Bi-Arrhenius Diffusion and Surface Trapping of ^{8}Li^{+} in Rutile TiO_{2}

We report measurements of the diffusion rate of isolated ion-implanted ^{8}Li^{+} within ∼120  nm of the surface of oriented single-crystal rutile TiO_{2} using a radiotracer technique. The α particles from the ^{8}Li decay provide a sensitive monitor of the distance from the surface and how the depth profile of ^{8}Li evolves with time. The main findings are that the implanted Li^{+} diffuses and traps at the (001) surface. The T dependence of the diffusivity is described by a bi-Arrhenius expression with activation energies of 0.3341(21) eV above 200 K, whereas at lower temperatures it has a much smaller barrier of 0.0313(15) eV. We consider possible origins for the surface trapping, as well the nature of the low-T barrier.

Identical and Nonidentical Twins: Risk and Factors Involved in Development of Islet Autoimmunity and Type 1 Diabetes

OBJECTIVE

There are variable reports of risk of concordance for progression to islet autoantibodies and type 1 diabetes in identical twins after one twin is diagnosed. We examined development of positive autoantibodies and type 1 diabetes and the effects of genetic factors and common environment on autoantibody positivity in identical twins, nonidentical twins, and full siblings.

RESEARCH DESIGN AND METHODS

Subjects from the TrialNet Pathway to Prevention Study (N = 48,026) were screened from 2004 to 2015 for islet autoantibodies (GAD antibody [GADA], insulinoma-associated antigen 2 [IA-2A], and autoantibodies against insulin [IAA]). Of these subjects, 17,226 (157 identical twins, 283 nonidentical twins, and 16,786 full siblings) were followed for autoantibody positivity or type 1 diabetes for a median of 2.1 years.

RESULTS

At screening, identical twins were more likely to have positive GADA, IA-2A, and IAA than nonidentical twins or full siblings (all P < 0.0001). Younger age, male sex, and genetic factors were significant factors for expression of IA-2A, IAA, one or more positive autoantibodies, and two or more positive autoantibodies (all P ≤ 0.03). Initially autoantibody-positive identical twins had a 69% risk of diabetes by 3 years compared with 1.5% for initially autoantibody-negative identical twins. In nonidentical twins, type 1 diabetes risk by 3 years was 72% for initially multiple autoantibody-positive, 13% for single autoantibody-positive, and 0% for initially autoantibody-negative nonidentical twins. Full siblings had a 3-year type 1 diabetes risk of 47% for multiple autoantibody-positive, 12% for single autoantibody-positive, and 0.5% for initially autoantibody-negative subjects.

CONCLUSIONS

Risk of type 1 diabetes at 3 years is high for initially multiple and single autoantibody-positive identical twins and multiple autoantibody-positive nonidentical twins. Genetic predisposition, age, and male sex are significant risk factors for development of positive autoantibodies in twins.

A Type 1 Diabetes Genetic Risk Score Predicts Progression of Islet Autoimmunity and Development of Type 1 Diabetes in Individuals at Risk

OBJECTIVE

We tested the ability of a type 1 diabetes (T1D) genetic risk score (GRS) to predict progression of islet autoimmunity and T1D in at-risk individuals.

RESEARCH DESIGN AND METHODS

We studied the 1,244 TrialNet Pathway to Prevention study participants (T1D patients' relatives without diabetes and with one or more positive autoantibodies) who were genotyped with Illumina ImmunoChip (median [range] age at initial autoantibody determination 11.1 years [1.2-51.8], 48% male, 80.5% non-Hispanic white, median follow-up 5.4 years). Of 291 participants with a single positive autoantibody at screening, 157 converted to multiple autoantibody positivity and 55 developed diabetes. Of 953 participants with multiple positive autoantibodies at screening, 419 developed diabetes. We calculated the T1D GRS from 30 T1D-associated single nucleotide polymorphisms. We used multivariable Cox regression models, time-dependent receiver operating characteristic curves, and area under the curve (AUC) measures to evaluate prognostic utility of T1D GRS, age, sex, Diabetes Prevention Trial-Type 1 (DPT-1) Risk Score, positive autoantibody number or type, HLA DR3/DR4-DQ8 status, and race/ethnicity. We used recursive partitioning analyses to identify cut points in continuous variables.

RESULTS

Higher T1D GRS significantly increased the rate of progression to T1D adjusting for DPT-1 Risk Score, age, number of positive autoantibodies, sex, and ethnicity (hazard ratio [HR] 1.29 for a 0.05 increase, 95% CI 1.06-1.6; P = 0.011). Progression to T1D was best predicted by a combined model with GRS, number of positive autoantibodies, DPT-1 Risk Score, and age (7-year time-integrated AUC = 0.79, 5-year AUC = 0.73). Higher GRS was significantly associated with increased progression rate from single to multiple positive autoantibodies after adjusting for age, autoantibody type, ethnicity, and sex (HR 2.27 for GRS >0.295, 95% CI 1.47-3.51; P = 0.0002).

CONCLUSIONS

The T1D GRS independently predicts progression to T1D and improves prediction along T1D stages in autoantibody-positive relatives.

Sleep and activity monitoring for Returning Soldier Adjustment Assessment

This paper describes the development of unobtrusive room sensors to discover relationships between sleep quality and the clinical assessments of combat soldiers suffering from post-traumatic stress disorder (PTSD) and mild traumatic brain injury (TBI). We consider the use of a remote room sensor unit composed of a Doppler radar, light, sound and other room environment sensors. We also employ an actigraphy watch. We discuss sensor implementation, radar data analytics and preliminary results using real data from a Warrior Transition Battalion located in Fort Gordon, GA. Two radar analytical approaches are developed and compared against the actigraphy watch estimates--one, emphasizing system knowledge; and the other, clustering on several radar signal features. The radar analytic algorithms are able to estimate sleep periods, signal absence and restlessness in the bed. In our test cases, the radar estimates are shown to agree with the actigraphy watch. PTSD and mild-TBI soldiers do often show signs of sporadic and restless sleep. Ongoing research results are expected to provide further insight.

[Specificity of alcoholism and resulting methods of therapeutic practice]

Addiction to alcohol is a bodily disease (DSM IV) kept up by certain psychological mechanisms, which are created in order to preserve and justify the need to drink. In the course of alcoholism those mechanisms are modified to form psychological addiction, thus creating, alongside with physical addiction, twofold psychopshysiological addiction. The specific character of the disease requires both medical treatment and psychotherapeutic actions carried out according to certain definite principles aimed at disarming the defence mechanisms which justify a persons right to drink. The actions of therapists working in order to break off a persons addiction should be of approving and instructive character, and at the same time manifest the therapists awareness of the interdependence of physical as well as psychological aspects of the disease. Due to the chronic character of alcoholism and the resulting threat of relapse, what is of particular importance in maintaining ones sobriety are AA support groups.

Thyroid scintigram. Sensitivity with sodium pertechnetate Tc 99m and gamma camera with pinhole collimator

To evaluate the reliability of thyroid scintigraphy in the diagnosis of nodular growth, scintigrams of patients who later underwent thyroidectomy were reviewed and correlated with pathologic findings. The scintigrams were all obtained with a 5-mm single-hole collimator-equipped gamma-scintillation camera after intravenous injection of 5 millicuries of sodium pertechnetate Tc 99m. In the group of 92 patients, six of whom had two histologically different lesions, 149 nodules were identified pathologically. There were 26 nodules 2 to 5 mm in diameter, of which 22 were benign and four were malignant. None of the 22 benign nodules were delineated scintigraphically. Superior image quality and resolution, low radiation dose, technical simplicity, and speed make 99mTc pinhole-camera scintigraphy the best procedure available for routine thyroid imaging.

99mTc-pertechnetate thyroid scintigraphy in patients predisposed to thyroid neoplasms by prior radiotherapy to the head and neck

Histories, physical examinations and 99mTc-pertechnetate imaging were used to evaluate 1,452 persons who had had x-ray therapy to the neck region for benign conditions 18 to 35 years previously. Thyroid abnormalities were found in 301 patients (21%) and thyroid malignancy was found in 29% of 193 patients with abnormal studies who were explored surgically. Thyroid imaging detected 96% of these abnormalities, 40% of which would not have been unequivocally established by physical examination alone. Nuclear imaging could not distinguish benign from malignant lesions.