Transparent thin thermoplastic biochip by injection-moulding and laser transmission welding

Recently microfluidic devices have emerged as a viable technology for the miniaturization of high throughput tools for analytical tasks related to structural biology such as screening of crystallization conditions and structural analysis. This work reports the manufacture of microfluidic chips in transparent thermoplastic polymers [poly(methylmethacrylate) (PMMA), and cyclic olefin copolymer (COC)] using two complementary technologies, injection moulding for the fabrication of the fluidic level and laser transmission welding for the sealing of the cover. A steel mould insert was produced by laser micro caving using a solid state laser radiation source (Nd:YAG, wavelength 1,064 nm). Fluidic chips of ~670 μm thickness comprising channels of 50 μm depth and width down to 50 μm were injection moulded in PMMA and COC. Joining of transparent thin cover film to the micro-injected fluidic level was performed by laser transmission welding using high power diode laser radiation (wavelength 940 nm) and an intermediate thin absorbing layer with a thickness of about several nanometers.     

Depression and conduct disorder in native and non-native children

OBJECTIVE: To compare depression and conduct disorder symptoms between North American Native and non-Native children as rated by teacher, parent, and self-reports. METHOD: The sample included 1,251 Native children in grades 2 and 4 in four different settings across North America and comparison samples of 457 non-Native children. Parents, teachers, and children rated children's mental health using culturally sensitive measures of depression and conduct disorder symptoms. RESULTS: According to parent ratings and child self-reports, there were no Native/non-Native differences in levels of conduct disorder symptoms. However, non-Native teachers rated higher levels of conduct disorder symptoms among Native children compared with non-Native students. Children reported higher levels of depression than the adults rating them. CONCLUSIONS: Results challenge assertions about high levels of psychopathology among Native youngsters. Cultural distance may introduce a negative bias in teacher evaluations of Native children's mental health.     

Resting EEG in first-episode and chronic schizophrenia

Prostatic acid phosphatase, prostate-specific antigen, and zinc as markers of prostate, and fructose as marker of seminal vesicles were investigated in the seminal plasma of 35 idiopathic asthenozoospermic and 20 normal subjects to evaluate their relationship with sperm motility. Total seminal plasma levels of the three prostatic markers and, to a lesser extent, total fructose levels were lower in asthenozoospermic patients, and in all the pooled subjects, the same levels were directly correlated with the motility of ejaculated spermatozoa. When the levels of the biochemical markers were expressed as concentrations in seminal plasma, only prostatic acid phosphatase levels remained lower in asthenozoospermic patients and they maintained a direct correlation with sperm motility in all the pooled subjects. The PAP/Zn/Fr (representing the ratio between PAP concentration and free Zn available for spermatozoan uptake) was lower in asthenozoospermic patients and it was also directly related to sperm motility in all the pooled subjects. These data suggest that altered sperm motility is associated with a probable impairment of sex accessory gland function in subjects with idiopathic asthenozoospermia, while prostatic acid phosphatase seems mainly related to sperm motility.     

Impairment of autonomically mediated heart rate control in patients with cardiac dysfunction

Patients with cardiac disorders have defective parasympathetic control of heart rate. To evaluate the possibility of similar changes in sympathetic control of heart rate, we compared reflex chronotropic responses to 80 degree upright tilt and nitroglycerin-induced hypotension in 31 cardiac patients and 7 normal individuals before and after partial parasympathetic blockade with atropine. Tilting revealed an attenuation of the normal heart rate increase in patients; the magnitude of this defect was greatest in patients with more severe symptoms (class III) and evidence of left ventricular dysfunction (the heart rate increase averaged 25 plus or minus 3 beats/min in normal subjects, 12 plus or minus 2 beats/min in class I-II patients, and 7 plus or minus 1 beats/min in class III patients). Class III symptoms due to mechanical causes (mitral stenosis), however, were not associated with this defect. A marked reduction in heart rate rise with hypotension was seen only in those class III patients without mitral stenosis (0.4 plus or minus 0.1 beats min-minus 1 mm Hg-minus 1 vs. 3.0 plus or minus 0.5 beats min-minus 1 mm Hg-minus 1 in normal subjects). This abnormality also persisted after atropine administration, thus confirming a defect in the sympathetic as well as the parasympathetic component of baroreceptor-mediated reflex heart rate control in patients with cardiac dysfunction. Infusions of isoproterenol produced equivalent rises in heart rate in patients and normal individuals, excluding a reduction in beta-receptor responsiveness as a cause of impaired sympathetic influence. Norepinephrine depletion, however, is a well-recognized concomitant of cardiac failure. It is possible that the reduction in sympathetically mediated heart rate responses results in part from depletion of the sympathetic neurotransmitter.     

Bayes prediction for the number of failures of a repairable system

After observing a repairable system for some time, one may wish to predict the number of failures of the system in some fixed future interval. Such a prediction depends on the: (1) assumed model for the failure process; and (2) length of the interval. The authors use a Bayes approach to obtain point and interval predictions for the number of failures in a future interval. Two situations are discussed: (1) the power law process (PLP) governs failure times during the period of observation, but in the future interval the homogeneous Poisson Process (HPP) governs the failure times; and (2) the failure process is the PLP. A rationale and an example of each situation is presented. They discuss the use of informative and noninformative priors for the parameters of the failure process. The Bayes approach can incorporate both sources of uncertainty: (1) the number of failures in the future interval is random, so even if the parameters of the failure process are known, the number of failures that would occur in a future interval would still not predict with certainty; and (2) the parameters of the failure process are not known and must be estimated from the observed data     

Intellectual decline after stroke: the Framingham Study

BACKGROUND AND PURPOSE: The causes and characteristics of cognitive decline after stroke are poorly defined, because most studies have relied on the diagnosis of dementia after stroke, without measurement of prestroke cognitive function. METHODS: The Mini-Mental State Examination (MMSE) was used to assess the cognitive performance of 74 subjects from the Framingham Study cohort who had suffered a stroke during a 13-year period. We compared their poststroke cognitive performance with the prestroke MMSE scores collected during their biennial examinations, and their prestroke/poststroke changes in MMSE score were then compared with those of 74 control subjects matched for age and sex. Cases and controls underwent testing for symptoms of depression using the Center for Epidemiologic Studies of Depression (CES-D) scale, and these findings were correlated with their cognitive performance. Changes in cognitive performance in the cases were correlated with the CT-documented characteristics of the stroke. RESULTS: The cases had a significantly lower mean+/-SE MMSE score at prestroke baseline (27.28+/-0.34) than did the control subjects (28.08+/-0.21), a difference that became more pronounced (23.57+/-0.92 versus 28.31+/-0.25; P<.001) after stroke. The poststroke decline in cognitive function in the cases was correlated only with a large, left-sided stroke on CT. The CES-D scores were significantly higher in the cases, but nondepressed cases had significantly lower MMSE scores than nondepressed controls. CONCLUSIONS: Stroke is followed by a significant decline in cognitive performance when prestroke and poststroke measurements are compared. Although depression is more frequent in the stroke patients, their intellectual decline appears to be independent from the presence of depression.     

The observer's temporal scope.

Comments on the article of P. E. Freedman et al (see record 1974-24406-001) in which the most basic law of learning theory, the law of effect, is explored. An attempt is made to understand how a reinforced response can be identified. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Smooth-pursuit eye tracking in first-episode psychotic patients and their relatives.

In order to determine the specificity of smooth-pursuit eye tracking dysfunction to schizophrenia (SC) and the prevalences of dysfunction among functionally psychotic and normal individuals, the authors investigated pursuit tracking in a large sample of psychotic patients, normal Ss, and 1st-degree relatives (N?=?482). Ss were recruited as part of an epidemiological study of 1st-episode psychosis that used a broadly based referral network to identify all cases in a major metropolitan area over a 2.5-yr period. Ss received diagnoses of SC, schizophreniform disorder, psychotic mood disorder, and paranoid or other psychotic disorder based on the Diagnostic and Statistical Manual of Mental Disorders (DSM-III). The distribution of tracking performance was bimodal for the SC Ss and their relatives, perhaps reflecting major gene action. Moreover, poor tracking ran in families. Pursuit tracking dysfunction was relatively specific to SC Ss and their relatives and occurred infrequently in other psychotic Ss and normal Ss. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Handedness in first-episode psychotic patients and their first-degree biological relatives.

We evaluated the handedness of 58 schizophrenia patients and 54 of their relatives, 23 patients with major depression with psychosis and 24 of their relatives, 36 patients with bipolar psychosis and 33 of their relatives, and 119 nonpsychiatric Ss and 42 of their relatives. Computerized tomography measures were also available for a subset of the psychotic patients. The schizophrenia patients were significantly more left-handed than any of the other groups, and increased sinistrality was also associated with larger lateral ventricle to brain area ratios. The relatives of the schizophrenia patients did not significantly differ on handedness from either the relatives of the affective psychosis patients or the nonpsychiatric Ss. Findings do not support the notion that left-handedness in schizophrenia is genetically influenced. More research with larger family member data sets is warranted to further explore this possibility. (PsycINFO Database Record (c) 2010 APA, all rights reserved)