Detecting defects that reduce breakdown voltage using machine learning and optical profilometry.

Semiconductor wafer manufacturing relies on the precise control of various performance metrics to ensure the quality and reliability of integrated circuits. In particular, GaN has properties that are advantageous for high voltage and high frequency power devices; however, defects in the substrate growth and manufacturing are preventing vertical devices from performing optimally. This paper explores the application of machine learning techniques utilizing data obtained from optical profilometry as input variables to predict the probability of a wafer meeting performance metrics, specifically the breakdown voltage (Vbk). By incorporating machine learning techniques, it is possible to reliably predict performance metrics that cause devices to fail at low voltage. For diodes that fail at a higher (but still below theoretical) breakdown voltage, alternative inspection methods or a combination of several experimental techniques may be necessary.

Using machine learning with optical profilometry for GaN wafer screening.

To improve the manufacturing process of GaN wafers, inexpensive wafer screening techniques are required to both provide feedback to the manufacturing process and prevent fabrication on low quality or defective wafers, thus reducing costs resulting from wasted processing effort. Many of the wafer scale characterization techniques-including optical profilometry-produce difficult to interpret results, while models using classical programming techniques require laborious translation of the human-generated data interpretation methodology. Alternatively, machine learning techniques are effective at producing such models if sufficient data is available. For this research project, we fabricated over 6000 vertical PiN GaN diodes across 10 wafers. Using low resolution wafer scale optical profilometry data taken before fabrication, we successfully trained four different machine learning models. All models predict device pass and fail with 70-75% accuracy, and the wafer yield can be predicted within 15% error on the majority of wafers.

Mitochondrial augmentation of hematopoietic stem cells in children with single large-scale mitochondrial DNA deletion syndromes.

Patients with single large-scale mitochondrial DNA (mtDNA) deletion syndromes (SLSMDs) usually present with multisystemic disease, either as Pearson syndrome in early childhood or as Kearns-Sayre syndrome later in life. No disease-modifying therapies exist for SLSMDs. We have developed a method to enrich hematopoietic cells with exogenous mitochondria, and we treated six patients with SLSMDs through a compassionate use program. Autologous CD34+ hematopoietic cells were augmented with maternally derived healthy mitochondria, a technology termed mitochondrial augmentation therapy (MAT). All patients had substantial multisystemic disease involvement at baseline, including neurologic, endocrine, or renal impairment. We first assessed safety, finding that the procedure was well tolerated and that all study-related severe adverse events were either leukapheresis-related or related to the baseline disorder. After MAT, heteroplasmy decreased in the peripheral blood in four of the six patients. An increase in mtDNA content of peripheral blood cells was measured in all six patients 6 to 12 months after MAT as compared baseline. We noted some clinical improvement in aerobic function, measured in patients 2 and 3 by sit-to-stand or 6-min walk testing, and an increase in the body weight of five of the six patients suffering from very low body weight before treatment. Quality-of-life measurements as per caregiver assessment and physical examination showed improvement in some parameters. Together, this work lays the ground for clinical trials of MAT for the treatment of patients with mtDNA disorders.

Medication Identification Device to Reduce Medication Errors in Nursing Homes: A Controlled Pilot Study.

A controlled pilot study was performed to evaluate implementation of a medication identification device intended to reduce errors in nursing homes. Naïve observation was used for data collection of medication errors on an intervention unit using the device and a control unit, along with field notes describing observation details. Ten staff were observed administering medications to 70 residents over the study time-frame. Of the 9,099 medication administrations observed (n = 4,588 intervention; n = 4,511 control), 1,068 (12%) errors were identified. The intervention unit had fewer non-time errors versus the control unit, including dose (n = 21 vs. n = 59; p < 0.01), drug (n = 4 vs. n = 21; p <0.01), route (n = 0 vs. n = 4; p < 0.01), and given without order (n = 1 vs. n = 8; p < 0.01). However, time errors were higher on the intervention unit and were often due to late start and interruptions. Non-time errors were due to reliance on memory and nursing judgment. A combination of technology and staff dedicated solely to medication administration likely affected error rate differences. [Journal of Gerontological Nursing, 48(4), 5-11.].

Optimizing performance and yield of vertical GaN diodes using wafer scale optical techniques.

To improve the manufacturing of vertical GaN devices for power electronics applications, the effects of defects in GaN substrates need to be better understood. Many non-destructive techniques including photoluminescence, Raman spectroscopy and optical profilometry, can be used to detect defects in the substrate and epitaxial layers. Raman spectroscopy was used to identify points of high crystal stress and non-uniform conductivity in a substrate, while optical profilometry was used to identify bumps and pits in a substrate which could cause catastrophic device failures. The effect of the defects was studied using vertical P-i-N diodes with a single zone junction termination extention (JTE) edge termination and isolation, which were formed via nitrogen implantation. Diodes were fabricated on and off of sample abnormalities to study their effects. From electrical measurements, it was discovered that the devices could consistently block voltages over 1000 V (near the theoretical value of the epitaxial layer design), and the forward bias behavior could consistently produce on-resistance below 2 mΩ cm2, which is an excellent value considering DC biasing was used and no substrate thinning was performed. It was found that high crystal stress increased the probability of device failure from 6 to 20%, while an inhomogeneous carrier concentration had little effect on reverse bias behavior, and slightly (~ 3%) increased the on-resistance (Ron). Optical profilometry was able to detect regions of high surface roughness, bumps, and pits; in which, the majority of the defects detected were benign. However a large bump in the termination region of the JTE or a deep pit can induce a low voltage catastrophic failure, and increased crystal stress detected by the Raman correlated to the optical profilometry with associated surface topography.

Sustained reduction of serum neurofilament light chain over 7 years by alemtuzumab in early relapsing-remitting MS.

BACKGROUND: Alemtuzumab efficacy and safety was demonstrated in CARE-MS I and extension studies (CAMMS03409; TOPAZ). OBJECTIVE: Evaluate serum neurofilament light chain (sNfL) in CARE-MS I patients and highly active disease (HAD) subgroup, over 7 and 2 years for alemtuzumab and subcutaneous interferon beta-1a (SC IFNB-1a), respectively. METHODS: Patients received SC IFNB-1a 44 µg 3×/week or alemtuzumab 12 mg/day at baseline and month 12, with further as-needed 3-day courses. sNfL was measured using single-molecule array (Simoa™). HAD definition was ⩾2 relapses in year before randomization and ⩾1 baseline gadolinium-enhancing lesion. RESULTS: Baseline median sNfL levels were similar in alemtuzumab (n = 354) and SC IFNB-1a-treated (n = 159) patients (31.7 vs 31.4 pg/mL), but decreased with alemtuzumab versus SC IFNB-1a until year 2 (Y2; 13.2 vs 18.7 pg/mL; p < 0.0001); 12.7 pg/mL for alemtuzumab at Y7. Alemtuzumab-treated patients had sNfL at/below healthy control median at Y2 (72% vs 47%; p < 0.0001); 73% for alemtuzumab at Y7. HAD patients (n = 102) had higher baseline sNfL (49.4 pg/mL) versus overall population; alemtuzumab HAD patients attained similar levels (Y2, 12.8 pg/mL; Y7, 12.7 pg/mL; 75% were at/below control median at Y7). CONCLUSION: Alemtuzumab was superior to SC IFNB-1a in reducing sNfL, with levels in alemtuzumab patients remaining stable through Y7. CLINICALTRIALS.GOV IDENTIFIER: NCT00530348, NCT00930553, NCT02255656.

Efficacy and safety of alemtuzumab over 6 years: final results of the 4-year CARE-MS extension trial.

BACKGROUND: In the 2-year CARE-MS I and II trials, alemtuzumab 12 mg administered on 5 consecutive days at core study baseline and on 3 consecutive days 12 months later significantly improved outcomes versus subcutaneous interferon beta-1a (SC IFNB-1a) in relapsing-remitting multiple sclerosis patients. Here, we present the final 6-year CARE-MS extension trial results (CAMMS03409), and compare outcomes over 6 years in patients randomized to both treatment groups at core study baseline. METHODS: Over a 4-year extension, alemtuzumab patients (alemtuzumab-only) received as-needed additional alemtuzumab (⩾12 months apart) for disease activity after course 2. SC IFNB-1a patients who entered the extension discontinued SC IFNB-1a and received 2 alemtuzumab 12 mg courses (IFN-alemtuzumab), followed by additional, as-needed, alemtuzumab. RESULTS: Through year 6, 63% of CARE-MS I and 50% of CARE-MS II alemtuzumab-only patients received neither additional alemtuzumab nor other disease-modifying therapy, with lasting suppression of disease activity, improved disability, and slowing of brain volume loss (BVL). In CARE-MS I patients (treatment-naive; less disability; shorter disease duration), disease activity and BVL were significantly reduced in IFN-alemtuzumab patients, similar to alemtuzumab-only patients at year 6. Among CARE-MS II patients (inadequate response to prior treatment; more disability; longer disease duration), alemtuzumab significantly improved clinical and magnetic resonance imaging outcomes, including BVL, in IFN-alemtuzumab patients; however, disability outcomes were less favorable versus alemtuzumab-only patients. Safety profiles, including infections and autoimmunities, following alemtuzumab were similar between treatment groups. CONCLUSION: This study demonstrates the high efficacy of alemtuzumab over 6 years, with a similar safety profile between treatment groups. CLINICALTRIALSGOV IDENTIFIERS: NCT00530348; NCT00548405; NCT00930553.

Effect of Alemtuzumab Infusions on Vital Signs: A Prospective Observational Study in Patients with Relapsing-Remitting Multiple Sclerosis.

BACKGROUND: Alemtuzumab efficacy and safety were established in phase 3 randomized trials. We characterize vital signs during and after the first alemtuzumab infusion course. METHODS: Patients with relapsing-remitting multiple sclerosis commercially prescribed alemtuzumab 12 mg/day on 5 consecutive days (initial course) were enrolled in this prospective, observational study. Preinfusion medications included methylprednisolone, antihistamine, and antipyretics. Primary end point: change from precourse baseline in vital signs during and 2 hours after each alemtuzumab infusion. Secondary end points: infusion duration and serious adverse events (AEs) starting within 24 hours and within 7 days after infusion (AEs collected up to 15 days after treatment). Potentially clinically significant vital sign abnormalities were based on predefined thresholds from literature review. RESULTS: In the 304 patients treated, minimal increases in mean systolic (≤8 mm Hg) and diastolic (≤3 mm Hg) blood pressures from precourse baseline were observed on infusion days 3 to 5. An increase in mean heart rate (20 beats per minute) during the first infusion day normalized by day 2, and smaller increases (5 beats per minute) occurred during subsequent infusions. Serious AEs occurred in two patients (0.7%) during or within 24 hours after infusion and in three patients (1.0%) within 7 days. Mean/median infusion duration was 4 hours. Vital sign abnormalities with potential clinical significance occurred in 62.5% of patients. CONCLUSIONS: Although most patients had potentially clinically significant vital sign abnormalities, mean changes from baseline during and after infusion of the first alemtuzumab course were clinically insignificant. No new safety signals were detected.

Proportion of alemtuzumab-treated patients converting from relapsing-remitting multiple sclerosis to secondary progressive multiple sclerosis over 6 years.

BACKGROUND: Few data exist concerning conversion to secondary progressive MS in patients treated with disease-modifying therapies. OBJECTIVE: Determine the proportion of alemtuzumab-treated patients converting from relapsing-remitting to secondary progressive MS during the CARE-MS core and extension studies. METHODS: Patients (N = 811) were analyzed post hoc for secondary progressive MS conversion. Optimal conversion definition: Expanded Disability Status Scale (EDSS) score ≥4, pyramidal functional system score ≥2, and confirmed progression over ≥3 months including confirmation within the functional system leading to progression, independent of relapse. RESULTS: Over 6.2 years median follow-up, 20 alemtuzumab-treated patients converted (Kaplan-Meier estimate, 2.7%; 95% confidence interval, 1.8%-4.2%). Sensitivity analysis accounting for dropouts showed similar results (3%), as did analyses using alternative definitions with different EDSS thresholds and/or confirmation periods, and analysis of core study subcutaneous interferon beta-1a-treated patients who received alemtuzumab in the extension. Patients converting to secondary progressive MS were older, and had higher EDSS scores and greater brain lesion volumes at baseline, but did not need additional alemtuzumab or other therapies. CONCLUSIONS: The 6-year conversion rate to secondary progressive MS was low for alemtuzumab-treated patients, supporting further study of the role alemtuzumab may play in reducing risk of secondary progression.ClinicalTrials.gov identifiers: NCT00530348, NCT00548405, NCT00930553.

Efficacy of alemtuzumab in relapsing-remitting MS patients who received additional courses after the initial two courses: Pooled analysis of the CARE-MS, extension, and TOPAZ studies.

BACKGROUND: Alemtuzumab is given as two annual courses. Patients with continued disease activity may receive as-needed additional courses. OBJECTIVE: To evaluate efficacy and safety of additional alemtuzumab courses in the CARE-MS (Comparison of Alemtuzumab and Rebif® Efficacy in Multiple Sclerosis) studies and their extensions. METHODS: Subgroups were based on the number of additional alemtuzumab courses received. Exclusion criteria: other disease-modifying therapy (DMT); <12-month follow-up after last alemtuzumab course. RESULTS: In the additional-courses groups, Courses 3 and 4 reduced annualized relapse rate (12 months before: 0.73 and 0.74, respectively; 12 months after: 0.07 and 0.08). For 36 months after Courses 3 and 4, 89% and 92% of patients were free of 6-month confirmed disability worsening, respectively, with 20% and 26% achieving 6-month confirmed disability improvement. Freedom from magnetic resonance imaging (MRI) disease activity increased after Courses 3 and 4 (12 months before: 43% and 53%, respectively; 12 months after: 73% and 74%). Safety was similar across groups; serious events occurred irrespective of the number of courses. CONCLUSION: Additional alemtuzumab courses significantly improved outcomes, without increased safety risks, in CARE-MS patients with continued disease activity after Course 2. How this compares to outcomes if treatment is switched to another DMT instead remains unknown.

Lymphocyte pharmacodynamics are not associated with autoimmunity or efficacy after alemtuzumab.

OBJECTIVE: To examine the association between peripheral blood lymphocyte pharmacodynamics and autoimmune adverse events (AEs) or return of disease activity in alemtuzumab-treated patients with relapsing-remitting MS. METHODS: Patients received 2 alemtuzumab courses (12 mg/d IV; 5 days at baseline, 3 days 12 months later) in the 2-year Comparison of Alemtuzumab and Rebif Efficacy in Multiple Sclerosis studies (NCT00530348 and NCT00548405) and could then receive as-needed alemtuzumab or other disease-modifying therapy in a 4-year extension (NCT00930553). Lymphocytes were phenotyped quarterly over 2 years using fluorescence-activated cell sorting. Pharmacodynamic assessments included counts of total lymphocytes, CD3+ T cells, CD4+/CD8+ T cells (total/naive/memory/regulatory [Treg]), and CD19+ B cells (total/immature/mature/memory) and ratios of CD19+ (total/immature/mature/memory) to Treg (CD4+/CD8+) counts. Assessed autoimmune AEs included immune thrombocytopenia, nephropathies, and thyroid events. Efficacy assessments included relapses, 6-month confirmed disability worsening (CDW), and MRI disease activity. RESULTS: Lymphocyte repopulation patterns, including ratios between distinct lymphocyte subsets (e.g., CD19+ to Treg cell count ratios), showed no significant differences over 2 years in patients developing/not developing autoimmune AEs, relapses, CDW, or MRI activity through 6 years following alemtuzumab. Lymphocyte kinetics were also unrelated to multiple autoimmune AEs or extreme clinical phenotypes. CONCLUSIONS: Repopulation kinetics of the evaluated peripheral lymphocyte subsets did not predict autoimmune AE occurrence or disease activity, including return of disease activity after 2 alemtuzumab courses. Further study is needed to investigate potential antigen-level markers of treatment response.

Placental Membrane Provides Improved Healing Efficacy and Lower Cost Versus a Tissue-Engineered Human Skin in the Treatment of Diabetic Foot Ulcerations.

Aseptically processed dehydrated human amnion and chorion allograft (dHACA) (AmnioBand) has shown great promise in the treatment of recalcitrant diabetic foot ulcers (DFUs) when compared with standard wound care but has not yet been compared to any other tissue forms used in treating DFUs. The hypothesis was to conduct a randomized controlled trial in which dHACA was compared to one of the earliest and most commonly accepted tissue-engineered skin substitutes (TESS) (Apligraf) in the treatment of nonhealing DFUs over a period of 12 weeks to assess the superiority of healing. METHODS: Following a 2-week screening period during which subjects with DFUs were treated with collagen alginate dressing, 60 subjects were randomized at 5 sites to receive either dHACA or TESS applied weekly, with weekly follow-up for up to 12 weeks. RESULTS: The mean time to heal within 6-week time period for the dHACA group was 24 days (95% CI, 18.9-29.2) versus 39 days (95% CI, 36.4-41.9) for the TESS group; the mean time to heal at 12 weeks was 32 days (95% CI, 22.3-41.0) for dHACA-treated wounds versus 63 days (95% CI, 54.1-72.6) for TESS-treated wounds. The proportion of wounds healed at study completion (12 weeks) was 90% (27/30) for the dHACA group versus 40% (12/30) for the TESS group. The mean product cost for the dHACA group was significantly lower than that for the TESS group [dHACA: $2,200 (median: $1,300); TESS: $7,900 (median: $6,500)]. The mean wastage (%) at 12 weeks was also significantly lower for the dHACA group than that for the TESS group (36% vs 95%). CONCLUSIONS: It was concluded that aseptically processed dHACA heals diabetic foot wounds more reliably, statistically significantly faster than and at significantly lower cost than TESS.

Efficacy and Safety of Alemtuzumab in Patients of African Descent with Relapsing-Remitting Multiple Sclerosis: 8-Year Follow-up of CARE-MS I and II (TOPAZ Study).

INTRODUCTION: Multiple sclerosis (MS) patients of African descent have increased risk for disease progression and may be less responsive to disease-modifying therapy. METHODS: Patients in the CARE-MS studies received alemtuzumab 12 mg/day [initial alemtuzumab treatment (IAT); baseline: 5 days; 12 months later: 3 days] or subcutaneous interferon beta-1a (SC IFNB-1a) 3 ×/week. Core study outcomes were compared between treatment groups. In the extension study CAMMS03409, SC IFNB-1a-treated patients switched to alemtuzumab [delayed alemtuzumab treatment (DAT)]. Data from IAT and DAT arms were pooled to assess outcomes through 6 years post alemtuzumab initiation; IAT patients had an additional 2 years of follow-up in TOPAZ. RESULTS: Of 1200 CARE-MS patients, 43 (4%) were of African descent (35 IAT; 8 DAT) and received alemtuzumab in the 2-year core and/or 6-year extension; 29 (67%) remained on study at the time of analysis (24 IAT patients completed year 8 post alemtuzumab; 5 DAT patients completed year 6 post alemtuzumab). In year 2, annualized relapse rate (ARR; 0.09 versus 0.42), percentage of patients with improved Expanded Disability Status Scale (EDSS; 18% versus 11%), 6-month confirmed disability improvement (CDI; 28% versus 13%), no evidence of disease activity (55% versus 13%), and cumulative brain volume loss (BVL; - 0.55% versus - 1.32%) favored alemtuzumab versus SC IFNB-1a. Alemtuzumab remained efficacious at year 6 (pooled IAT/DAT) and at year 8 (IAT only) post alemtuzumab (ARR: 0.15 and 0.30; improved EDSS: 17% and 25%; CDI: 47% and 55%; BVL: - 1.14% and - 0.70%, respectively). No safety signals were unique to this population. CONCLUSIONS: Alemtuzumab was efficacious in a small cohort of relapsing-remitting MS patients of African descent over 8 years. Safety was consistent with the overall CARE-MS population, although the small sample size may have prevented the detection of known low-frequency adverse events. CLINICALTRIALS. GOV REGISTRATION NUMBERS: CARE-MS I, II, extension, TOPAZ: NCT00530348, NCT00548405, NCT00930553, NCT02255656. FUNDING: Sanofi (Cambridge, MA, USA) and Bayer HealthCare Pharmaceuticals (Leverkusen, Germany).

Detecting Non-cognitive Features of Prodromal Neurodegenerative Diseases.

BACKGROUND: Prodromal Neurodegenerative Disease (ND) due to tauopathies such as Alzheimer's Disease (AD) and Synucleinopathies (SN) such as Parkinson's Disease (PD) and Dementia with Lewy Bodies (DLB) present subtly. Although ND are considered cognitive disorders, in fact ND present with behavioral and even medical symptomatology years to decades prior to the onset of cognitive changes. Recognizing prodromal ND syndromes is a public health priority because ND is common, disabling and expensive. Diagnosing prodromal ND in real world clinical settings is challenging because ND of the same pathology can present with different symptoms in different people. Individual variability in nature and variability in nurture across the life course influence how ND pathology manifests clinically. The objective of this study was to describe how non-cognitive symptoms from behavioral, medical, neurological and psychiatric domains cluster in prodromal and early stages of ND. METHODS: This was an observational study of patients receiving routine clinical care for memory disorders. All patients receiving a standardized evaluation including complete neurological history and examination and standardized brief neuropsychological testing. A Principal Component Analysis (PCA) considering emotion, motor, sensory and sleep factors was performed on the entire sample of patients in order to identify co-occurring symptom clusters. All patients received a consensus diagnosis adjudicated by at least two dementia experts. Patients were grouped into Cognitively Normal, Detectable Cognitive Impairment, and Mild Cognitive Impairment categories due to AD and/or PD/LBD or NOS pathology. Symptom cluster scores were compared between clinical diagnostic groups. RESULTS: In this study 165 patients completed baseline neuropsychological testing and reported subjective measures of non-cognitive symptoms. Four syndrome specific symptom factors emerged and eight non-specific symptom factors. Symptoms of personality changes, paranoia, hallucinations, cravings, agitation, and changes in appetite grouped together into a cluster consistent with an "SN Non-motor Phenotype". Appetite, walking, balance, hearing, increased falls, and dandruff grouped together into a cluster consistent with an "SN Motor Phenotype". The Prodromal AD phenotype included symptoms of anxiety, irritability, apathy, sleep disturbance and social isolation. The fourth factor included symptoms of increased sweating, twitching, and tremor grouped into a cluster consistent with an Autonomic phenotype. CONCLUSION: Non-cognitive features can be reliably measured by self-report in busy clinical settings. Such measurement can be useful in distinguishing patients with different etiologies of ND. Better characterization of unique, prodromal, non-cognitive ND trajectories could improve public health efforts to modify the course of ND for all patients at risk.

Emotional Consequences of Finasteride: Fool's Gold.

Androgenetic alopecia, the gradual, progressive loss of hair frequently results in psychological despair, in part related to changes in self-image. Current androgenetic alopecia treatments are limited to hair transplantation and medications that inhibit dihydrotestosterone, a potent androgen associated with follicular micronization. Users of finasteride, which prevents dihydrotestosterone production, report serious physical and emotional adverse effects, collectively known as post-finasteride syndrome. Psychiatric illnesses and personality traits, specifically neuroticism influence emotional well-being. Limited research exists exploring the psychological corollaries of post-finasteride syndrome and preexisting Axis I and Axis II mental health conditions. The aim of this study was to explore how having a preexisting personal and/or familial history of a psychiatric diagnosis and certain personality traits may influence anxiety and depression among finasteride users. Participants in this online survey completed the Beck Depression Inventory, the Beck Anxiety Inventory, and Ten-Item Personality Inventory. An important finding in this study was that almost 57% ( n = 97) of men reported a psychiatric diagnosis and 28% ( n = 27) had a first-degree relative with a mental health disorder, of this group 17 only had a family history. Nearly 50% of the men surveyed reported clinically significant depression as evidenced by Beck Depression Inventory score and 34% experienced anxiety on the Beck Anxiety Inventory. There were no statistically significant trends in personality traits reported. Results provide evidence on the need to screen for psychiatric history and counseling patients about the potential psychological consequences of finasteride. Prescribing clinicians should carefully weigh the risk/benefit ratio with these patients.

Ultrafast Self-Assembly of Sub-10 nm Block Copolymer Nanostructures by Solvent-Free High-Temperature Laser Annealing.

Laser spike annealing was applied to PS-b-PDMS diblock copolymers to induce short-time (millisecond time scale), high-temperature (300 to 700 °C) microphase segregation and directed self-assembly of sub-10 nm features. Conditions were identified that enabled uniform microphase separation in the time frame of tens of milliseconds. Microphase ordering improved with increased temperature and annealing time, whereas phase separation contrast was lost for very short annealing times at high temperature. PMMA brush underlayers aided ordering under otherwise identical laser annealing conditions. Good long-range order for sub-10 nm cylinder morphology was achieved using graphoepitaxy coupled with a 20 ms dwell laser spike anneal above 440 °C.

Transient Ischemic Attack and Cognitive Impairment: A Review.

Transient ischemic attack (TIA) is a neurologic deficit resulting from focal ischemia in the brain, spinal cord, or retina. Historically, the definition included symptom resolution within 24 hours. However, recent studies investigating cognition after TIA suggest that deficits in executive function persist at 7 days post-TIA, although few studies have examined these effects long term. Recent advances in neuroimaging techniques provide emerging evidence of permanent microvascular tissue damage in the brain, suggesting that the effects of TIA may persist beyond resolution of focal symptoms. A further challenge is that there is debate concerning the clinical definition of TIA and the use of diagnostic neuroimaging studies and standardization of neuropsychological tests used to evaluate cognitive deficits in this population. Subtle changes in memory, attention, and problem-solving abilities may negatively influence an individual's ability to adopt positive health behaviors. Despite advances in the field, more research is needed; hence, the purpose of this article is to provide an overview of clinical factors for clinicians and researchers to consider when investigating cognitive deficits among post-TIA populations. Definitions of TIA are reviewed, and the importance of neuropsychological evaluation and neuroimaging correlates of TIA in establishing a positive diagnosis will be discussed. Nurses especially in advanced practice roles are uniquely positioned to assess and implement treatments in at-risk groups and therefore should be knowledgeable about these possible cognitive effects.

Lateral Temperature-Gradient Method for High-Throughput Characterization of Material Processing by Millisecond Laser Annealing.

A high-throughput method for characterizing the temperature dependence of material properties following microsecond to millisecond thermal annealing, exploiting the temperature gradients created by a lateral gradient laser spike anneal (lgLSA), is presented. Laser scans generate spatial thermal gradients of up to 5 °C/µm with peak temperatures ranging from ambient to in excess of 1400 °C, limited only by laser power and materials thermal limits. Discrete spatial property measurements across the temperature gradient are then equivalent to independent measurements after varying temperature anneals. Accurate temperature calibrations, essential to quantitative analysis, are critical and methods for both peak temperature and spatial/temporal temperature profile characterization are presented. These include absolute temperature calibrations based on melting and thermal decomposition, and time-resolved profiles measured using platinum thermistors. A variety of spatially resolved measurement probes, ranging from point-like continuous profiling to large area sampling, are discussed. Examples from annealing of III-V semiconductors, CdSe quantum dots, low-κ dielectrics, and block copolymers are included to demonstrate the flexibility, high throughput, and precision of this technique.

µ-Rainbow: CdSe Nanocrystal Photoluminescence Gradients via Laser Spike Annealing for Kinetic Investigations and Tunable Device Design.

Much of the promise of nanomaterials derives from their size-dependent, and hence tunable, properties. Impressive advances have been made in the synthesis of nanoscale building blocks with precisely tailored size, shape and composition. Significant attention is now turning toward creating thin film structures in which size-dependent properties can be spatially programmed with high fidelity. Nonequilibrium processing techniques present exciting opportunities to create nanostructured thin films with unprecedented spatial control over their optical and electronic properties. Here, we demonstrate single scan laser spike annealing (ssLSA) on CdSe nanocrystal (NC) thin films as an experimental test bed to illustrate how the size-dependent photoluminescence (PL) emission can be tuned throughout the visible range and in spatially defined profiles during a single annealing step. Through control of the annealing temperature and time, we discovered that NC fusion is a kinetically limited process with a constant activation energy in over 2 orders of magnitude of NC growth rate. To underscore the broader technological implications of this work, we demonstrate the scalability of LSA to process large area NC films with periodically modulated PL emission, resulting in tunable emission properties of a large area film. New insights into the processing-structure-property relationships presented here offer significant advances in our fundamental understanding of kinetics of nanomaterials as well as technological implications for the production of nanomaterial films.

Persistent sexual, emotional, and cognitive impairment post-finasteride: a survey of men reporting symptoms.

Finasteride is a synthetic 5-α reductase inhibitor, which prevents the conversion of testosterone to dihydrotestosterone and has been used for more than 20 years in the treatment of male pattern hair loss. Randomized, controlled trials have associated finasteride with both reversible and persistent adverse effects. In this pilot study, we sought to characterize sexual and nonsexual adverse effects that men reported experiencing at least 3 months after stopping the medication. Based on previous research on persistent side effects of finasteride, we constructed an Internet survey targeting six domains: physical symptoms, sexual libido, ejaculatory disorders, disorders of the penis and testes, cognitive symptoms, and psychological symptoms and was e-mailed to patients who reported experiencing symptoms of side effects of finasteride. Responses from 131 generally healthy men (mean age, 24 years) who had taken finasteride for male pattern hair loss was included in the analysis. The most notable finding was that adverse effects persisted in each of the domains, indicating the possible presence of a "post-finasteride syndrome."