In the past Ling Ren has collaborated on articles with Ni He and Yang Li. One of their most recent publications is Do race and gender matter in police stress? A preliminary assessment of the interactive effects. Which was published in journal Journal of Criminal Justice.

More information about Ling Ren research including statistics on their citations can be found on their Copernicus Academic profile page.

Ling Ren's Articles: (13)

Do race and gender matter in police stress? A preliminary assessment of the interactive effects

AbstractThe interactive effects of race and gender in a multi-dimensional assessment of police occupational stress were examined in this study. The sample from a large urban police department was divided into four subgroups: White males, African-American males, White females, and African-American females. Comparisons were carried out to assess group differences in three major domains of stress process: stressors, coping mechanisms, and multiple psychological manifestations of stress. Specific attentions were paid to observe any similar or dissimilar interactive effects of race and gender on the stress process. The results showed that dynamic factors such as measures of work environment and coping mechanisms contributed more in explaining police stress than static factors such as race and gender. Additionally, destructive coping and work-family conflict (spillover) were the most stable correlates of police stress across all subgroups included in the analysis. The impacts of negative exposure and camaraderie on police stress were conditional on the subgroup statuses. Limitations and implications of the study are discussed.

Liberal versus conservative public policies on crime: What was the comparative track record during the 1990s?

AbstractThe purpose of this study was to examine the efficacy of social control and social support policies associated with conservative and liberal political ideologies with respect to violent crime in large U.S. cities during the 1990s. Eighty-five cities with populations of 150,000+ were included in the analysis; these cities accounted for fifty-two million urban area residents of the U.S. The use of the two-way, fixed-effect panel data method of statistical analysis enabled the authors to assess the relationship between change in local government expenditures for police and court services (social control) and expenditures on community development and park/recreation (support policy) and corresponding changes in crime rates documented within these cities. The findings indicated that expenditure on both police services and community development initiatives had significantly suppressive effects on crime in these cities during the period of the 1990s. It appeared that both conservative and liberal policies had their merits as effective countermeasures to crime.

Biodegradable Mg-Cu alloy implants with antibacterial activity for the treatment of osteomyelitis: In vitro and in vivo evaluations

AbstractTreatment of chronic osteomyelitis (bone infection) remains a clinical challenge; in particular, it requires an implantable material with improved antibacterial activity. Here, we prepared biodegradable magnesium (Mg)-copper (Cu) alloys with different Cu contents (0.05, 0.1, and 0.25 wt%) and assessed their potential for treating methicillin-resistant Staphylococcus aureus-induced osteomyelitis. We evaluated the microstructures, mechanical properties, corrosion behavior, and ion release of the alloys in vitro, and their biocompatibility and antibacterial activity in vitro and in vivo. The antibacterial activity of the Mg-Cu alloys in vitro was demonstrated by microbiological counting assays, bacterial viability assays, biofilm formation observations, and the expression of biofilm, virulence, and antibiotic-resistance associated genes. The antibacterial activity of Mg-Cu alloys in vivo was confirmed by imaging examination, microbiological cultures, and histopathology. The biocompatibility of Mg-Cu alloys was confirmed by cell proliferation, vitality, and morphology assays in vitro and Cu2+ or Mg2+ ion assays, blood biochemical tests, and histological evaluation in vivo. The alloy containing 0.25 wt% Cu exhibited the highest antibacterial activity among the tested alloys, with favorable biocompatibility. Collectively, our results indicate the potential utility of Mg-Cu alloy implants with 0.25 wt% Cu in treating orthopedic infections.

Effect of surface coating on antibacterial behavior of magnesium based metals

AbstractAntibacterial behaviors of magnesium (Mg) based metal, pure Mg and AZ31 alloy, with and without surface coatings were studied. The results indicated that both pure Mg and AZ31 alloy had strong antibacterial effect against Escherichia coli and Staphylococcus aureus with rapid increases of pH values of the bacterial suspensions. Pure Mg with porous silicon-contained (Si) coating by micro-arc oxidation still maintained its antibacterial ability while with a mild increase of the pH value. However, pure Mg and AZ31 alloy with fluorine-contained (F) and Si coatings by chemical conversion, respectively, lost their antibacterial abilities with nearly no change of the pH values, owing to the much dense coatings on surfaces.

Effect of surface passivation on corrosion resistance and antibacterial properties of Cu-bearing 316L stainless steel

Highlights•A new passivation solution that adding proper concentration of Cu2+ ions into nitric acid solution was proposed.•The new passivation method can simultaneously guarantee the better corrosion resistance and stable antibacterial property for 316L-CuSS.•The results of XPS analysis and Cu2+ ions release explained the antibacterial mechanism.•The 316L-CuSS after antibacterial passivation determined by RTCA assay was completely biocompatible.

Short CommunicationDifferential scanning calorimetry analysis on Cu precipitation in a high Cu austenitic stainless steel

AbstractThe Cu precipitation in a high Cu austenitic antibacterial stainless steel (3.8–5.0% Cu) was studied by using differential scanning calorimetry (DSC) analysis. The results indicated that DSC analysis could be used to detect the Cu precipitation in the experimental steel with different Cu additions. Two stages of precipitation were identified in the steel by DSC analysis, clustering of Cu-rich phases and dissolution/coarsening of the precipitates formed at the first stage. DSC analyses also showed that with increase of the Cu content in the steel, the start temperature of Cu precipitation was decreased and the peak area of Cu precipitation was enlarged. The activation energy for Cu precipitation in the steel was determined to be 181 kJ/mol, indicating that the process should be mainly related to the diffusion of Cu atoms in the steel.

A novel coping metal material CoCrCu alloy fabricated by selective laser melting with antimicrobial and antibiofilm properties

Highlights•Novel CoCrCu alloys were fabricated by using selective laser melting (SLM).•SLM CoCrCu alloys showed satisfied antimicrobial and antibiofilm activities.•SLM CoCrCu alloys have no cytotoxic effect on normal cells.•Other properties of SLM CoCrCu alloys were similar to SLM CoCr alloys.•SLM CoCrCu alloys have the potential to be used as coping metals.

Global asymptotic stability of periodic solutions for inertial delayed BAM neural networks via novel computing method of degree and inequality techniques☆

AbstractFirstly, by combining Mawhin’s continuation theorem of coincidence degree theory with Lyapunov functional method and by using inequality techniques, a sufficient condition on the existence of periodic solutions for inertial BAM neural networks is obtained. Secondly, a novel sufficient condition which can ensure the global asymptotic stability of periodic solutions of the system is obtained by using Lyapunov functional method and by using inequality techniques. In our paper, the assumption for boundedness on the activation functions in existing paper is removed, the conditions in inequality form in existing papers are replaced with novel conditions, and the prior estimate method of periodic solutions is replaced with Lyapunov functional method. Hence, our result on global asymptotic stability of periodic solutions for above system is less conservative than those obtained in existing paper and more novel than those obtained in existing papers.

Bio-functional Design for Metal Implants, a New Concept for Development of Metallic Biomaterials

A new concept for development of metallic biomaterials is proposed in this article, i.e., a certain bio-function can be realized for a metal implant through continuous release of a designed bio-functional metal element from surface of the metal implant in the body environment. This creative idea has been verified to be possible by several different in vitro and in vivo experimental evidences on the Cu-bearing stainless steels and magnesium based metals. It was indicated that a trace amount of Cu release from the Cu-bearing steels could have obvious bio-functions of reduction of the in-stent restenosis (ISR), anti-bacterial infection, inhibiting the inflammatory cells and even promoting the early osteogenesis. Furthermore, the degradation of magnesium based metals in bones could promote the new bone formation, enhance the bone mineral density for the osteoporosis modeled animal, and even have strong anti-bacterial ability and strong cytotoxicity to bone tumor cells due to the enhancement of pH. Special bio-function with satisfied load-bearing capacity for metallic biomaterials will bring higher application values for the implant made of this novel material. This is an attractive direction for research and development with many challenges, but the final success will be much beneficial to the majority of patients.

Hot deformation behavior of Cu-bearing antibacterial titanium alloy

AbstractWe investigated the deformation behavior of a new biomedical Cu-bearing titanium alloy (Ti-645 (Ti-6.06Al-3.75V-4.85Cu, in wt%)) to optimize its microstructure control and the hot-working process. The results showed that true stress–true strain curve of Ti-645 alloy was susceptible to both deformation temperature and strain rate. The microstructure of Ti-645 alloy was significantly changed from equiaxed grain to acicular one with the deformation temperature while a notable decrease in grain size was recorded as well. Dynamic recovery (DRV) and dynamic recrystallization (DRX) obviously existed during the thermal compression of Ti-645 alloy. The apparent activation energies in (α + β) phase and β single phase regions were calculated to be 495.21 kJ mol−1 and 195.69 kJ mol−1, respectively. The processing map showed that the alloy had a large hot-working region whereas the optimum window occurred in the strain rate range of 0.001–0.1 s−1, and temperature range of 900–960 °C and 1000–1050 °C. The obtained results could provide a technological basis for the design of hot working procedure of Ti-645 alloy to optimize the material design and widen the potential application of Ti-645 alloy in clinic.

Regular ArticleSwellGel: An Affinity Chromatography Technology for High-Capacity and High-Throughput Purification of Recombinant-Tagged Proteins☆

AbstractThe revolution in genomics and proteomics is having a profound impact on drug discovery. Today's protein scientist demands a faster, easier, more reliable way to purify proteins. A high capacity, high-throughput new technology has been developed in Perbio Sciences for affinity protein purification. This technology utilizes selected chromatography media that are dehydrated to form uniform aggregates. The SwellGel aggregates will instantly rehydrate upon addition of the protein sample, allowing purification and direct performance of multiple assays in a variety of formats. SwellGel technology has greater stability and is easier to handle than standard wet chromatography resins. The microplate format of this technology provides high-capacity, high-throughput features, recovering milligram quantities of protein suitable for high-throughput screening or biophysical/structural studies. Data will be presented applying SwellGel technology to recombinant 6× His-tagged protein and glutathione-S-transferase (GST) fusion protein purification.

Synthesis of Co3O4 nanostructures using a solvothermal approach

AbstractThe controlled synthesis of Co3O4 nanostructures with morphologies of micro-spheres, nanobelts, and nanoplates was successfully achieved by a simple solvothermal method. Various comparison experiments showed that several experimental parameters, such as the reaction temperature and the concentration of NH3·H2O, play important roles in the morphological control of Co3O4 nanostructures. A lower temperature and a lower concentration of NH3·H2O favor spherical products with a diameter of 1–1.5 μm, whereas a higher temperature and a higher concentration of NH3·H2O generally lead to the formation of nanobelts with a width of 20–150 nm. In addition, Co3O4 hexagonal nanoplates with an edge length of about 200–300 nm are also obtained by adding surfactant CTAB. A rational mechanism is proposed for the selective formation of various morphologies. X-ray powder diffraction (XRD), transmission electron microscopy (TEM), selected-area electron diffraction (SAED), and field-emission scanning electron microscope (FE-SEM) were used to characterize the products.

Research on Pyrolysis Mechanism of Huadian Oil Shale☆

AbstractThe extraction of shale oil similar to petroleum by pyrolysis of oil shale is of potential value. Based on the solid-phase thermolysis model, the double extrapolated method is applied to analyze the thermogravimetric data of Huadian oil shale. It is found that the essential procedure of Huadian oil shale pyrolysis accords with internal diffusion, which can be described by three-dimensional diffusion model, and of which the activation energy is 194KJ/mol. Combined the gas-solid reaction model with the solid-phase thermolysis model, the dynamics model of oil shale pyrolysis influenced by internal diffusion is established.

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