Wear mechanisms description in nanoscale by SEM/TEM of multilayer Zr/ZrN coatings in dependence on phases ratio.

As a result of loading with an external force during the wear process, coating deforms uniformly. After a certain limit load is exceeded, coating deformation is localised through the formation of the so-called shear bands. It has been showed experimentally the process of shear bands formation. The microstructural characterisation before and after the mechanical tests was performed using scanning and transmission electron microscopy (SEM and TEM) on cross-sections of the samples. The analysis indicated that in the case of multilayer coatings where the ratio of the metallic to the ceramic phase is 1:1, the shear bands are formed at an angle of 45°. With a greater proportion of the ceramic phase to metallic (ratio 1:2), the shear band changed the shear angle from ∼45° to ∼90°. Mechanical in situ tests were carried out in the chambers of SEM and TEM. The scratch tests in the SEM were done with the simultaneous observation of the phenomena occurring on the surface of the tested materials showed that at a scratch force of 0.04 N, the additional outer a-C:H layer was damaged, which was shown in the form of a fault in the force-displacement diagram, and in the form of splits visible in the SEM image. However, the application of this additional layer had a positive effect on the wear mechanism of the entire coating structure. The test also indicated that in the case of coatings with phases ratio 1:2 and 1:4 (metallic to ceramic), the characteristics of the brittle material were demonstrated, unlike the coating with a 1:1 phase ratio, where plastic properties predominated. However, for the 1:2 phase ratio coating, the chip was more ductile than for the chip formed when testing a 1:4 phase ratio coating. For in situ mechanical testing in the TEM, a straining holder was used. The test showed that the shear band angle for a 1:1 ratio coating has changed from 45° to 90° due to the different direction of force interaction.

Arthroplasty Rates Not Increasing in Young Patients With Rheumatoid Arthritis: A National Database Review, 2005 Versus 2014.

BACKGROUND: For 20 years, authors have predicted an expansion in total knee arthroplasty (TKA) and total hip arthroplasty (THA) utilization. Over this same period, the introduction of biological disease-modifying antirheumatic drugs has dramatically altered the treatment of rheumatoid arthritis (RA) with hopes of preventing articular damage and obviating the need for prosthetic replacement. The goal of our investigation was to evaluate TKA and THA utilization in young patients with RA (<65 years) in 2005 vs 2014 compared to patients with osteoarthritis (OA). METHODS: Using relevant International Classification of Disease Ninth Revision (ICD-9) and Current Procedural Terminology codes, the Truven MarketScan Database (over 46 million enrollees) was queried to determine THA and TKA incidence rates for RA and OA patients aged <65 years during the final decade of ICD-9 use. Patients with potentially confounding ICD-9 codes were excluded to limit coding variation. Statistical analysis consisted of student t-tests, Pearson's chi-square tests, and Breslow-Day tests. RESULTS: For patients with OA, TKAs increased substantially from 0.07% in 2005 to 0.1% in 2014 (+42.9% change, P < .001). Similarly for patients with OA, THAs increased from 0.04% to 0.06% over the same time period (+66.0% change, P < .001). For young patients with RA, the rate of TKA remained relatively stable-1.06% in 2005 to 1.04% in 2014 (-1.7% change, P = .65)-as did THA-0.44% to 0.48% (+9.0% change, P = .14). CONCLUSIONS: Dramatic increases in THA and TKA rates for OA patients aged <65 years were indeed observed from 2005 to 2014. This trend, however, was not seen in the RA population where TKA and THA rates remained unchanged.

Incidence and risk factors of reoperation in patients with adjacent segment disease: A meta-analysis.

STUDY DESIGN: This was a systematic review of the literature and meta-analysis. OBJECTIVE: The objective of this study was to evaluate the current literature regarding the risk factors contributing to reoperation due to adjacent segment disease (ASD). SUMMARY OF BACKGROUND DATA: ASD is a broad term referring to a variety of complications which might require reoperation. Revision spine surgery is known to be associated with poor clinical outcomes and high rate of complications. Unplanned reoperation has been suggested as a quality marker for the hospitals. MATERIALS AND METHODS: An electronic search was conducted using PubMed. A total of 2467 articles were reviewed. Of these, 55 studies met our inclusion criteria and included an aggregate of 1940 patients. Data were collected pertaining to risk factors including age, sex, fusion length, lumbar lordosis, body mass index, pelvic incidence, sacral slope, pelvis tilt, initial pathology, type of fusion procedure, floating versus sacral or pelvic fusion, presence of preoperative facet or disc degeneration at the junctional segment, and sagittal orientation of the facets at the junctional segment. Analysis of the data was performed using Comprehensive Meta-Analysis software (Biostat, Inc.). RESULTS: The overall pooled incidence rate of reoperation due to ASD from all included studies was 0.08 (confidence interval: 0.065-0.098). Meta-regression analysis demonstrated no significant interaction between age and reoperation rate (P = 0.48). A comparison of the event rates between males and females demonstrated no significant difference between male and female reoperation rates (P = 0.58). There was a significantly higher rate of ASD in patients with longer fusion constructs (P = 0.0001). CONCLUSIONS: We found that 8% of patients in our included studies required reoperation due to ASD. Our analysis also revealed that longer fusion constructs correlated with a higher rate of subsequent revision surgery. Therefore, the surgeon should limit the number of fusion levels if possible to reduce the risk of future reoperation due to ASD. LEVEL OF EVIDENCE: IV.

Α 10-gigawatt attosecond source for non-linear XUV optics and XUV-pump-XUV-probe studies.

The quantum mechanical motion of electrons and nuclei in systems spatially confined to the molecular dimensions occurs on the sub-femtosecond to the femtosecond timescales respectively. Consequently, the study of ultrafast electronic and, in specific cases, nuclear dynamics requires the availability of light pulses with attosecond (asec) duration and of sufficient intensity to induce two-photon processes, essential for probing the intrinsic system dynamics. The majority of atoms, molecules and solids absorb in the extreme-ultraviolet (XUV) spectral region, in which the synthesis of the required attosecond pulses is feasible. Therefore, the XUV spectral region optimally serves the study of such ultrafast phenomena. Here, we present a detailed review of the first 10-GW class XUV attosecond source based on laser driven high harmonic generation in rare gases. The pulse energy of this source largely exceeds other laser driven attosecond sources and is comparable to the pulse energy of femtosecond Free-Electron-Laser (FEL) XUV sources. The measured pulse duration in the attosecond pulse train is 650 ± 80 asec. The uniqueness of the combined high intensity and short pulse duration of the source is evidenced in non-linear XUV-optics experiments. It further advances the implementation of XUV-pump-XUV-probe experiments and enables the investigation of strong field effects in the XUV spectral region.

Wear mechanisms of the biotribological nanocomposite a-C : H coatings implanted by metallic nanoparticles.

Recently, to reduce the residual stress and increase the mechanical properties of a-C:H coatings, metallic nanoparticles have been implanted into their structure. In the present work, to improve the properties of the coating, metallic nanoparticles, including Cu, Nb, Ta, Zr, AgPt and Ag, were inserted into the a-C:H structure. The applied biological and mechanical analysis allowed the optimal biotribological parameters to be indicated for the potential application as protective coatings for metallic medical tools. Wear mechanisms operating at the small length of the designed biotribological coating, such as a-C:H implanted by Zr nanoparticles, were studied by means of transmission electron microscopy (TEM). The TEM analysis confirmed very good coating adhesion to the metallic substrate.

The Effect of Patient Weight and Provider Training and Experience on Dosing of Rocuronium.

Introduction. Maintenance dosing of neuromuscular blocking agents is complex and varies with patient, procedure, and clinical situation. With this in mind, we sought to identify factors impacting the maintenance dosing of neuromuscular blockers as a step toward identifying best practice with respect to minimizing residual neuromuscular blockade. Methods. Cases utilizing rocuronium from July 1, 2010, to June 30, 2014, at the sponsoring institution were analyzed. Using a mixed model to account for repeated measures, patients were analyzed by dose and weight category as defined by the World Health Organization (eight categories ranging from very severely underweight to very severely obese) as well as by the administering provider's level of experience. Results. The study included 12,671 patients with a mean age of 49.7 (SD 16.7). Increasing weight category and higher levels of provider experience were associated with higher doses for rocuronium. There were no differences in initial dose or in frequency of maintenance dosing by weight category after controlling for case length. Discussion. The two dosing patterns identified, higher doses for overweight patients and higher doses administered by experienced providers, are modifiable factors that could enhance patient safety.

Use of Whole Genome Sequencing and Patient Interviews To Link a Case of Sporadic Listeriosis to Consumption of Prepackaged Lettuce.

We report on a case of listeriosis in a patient who probably consumed a prepackaged romaine lettuce-containing product recalled for Listeria monocytogenes contamination. Although definitive epidemiological information demonstrating exposure to the specific recalled product was lacking, the patient reported consumption of a prepackaged romaine lettuce-containing product of either the recalled brand or a different brand. A multinational investigation found that patient and food isolates from the recalled product were indistinguishable by pulsed-field gel electrophoresis and were highly related by whole genome sequencing, differing by four alleles by whole genome multilocus sequence typing and by five high-quality single nucleotide polymorphisms, suggesting a common source. To our knowledge, this is the first time prepackaged lettuce has been identified as a likely source for listeriosis. This investigation highlights the power of whole genome sequencing, as well as the continued need for timely and thorough epidemiological exposure data to identify sources of foodborne infections.

Microstructure characterization of advanced protective Cr/CrN+a-C:H/a-C:H:Cr multilayer coatings on carbon fibre composite (CFC).

Studies of advanced protective chromium-based coatings on the carbon fibre composite (CFC) were performed. Multidisciplinary examinations were carried out comprising: microstructure transmission electron microscopy (TEM, HREM) studies, micromechanical analysis and wear resistance. Coatings were prepared using a magnetron sputtering technique with application of high-purity chromium and carbon (graphite) targets deposited on the CFC substrate. Selection of the CFC for surface modification in respect to irregularities on the surface making the CFC surface more smooth was performed. Deposited coatings consisted of two parts. The inner part was responsible for the residual stress compensation and cracking initiation as well as resistance at elevated temperatures occurring namely during surgical tools sterilization process. The outer part was responsible for wear resistance properties and biocompatibility. Experimental studies revealed that irregularities on the substrate surface had a negative influence on the crystallites growth direction. Chromium implanted into the a-C:H structure reacted with carbon forming the cubic nanocrystal chromium carbides of the Cr23 C6 type. The cracking was initiated at the coating/substrate interface and the energy of brittle cracking was reduced because of the plastic deformation at each Cr interlayer interface. The wear mechanism and cracking process was described in micro- and nanoscale by means of transmission electron microscope studies. Examined materials of coated CFC type would find applications in advanced surgical tools.

Cannabis use and first-episode psychosis: relationship with manic and psychotic symptoms, and with age at presentation.

BACKGROUND: Cannabis use has been reported to be associated with an earlier onset of symptoms in patients with first-episode psychosis, and a worse outcome in those who continue to take cannabis. In general, studies have concentrated on symptoms of psychosis rather than mania. In this study, using a longitudinal design in a large naturalistic cohort of patients with first-episode psychosis, we investigated the relationship between cannabis use, age of presentation to services, daily functioning, and positive, negative and manic symptoms. METHOD: Clinical data on 502 patients with first-episode psychosis were collected using the MiData audit database from seven London-based Early Intervention in psychosis teams. Individuals were assessed at two time points--at entry to the service and after 1 year. On each occasion, the Positive and Negative Syndrome Scale, Young Mania Rating Scale and Global Assessment of Functioning Scale disability subscale were rated. At both time points, the use of cannabis and other drugs of abuse in the 6 months preceding each assessment was recorded. RESULTS: Level of cannabis use was associated with a younger age at presentation, and manic symptoms and conceptual disorganization, but not with delusions, hallucinations, negative symptoms or daily functioning. Cannabis users who reduced or stopped their use following contact with services had the greatest improvement in symptoms at 1 year compared with continued users and non-users. Continued users remained more symptomatic than non-users at follow-up. CONCLUSIONS: Effective interventions for reducing cannabis use may yield significant health benefits for patients with first-episode psychosis.

On the background of enhanced stability and reusability of enzymes in ionic liquids.

The ability of ILs (ionic liquids) to provide an environment of increased stability and, in this way, improve the recyclability of enzymes has been studied. The description of this phenomenon is not easy; there are several approaches for explanation. In this mini-review, the results from different research groups are summarized, with the aim of explaining the strong stability effect of ILs on several enzymes. Spectroscopic methods (e.g. fluorescence and CD, IR spectroscopy, mass spectroscopy and NMR) and investigations of polarity and kosmotropicity of ions are promising methods. Since higher stability means that we may be able to reuse enzymes more times, the recyclability of enzymes was also in the focus. From this point of view, the advantages and disadvantages of applying monophasic or biphasic systems are discussed too, presenting the coupled techniques as well.

Advances and problems with TEM characterization of Cr/CrN multilayer coatings.

Multilayer Cr/CrN/Cr/Cr(N,C) and Cr/CrN with 8 and 32 layer coatings were deposited on austenite substrates using pulsed laser deposition (PLD) technique. The microstructure observations were performed using Philips CM20trade mark, TECNAI G(2) F20 - TWINtrade mark and JEOL EX4000trade mark transmission microscopes. The performed experiments indicated that lowering the argon flow from 60 to 30 cm(3)/s during chromium ablation changes buffer layers microstructure from nearly amorphous to nano-crystalline. The nitride or carbo-nitride layers turned out to be less sensitive to changes in nitrogen flow during deposition. The columnar microstructure of Cr layers is coarser than those in CrN ones under the same deposition condition. This observation proved also that relying on PLD technique as thin as 30 nm layers might be formed within multilayer Cr/CrN coatings.

Devaluing domains in response to threatening intergroup comparisons: perceived legitimacy and the status value asymmetry.

Group status and status legitimacy were tested as moderators of devaluing in response to threatening intergroup comparisons. In 3 experiments, participants received feedback comparing their in-group (based on school or gender) to a higher or lower status out-group. When the legitimacy of group status differences was assumed (Studies 1 and 2) or manipulated (Study 3), participants devalued the domain when their in-group compared unfavorably with a lower status out-group but did not devalue the domain when their in-group compared unfavorably with a higher status out-group. In Study 3, this status value asymmetry was eliminated when status differences were delegitimized. Mediational analyses suggested that the status value asymmetry was explained by the perceived utility of the domain for gaining status-relevant rewards.

Adolescents and adjustment to abortion: are minors at greater risk?

The authors tested the Supreme Court's assumption that minors are particularly susceptible to psychological distress following abortion. The responses of 38 minors (age < 18 years) were compared with those of 402 adults, 1 month and 2 years after an elective, 1st-trimester abortion. Minors were relatively less satisfied with their abortion decision and felt less benefit from the abortion than did adults 1 month postabortion, but they did not differ from adults in adjustment 2 years postabortion. Minors were not more depressed than adults at either time period, and their decision satisfaction and perceived benefit at both time periods did not suggest a population at risk. Age group differences in adjustment 1 month postabortion were explained by minors' reduced self-efficacy appraisals for coping, greater use of avoidant coping strategies, and greater perceived parental conflict. These findings challenge the Court's assumption that minors are particularly vulnerable to psychological harm following abortion.

APOE epsilon4 genotype is associated with an earlier onset of chronic temporal lobe epilepsy.

The authors analyzed the association between APOE epsilon4 genotype and clinical and MRI findings in 43 refractory temporal lobe epilepsy patients. The distribution of the alleles were normal. Ten patients (23%) had an APOE epsilon 4 allele and had an earlier onset of habitual seizures (with epsilon4 5 +/- 5 years; without epsilon4 15 +/- 10 years). Quantitative MRI findings were not influenced by the APOE epsilon4 genotype. APOE epsilon4 may shorten the latency between an initial injury and seizure onset.

Psychological responses of women after first-trimester abortion.

BACKGROUND: Controversy exists over psychological risks associated with abortion. The objectives of this study were to examine women's emotions, evaluations, and mental health after an abortion, as well as changes over time in these responses and their predictors. METHODS: Women arriving at 1 of 3 sites for an abortion of a first-trimester unintended pregnancy were randomly approached to participate in a longitudinal study with 4 assessments-1 hour before the abortion, and 1 hour, 1 month, and 2 years after the abortion. Eight hundred eighty-two (85%) of 1043 eligible women approached agreed; 442 (50%) of 882 were followed for 2 years. Preabortion and postabortion depression and self-esteem, postabortion emotions, decision satisfaction, perceived harm and benefit, and posttraumatic stress disorder were assessed. Demographic variables and prior mental health were examined as predictors of postabortion psychological responses. RESULTS: Two years postabortion, 301 (72%) of 418 women were satisfied with their decision; 306 (69%) of 441 said they would have the abortion again; 315 (72%) of 440 reported more benefit than harm from their abortion; and 308 (80%) of 386 were not depressed. Six (1%) of 442 reported posttraumatic stress disorder. Depression decreased and self-esteem increased from preabortion to postabortion, but negative emotions increased and decision satisfaction decreased over time. Prepregnancy history of depression was a risk factor for depression, lower self-esteem, and more negative abortion-specific outcomes 2 years postabortion. Younger age and having more children preabortion also predicted more negative abortion evaluations. CONCLUSIONS: Most women do not experience psychological problems or regret their abortion 2 years postabortion, but some do. Those who do tend to be women with a prior history of depression.

Peripherally inserted central catheters in the patient with cardiomyopathy. The most cost-effective venous acess.

While waiting for a heart transplant, patients with cardiomyopathy receive positive inotropic agents and other medications that require ongoing venous access. To evaluate the cost effectiveness of bedside peripherally inserted central catheter (PICC) placement, a retrospective analysis was conducted comparing four types of venous access. Almost 4000 dwell days support the premise that bedside PICC placement is the most cost-effective method of providing ongoing venous access to the patient with cardiomyopathy.

Abortion as stigma: cognitive and emotional implications of concealment.

This study examined the stigma of abortion and psychological implications of concealment among 442 women followed for 2 years from the day of their abortion. As predicted, women who felt stigmatized by abortion were more likely to feel a need to keep it a secret from family and friends. Secrecy was related positively to suppressing thoughts of the abortion and negatively to disclosing abortion-related emotions to others. Greater thought suppression was associated with experiencing more intrusive thoughts of the abortion. Both suppression and intrusive thoughts, in turn, were positively related to increases in psychological distress over time. Emotional disclosure moderated the association between intrusive thoughts and distress. Disclosure was associated with decreases in distress among women experiencing intrusive thoughts of their abortion, but was unrelated to distress among women not experiencing intrusive thoughts.

Personal resilience, cognitive appraisals, and coping: an integrative model of adjustment to abortion.

We hypothesized that the effects of personality (self-esteem, control, and optimism) on postabortion adaptation (distress, well-being, and decision satisfaction) would be fully mediated by preabortion cognitive appraisals (stress appraisals and self-efficacy appraisals) and postabortion coping. We further proposed that the effects of preabortion appraisals on adaptation would be fully mediated by postabortion coping. Results of a longitudinal study of 527 women who had first-trimester abortions supported our hypotheses. Women with more resilient personalities appraised their abortion as less stressful and had higher self-efficacy for coping with the abortion. More positive appraisals predicted greater acceptance/reframing coping and lesser avoidance/denial, venting, support seeking, and religious coping. Acceptance-reframing predicted better adjustment on all measures, whereas avoidance-denial and venting related to poorer adjustment on all measures. Greater support seeking was associated with reduced distress, and greater religious coping was associated with less decision satisfaction.

PIP: An integrative model of psychological adjustment to abortion, derived from existing cognitive-phenomenological models of coping with stressful life events, was tested in a longitudinal study of 527 women (mean age, 23.9 years) who underwent first-trimester abortion in Buffalo, New York (US), in 1993. It was hypothesized that the effects of personality (self-esteem, control, and optimism) on postabortion adaptation (distress, well-being, and decision satisfaction) would be mediated by pre-abortion cognitive appraisals of stress and self-efficacy. As hypothesized, women with more resilient personalities appraised their abortion as less stressful and had higher self-efficacy for coping with the event. The lower women's stress appraisals, the more they used acceptance/positive reframing for coping and the less they relied on avoidance/denial. Acceptance/reframing predicted better adjustment on all measures, while avoidance/denial and venting predicted poorer adjustment. Greater support seeking was associated with reduced postabortion distress, and greater religious coping was linked with less decision satisfaction. Collectively, the analyses suggested that the hypothesized model provided a parsimonious and theoretically grounded explanation of the pattern of associations in the data. These findings suggest a need for clinical interventions that help women learn to use more beneficial forms of coping with abortion.

Effect of antagonism of the parathyroid hormone (PTH)/PTH-related protein receptor on decidualization in rat uterus.

Parathyroid hormone-related protein (PTHrP) was detected at 32.8 +/- 3.9 pmol 1-1 in uterine luminal fluid from immature rats treated with oestradiol. As mRNA encoding PTHrP has previously been localized to implantation sites in pregnant rats, the role of luminal PTHrP during pregnancy was explored. Infusion of a parathyroid hormone (PTH)/PTHrP receptor antagonist, [Asn10,Leu11]PTHrP(7-34) amide, into the uterine lumen during pregnancy in rats resulted in excessive decidualization. This effect was also observed after intrauterine infusion of a monoclonal antibody raised against PTHrP. The effect of infusion of PTH/PTHrP receptor antagonist was dependent upon successful implantation, was dose-dependent and confined to the treated horn. A decrease in the number of apoptotic decidual cells in antagonist-infused uterine horns compared with vehicle or non-infused horns was detected immunohistochemically at day 13 of pregnancy, and this decrease is likely to contribute to the 'over-decidualization' observed. In pseudopregnant rats, infusion of PTH/PTHrP receptor antagonist into the uterine lumen resulted in an increase in uterine wet weight of the infused horn compared with the non-infused horn, indicating a direct effect on deciduoma formation. Thus, activation of the PTH/PTHrP receptor by locally produced PTHrP appears to be crucial for normal decidualization during pregnancy in rats.