective: To explore clinical results of posterior debridement combined with atlantoaxial fusion for upper cervical Tuberculosis. Methods: From March 2007 to April 2012, 8 patients with upper cervical Tuberculosis underwent posterior debridement combined with atlantoaxial fusion in our hospital were selected for retrospective analysis. 3 cases were males and 5 females, aged 29-65 (43.5±13.2) years. According to the pedicle destruction, using different screws (pedicle screw or laminar screw) fixation.In the preoperative and final follow-up, Japanese Orthopaedic Association score (JOA) and neck disability index (NDI) were used to evaluate neurological function and calculate improvement rate JOA score. At final follow-up, clinical efficacy was evaluated by Odom's grade. situation of internal fixation, fusion of upper cervical were assessed by imaging examination. During follow-up, complications were documented and analyzed. Results: Postoperatively 12 months, all bony fusion were achieved. Tuberculosis were reached clinical cure in 12-18 months. The JOA score increased from 10.5±2.0 preoperatively to 15.6 ±1.1 in final follow-up(P<0.05), and the NDI decreased from 29.9 ± 6.2 preoperatively to 8.6±1.6 (P<0.05). At last follow-up, according to Odom's standard, excellent were obtained in 6 cases (75.0%), good 1 cases (12.5%) and ordinary 1 case (12.5%). No severe complications was documented during follow-up. Conclusions: The treatment of posterior debridement combine with atlantoaxial fusion, and structure grafting and local anti-Tuberculosis drug using intraoperative, not only could obtain reliable clinical efficacy, completely removal of lesions, but also obtain strong stability, which plays an important role in the treatment of cervical tuberculosis.

[Anterior retropharyngeal debridement combined with posterior atlantoaxial fusion for atlantoaxial Tuberculosis]

OBJECTIVE

To evaluate the clinical efficacy of anterior debridement combined with posterior atlantoaxial fusion for atlantoaxial Tuberculosis.

METHODS

From February 2005 to February 2013, 7 patients, 3 males and 4 females, with atlantoaxial Tuberculosis underwent anterior debridement combined with posterior atlantoaxial fusion in Department of Orthopedics Zhengzhou University People's Hospital were selected.In the preoperative and final follow-up, Japanese Orthopaedic Association score (JOA), neck disability index (NDI) and Frankel Classification were used to evaluate neurological function and calculate improvement rate.At final follow-up, clinical efficacy was evaluated by Odom's grade.Situation of internal fixation, fusion of upper cervical were assessed by X-ray, CT scan and MRI scan.

RESULTS

Bony fusion were achieved in 7 cases after operation in 12 months. Tuberculosis were reached clinical cure between 17 and 21 months. At follow The JOA score increased from (11.1±0.7) preoperatively to (15.3±0.5) in final follow-up(P<0.05), and the NDI decreased from (34.0±4.6) preoperatively to (10.1±1.3) in final follow-up (P<0.05). At last follow-up, according to Odom's standard, excellent were obtained in 5 cases, good 1 cases and ordinary 1 case. Frankel Classification of all cases improved from D class to E.

CONCLUSIONS

The treatment of anterior retropharyngeal debridement combine with atlantoaxial fusion, and local anti-tuberculosis drug using intraoperative, not only could obtain reliable clinical efficacy, completly removal of lesions, but also obtain strong stability, which plays an important role in the treatment of atlantoaxial Tuberculosis.

Increased spontaneous neuronal activity in structurally damaged cortex is correlated with early motor recovery in patients with subcortical infarction

BACKGROUND AND PURPOSE

Secondary cortical thinning and volumetric atrophy in the motor-related cortex can inhibit early functional recovery after subcortical infarction. However, the relationship between the spontaneous neuronal activity in these cortices and motor recovery in patients with focal cerebral infarct remains unknown.

METHODS

Structural magnetic resonance imaging (MRI) and resting-state functional MRI were conducted 1, 4 and 12 weeks after onset in 22 patients with an acute subcortical infarct and in 22 normal subjects. Group differences in cortical thickness and in the amplitude of low-frequency fluctuation (ALFF) in motor-related areas were evaluated, and the relationships between ALFF, cortical thickness changes and changes in the Fugl-Meyer scores of physical performance were further analyzed.

RESULTS

In patients with subcortical infarction, progressively decreasing cortical thickness was found over the observation period ipsilesionally in the primary motor cortex (PMC), supplementary motor cortex (SMC) and precuneus (all P < 0.05). Contralesionally, progressive increases in cortical thickness were detected in SMC and insula (all P < 0.05). Increases in ALFF were observed only in PMC (bilaterally) and only at 12 weeks after stroke (all P < 0.05). The cortical thickness changes in the contralesional SMC (rs = 0.483, P = 0.023) and the ALFF changes in bilateral PMC (ipsilesional, rs = 0.51, P = 0.015; contralesional, rs = 0.463, P = 0.03) were positively correlated with changes in the Fugl-Meyer scores.

CONCLUSIONS

These results suggest that increased spontaneous neuronal activity of the PMC, a region structurally damaged secondarily to ischaemic lesion, may contribute to early motor recovery in patients with subcortical infarction.

A robust synthesis of N-glycolyl muramyl dipeptide via azidonitration/reduction

A novel synthetic route leading to N-glycolyl muramyl dipeptide (MDP), a bacterial glycopeptide of particular interest in studies of nucleotide-binding oligomerization domain-containing protein 2 (NOD2), is described. The synthetic strategy hinges on the alkylation of benzylidene-protected glucal with 2-bromopropionic acid and thus circumvents a challenging and non-reproducible SN2 step at the C-3 position of glucosamine derivatives. The subsequent sequence includes an azidonitration and an unusual azide reduction/acylation step via an aza ylide/oxaphospholidine intermediate. This approach generates a protected N-glycolyl MDP that can be either subjected to a one-step global deprotection or differentially deprotected to obtain further derivatives.

Increased expression of macrophage migration inhibitory factor in aorta of patients with coronary atherosclerosis

AIM

The aim of the present study was to investigate the changes of macrophage migration inhibitory factor (MIF) in the aorta of patients with coronary atherosclerosis and to evaluate the relationship between aortic expression levels of MIF and atherosclerotic risk factors.

METHODS

We collected discarded aortic specimens from patients (N.=36) undergoing coronary artery bypass graft surgery (CABG), and studied the presence and distribution of MIF by immunohistochemistry. The arterial tissues from 10 subjects without known atherosclerosis through the kidney donation program were taken as control group. The preoperative serum triglycerides, total cholesterol, low density lipoprotein cholesterol, high density lipoprotein cholesterol, lipoprotein(a), apolipoprotein A, apolipoprotein B, total bilirubin, direct bilirubin, and indirect bilirubin levels of patients were examined and the coronary angiography was performed in order to assess the severity of atherosclerotic lesions.

RESULTS

MIF was detectable in aorta from CABG patients. The aortic MIF expression was elevated in smokers, and patients with hypertension or diabetes. In addition, the aortic MIF expression was associated with the levels of triglycerides, total cholesterol, low density lipoprotein cholesterol, lipoprotein (a), apolipoprotein B, total bilirubin, direct bilirubin, indirect bilirubin and coronary severity scores in simple regression analysis. However, the expression of MIF was only correlated to coronary severity scores in multiple regression analysis.

CONCLUSION

MIF is overexpressed in aorta from patients with coronary atherosclerosis and the aortic MIF expression is correlated with the severity of coronary artery disease.

Inactivation of mammalian target of rapamycin increases STAT1 nuclear content and transcriptional activity in alpha4- and protein phosphatase 2A-dependent fashion

Target of rapamycin (TOR) is a highly conserved serine/threonine kinase that controls cell growth, primarily via regulation of protein synthesis. In Saccharomyces cerevisiae, TOR can also suppress the transcription of stress response genes by a mechanism involving Tap42, a serine/threonine phosphatase subunit, and the transcription factor Msn2. A physical association between mammalian TOR (mTOR) and the transcription factor signal transducer and activator of transcription-1 (STAT1) was recently identified in human cells, suggesting a similar role for mTOR in the transcription of interferon-gamma-stimulated genes. In the current study, we identified a macromolecular protein complex composed of mTOR, STAT1, the Tap42 homologue alpha4, and the protein phosphatase 2A catalytic subunit (PP2Ac). Inactivation of mTOR enhanced its association with STAT1 and increased STAT1 nuclear content in PP2Ac-dependent fashion. Depletion of alpha4, PP2A, or mTOR enhanced the induction of early (i.e. IRF-1) and late (i.e. caspase-1, hiNOS, and Fas) STAT1-dependent genes. The regulation of IRF-1 or caspase-1 by mTOR was independent of other known mTOR effectors p70 S6 kinase and Akt. These results describe a new role for mTOR and alpha4/PP2A in the control of STAT1 nuclear content, and the expression of interferon-gamma-sensitive genes involved in immunity and apoptosis.

Redox regulation and flower development: a novel function for glutaredoxins

Glutaredoxins (GRXs) are small, ubiquitous oxidoreductases that have been intensively studied in E. COLI, yeast and humans. They are involved in a large variety of cellular processes and exert a crucial function in the response to oxidative stress. GRXs can reduce disulfides by way of conserved cysteines, located in conserved active site motifs. As in E. COLI, yeast, and humans, GRXs with active sites of the CPYC and CGFS type are also found in lower and higher plants, however, little has been known about their function. Surprisingly, 21 GRXs from ARABIDOPSIS THALIANA contain a novel, plant-specific CC type motif. Lately, information on the function of CC type GRXs and redox regulation, in general, is accumulating. This review focuses on recent findings indicating that GRXs, glutathione and redox regulation, in general, seem to be involved in different processes of development, so far, namely in the formation of the flower. Recent advances in EST and genome sequencing projects allowed searching for the presence of the three different types of the GRX subclasses in other evolutionary informative plant species. A comparison of the GRX subclass composition from PHYSCOMITRELLA, PINUS, ORYZA, POPULUS, and ARABIDOPSIS is presented. This analysis revealed that only two CC type GRXs exist in the bryophyte PHYSCOMITRELLA and that the CC type GRXs group expanded during the evolution of land plants. The existence of a large CC type subclass in angiosperms supports the assumption that their capability to modify target protein activity posttranslationally has been integrated into crucial plant specific processes involved in higher plant development.

Postoperative Irradiation for Pterygium

BACKGROUND AND PURPOSE

Irradiation of ocular pterygium is considered a valuable treatment supplementation after surgical therapy. Since prospective randomized trials are scare and only limited patient data are available, the aim of this study was to evaluate the patient population treated with fractioned 90Sr irradiation after surgical pterygium resection.

PATIENTS AND METHODS

Between September 1993 and March 2001, 1,147 patients with pterygium lesions (1,320 lesions) were treated surgically and with 90Sr postoperative beta-irradiation. A total dose of 30 Gy was used for patients treated within 48 h after surgery, while those treated>48 h postoperatively received a total dose of 35 Gy. A minimum follow-up period of 3 months was required for inclusion in the analysis, and 1,253 lesions were ultimately analyzed.

RESULTS

Recurrence of the pterygium after postoperative 90Sr irradiation was observed in 97 of 1,253 cases (7.7%). Statistical analysis (uni- and multivariate) revealed, that male gender, younger age (<40 years), prior treatment (surgery and radiotherapy) and immediate irradiation (<2 h after surgery) were negative predictors for local recurrence. Temporary radiotherapy-induced side effects were observed in 15.2% of patients, including moderate conjunctivitis, local pain, visual disturbance and photophobia or an increase in tear flow. However, no long-term serious side effects were documented.

CONCLUSION

90Sr irradiation of pterygium after surgery represents a safe and effective treatment option to prevent disease recurrence. The data obtained in this study indicate that a certain interval after surgery might improve therapy outcome.

Predictive value of image cytometry for diagnosis of lung cancer in heavy smokers

The Research Institute for Diagnosis and Treatment of Early Lung Cancer (RIDTELC) Lung Study was initiated to determine whether lung cancer screening by automated sputum cytometry combined with conventional sputum cytology and auto-fluorescence in addition to white light bronchoscopy could enhance the detection rate of early lung cancer. The present study analyses the initial findings to evaluate the efficiency of automated sputum cytology in predicting the diagnosis of lung cancer. In this study, malignancy grade was used as a predictive parameter for lung cancer. In total, 2,480 heavy smokers (>30 pack-yrs), aged 50-74 yrs, with no previous cancer in the last 5 yrs, received chest radiology, conventional sputum cytology and sputum cytometry screening. In total, twenty-seven lung cancers were diagnosed, representing a prevalence of 1.1%, 25 of which provided sputum samples. Positive automated sputum cytology results were seen in 176 smokers (7.2%), 10 (0.4%) of whom had severe dysplasia or higher lesions (positive results) by conventional sputum cytology examination. Out of 25 tumour cases, 20 had suspicious results using automated sputum cytology, representing 80% sensitivity. One patient out of 24 with tumours had positive results on conventional sputum cytology, representing a sensitivity of 4.2%. For all stages of squamous cell lung cancer and later stage adenocarcinoma the sensitivity of automated sputum cytology was 100%. For adenocarcinoma stage I sensitivity was 25%. In conclusion, DNA analysis of sputum slides by automated sputum cytology may be a suitable tool for the detection of early lung cancer and the characterisation of a high-risk group with pre-invasive lesions for follow-up.

In vitro interaction between silicone gel and human monocyte-macrophages

Controversy remains regarding the ability of silicone materials to induce a specific immune reaction versus a nonspecific inflammatory response. Histopathological analysis of the tissue around failed breast implants reveals chronic inflammation with silicone gel droplets either surrounded by giant cells or engulfed by macrophages, areas of fibrosis, and necrosis. Macrophages are the key cells engulfing or forming foreign body giant cells. To address the mechanisms of silicone-induced inflammation a model of human monocyte-derived macrophages (MDMs) was developed. After sonication of silicone gel, the silicone droplets were embedded in Type I collagen and used to coat glass coverslips; human MDMs were subsequently seeded on the coverslips and maintained in culture for up to 7 days. The advantage of the model was that human macrophages could be studied histologically, and cytochemically as they interacted with well-characterized silicone materials. Initial analysis of the human macrophages shows phagocytosis of the silicone gel within hours of exposure to the material. Analysis for pro-inflammatory cytokines reveals significant transient secretion of IL-1 (p < 0.01) over controls by human macrophages upon exposure to silicone gel at 24 h.

The effect of polyethylene particle phagocytosis on the viability of mature human macrophages

Macrophages are the major cell type observed in the inflammatory membrane retrieved at implant revision surgery. In this study, mature human monocyte-derived macrophages (MDM) were adapted to a previously established in vitro model to examine the influence of high-density polyethylene (HDPE) particulate (4-10 microm) on MDM viability. HDPE particles were suspended in soluble type I collagen, which subsequently was solidified on glass coverslips. Mature human macrophages, derived from differentiating peripheral blood monocytes on polystyrene for 10 days, were incubated in culture media on collagen controls and collagen-particle substrata for 31 days. Histologic analysis demonstrated that MDMs were in contact with the particles at 2 h. The majority of the particles were associated with the cells within 24 h. Based on electron microscopy, those cells associated with the particles appeared to be morphologically activated rather than necrotic or apoptotic. Assessment of cell viability revealed no differences among the groups at 24 h, but at 31 days significantly more viable cells and higher DNA values were found associated with the particle groups versus the collagen controls. The histologic results validate human mature MDMs as a clinically relevant cell type for study of the role of polyethylene particulate in aseptic loosening. The cell viability results indicate that phagocytosis of HDPE is not toxic to MDMs but in fact prolongs MDM survival. The long-lived MDMs may play a role in perpetuating chronic inflammation surrounding implants.

Differential response to chemically altered polyethylene by activated mature human monocyte-derived macrophages

Macrophages and polyethylene (PE) particulate are currently recognized as being the two common denominators in the development of chronic inflammation, periprosthetic osteolysis, and subsequent implant failure. In this study, the effect of PE particulate surface chemistry on mature human monocyte-derived macrophage (MDM) function was investigated. Virgin high-density PE (HDPE: 4-10 microm) and HDPE oxidized by irradiation, thermal and chemical treatment were characterized by FT-IR and suspended in soluble type I collagen, which was subsequently solidified on glass coverslips. Human MDMs, derived from differentiating monocytes on polystyrene for 14 days, were trypsinized and cultured on collagen-particle substrata and collagen controls for 31 days. Analysis of conditioned media collected at 24h incubation showed a significantly higher level of IL-1beta secretion in virgin HDPE over oxidized HDPE or collagen controls, and a significant inhibition of IL-6 secretion in both virgin and oxidized samples. Esterase activity was increased in the medium at a significantly higher level in the virgin HDPE versus controls with the highest activity observed in oxidized HDPE at 31 days. These results illustrate the effect of PE particle surface chemistry (oxidation) on MDM cytokine secretion and esterase activity, and highlight the need to further investigate the potential of PE surface chemistry on modulating MDM function.

[Analysis on the dermal irritation caused by imported cosmetics]

Dermal irritation tests on 902 kinds of cosmetics were conducted. The acute dermal irritation/corrosion tests for 175 samples showed no irritation in 65.1% of them, and 34.9% of them were considered as slight irritation. The chronic dermal irritation/corrosion tests for another 727 samples showed no irritation for 32.2% of them, and 67.8% of them were considered as slight irritation, most of which are lipsticks, eye shadows, fluid powder foundations and powder foundations.