Importance of surface morphology on secondary electron emission: a case study of Cu covered with carbon, carbon pairs, or graphitic-like layers

Understanding the relationship between surface adsorbates and secondary electronic emission is critical for a variety of technologies, since the secondary electrons can have deleterious effects on the operation of devices. The mitigation of such phenomena is desirable. Here, using the collective efforts of first-principles, molecular dynamics, and Monte Carlo simulations, we studied the effects of a variety of carbon adsorbates on the secondary electron emission of Cu (110). It was demonstrated that the adsorption of atomic C and C[Formula: see text] pair layers can both reduce and increase the number of secondary electrons depending on the adsorbate coverage. It was shown that under electron irradiation, the C-Cu bonds can be dissociated and reformed into C[Formula: see text] pairs and graphitic-like layers, in agreement with experimental observation. It was verified that the lowest secondary electron emission was due to the formation of the graphitic-like layer. To understand the physical reason for changes in number of secondary electrons for different systems from an electronic structure perspective, two-dimensional potential energy surfaces and charge density contour plots were calculated and analyzed. It was shown that the changes are strongly influenced by the Cu surface morphology and depends highly on the nature of the interactions between the surface Cu and C atoms.

BTEX (benzene, toluene, ethylbenzene, and xylene) and risk of cancer - a study from Centers for Disease Control and Prevention's National Health and Nutrition Examination Survey

Introduction/Objective

BTEX (benzene, toluene, ethylbenzene, and xylene) is well know for its toxicity via through environmental, occupational and recreational exposures. However, there is limited literature about the carcinogenic effect of BTEX. Hence, we aim to study the prevalence and association of cancer amongst individuals with exposure of BTEX.

Methods/Case Report

A retrospective cross-sectional study was performed between 2013 and 2018 utilizing the NHANES database. Adult individuals having data on socio-demographic questionnaires and lab findings on exposure to BTEX were included. Prevalence of cancer was identified amongst exposure to BTEX (vs no-BTEX). Univariate (chi-squre test and Mann–Whitney U test) and Multivariate (survey logistic regression) analysis was performed to evaluate the epidemiologic characteristics of individuals exposred to BTEX and association of cancer with BTEX exposure in comparison to no BTEX exposure.The p value of <0.05 considered statistically significant.

Results (if a Case Study enter NA)

124,162 participants were identified with BTEX exposure. Individuals with BTEX exposure were young (40 vs 51 year old), male (91% vs female: 87%), and Mexican American (92% vs Non-Hispanic Black: 89% vs Non-Hispanic White: 89% vs other Hispanic: 87%). Univariate analysis showed higher total prevalence of cancer in BTEX (9.3% vs. 1.3%; p<0.0001) compared to no BTEX. Individuals with BTEX exposure had higher prevalnece of blood cancer (0.47% vs 0.00; p<0.0001), leukemia (0.56% vs 0.00; p<0.001), and lymphoma (1.72% vs 0.39%; p<0.0001) in comparison with no exposure. Multivaritate analysis showed participants with BTEX exposure had 10% higher risk of cancer (aOR: 1.10; 95%CI: 1.10-1.10; p<0.0001) compared to no BTEX exposure. Additionally, exposure to individual components of benzene (aOR: 1.24; 95%CI: 1.24; p<0.0001), ethylbenzene (aOR: 1.08; 95%CI: 1.08-1.08; p<0.0001), and o-xylene (aOR: 1.19; 95%CI: 1.19-1.19; p<0.0001) had higher risk of cancer compared to no exposure participants.

Conclusion

Our study conclude higher risk of cancer among participants with exposure to benzene, ethylbenzene and o-xylene. Future studies are warranted to evaluate the association of various types of cancers in BTEX exposure.

Carbon-oxygen surface formation enhances secondary electron yield in Cu, Ag and Au

First-principles calculations coupled with Monte Carlo simulations are used to probe the role of a surface CO monolayer formation on secondary electron emission (SEE) from Cu, Ag, and Au (110) materials. It is shown that formation of such a layer increases the secondary electron emission in all systems. Analysis of calculated total density of states (TDOS) in Cu, Ag, and Au, and partial density of states (PDOS) of C and O confirm the formation of a covalent type bonding between C and O atoms. It is shown that such a bond modifies the TDOS and extended it to lower energies, which is then responsible for an increase in the probability density of secondary electron generation. Furthermore, a reduction in inelastic mean free path is predicted for all systems. Our predicted results for the secondary electron yield (SEY) compare very favorably with experimental data in all three materials, and exhibit increases in SEY. This is seen to occur despite increases in the work function for Cu, Ag, and Au. The present analysis can be extended to other absorbates and gas atoms at the surface, and such analyses will be present elsewhere.

The Design and Rationale of a Phase 2b, Randomized, Double-Blinded, and Placebo-Controlled Trial to Evaluate the Safety and Efficacy of Lomecel-B in Older Adults with Frailty

BACKGROUND

Frailty in older adults is a rapidly growing unmet medical need. It is an aging-related syndrome characterized by physical decline leading to higher risk of adverse health outcomes.

OBJECTIVES

To evaluate the efficacy of Lomecel-B, an allogeneic medicinal signaling cell (MSC) formulation, in older adults with frailty.

DESIGN

This multicenter, randomized, parallel-arm, double-blinded, and placebo-controlled phase 2b trial is designed to evaluate dose-range effects of Lomecel-B for frailty on physical functioning, patient-reported outcomes (PROs), frailty status, and biomarkers.

SETTING

Eight enrolling clinical research centers, including the Miami Veterans Affairs Medical Center.

PARTICIPANTS

Target enrollment is 150 subjects aged 70-85 years of any race, ethnicity, or gender. Enrollment criteria include a Clinical Frailty Score of 5 ("mild") or 6 ("moderate"), a 6MWT of 200-400 m, and serum tumor necrosis factor-alpha (TNF-α) ≥2.5 pg/mL.

INTERVENTION

A single intravenous infusion of Lomecel-B (25, 50, 100, or 200 million cells) or placebo (N=30/arm). Patients are followed for 365 days for safety, and the efficacy assessments performed at 90, 180, and 270 days.

MEASUREMENTS

The primary endpoint is change in 6MWT in the Lomecel-B-treated arms versus placebo at 180 days post-infusion. Secondary and exploratory endpoints include change in: 6MWT and other physical function measures at all time points; PROs; frailty status; cognitive status; and an inflammatory biomarkers panel. A pre-specified sub-study examines vascular/endothelial biomarkers. Safety is evaluated throughout the trial.

RESULTS

The trial is conducted under a Food and Drug Administration Investigational New Drug (IND), with Institutional Review Board approval, and monitoring by an NIH-appointed independent Data Safety Monitoring Board.

CONCLUSION

This clinical trial investigates the use of a regenerative medicine strategy for frailty in older adults. The results will further the understanding of the potential for Lomecel-B in the geriatric condition of frailty.

Psychiatric comorbidity in a patient with opsoclonus-myoclonus syndrome. differences in the transition from childhood to adulthood: A case report

Introduction

Opsoclonus-Myoclonus syndrome (OMS), also known as Kinsbourne syndrome, is a paraneoplasic pediatric condition characterized by erratic eye movements and generalized myoclonus. Previous studies have described a wide range of psychiatric comorbidities in children with this syndrome. Cognitive impairment (especially intellectual capacity and language), affective symptoms (irritability, poor mood regulation) and behavioral problems are the most frequent presentations (1). However, there is a lack of literature describing the progression of this symptoms when the patient reaches the adulthood.

Objectives

To illustrate the psychiatric comorbidity of an adult patient with Opsoclonus-Myoclonus syndrome.

Methods

We present one case-report and literature research of the topic.

Results

We present a 18 year old girl diagnosed with OMS and Graves-Basedow hyperthyroidism. During her childhood she started presenting attention and comprehension difficulties. She was diagnosed with an Attention Deficit Hyperactivity Disorder (ADHD) and started treatment with methylphenidate. She completed elementary and secondary education. During the adulthood, the main psychiatric comorbidity was related to affective symptoms. We observed an impaired mood regulation, hypothymia, anhedonia, and frequent episodes of irritability, which persisted after the thyroid regulation. This caused incremented anxious symptoms and insomnia that were treated with mirtazapine and lormetazepam. After some weeks, she fulfilled criteria of a depressive episode and we started antidepressant treatment with vortioxetine.

Conclusions

- Adult patients diagnosed with OMS during childhood can persist presenting ADHD as a comorbidity. - Affective symptoms, and even a major depressive episode, should be considered during the follow-up of this population. Insight of the cognitive limitations could be a risk factor for a depression.

Disclosure

No significant relationships.

Infection after spinal surgery and procedures

Postoperative infections after spinal surgery are a challenging issue, difficult to diagnose and treat, that requires prolonged medical therapy and even surgery. In this paper, we aim to review the current standards in the diagnosis and treatment of post-procedural Spondylodiscitis (SD). We performed a review of the available literature focusing on diagnostic and therapeutic standards of post-procedural SD, both after minimally invasive procedures and open surgery. Spinal infections can occur in less invasive procedures with an incidence ranging from 0.26% to 2.75%. Post-surgical spinal infections range from 2.1% to 8.5% for instrumented surgery, whereas these are less than 1% in open surgery without instrumentation. MRI is currently the most sensitive and specific technique to diagnose postoperative SD. CT guided aspiration culture should be performed in all patients with deep-seated infections with negative blood cultures. Early infections start with wound healing problems within a few weeks from surgery, and the occurrence of fever and an increase in serum markers of inflammation. Late infections often cause chronic pain, implant failure, non-union or wound dehiscence even a long time after surgery. The onset of the infection differentiates the specific treatment. Indeed, in the early postoperative period spinal fusion is not appropriate yet, and the stability of the fusion site only relies on the instrumentation. Therefore, even when suitable, implant removal may lead to undesirable consequences. In chronic infections, on the other hand, implant removal is unlikely to determine instability since the fusion has already been accomplished.

Prevalence of Batrachochytrium dendrobatidis in immature eastern hellbenders Cryptobranchus alleganiensis from North Carolina, USA

Batrachochytrium dendrobatidis (Bd) has been detected in wild hellbender Cryptobranchus alleganiensis populations, with rare instances of chytridiomycosis and Bd-induced mortality. To date, Bd surveillance in hellbender populations has been disproportionately focused on adult age classes. A lingering question is whether Bd might contribute to hellbender declines through disproportionate negative effects on immature age classes. The objective of this study was to quantify Bd prevalence and load in immature hellbenders in western North Carolina, USA. We conducted field surveys during 2018 and 2019 and collected 88 skin swabs from 84 hellbenders spanning 3 age classes. Bd was detected on 11% of individuals, including 8 larvae and 1 juvenile. We did not detect symptoms of chytridiomycosis or a decline in body condition in Bd-positive hellbenders. Load varied from approximately 1-153 zoospore equivalents for the 9 Bd-positive hellbenders and was not associated with size class of the individual. While hellbenders appeared to be abundant in each survey reach, more work is needed to determine whether Bd may increase the vulnerability of immature hellbenders to anthropogenic stressors.

Personality dimensions and drug of choice: A descriptive study using Cloninger's temperament and character inventory revised

Personality dimensions related with drug use are novelty seeking, impulsivity and harm avoidance. Studies predicting drug of choice over personality variables are controversial.

Objective

To describe personality profile of drug users in relation to substance of choice.

Aims

To know personality dimension differences according to drug used.

Methods

Cloninger's TCI-R was administered to 218 patients in a dual diagnosis unit.

SPSS was applied.

Results

Of the patients, 33.94% had personality disorder. Principal substances used were alcohol, cocaine and cannabis.

Most of drug users had normal scores in each dimension. No high scores were found in reward dependence, self-directedness and cooperativeness with any drug.

High scores were observed for novelty seeking in 42.9% of timulants users; for arm avoidance in a quarter of cocaine, alcohol and methadone users and for persistence in 18.2% of hypnotics users.

Low scores were observed for reward dependence in 45% of heroine and hypnotics users; for persistence in 50% of methadone and 32% of cocaine users; for self-directedness in most of types of drug users and for cooperativeness in up to 50% in heroine, hypnotics, stimulants and cocaine users.

Statistical significant differences were observed for cocaine use and high novelty seeking and low cooperation; for non cannabis use and high harm avoidance; for non anfetamine use and low scores in reward dependence; for opiate use and low self-directedness.

Conclusions

Most of patients had normal scores in the different dimensions.

Presence of comorbid personality disorder led us to consider the results with caution.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Zusammenhänge zwischen Alter, Parität, endometrialer Fibrosierung, Frühgraviditätsrate und uteriner Durchblutung bei der Stute

Ziel der Arbeit war zu untersuchen, ob bei der Stute Zusammenhänge zwischen Alter, Parität, endometrialer Fibrosierung bzw. Frühgraviditätsrate und dem uterinen Blutfluss bestehen. Material und Methoden: Insgesamt 22 Stuten wurden täglich zwischen den Tagen –2 und 12 (0 = Ovulation) untersucht. Nach dem Alter und der Parität erfolgte eine Einteilung in je zwei Kategorien. Stuten, die zwischen 3 und 9 Jahre alt waren, wurden als „jung“ (n = 11) bezeichnet, Tiere im Alter von 10 bis 19 Jahren als „alt“ (n = 11). Zehn der Stuten waren nullipar und 12 uni- bzw. pluripar. Die Beurteilung der endometrialen Fibrosierung fand nach dem von Kenney und Doig (1986) beschriebenen Verfahren statt. Ergebnisse: Dreizehn von 22 Tieren wiesen endometriale Fibrosierungen (Kartegorie IIa, IIb bzw. III) auf. Eine einmalige Besamung 12 Stunden vor der Ovulation mit flüssigkonserviertem Sperma führte bei 8 der 22 Stuten zu einer Trächtigkeit. Die Untersuchungen wurden mit dem Farbdopplersonographen SSH 140 A und einer 7,0-MHz-Mikrokonvexsonde durchgeführt. Aus den ermittelten Parametern mittlere Blutflussgeschwindigkeit (TAMV) und Gefäßdurchmesser (D) wurde das Blutflussvolumen (VOL) errechnet. VOL unterlag bei allen Stuten ähnlichen zyklus - bedingten Schwankungen (p < 0,05), die auf Änderungen der Blutflussgeschwindigkeit TAMV beruhten. Der Gefäßdurchmesser blieb im Untersuchungszeitraum konstant (p > 0,05). VOL war bei alten sowie bei uni- bzw. pluriparen Stuten und bei Tieren mit endometrialer Fibrosierung höher (p < 0,05) als bei jungen, nulliparen Stuten und solchen ohne endometriale Fibrosierung. Bei den güst gebliebenen Tieren ergab sich im Gegensatz zu den Stuten, die trächtig wurden, 12 Stunden nach der Insemination kurzzeitig ein signi - fikanter Anstieg des uterinen Blutflussvolumens (p < 0,05). Schlussfolgerung und klinische Relevanz: Die Ergebnisse zeigen, dass anhand der transrektalen Farbdopplersonographie wertvolle Erkenntnisse über die Fertilität von Stuten gewonnen werden können.

Syndrome of Inappropriate Anti-Diuretic Hormone Secretion Secondary to Strongyloides stercoralis Infection in an Allogeneic Stem Cell Transplant Patient: A Case Report and Literature Review

Syndrome of inappropriate anti-diuretic hormone (SIADH) has been reported to be associated with systemic Strongyloides stercoralis. Here, we report a case of a stem cell transplant (SCT) recipient who developed severe SIADH secondary to systemic S Stercoralis. The SIADH resolved quickly after treating the systemic S Stercoralis with ivermectin. A systematic review of the literature was performed by PubMed, Scopus, and Cochrane database search. Only eight cases of S Stercoralis in allogeneic SCT recipients have been previously reported. To our knowledge, ours is the first reported case of SIADH secondary to S Stercoralis infection in an allogeneic SCT recipient. Prior to transplantation, even if asymptomatic, patients from endemic regions should be screened with strongyloides immunoglobulin (Ig)G serology. Pretransplantation eosinophilia should be evaluated by screening multiple stool samples for ova and parasites. Transplant candidates with positive serology or stool tests can be treated pretransplantation to eradicate infection. Patients at risk for S Stercoralis who develop nonspecific gastrointestinal complaints, rash, pulmonary infiltrates, or gram-negative bacteremia or meningitis may have S Stercoralis hyperinfection syndrome. Our case indicates that the development of SIADH may be an additional clue to this diagnosis. Appropriate diagnostic studies, including repeat stool and other body fluid sampling, should be expedited and ivermectin therapy initiated rapidly to prevent significant morbidity and mortality.

Case Series: Fetal Pulmonary Vein A-Wave Reversal: An Early Marker of Left-Sided Cardiac Anomalies?

Background Improvements in congenital heart disease (CHD) screening are needed based on the lack of sensitivity of current screening methods and the understanding that the early detection of certain CHDs may improve outcomes. Fetal venous circulation has caught medical attention, and two studies demonstrated that it is feasible to register pulmonary vein flow velocity waveforms (FVWs) during early gestation. Meanwhile, the latter study proposed pulmonary vein A-wave reversal as a marker of cardiac anomaly. Methods We report a series of six consecutive fetuses with confirmed cardiac anomalies that underwent first-trimester screening, including pulmonary vein FVWs, at our center during 2013. CHD was confirmed by late pregnancy echocardiography, and in three cases fetal autopsies were performed. Result/Discussion The ductus venosus (DV) and nuchal translucency (NT) predicted 50% of CHD cases, whereas the combination of markers identified 66.6% of CHD cases. When adding pulmonary vein assessment, the rate of detection rose to 83.3%. Total five of six cases of CHD had reversal of pulmonary vein A-wave during early pregnancy. The sixth case with CHD and nonreversal of A-wave was described as right ventricle hypoplasia with type 1 tricuspid atresia and persistent ductus arteriosus. Conclusion This is the first series reporting pulmonary vein end-diastolic reversal as a CHD screening add-on during early pregnancy. The addition of pulmonary vein FVW assessment to the current CHD screening bundle could increase the rate detection of cardiac anomalies. This pilot study suggests that pulmonary vein end-diastolic flow reversal favors detection of left-sided CHD over the right-sided ones.

Effect of heat treatment of magnesium alloy substrates on corrosion resistance of a hybrid organic–inorganic sol–gel film

The influence of heat treatment of magnesium alloy substrates on corrosion resistance of a sol–gel coating has been assessed during immersion tests in 0.6 M NaCl aqueous solution.

Abstract P6-04-29: Vitamin D induces expression of estrogen receptor and restores endocrine therapy response in estrogen receptor-negative breast cancer

Background: Approximately 30% of all breast tumors do not express estrogen receptor (ER) and patients with these tumors present poor prognosis and respond poorly to hormone therapy. Calcitriol through its vitamin D receptor (VDR) exerts antiproliferative, apoptotic and pro-differentiating effects in cancer. Calcitriols effects upon ER expression in breast cancer cells is controversial. Therefore, in order to clarify this issue, the aim of the present study was to determine if calcitriol induces ERα expression in ERα-negative breast cancer cells and could restore antiestrogen responses. The evaluation of calcitriol effects was performed in terms of proliferation and regulation of the following genes: Cyclin D1, involved in cell cycle, and Ether-à-go-go 1 (Eag1), related to cell proliferation and tumor progression.

Methods: Cultured cells derived from ERα-negative breast tumors and an established ERα-negative breast cancer cell line (SUM 229) were used in this study. These cells were treated with calcitriol and reverse transcription-PCR or western blotting analyses were performed to assess ERα expression. Growth assays with XTT were used to evaluate the antiproliferative response to the antiestrogens fulvestran and tamoxifen. Gene expression analysis for Cyclin D1 and Eag1 was evaluated by real time PCR in cells treated simultaneously with calcitriol plus estradiol or fulvestran.

Results: The treatment with calcitriol in ER-negative breast cancer cells resulted in the induction of ERα. This effect was specifically mediated through the vitamin D3 receptor (VDR), since the VDR antagonist TEI-9647 effectively inhibited the ability of calcitriol to stimulate ERα gene expression. Consequently, the induction of ERα by calcitriol restores the response to antiestrogens in breast cancer cells by inhibiting cell proliferation. Co-treatment of calcitriol and antiestrogens down-regulated Cyclin D1 and Eag1 gene expression.

Conclusion: Calcitriol induced the expression of ERα and restored antiestrogenic responses in ERα-negative breast cancer cells. Moreover, fulvestran down regulated mRNA expression of Cyclin D1 and Eag1 when ERα-negative cells were pre-treated with calcitriol. These results suggest that the combined treatment with calcitriol and antiestrogens could be a new therapeutic strategy for ERα-negative breast cancer patients.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P6-04-29.

Effect of light-cure initiation time on polymerization efficiency and orthodontic bond strength with a resin-modified glass-ionomer

OBJECTIVES

The polymerization and acid-base reactions in resin-modified glass-ionomers (RMGI) are thought to compete with and inhibit one another. To examine the effect of visible light-cure (VLC) delay on the polymerization efficiency and orthodontic bond strength of a dual-cured RMGI.

SETTING AND SAMPLE POPULATION

The Orthodontics Graduate Program at Marquette University. An in vitro study utilizing 72 freshly extracted human bicuspid teeth.

MATERIALS AND METHODS

A RMGI light-cured immediately, 2.5, 5, or 10 min after mixing comprised the experimental groups. Isothermal and dynamic temperature scan differential scanning calorimetry (DSC) analysis of the RMGI was performed to determine extents of VLC polymerization and acid-base reaction exotherms. Human premolars (n = 18/group) were bonded with the RMGI. Shear bond strength and adhesive remnant index (ARI) scores were determined.

RESULTS

Differential scanning calorimetry results showed the 10-min-delay RMGI group experienced significantly (p < 0.05) lower VLC polymerization compared with the other groups. Acid-base reaction exotherms were undetected in all groups except the 10-min delay group. No significant differences (p > 0.05) were noted among the groups for mean shear bond strength. A chi-square test showed no significant difference (p = 0.428) in ARI scores between groups.

CONCLUSIONS

Delay in light-curing may reduce polymerization efficiency and alter the structure of the RMGI, but orthodontic shear bond strength does not appear to be compromised.

Assessment of in vitro dermal absorption of the kaurenic acid from Coespeletia moriziana extracts

Espeletiinae are plants which grow above 3000 m of altitude in the Northern Andes and kaurenic acid was extracted from the leaves of Coespeletia moritziana. This compound has shown a wide range of biological activities, including cytotoxicity which is efficient in cancer therapy. The percutaneous penetration of this compound was measured in vitro using Franz cells. At appropriate intervals for up to 24h, diffusion samples were analyzed using HPLC. At the end of the test period, the amount of kaurenic acid was determined in each compartment and approximately 10% of kaurenic acid had been absorbed and was found in the skin layers.