In this paper, we fabricated and investigated the electroforming process and switching behavior of Al/SiOx/Si MOS resistive random access memory (RRAM) devices. The switching mechanism and device ...performance including forming voltage, set/reset voltage, on/off ratio and retention have been analyzed. Memory structure was formed, or electroformed by applying voltage across the MOS device. This SiOx RRAMs show a unique switching behavior with set voltage lower than reset voltage. Thus, unlike other RRAMs, our RRAM devices do not need current compliance in the switching process. Furthermore, our device utilizes SiOx, which has been extensively used and is completely compatible with CMOS technology. The results show that introducing a plasma treatment process and optimizing the plasma conditions significantly reduced electroforming voltage.
To differentiate withdrawal-related abnormalities in brain glucose metabolism among alcoholics from abnormalities that may be irreversible or antedate alcohol use, the authors evaluated metabolic ...recovery during alcohol detoxification.
Regional brain glucose metabolism was measured with positron emission tomography and 2-deoxy-2-18Ffluoro-D-glucose in 10 male alcoholics at 8-15 days, 16-30 days, and 31-60 days after last use of alcohol. The alcoholics' metabolic values were compared with those of 10 age-matched male healthy volunteers.
Brain metabolism increased significantly during detoxification. There were significant differences in global and regional measures between the first and last time points but not between the second and third points, suggesting that recovery occurred predominantly within 16-30 days. Regional increases in metabolism were greater in the frontal regions. Whereas during the first evaluation the alcoholics showed significantly lower metabolism in various brain regions than the comparison group, at the end of detoxification the alcoholics showed significantly lower absolute and relative metabolic values in the basal ganglia and lower relative metabolic values in the parietal cortex. Among the alcoholics, but not the comparison group, metabolism in the frontal, parietal, and left temporal cortexes was negatively correlated with years of alcohol use and with age.
This study shows significant increases in brain metabolism during alcohol withdrawal and documents persistent low metabolic levels in the basal ganglia of detoxified alcoholics.
The measure of changes in synaptic dopamine (DA) concentration in response to the psychostimulant drug methylphenidate (MP) has been used as an indicator of responsiveness of the DA system. The ...purpose of this study was to assess the reproducibility of these measures.
Seven healthy subjects were scanned with PET and 11Craclopride twice in the same day: 7 min after placebo or methylphenidate (0.5 mg/kg) administration. In parallel we also measured the physiologic and behavioral responses to placebo and to methylphenidate. The same procedures were repeated 1-2 wk later to assess test-retest reproducibility.
Measures of plasma to brain transfer constant (K1), striatal distribution volume (DVstr) and DA D2 receptor availability (Bmax/Kd), for the placebo condition were similar for the first (E1) and second (E2) evaluations (Bmax/Kd, E1: 2.77+/-0.44; E2: 2.97+/-0.44). MP administration did not change K1, but it significantly decreased DVstr (E1: -25.9%+/-8.7%, P < or = 0.0002; E2: -20.7%+/-11.7%, P < or = 0.007) and Bmax/Kd (E1: -18.4%+/-8.7%, P < or = 0.002; E2: -13.4%+/-9.2%, P < or = 0.008), and the magnitude of these changes, though lower for E2, did not differ significantly. MP increased pulse rate (E1: +64%+/-43%, P < or = 0.002; E2: +69%+/-33%, P < or = 0.001), systolic pressure (E1: +37%+/-19%, P < or = 0.0006; E2: +29%+/-15%, P < or = 0.0009), self reports for drug effects (0: nothing to 10: extreme) of "rush" (E1: +8+/-3, P < or = 0.0004; E2: +6+/-4, P < or = 0.01) and "high" (E1: +8+/-3, P < or = 0.0001, E2: +8+/-3, P < or = 0.0003), anxiety (E1: +5+/-4, P < or = 0.02; E2: +4+/-4, P = 0.1) and restlessness (E1: +4+/-4, P < or = 0.04; E2: +4+/-5, P = 0.1). The magnitude of the cardiovascular and behavioral effects did not differ between E1 and E2.
MP-induced changes in striatal DV and in Bmax/Kd, as well as the behavioral and cardiovascular effects, were reproducible with repeated administration.
Neuromorphic Computing
In article number 1900189, Mostafa Rahimi Azghadi, Yao‐Feng Chang, and co‐workers discuss challenges and opportunities and shed light on recent advances in CMOS, SiOx‐based ...memristive, and mixed CMOS‐memristive hardware for neuromorphic systems. New and published results are provided from various devices that are developed to replicate selected functions of neurons, synapses, and simple spiking networks, which are used for MNIST and pattern classification.
Drugs and food exert their reinforcing effects in part by increasing dopamine in limbic regions, which has generated interest in understanding how drug abuse/addiction relates to obesity. Both in ...abuse/addiction and in obesity there is an enhanced value of one type of reinforcer (drugs and food respectively) at the expense of other reinforcers, which is a consequence of conditioned learning and resetting of reward thresholds secondary to repeated stimulation by drugs (abuse/addiction) and by large quantities of palatable food (obesity) in vulnerable individuals. In this model, exposure to the reinforcer or to conditioned‐cues (processed by the memory circuit) results in overactivation of the reward and motivation circuits and inhibition of the cognitive control circuit resulting in an inability to inhibit the drive to consume the drug or food. These neuronal circuits, which are modulated by dopamine, interact with one another so that disruption in one circuit can be buffered by another, which highlights the need of multiprong approaches in the treatment of addiction and obesity.
Changes in GABA function have been postulated to be involved in alcohol tolerance, withdrawal and addiction. In this study we measured regional brain metabolic responses to lorazepam, to indirectly ...assess GABA function (benzodiazepines facilitate GABAergic neurotransmission), in alcoholics during early and late withdrawal. Brain metabolism was measured using PET and 2‐deoxy‐218Ffluoro‐D‐glucose after placebo (baseline) and after lorazepam (30 μg/kg intravenously) in 10 alcoholics and 16 controls. In the alcoholics evaluations were performed 2 to 3 weeks after detoxification and were repeated 6 to 8 weeks later. Controls were also evaluated twice at a 6 to 8 weeks interval. While during the initial evaluation metabolism was significantly lower for most brain regions in the alcoholics than in controls in the repeated evaluation the only significant differences were in cingulate and orbitofrontal cortex. Lorazepam‐induced decrements in metabolism did not change with protracted alcohol withdrawal and the magnitude of these changes were similar in controls and alcoholics except for a trend towards a blunted response to lorazepam in orbitofrontal cortex in alcoholics during the second evaluation. Abnormalities in orbitofrontal cortex and cingulate gyms in alcoholics are unlikely to be due to withdrawal since they persist 8 to 11 weeks after detoxification. The fact that there was only a trend of significance for an abnormal response to lorazepam in orbitofrontal cortex indicates that mechanisms other than GABA are involved in the brain metabolic abnormalities observed in alcoholic subjects.
We report on a highly compact, one diode-one resistor (1D-1R) nanopillar device architecture for SiO sub(x)-based ReRAM fabricated using nanosphere lithography (NSL). The intrinsic SiO sub(x)-based ...resistive switching element and Si diode are self-aligned on an epitaxial silicon wafer using NSL and a deep-Si-etch process without conventional photolithography. AC-pulse response in 50 ns regime, multibit operation, and good reliability are demonstrated. The NSL process provides a fast and economical approach to large-scale patterning of high-density 1D-1R ReRAM with good potential for use in future applications.
We present a numerical integration scheme for evaluating the convolution of a Green's function with a screened Coulomb potential on the real axis in the GW approximation of the self energy. Our ...scheme takes the zero broadening limit in Green's function first, replaces the numerator of the integrand with a piecewise polynomial approximation, and performs principal value integration on subintervals analytically. We give the error bound of our numerical integration scheme and show by numerical examples that it is more reliable and accurate than the standard quadrature rules such as the composite trapezoidal rule. We also discuss the benefit of using different self energy expressions to perform the numerical convolution at different frequencies.
The high prevalence of anger, impulsivity and violence in cocaine addiction implicates chronic cocaine use in the compromise of higher-order inhibitory control neurocognitive processes. We used the ...Minnesota Multiphasic Personality Inventory-2 (MMPI-2) anger content scale as a personality measure of inhibitory control and examined its association with glucose metabolism in the lateral orbitofrontal gyrus (LOFG) at rest as measured by positron emission tomography with 2-deoxy-2
18Ffluoro-
d-glucose (PET
18FDG) in 17 recently abstinent cocaine-dependent subjects and 16 comparison subjects. Three additional variables—the MMPI-2 depression content scale, metabolism in the medial orbitofrontal gyrus (MOFG) and the anterior cingulate (AC) gyrus—were inspected. When level of education was statistically controlled for, the LOFG was significantly associated with anger within the cocaine group. No other region was associated with anger within the cocaine-dependent group, and the LOFG did not correlate with depression within any of the study groups. The present study confirms earlier reports in demonstrating a positive association between relative metabolism at rest in the LOFG and cognitive-behavioral and personality measures of inhibitory control in drug addiction: the higher the metabolism, the better the inhibitory control.
Background This is a prospective clinical study to assess the effectiveness of autologous chondrocyte implantation in patients who failed
prior treatments for articular cartilage defects of the knee.
...Hypothesis Autologous chondrocyte implantation provides clinical benefit in patients with failed articular cartilage treatments.
Study Design Cohort study; Level of evidence, 2.
Methods One hundred fifty-four patients with failed treatment for articular cartilage defects of the knee received autologous chondrocyte
implantation in a multicenter, prospective study. Follow-up was 48 months. Outcomes included change from baseline in knee
function, knee pain, quality of life, and overall health. Duration of benefit after autologous chondrocyte implantation was
compared with the failed prior nonâautologous chondrocyte implantation procedure. Safety information was recorded. Additional
analyses were performed on the 2 major cohorts of prior procedures entered into the study, marrow-stimulation technique or
debridement alone, to assess if there were any significant differences in baseline characteristics, outcomes, or prognosis
between the 2 groups.
Results One hundred twenty-six patients (82%) completed the protocol. Seventy-six percent of patients were treatment successes at
study end, while 24% were deemed treatment failures. Preoperative mean knee pain score was 3.0 (SD, 1.8; 0 = severe, 10 =
normal). Mean improvements were observed from baseline to all time points ( P < .001) for all outcome measures. Preoperative to 48-month values, respectively, were as follows: On the Knee injury and
Osteoarthritis Outcome Score subscales of pain: 48.7 to 72.2; other symptoms: 51.8 to 70.8; sports/recreation: 25.8 to 55.8;
knee quality of life: 20.9 to 52.2; and activities of daily living: 58.6 to 81.0; on the Modified Cincinnati Overall Knee
score: 3.3 to 6.3; on the visual analog scale: 28.8 to 69.9; and on the SF-36 Overall Physical Health: 33.0 to 44.4. Results
did not differ between patients whose primary surgery had been a marrow-stimulating procedure and those whose primary procedure
had been a debridement alone. The median difference in duration of benefit between autologous chondrocyte implantation and
the failed nonâautologous chondrocyte implantation prior procedure was at least 31 months ( P < .001). Seventy-six patients (49%) had subsequent surgical procedure(s), predominantly arthroscopic. Need for a subsequent
surgical procedure was not predictive of failure.
Conclusion Patients with moderate to large chondral lesions with failed prior cartilage treatments can expect sustained and clinically
meaningful improvement in pain and function after autologous chondrocyte implantation. The subsequent surgical procedure rate
observed in this study (49% overall; 40% related to autologous chondrocyte implantation) appears higher than generally reported
after autologous chondrocyte implantation.
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