Correlation-Driven Insulator-Metal Transition in Near-Ideal Vanadium Dioxide Films.

We use polarization- and temperature-dependent x-ray absorption spectroscopy, in combination with photoelectron microscopy, x-ray diffraction, and electronic transport measurements, to study the driving force behind the insulator-metal transition in VO_{2}. We show that both the collapse of the insulating gap and the concomitant change in crystal symmetry in homogeneously strained single-crystalline VO_{2} films are preceded by the purely electronic softening of Coulomb correlations within V-V singlet dimers. This process starts 7 K (±0.3 K) below the transition temperature, as conventionally defined by electronic transport and x-ray diffraction measurements, and sets the energy scale for driving the near-room-temperature insulator-metal transition in this technologically promising material.

Body mass index and early CD4 T-cell recovery among adults initiating antiretroviral therapy in North America, 1998-2010.

OBJECTIVES: Adipose tissue affects several aspects of the cellular immune system, but prior epidemiological studies have differed on whether a higher body mass index (BMI) promotes CD4 T-cell recovery on antiretroviral therapy (ART). The objective of this analysis was to assess the relationship between BMI at ART initiation and early changes in CD4 T-cell count. METHODS: We used the North American AIDS Cohort Collaboration on Research and Design (NA-ACCORD) data set to analyse the relationship between pre-treatment BMI and 12-month CD4 T-cell recovery among adults who started ART between 1998 and 2010 and maintained HIV-1 RNA levels < 400 copies/mL for at least 6 months. Multivariable regression models were adjusted for age, race, sex, baseline CD4 count and HIV RNA level, year of ART initiation, ART regimen and clinical site. RESULTS: A total of 8381 participants from 13 cohorts contributed data; 85% were male, 52% were nonwhite, 32% were overweight (BMI 25-29.9 kg/m(2) ) and 15% were obese (BMI > 30 kg/m(2) ). Pretreatment BMI was associated with 12-month CD4 T-cell change (P < 0.001), but the relationship was nonlinear (P < 0.001). Compared with a reference of 22 kg/m(2) , a BMI of 30 kg/m(2) was associated with a 36 cells/µL [95% confidence interval (CI) 14, 59 cells/µL] greater CD4 T-cell count recovery among women and a 19 cells/µL (95% CI 9, 30 cells/µL) greater recovery among men at 12 months. At a BMI > 30 kg/m(2) , the observed benefit was attenuated among men to a greater degree than among women, although this difference was not statistically significant. CONCLUSIONS: A BMI of approximately 30 kg/m(2) at ART initiation was associated with greater CD4 T-cell recovery at 12 months compared with higher or lower BMI values, suggesting that body composition may affect peripheral CD4 T-cell recovery.

Body mass index and the risk of incident noncommunicable diseases after starting antiretroviral therapy.

OBJECTIVES: Obesity and HIV infection are associated with an increased incidence of noninfectious comorbid medical conditions, but the relationship between body mass index (BMI) and the development of noncommunicable diseases (NCDs) among individuals on antiretroviral therapy (ART) has not been well characterized. METHODS: A cohort study of adults initiating ART between 1998 and 2010 at an academic centre with systematic laboratory and clinical data collection, including AIDS and NCD diagnoses, was carried out. The relationship between BMI at ART initiation and the risk of incident cardiovascular, hepatic, renal or oncological NCDs was assessed using Cox proportional hazard models. BMI was fitted using restricted cubic splines and models adjusted for age, sex, race, CD4 count, protease inhibitor use, year of initiation, and prior AIDS-defining illness. RESULTS: Among 1089 patients in the analysis cohort, 54% had normal BMI, 28% were overweight, and 18% were obese. Baseline BMI was associated with developing an incident NCD (P<0.01), but the relationship was nonlinear. Compared with a BMI of 25 kg/m(2) , a BMI of 30 kg/m(2) conferred a lower risk of an incident NCD diagnosis [adjusted hazard ratio (AHR) 0.59; 95% confidence interval (CI) 0.40, 0.87]. This protective effect was attenuated at a BMI of 35 kg/m(2) (AHR 0.78; 95% CI 0.49, 1.23). Results were similar in sensitivity analyses incorporating tobacco, alcohol and illicit drug use, statin and antihypertensive exposure, and virological suppression. CONCLUSIONS: Overweight individuals starting ART have a lower risk of developing NCDs compared with normal BMI individuals, which may reflect a biological effect of adipose tissue or differences in patient or provider behaviours.

Ferrous iron formation following the co-aggregation of ferric iron and the Alzheimer's disease peptide ß-amyloid (1-42).

For decades, a link between increased levels of iron and areas of Alzheimer's disease (AD) pathology has been recognized, including AD lesions comprised of the peptide ß-amyloid (Aß). Despite many observations of this association, the relationship between Aß and iron is poorly understood. Using X-ray microspectroscopy, X-ray absorption spectroscopy, electron microscopy and spectrophotometric iron(II) quantification techniques, we examine the interaction between Aß(1-42) and synthetic iron(III), reminiscent of ferric iron stores in the brain. We report Aß to be capable of accumulating iron(III) within amyloid aggregates, with this process resulting in Aß-mediated reduction of iron(III) to a redox-active iron(II) phase. Additionally, we show that the presence of aluminium increases the reductive capacity of Aß, enabling the redox cycling of the iron. These results demonstrate the ability of Aß to accumulate iron, offering an explanation for previously observed local increases in iron concentration associated with AD lesions. Furthermore, the ability of iron to form redox-active iron phases from ferric precursors provides an origin both for the redox-active iron previously witnessed in AD tissue, and the increased levels of oxidative stress characteristic of AD. These interactions between Aß and iron deliver valuable insights into the process of AD progression, which may ultimately provide targets for disease therapies.

Interfacial ferromagnetism in LaNiO3/CaMnO3 superlattices.

We observe interfacial ferromagnetism in superlattices of the paramagnetic metal LaNiO3 and the antiferromagnetic insulator CaMnO3. LaNiO3 exhibits a thickness dependent metal-insulator transition and we find the emergence of ferromagnetism to be coincident with the conducting state of LaNiO3. That is, only superlattices in which the LaNiO3 layers are metallic exhibit ferromagnetism. Using several magnetic probes, we have determined that the ferromagnetism arises in a single unit cell of CaMnO3 at the interface. Together these results suggest that ferromagnetism can be attributed to a double exchange interaction among Mn ions mediated by the adjacent itinerant metal.

Anal squamous intraepithelial lesions among HIV positive and HIV negative men who have sex with men in Thailand.

OBJECTIVES: To evaluate the prevalence and risk factors of anal squamous intraepithelial lesions (ASIL), the putative anal cancer precursor, in Asian HIV positive and HIV negative men who have sex with men (MSM). METHODS: Men who underwent anal Pap smear reported clinical, sociodemographic and behavioural information collected through questionnaire and interview between January 2007 and April 2008. Chi(2) and logistic regression were used to evaluate ASIL prevalence and risk factors among HIV positive and HIV negative MSM. RESULTS: Of the 174 MSM (mean age 32.1 years), 118 (67.8%) were HIV positive. Overall, 27% had abnormal anal cytology: 13.2% had atypical squamous cells of undetermined significance (ASC-US), 11.5% had low-grade squamous intraepithelial lesion (LSIL) and 2.3% had high-grade squamous intraepithelial lesion (HSIL). Prevalence of ASIL was higher among HIV positive than HIV negative MSM (33.9% vs 12.5%; p = 0.003). Among HIV positive MSM, 16.1% had ASC-US, 14.4% had LSIL and 3.4% had HSIL and 7.1%, 5.4% and 0% in HIV negative MSM, respectively. Anal condyloma was detected in 22% of HIV positive and 16.1% (9/56) of HIV negative MSM (p = 0.5). In HIV positive MSM, anal condyloma (OR 3.42, 95% CI 1.29 to 9.04; p = 0.01) was a significant risk factor for ASIL. Highly active antiretroviral therapy use and CD4+ T cell count were not associated with ASIL. CONCLUSIONS: One-third of HIV positive and 12.5% of HIV negative MSM had ASIL. Thus, as greater numbers of HIV positive MSM live longer due to increasing access to HAART worldwide, effective strategies to screen and manage anal precancerous lesions are needed.

Difficulties in diagnosing neuropsychiatric complications of corticosteroids in advanced cancer patients: two case reports.

Because of their variety of uses, corticosteroids are frequently prescribed in advanced cancer patients. Two patients who developed neuropsychiatric complications on corticosteroids and their subsequent management are described. The first patient, who had a known history of steroid-induced psychotic depression, required corticosteroids to treat recurrent brain edema from a malignant meningioma. The patient was managed by using low-dose corticosteroids and concomitant haloperidol. The second patient was prescribed corticosteroids for a constellation of symptoms, including pain and nausea from a possible bowel obstruction, and developed a severe delirium that required discontinuation of the corticosteroids. The difficulties of diagnosing steroid-related cognitive and mood changes in advanced cancer patients who often have multisystem disease are discussed, as well as strategies for minimizing the effects of corticosteroids' neuropsychological complications.

Demographic, symptom, and medication profiles of cancer patients seen by a palliative care consult team in a tertiary referral hospital.

In this retrospective study, the charts of 100 consecutive cancer patients who had been referred to a palliative care consult team within a tertiary acute care hospital were reviewed. Demographic characteristics, including reason for admission and disease status upon admission, length of stay, and discharge and admission location, were recorded. Symptom acuity, cognitive status, and risk for substance abuse were evaluated. Medications before and after the consult were tabulated and compared to recommended medications; compliance with the recommendations was assessed. Five patients were not palliative at the time of the consult. Only 46/95 (48%) were known to have untreatable cancer at the time of their admission. The CAGE questionnaire for alcoholism and the Mini-Mental State Questionnaire (MMSQ) were abnormal in 19/78 (24%) and 40/91 (44%), respectively. The most intense symptoms, as measured by the 100-mm scales of the Edmonton Symptom Assessment Scale (ESAS) were fatigue (72 +/- 24), appetite (60 +/- 32), and well-being (50 +/- 29). Eighty-nine of the 95 patients were living at home prior to admission and 34/95 were able to return home. Twenty died during hospitalization, 23 were transferred to a palliative care unit, and the remaining 18 were discharged to another hospital or long-term care. The patient's physician complied with the palliative care consult team's recommendation in 122/137 cases (89%).

Nonsteroidal anti-inflammatory drugs as adjuvant analgesics in cancer patients.

The role of nonsteroidal anti-inflammatory drugs (NSAIDs) is examined in the control of cancer pain with a particular focus on their use as adjuvants to opioids in advanced cancer pain. These agents have both a peripheral effect on inflammation and a role in attenuating central pain pathways. The possibility of obtaining the benefits of NSAIDs with fewer side-effects by using COX-2-specific agents is discussed. The gastrointestinal, renal, haemostatic, cognitive and hypersensitivity side-effects of NSAIDs are reviewed and their potential impact assessed. The evidence for the efficacy of NSAIDs as single agents for cancer pain is reviewed together with the nine papers which have reported the effects of NSAIDs as adjuvants to opioids in cancer pain. All of these papers reported positive results of NSAIDs, but, in the absence of any randomized, double-blind controlled trials, where NSAIDs were used as adjuvants on a long-term basis alongside optimal opioid use, definite conclusions cannot be reached. Guidelines for the safe use of NSAIDs are suggested. Finally, suggestions for future research are made.

Initial demographic, symptom, and medication profiles in patients admitted to continuing palliative care units.

We retrospectively reviewed 110 consecutive admissions to continuing palliative care units, which were designed as part of a regionalized, comprehensive palliative care program in Edmonton, Canada. Ninety-six patient charts met the criteria for evaluation. Demographic characteristics, and, when available, symptom profiles, cognitive status, and risk for a history of substance abuse were described. The medications on admission were tabulated, and in those 93 patients who had consults done by a palliative care consultant, these are compared to recommended medications. This study showed an older cohort of patient (mean +/- SD = 75 +/- 11 years) than had previously been described in a tertiary unit in the same community. Median length of stay was 21 days (range, 0-> 200 days). Cognitive impairment was higher than would be anticipated on the basis of age alone, with 32/47 [64% (confidence interval (CI) 55%-81%)] of patients who had had cognitive testing done on the day of consult being found to be cognitively impaired. Symptoms, as measured by the Edmonton Symptom Assessment Scale, were similar to those found for patients admitted to the tertiary palliative care unit. In the 93 patients who had palliative care consults done on admission, there were a total of 179 recommendations for medication or hydration changes. Overall compliance with these recommendations was 84% (CI, 79%-89%). The highest compliance was observed for recommendations to start hydration clysis [27/27, 100% (CI, 100%)], and the lowest rate was observed for altering or decreasing hypnotic medications [11/22, 50% (CI, 29%-71%)]. We conclude that the patients were of higher acuity than anticipated.

Integration of palliative care with alternative medicine in patients who have refused curative cancer therapy: a report of two cases.

This article describes two young, potentially curable patients who chose a course of treatment that ultimately resulted in death. Their choice was in part influenced by the prospect of the disfiguring surgery that would have been required for cure. In the first patient this would have meant massive head and neck surgery, in the second, a radical hysterectomy that would have resulted in surgical menopause. The availability of practitioners who promised an easier cure was also a factor in swaying the first patient away from truly curative therapy. Denial also played a role in both of these patients' decisions. Part of their denial may have been exacerbated by the fact that both of their cancers have as risk factors behaviors that the patients may have considered inconsistent with their value system. In the first type of cancer, alcohol and chewing tobacco are major risk factors (11), neither of which would have been acceptable to the patient's family. In the second type, multiple sexual partners are a major risk for cervical cancer (12), a behavior which is inconsistent with the teachings of the patient's fundamentalist Christian beliefs. The approach that we have described--expressions of respect for the patient's belief system combined with the nonconfrontational offering of treatments with immediate symptomatic benefit--resulted in the development of an effective working relationship between patient, family, and palliative care team.

Effects of a common linguistic misrepresentation on judgments about the relationship between height and weight.

Researchers have debated whether laypeople can detect covariation and have tried to identify conditions that might facilitate or retard this ability. Language, especially linguistic representation of variables, seems important to consider since misrepresentation appears to be relatively common in linguistic exchanges. In the present theory-based experiment, 16 subjects were asked to make judgments about the relationship between height and either weight (heavy or light) or bodyfat (fat or thin). Data provided evidence of a powerful illusory association, that is, if tall, then thin; if short, then fat, and there was no compelling evidence to suggest that subjects understood the relationship between height and weight.