Nucleation of a sodium droplet on C60

We investigate theoretically the progressive coating of C60 by several sodium atoms. Density functional calculations using a nonlocal functional are performed for NaC60 and Na2C60 in various configurations. These data are used to construct an empirical atomistic model in order to treat larger sizes in a statistical and dynamical context. Fluctuating charges are incorporated to account for charge transfer between sodium and carbon atoms. By performing systematic global optimization in the size range 1<=n<=30, we find that Na_nC60 is homogeneously coated at small sizes, and that a growing droplet is formed above n=>8. The separate effects of single ionization and thermalization are also considered, as well as the changes due to a strong external electric field. The present results are discussed in the light of various experimental data.Comment: 17 pages, 10 figure

Interleukin 6 in autoimmune and inflammatory diseases: a personal memoir

In this review, the author discusses the research that led to the identification and characterization of interleukin 6 (IL-6), including his own experience isolating IL-6, and the roles this cytokine has on autoimmune and inflammatory diseases. The cDNAs encoding B-cell stimulatory factor 2 (BSF-2), interferon (IFN)-β2 and a 26-kDa protein were independently cloned in 1986, which in turn led to the identification of each. To resolve the confusing nomenclature, these identical molecules were named IL-6. Characterization of IL-6 revealed a multifunctional cytokine that is involved in not only immune responses but also hematopoiesis, inflammation, and bone metabolism. Moreover, IL-6 makes significant contributions to such autoimmune and inflammatory diseases as rheumatoid arthritis (RA)

Interleukin 6 in autoimmune and inflammatory diseases: a personal memoir

In this review, the author discusses the research that led to the identification and characterization of interleukin 6 (IL-6), including his own experience isolating IL-6, and the roles this cytokine has on autoimmune and inflammatory diseases. The cDNAs encoding B-cell stimulatory factor 2 (BSF-2), interferon (IFN)-β2 and a 26-kDa protein were independently cloned in 1986, which in turn led to the identification of each. To resolve the confusing nomenclature, these identical molecules were named IL-6. Characterization of IL-6 revealed a multifunctional cytokine that is involved in not only immune responses but also hematopoiesis, inflammation, and bone metabolism. Moreover, IL-6 makes significant contributions to such autoimmune and inflammatory diseases as rheumatoid arthritis (RA)

Psychiatric inpatient expenditures and public health insurance programmes: analysis of a national database covering the entire South Korean population

<p>Abstract</p> <p>Background</p> <p>Medical spending on psychiatric hospitalization has been reported to impose a tremendous socio-economic burden on many developed countries with public health insurance programmes. However, there has been no in-depth study of the factors affecting psychiatric inpatient medical expenditures and differentiated these factors across different types of public health insurance programmes. In view of this, this study attempted to explore factors affecting medical expenditures for psychiatric inpatients between two public health insurance programmes covering the entire South Korean population: National Health Insurance (NHI) and National Medical Care Aid (AID).</p> <p>Methods</p> <p>This retrospective, cross-sectional study used a nationwide, population-based reimbursement claims dataset consisting of 1,131,346 claims of all 160,465 citizens institutionalized due to psychiatric diagnosis between January 2005 and June 2006 in South Korea. To adjust for possible correlation of patients characteristics within the same medical institution and a non-linearity structure, a Box-Cox transformed, multilevel regression analysis was performed.</p> <p>Results</p> <p>Compared with inpatients 19 years old or younger, the medical expenditures of inpatients between 50 and 64 years old were 10% higher among NHI beneficiaries but 40% higher among AID beneficiaries. Males showed higher medical expenditures than did females. Expenditures on inpatients with schizophrenia as compared to expenditures on those with neurotic disorders were 120% higher among NHI beneficiaries but 83% higher among AID beneficiaries. Expenditures on inpatients of psychiatric hospitals were greater on average than expenditures on inpatients of general hospitals. Among AID beneficiaries, institutions owned by private groups treated inpatients with 32% higher costs than did government institutions. Among NHI beneficiaries, inpatients medical expenditures were positively associated with the proportion of patients diagnosed into dementia or schizophrenia categories. However, for AID beneficiaries, inpatient medical expenditures were positively associated with the proportion of all patients with a psychiatric diagnosis that were AID beneficiaries in a medical institution.</p> <p>Conclusions</p> <p>This study provides evidence that patient and institutional factors are associated with psychiatric inpatient medical expenditures, and that they may have different effects for beneficiaries of different public health insurance programmes. Policy efforts to reduce psychiatric inpatient medical expenditures should be made differently across the different types of public health insurance programmes.</p

Optogenetic Manipulation of Cerebellar Purkinje Cell Activity In Vivo

Purkinje cells (PCs) are the sole output neurons of the cerebellar cortex. Although their anatomical connections and physiological response properties have been extensively studied, the causal role of their activity in behavioral, cognitive and autonomic functions is still unclear because PC activity cannot be selectively controlled. Here we developed a novel technique using optogenetics for selective and rapidly reversible manipulation of PC activity in vivo. We injected into rat cerebellar cortex lentiviruses expressing either the light-activated cationic channel channelrhodopsin-2 (ChR2) or light-driven chloride pump halorhodopsin (eNpHR) under the control of the PC-specific L7 promoter. Transgene expression was observed in most PCs (ChR2, 92.6%; eNpHR, 95.3%), as determined by immunohistochemical analysis. In vivo electrophysiological recordings showed that all light-responsive PCs in ChR2-transduced rats increased frequency of simple spike in response to blue laser illumination. Similarly, most light-responsive PCs (93.8%) in eNpHR-transduced rats decreased frequency of simple spike in response to orange laser illumination. We then applied these techniques to characterize the roles of rat cerebellar uvula, one of the cardiovascular regulatory regions in the cerebellum, in resting blood pressure (BP) regulation in anesthetized rats. ChR2-mediated photostimulation and eNpHR-mediated photoinhibition of the uvula had opposite effects on resting BP, inducing depressor and pressor responses, respectively. In contrast, manipulation of PC activity within the neighboring lobule VIII had no effect on BP. Blue and orange laser illumination onto PBS-injected lobule IX didn't affect BP, indicating the observed effects on BP were actually due to PC activation and inhibition. These results clearly demonstrate that the optogenetic method we developed here will provide a powerful way to elucidate a causal relationship between local PC activity and functions of the cerebellum

Hemodynamic Responses Evoked by Neuronal Stimulation via Channelrhodopsin-2 Can Be Independent of Intracortical Glutamatergic Synaptic Transmission

Maintenance of neuronal function depends on the delivery of oxygen and glucose through changes in blood flow that are linked to the level of ongoing neuronal and glial activity, yet the underlying mechanisms remain unclear. Using transgenic mice expressing the light-activated cation channel channelrhodopsin-2 in deep layer pyramidal neurons, we report that changes in intrinsic optical signals and blood flow can be evoked by activation of a subset of channelrhodopsin-2-expressing neurons in the sensorimotor cortex. We have combined imaging and pharmacology to examine the importance of glutamatergic synaptic transmission in this form of neurovascular coupling. Blockade of ionotropic glutamate receptors with the antagonists CNQX and MK801 significantly reduced forepaw-evoked hemodynamic responses, yet resulted in no significant reduction of channelrhodopsin-evoked hemodynamic responses, suggesting that stimulus-dependent coupling of neuronal activity to blood flow can be independent of local excitatory synaptic transmission. Together, these results indicate that channelrhodopsin-2 activation of sensorimotor excitatory neurons produces changes in intrinsic optical signals and blood flow that can occur under conditions where synaptic activation of neurons or other cells through ionotropic glutamate receptors would be blocked

Regional Differences in Prevalence of HIV-1 Discordance in Africa and Enrollment of HIV-1 Discordant Couples into an HIV-1 Prevention Trial

Background: Most HIV-1 transmission in Africa occurs among HIV-1-discordant couples (one partner HIV-1 infected and one uninfected) who are unaware of their discordant HIV-1 serostatus. Given the high HIV-1 incidence among HIV-1 discordant couples and to assess efficacy of interventions for reducing HIV-1 transmission, HIV-1 discordant couples represent a critical target population for HIV-1 prevention interventions and prevention trials. Substantial regional differences exist in HIV-1 prevalence in Africa, but regional differences in HIV-1 discordance among African couples, has not previously been reported. Methodology/Principal Findings: The Partners in Prevention HSV-2/HIV-1 Transmission Trial (“Partners HSV-2 Study”), the first large HIV-1 prevention trial in Africa involving HIV-1 discordant couples, completed enrollment in May 2007. Partners HSV-2 Study recruitment data from 12 sites from East and Southern Africa were used to assess HIV-1 discordance among couples accessing couples HIV-1 counseling and testing, and to correlate with enrollment of HIV-1 discordant couples. HIV-1 discordance at Partners HSV-2 Study sites ranged from 8–31% of couples tested from the community. Across all study sites and, among all couples with one HIV-1 infected partner, almost half (49%) of couples were HIV-1 discordant. Site-specific monthly enrollment of HIV-1 discordant couples into the clinical trial was not directly associated with prevalence of HIV-1 discordance, but was modestly correlated with national HIV-1 counseling and testing rates and access to palliative care/basic health care (r = 0.74, p = 0.09). Conclusions/Significance: HIV-1 discordant couples are a critical target for HIV-1 prevention in Africa. In addition to community prevalence of HIV-1 discordance, national infrastructure for HIV-1 testing and healthcare delivery and effective community outreach strategies impact recruitment of HIV-1 discordant couples into HIV-1 prevention trials