ABSTRACT
Al alloys have widespread industrial applications. However, their mechanical strength is often much lower than steels. Here, we investigate the influence of solutes on achieving ultrahigh strength and thermal stability of nanotwinned Al alloys. In situ micropillar compression tests show the addition of a small amount of Ti can significantly increase the mechanical strength of Al-Ni alloys to 2 GPa. Deformation induced detwinning, Ni segregation and grain coarsening as discovered in binary Al-Ni alloys are mostly absent in the ternary Al-Ni-Ti alloys. Moreover, the ternary Al-Ni-Ti alloys have outstanding thermal stability. Density function theory calculations reveal the synergetic pinning effect of Ni-Ti solute pairs on incoherent twin boundaries. This study demonstrates that the proper selection of synergistic solute pairs is critical to improve the thermal stability and mechanical properties of nanotwinned Al alloys.
ABSTRACT
BACKGROUND AND PURPOSE: Primitive reflexes may reoccur in various neurodegenerative diseases. However, little is known about their structural and functional correlates in the human brain. Notably, the neural mechanisms underlying a positive palmomental reflex (PMR) are poorly understood. As recent studies link Alzheimer's disease (AD)-related primitive reflexes to a dysfunction of the corticostriatal motor circuit (CMC), we conducted the present study to investigate functional and structural correlates of a positive PMR. We hypothesized an involvement of frontostriatal structures and an impairment of the CMC. METHODS: Using whole-brain resting-state functional connectivity (FC), hypothesis and FC result-based probabilistic tractography, and voxel-based morphometry analyses, we compared two groups of AD patients with either positive (n = 12) or negative PMR (n = 12). RESULTS: No significant differences in grey matter volume or structural connectivity (SC) could be observed between the PMR-positive and PMR-negative groups. In contrast, the PMR-positive group showed a decreased seed-to-voxel FC between the bilateral supplementary motor area and parts of the right-hemispherical caudate nucleus and thalamus and a decreased region of interest (ROI)-to-ROI FC between the left putamen and the left superior frontal gyrus. CONCLUSION: Data suggest that dysfunction of the CMC reflected by decreased FC underlies a positive PMR in patients with AD. The lack of significant grey matter or SC differences might reflect that changes in FC appear before changes in SC in the structures of the CMC and brain atrophy.
Subject(s)
Alzheimer Disease , Alzheimer Disease/diagnostic imaging , Brain , Brain Mapping , Humans , Magnetic Resonance Imaging , ReflexABSTRACT
Approximately 10% of patients with ascites associated with cirrhosis fail to respond to dietary rules and diuretic treatment and therefore present with refractory ascites. In order to avoid iterative large-volume paracentesis in patients with contraindication to TIPS, the automated low flow ascites pump system (Alfapump) was developed to pump ascites from the peritoneal cavity into the urinary bladder, where it is eliminated spontaneously by normal micturition. This manuscript reports the surgical technique for placement of the Alfapump.
Subject(s)
Ascites/surgery , Liver Cirrhosis/complications , Paracentesis/instrumentation , Paracentesis/methods , Peritoneal Cavity/surgery , Urinary Bladder/surgery , Anastomosis, Surgical/instrumentation , Anastomosis, Surgical/methods , Ascites/etiology , Ascites/therapy , HumansABSTRACT
BACKGROUND: A growing number of patients with biliary atresia and congenital cholestatic syndromes are reaching adulthood. These patients often have a number of typical medical features, including specific characteristics of liver transplantation medicine. OBJECTIVE: What are the special features in the care of adults suffering from liver diseases with manifestation in childhood and adolescence, both before and after liver transplantation (LTX). How does the progression of individual diseases differ depending on age at manifestation? What are specific aspects following pediatric LTX? PATIENTS AND METHODS: Evaluation and discussion of existing guidelines and recommendations of the individual disciplines and professional societies as well as the current literature. Joint discussion of the recommendations between disciplines (gastroenterology, pediatric gastroenterology, surgery). Inclusion of center-specific experiences with transition from existing transition outpatient departments and training. RESULTS: The recommendations are presented specifically for each disease. Special features in individual diseases after LTX are also discussed. Diagnosis-independent general treatment concepts for cholestasis and chronic liver disease are presented. CONCLUSION: Patients with biliary atresia and congenital cholestatic syndromes have a life-long chronic liver disease with and without LTX and require specific medical care. The patients benefit from the pooling of expertise in the individual disciplines.
Subject(s)
Biliary Atresia , Cholestasis , Continuity of Patient Care , Transition to Adult Care , Adult , Alagille Syndrome , Child , Cholestasis/congenital , Humans , Liver TransplantationABSTRACT
In recent years, changes in resting-state networks (RSN), identified by functional magnetic resonance imaging (fMRI), have gained increasing attention as potential biomarkers and trackers of neurological disorders such as Alzheimer's disease (AD). Intersession reliability of RSN is fundamental to this approach. In this study, we investigated the test-retest reliability of three memory related RSN (i.e., the default mode, salience, and executive control network) in 15 young, 15 healthy seniors (HS), and 15 subjects affected by mild cognitive impairment (MCI) with positive biomarkers suggestive of incipient AD (6 females each). FMRI was conducted on three separate occasions. Independent Component Analysis decomposed the resting-state data into RSNs. Comparisons of variation in functional connectivity between groups were made applying different thresholds in an explorative approach. Intersession test-retest reliability was evaluated by intraclass correlation coefficient (ICC) comparisons. To assess the effect of gray matter volume loss, motion, cerebrospinal fluid based biomarkers and the time gap between sessions on intersession variation, the former four were correlated separately with the latter. Data showed that i) young subjects ICCs (relative to HS/MCI-subjects) had higher intersession reliability, ii) stringent statistical thresholds need to be applied to prevent false-positives, iii) both HS and MCI-subjects (relative to young) showed significantly more clusters of intersession variation in all three RSN, iv) while intersession variation was highly correlated with head motion, it was also correlated with biomarkers (especially phospho-tau), the time gap between sessions and local GMV. Results indicate that time gaps between sessions should be kept constant and that head motion must be taken into account when using RSN to assess aging and neurodegeneration. In patients with prodromal AD, re-test reliability may be increased by accouting for overall disease burden by including biomarkers of neuronal injury (especially phospho-tau) in statistical analyses. Local atrophy however, does not seem to play a major role in regards to reliability, but should be used as covariate depending on the research question.
Subject(s)
Alzheimer Disease/diagnostic imaging , Brain/diagnostic imaging , Cognitive Dysfunction/diagnostic imaging , Nerve Net/diagnostic imaging , Adult , Aged , Brain Mapping , Disease Progression , Female , Healthy Aging , Humans , Image Processing, Computer-Assisted , Magnetic Resonance Imaging , Male , Middle Aged , Reproducibility of Results , Young AdultABSTRACT
In cases of chronic renal insufficiency, successful kidney transplantation is the method of choice to restore patients' health, well-being and physical fitness. The interdisciplinary collaboration of nephrologists and transplant surgeons has always been a prerequisite for the successful pre-, peri- and post-transplant care of renal transplant patients. The same holds true for liver transplant patients. Here the nephrologist is often involved in cases requiring pre- or post-transplant dialysis as well as in decision making for combined liver-kidney transplantation. This review focuses on nephrological aspects in patient care before and after kidney and liver transplantation.
Subject(s)
Interdisciplinary Communication , Intersectoral Collaboration , Kidney Transplantation , Liver Transplantation , Patient Care Team , Graft Rejection/diagnosis , Graft Rejection/therapy , Humans , Postoperative Complications/diagnosis , Postoperative Complications/therapy , Primary Graft Dysfunction/diagnosis , Primary Graft Dysfunction/therapyABSTRACT
We investigate the pure spin-current assisted depinning of magnetic domain walls in half ring based Py/Al lateral spin valve structures. Our optimized geometry incorporating a patterned notch in the detector electrode, directly below the Al spin conduit, provides a tailored pinning potential for a transverse domain wall and allows for a precise control over the magnetization configuration and as a result the domain wall pinning. Due to the patterned notch, we are able to study the depinning field as a function of the applied external field for certain applied current densities and observe a clear asymmetry for the two opposite field directions. Micromagnetic simulations show that this can be explained by the asymmetry of the pinning potential. By direct comparison of the calculated efficiencies for different external field and spin current directions, we are able to disentangle the different contributions from the spin transfer torque, Joule heating and the Oersted field. The observed high efficiency of the pure spin current induced spin transfer torque allows for a complete depinning of the domain wall at zero external field for a charge current density of [Formula: see text] A m-2, which is attributed to the optimal control of the position of the domain wall.
ABSTRACT
The potential of a number of enantiocomplementary ω-transaminases (ω-TAms) in the amination of cyclic ketones has been investigated. After a preliminary screening of several compounds with increasing complexity, different approaches to shift the equilibrium of the reaction to the amine products were studied, and reaction conditions (temperature and pH) optimised. Interestingly, 2-propylamine as an amine donor was tolerated by all five selected ω-TAms, and therefore used in further experiments. Due to the higher conversions observed and interest in chiral amines studies then focused on the amination of α-tetralone and 2-methylcyclohexanone. Both ketones were aminated to give the corresponding amine with at least one of the employed enzymes. Moreover, the amination of 2-methylcyclohexanone was investigated in more detail due to the different stereoselectivities observed with TAms used. The highest yields and stereoselectivities were obtained using the ω-TAm from Chromobacterium violaceum (CV-TAm), producing 2-methylcyclohexylamine with complete stereoselectivity at the (1S)-amine position and up to 24 : 1 selectivity for the cis : trans [(1S,2R) : (1S,2S)] isomer.
Subject(s)
Ketones/metabolism , Transaminases/metabolism , Amination , Catalytic Domain , Cyclization , Hydrogen-Ion Concentration , Models, Molecular , Quinones/chemistry , TemperatureABSTRACT
The feasibility of de novo everolimus without calcineurin inhibitor (CNI) therapy following liver transplantation was assessed in a multicenter, prospective, open-label trial. Liver transplant patients were randomized at 4 weeks to start everolimus and discontinue CNI, or continue their current CNI-based regimen. The primary endpoint was adjusted estimated GFR (eGFR; Cockcroft-Gault) at month 11 post randomization. A 24-month extension phase followed 81/114 (71.1%) of eligible patients to month 35 post randomization. The adjusted mean eGFR benefit from randomization to month 35 was 10.1 mL/min (95% confidence interval [CI] -1.3, 21.5 mL/min, p = 0.082) in favor of CNI-free versus CNI using Cockcroft-Gault, 9.4 mL/min/1.73 m(2) (95% CI -0.4, 18.9, p = 0.053) with Modification of Diet in Renal Disease (four-variable) and 9.5 mL/min/1.73 m(2) (95% CI -1.1, 17.9, p = 0.028) using Nankivell. The difference in favor of the CNI-free regimen increased gradually over time due to a small progressive decline in eGFR in the CNI cohort despite a reduction in CNI exposure. Biopsy-proven acute rejection, graft loss and death were similar between groups. Adverse events led to study drug discontinuation in five CNI-free patients and five CNI patients (12.2% vs. 12.5%, p = 1.000) during the extension phase. Everolimus-based CNI-free immunosuppression is feasible following liver transplantation and patients benefit from sustained preservation of renal function versus patients on CNI for at least 3 years.
Subject(s)
Calcineurin Inhibitors , Cyclosporine/administration & dosage , Graft Rejection/drug therapy , Immunosuppressive Agents/administration & dosage , Liver Diseases/surgery , Liver Transplantation , Sirolimus/analogs & derivatives , Adolescent , Adult , Aged , Cyclosporine/adverse effects , Everolimus , Feasibility Studies , Female , Follow-Up Studies , Graft Rejection/etiology , Graft Survival/drug effects , Humans , Immunosuppressive Agents/adverse effects , Male , Middle Aged , Prognosis , Prospective Studies , Sirolimus/administration & dosage , Time Factors , Withholding Treatment , Young AdultABSTRACT
Besides several risk factors for suicide, there is a recent increase in clinical and epidemiological studies pointing to a potential relationship between sleep loss or sleep disturbances and suicidality. This work, based on a systematic literature research, gives an overview on the findings of relationships between suicidality (i. e., suicidal thoughts, suicide attempts, suicides) and sleep disturbances, especially insomnia, nightmares, but also hypersomnia and nocturnal panic attacks. There is evidence that sleep disturbances in suicidal insomniacs with comorbid psychiatric disorder are independently predictive for suicidality, too. Shared aspects of pathogenesis of the two entities and therapeutic options are also discussed. Recognition of sleep disturbances is essential for suicide prevention in clinical practice.
Subject(s)
Sleep Wake Disorders/psychology , Suicidal Ideation , Suicide/psychology , Disorders of Excessive Somnolence/complications , Disorders of Excessive Somnolence/epidemiology , Disorders of Excessive Somnolence/psychology , Humans , Mental Disorders/epidemiology , Mental Disorders/psychology , Panic Disorder/epidemiology , Panic Disorder/psychology , Risk Factors , Sleep Initiation and Maintenance Disorders/complications , Sleep Initiation and Maintenance Disorders/epidemiology , Sleep Initiation and Maintenance Disorders/psychology , Sleep Wake Disorders/epidemiology , Sleep Wake Disorders/physiopathology , Suicide/statistics & numerical data , Suicide, Attempted/statistics & numerical data , Suicide PreventionABSTRACT
Despite the apparent robustness of language learning in humans, a large number of children still fail to develop appropriate language skills despite adequate means and opportunity. Most cases of language impairment have a complex etiology, with genetic and environmental influences. In contrast, we describe a three-generation German family who present with an apparently simple segregation of language impairment. Investigations of the family indicate auditory processing difficulties as a core deficit. Affected members performed poorly on a nonword repetition task and present with communication impairments. The brain activation pattern for syllable duration as measured by event-related brain potentials showed clear differences between affected family members and controls, with only affected members displaying a late discrimination negativity. In conjunction with psychoacoustic data showing deficiencies in auditory duration discrimination, the present results indicate increased processing demands in discriminating syllables of different duration. This, we argue, forms the cognitive basis of the observed language impairment in this family. Genome-wide linkage analysis showed a haplotype in the central region of chromosome 12 which reaches the maximum possible logarithm of odds ratio (LOD) score and fully co-segregates with the language impairment, consistent with an autosomal dominant, fully penetrant mode of inheritance. Whole genome analysis yielded no novel inherited copy number variants strengthening the case for a simple inheritance pattern. Several genes in this region of chromosome 12 which are potentially implicated in language impairment did not contain polymorphisms likely to be the causative mutation, which is as yet unknown.
Subject(s)
Auditory Perceptual Disorders/genetics , Chromosomes, Human, Pair 12/genetics , Dyslexia/genetics , Genetic Predisposition to Disease/genetics , Language Development Disorders/genetics , Adolescent , Adult , Aged , Child , Child, Preschool , Chromosome Mapping , Female , Genetic Linkage , Genotype , Humans , Language Development Disorders/physiopathology , Lod Score , Male , Nuclear Family , PedigreeABSTRACT
Previous studies pointed out the high prevalence of the metabolic syndrome among patients with bipolar disorder and major depression. A link between depression and a metabolic syndrome remains in dispute despite these studies. This study was conducted to evaluate the occurrence of the metabolic syndrome in depressive inpatients, to analyze the association between the severity of depression and the metabolic syndrome and to screen specific laboratory values in the course of depressive illness. 60 acute depressive patients were recruited for the study and underwent psychometric testing [21-item Hamilton Depression Rating Scale (HAMD), Beck Depression Inventory (BDI), Clinical Global Impression Scale (CGI) and Global Assessment of Functioning Scale (GAF)] and a metabolic syndrome screening using the modified criteria of the American National Cholesterol Education Program (NCEP) Treatment Panel III (ATP III). Moreover, CRP, cholesterol, HDL-cholesterol, fasting glucose, triglyceride and leptin levels were measured. 42 patients were reexamined in state of (partial) remission. Depression was reassessed using the 21-item HAMD, and laboratory values were analyzed a second time. 25% of the depressive patients fulfilled the criteria of metabolic syndrome (MS+). Only in the MS+ group, a positive correlation between triglyceride blood levels and severity of depression became evident as well in the state of acute depression as in the state of remission. In the group of patients without metabolic syndrome, laboratory values were not associated with severity of depression. An association between metabolic parameters and the course of depression could only be detected in the group of patients with metabolic syndrome. These findings suggest that, in these patients, a beneficial outcome of depressive illness may improve the metabolic situation.
Subject(s)
Depression/complications , Metabolic Syndrome/complications , Adult , Aged , Female , Follow-Up Studies , Humans , Male , Metabolic Syndrome/blood , Middle Aged , Psychiatric Status Rating Scales , Psychometrics , Retrospective Studies , Triglycerides/blood , Young AdultABSTRACT
Human antigen presenting cells commonly express CD4 but the significance of this phenomenon has not been clarified. We analyzed a panel of Epstein-Barr virus-immortalized B cells (so called lymphoblastoid cell lines, LCL) by using flow cytometry, DNA-microarray analysis, and reverse transcriptase-polymerase chain reaction (RT-PCR). The number of CD4(+) cells varied from cell line to cell line but expression of CD4 was detected by flow cytometry and RT-PCR in all investigated cell lines. To characterize CD4 expressing LCL in more detail, we separated CD4(+) and CD4(-) cells from single cell lines by using immunomagnetic beads. When we cultured sorted CD4(+) and CD4(-) cells, we observed that CD4 expression was stable for several passages. However, the number of CD4(+) cells decreased with time in culture. We never observed that CD4(-) cell lines returned back to a CD4(+) phenotype. DNA-microarray analysis of isolated CD4(+) and CD4(-) cells indicated that the overall gene expression profile of both cell populations was highly similar. In addition, CD4(+) and CD4(-) cells showed the same allostimulatory capacity. CD4(+) LCL showed a slightly increased interleukin-16 induced chemotaxis. Differences in the gene expression profile of CD4(+) and CD4(-) cell lines suggested that loss of CD4 expression occurred during a differentiation step involving achaete-scute complex homolog-like 1.
Subject(s)
B-Lymphocytes/metabolism , Basic Helix-Loop-Helix Transcription Factors/metabolism , CD4 Antigens/metabolism , Herpesvirus 4, Human , Antigens, CD/metabolism , B-Lymphocytes/virology , Cell Line, Tumor , Chemotaxis/drug effects , Chemotaxis/physiology , Gene Expression Profiling , Humans , Interleukin-16/pharmacology , Oligonucleotide Array Sequence AnalysisABSTRACT
Using single-trial parameters as a regressor in the General Linear Model (GLM) is becoming an increasingly popular method for informing fMRI analysis. However, the parameter used to characterise or to differentiate brain regions involved in the response to a particular task varies across studies (e.g. ERP amplitude, ERP latency, reaction time). Furthermore, the way in which the single-trial information is used in the fMRI analysis is also important. For example, the single-trial parameters can be used as regressors in the GLM or to modify the duration of the events modelled in the GLM. The aim of this study was to investigate the BOLD response to a target detection task when including P3 amplitude, P3 latency and reaction time parameters in the GLM. Simultaneous EEG-fMRI was recorded from fifteen subjects in response to a visual choice reaction time task. Including P3 amplitude as a regressor in the GLM yielded activation in left central opercular cortex, left postcentral gyrus, left insula, left middle frontal gyrus, left insula and left parietal operculum. Using P3 latency and reaction time as an additional regressor yielded no additional activation in comparison with the conventional fMRI analysis. However, when P3 latency or reaction time was used to determine the duration of events at a single-trial level, additional activation was observed in the left postcentral gyrus, left precentral gyrus, anterior cingulate cortex and supramarginal gyrus. Our findings suggest that ERP amplitudes and latencies can yield different activation patterns when used to modify relevant aspects of the GLM.
Subject(s)
Choice Behavior/physiology , Electroencephalography/methods , Event-Related Potentials, P300/physiology , Magnetic Resonance Imaging/methods , Pattern Recognition, Visual/physiology , Reaction Time/physiology , Task Performance and Analysis , Adult , Algorithms , Brain Mapping/methods , Female , Humans , Male , Reproducibility of Results , Sensitivity and SpecificityABSTRACT
The long-term problems after kidney transplantation have changed considerably in recent years. While formerly immunosuppression and prevention of acute rejection were of prime concern, now attention focuses on chronic alterations of the transplanted organ and long-term survival of the patients. The transplantation procedure itself has evolved into a standardized technique with a high level of surgical quality. Problems involving organ preservation and ischemia/reperfusion damage also play a role, especially in view of chronic aspects. Monitoring of long-term complications should follow a program for the transplanted organ as well as a program for the patient. Monitoring kidney function should address the organ more precisely than has previously been the case. Serum creatinine level and proteinuria alone provide insufficient information and only change long after cellular deterioration has begun. Hence it is imperative that new testing methods be developed. One possibility is offered by protocol biopsies that allow histological and molecular analysis of the kidney at regular intervals. The patient programs concentrate on diagnostics and treatment of the cardiovascular diseases. Furthermore, the patients must be screened for occurrence of neoplasia. There are no prospective studies covering all cardiovascular risk factors after kidney transplantation. This pertains particularly to the subject of hypertension.
Subject(s)
Graft Occlusion, Vascular/etiology , Graft Rejection/etiology , Kidney Transplantation/adverse effects , Kidney Transplantation/trends , HumansABSTRACT
OBJECTIVE: This study explores the effects of group work intervention on female survivors' senses of guiltlessness, affiliation and hopefulness. METHOD: Secondary comparative analyses of a large quasi-experiment-based clinical data base were accomplished (Richter, Snider, & Gorey): group work intervention (N = 78) and a waiting-list condition (N = 80). RESULTS: Group work was found to have beneficial effects on adult female survivors' appropriate sense of guiltlessness for their childhood sexual abuse, as well as on their sense of affiliation and hopefulness. Consistent across the three outcome measures of guilt/guiltlessness, isolation/affiliation and hopelessness/hopefulness, 16 to 18 of every 20 such women who participated in group work did better than the average woman in the waiting-list comparison group. Moreover, these apparent clinical benefits were maintained for 6 months (all p < .01). CONCLUSION: Such effects may be characterized as very large, and are generally larger than those previously observed in this field of practice that have typically been based on more general measures of depression, self-esteem or global symptoms.
Subject(s)
Attitude , Child Abuse, Sexual/psychology , Guilt , Psychotherapy, Group , Adult , Child , Female , Humans , Self Concept , Treatment OutcomeABSTRACT
Eukaryotic initiation factor (eIF) 4A is a DEAD box RNA helicase that works in conjunction with eIF4B, eIF4H, or as a subunit of eIF4F to unwind secondary structure in the 5'-untranslated region of mRNA, which facilitates binding of the mRNA to the 40 S ribosomal subunit. This study demonstrates how the helicase activity of eIF4A is modulated by eIF4B, eIF4H, or as a subunit of eIF4F. Results indicate that a linear relationship exists between the initial rate or amplitude of unwinding and duplex stability for all factor combinations tested. eIF4F, like eIF4A, behaves as a non-processive helicase. Either eIF4B or eIF4H stimulated the initial rate and amplitude of eIF4A-dependent duplex unwinding, and the magnitude of stimulation is dependent on duplex stability. Furthermore, eIF4A (or eIF4F) becomes a slightly processive helicase in the presence of eIF4B or eIF4H. All combinations of factors tested indicate that the rate of duplex unwinding is equivalent in the 5' --> 3' and 3' --> 5' directions. However, the optimal rate of unwinding was dependent on the length of the single-stranded region of the substrate when different combinations of factors were used. The combinations of eIF4A, eIF4A + eIF4B, eIF4A + eIF4H, and eIF4F showed differences in their ability to unwind chemically modified duplexes. A simple model of how eIF4B or eIF4H affects the duplex unwinding mechanism of eIF4A is proposed.