A Coupled Cavity Micro Fluidic Dye Ring Laser

We present a laterally emitting, coupled cavity micro fluidic dye ring laser, suitable for integration into lab-on-a-chip micro systems. The micro-fluidic laser has been successfully designed, fabricated, characterized and modelled. The resonator is formed by a micro-fluidic channel bounded by two isosceles triangle mirrors. The micro-fluidic laser structure is defined using photo lithography in 10 microns thick SU-8 polymer on a glass substrate. The micro fluidic channel is sealed by a glass lid, using PMMA adhesive bonding. The laser is characterized using the laser dye Rhodamine 6G dissolved in ethanol or ethylene glycol as the active gain medium, which is pumped through the micro-fluidic channel and laser resonator. The dye laser is optically pumped normal to the chip plane at 532 nm by a pulsed, frequency doubled Nd:YAG laser and lasing is observed with a threshold pump pulse energy flux of around 55 micro-Joule/square-milimeter. The lasing is multi-mode, and the laser has switchable output coupling into an integrated polymer planar waveguide. Tuning of the lasing wavelength is feasible by changing the dye/solvent properties.Comment: Accepted for Microelectronic Engineerin

Exploring 'The autisms' at a cognitive level

The autism spectrum is characterized by genetic and behavioral heterogeneity. However, it is still unknown whether there is a universal pattern of cognitive impairment in autism spectrum disorder (ASD) and whether multiple cognitive impairments are needed to explain the full range of behavioral symptoms. This study aimed to determine whether three widely acknowledged cognitive abnormalities (Theory of Mind (ToM) impairment, Executive Function (EF) impairment, and the presence of a Local Processing Bias (LB)) are universal and fractionable in autism, and whether the relationship between cognition and behavior is dependent on the method of behavioral assessment. Thirty-one high-functioning children with ASD and thirty-seven children with neurotypical development (NTD), comparable in age, gender and Intelligence Quotient (IQ), completed several tasks tapping into ToM, EF, and LB, and autistic symptomatology was assessed through parental and teacher questionnaires, parental interview and direct observation. We found that ToM and EF deficits differentiated the groups and some ToM and EF tasks were related to each other. ToM and EF were together able to correctly classify more than three-quarters of the children into cases and controls, despite relating to none of the specific behavioral measures. Only a small subgroup of individuals displayed a LB, which was unrelated to ToM and EF, and did not aid diagnostic classification, most likely contributing to non-diagnostic symptoms in a subgroup. Despite the characteristic heterogeneity of the autism spectrum, it remains a possibility therefore that a single cognitive cause may underlie the range of diagnostic symptoms in all individuals with autism

Concentrating and labeling genomic DNA in a nanofluidic array

Genomic DNA is concentrated in a dense nanofluidic array and labeled by a polymerase ϕ29 reaction where neither the DNA nor the enzyme is attached to a solid support.</p

Early-Onset Schizophrenia: Exploring the Contribution of the Thought Disorder Index to Clinical Assessment

Background: Differentiating diagnostically between schizophrenia and emotional and personality disorders with psychotic or psychotic-like symptoms is a challenging task. It is especially difficult when working with adolescent patients, because their symptoms tend to manifest at lower levels as compared with adult patients. Thought disorder is a core symptom of schizophrenia, and the Rorschach Inkblot Method is widely used for the assessment of formal thought disorder. Objective: In this study, which is situated within ongoing clinical practice, we investigated whether the Rorschach test is helpful for assessing early-onset schizophrenia due to its ability to detect thought disorder. We also wanted to examine whether the Thought Disorder Index (TDI) is superior to the Comprehensive System (CS) for differentiating between patients with early-onset schizophrenia and non-psychotic patients experiencing auditory and visual hallucinations. An additional aim was to examine whether the TDI correlated with the Positive and Negative Syndrome Scale (PANSS). Methods: Twenty-three subjects between the ages of 12 and 18 years were examined with the use of the Rorschach test, and the protocols were scored according to both the TDI and the CS. All subjects were also assessed with the Positive and Negative Syndrome Scale. The sample included 14 subjects who fulfilled the criteria for schizophrenia and 9 subjects who were experiencing hallucinations that emanated from severe emotional and relational problems but who had different non-psychotic disorders. Results: Although the two groups could not be distinguished with regard to their total scores for thought disorder, the identification of specific thought disorder types proved useful for differential diagnosis. Verbalizations that were categorized by the TDI as “absurd responses,” “fluidity,” “contamination,” “autistic logic,” and “word-finding difficulty” were only given by patients who had been diagnosed with schizophrenia. When patients’ responses were scored with the use of the CS, the “contamination” score was the only one found to be specific to schizophrenia. Conclusions: Although the sample size limits the conclusions that can be drawn, the results indicate that the TDI may be superior to the CS for the identification of thought disorder specific to—but not always present in—adolescents with schizophrenia. In other words, the absence of severe thought disorder is not synonymous with the absence of severe psychopathology, but the presence of the most severe thought disorder types (i.e., “absurd responses,” “fluidity,” “incoherence,” “contamination,” and “autistic logic”) seems to be a strong indicator of schizophrenic psychopathology