Optical Transceiver Chips Based on Co-Integration of Capacitively Coupled Proximity Interconnects and VCSELs

Combining the strengths of both proximity communication and optical communication, a new hybrid input-output (I/O) platform delivers on-chip bandwidth off-chip and over distance. We demonstrate, for the first time, a four-channel hybrid I/O interface by integrating proximity communication and vertical-cavity surface-emitting-laser-based parallel optical interconnects on the same commercial 90-nm complementary metal-oxide-semiconductor platform. The optical I/O can operate at 5 Gb/s per channel, and the complete hybrid I/O interface achieved 2.5 Gb/s per channel. We characterize the I/O link performance for various data rates and chip separations, and show 10-mum chip separation tolerance for proximity communication     

Time-frequency analysis using the matching pursuit algorithm applied to seizures originating from the mesial temporal lobe

A Spanish-language questionnaire designed for measuring the impact of asthma on quality of life in adults was developed. It was derived, by the application of a rigorous translation protocol, from a previously validated, English-language Asthma Quality of Life (AQL) questionnaire which had been developed in Australia. The aim of this study was to evaluate the psychometric properties of the Spanish AQL questionnaire using a cross-sectional and longitudinal design. Two hundred ninety-four clinically stable subjects with asthma (168 women, mean baseline forced expiratory volume in 1 sec [FEV1] = 85% predicted), aged 17-70, attended for the initial baseline assessment. All subjects completed the AQL questionnaire and a full history and physical examination were performed. The clinical assessment of severity was based on the classification recommended by the Global Initiative on Asthma (GINA). One week after the initial assessment subjects completed the AQL questionnaire for a second time. Six months later, subjects were assessed clinically and completed all the assessment measures at baseline. Principal components analysis of the AQL questionnaire responses at the baseline visit revealed a structure that was almost identical to that seen in the original English-language questionnaire. The questionnaire was shown to be internally consistent (Cronbach's alpha 0.91 for total score and 0.80-0.86 for the four subscales) and repeatable (intraclass correlation coefficient 0.91 for the total scale and 0.78-0.92 for the subscales). The finding of expected strong correlations with the subject's global assessment of severity (p = 0.70) and dyspnea (p = 0.63), a weak inverse correlation with FEV1 (p = -0.17), and good discrimination among the four GINA severity categories (F3,291 = 37.16, p < 0.0001) supports the construct validity of the questionnaire. AQL scores increased with age (p = 0.31) and were higher in women (p < 0.005). The AQL was responsive to both improvement (mean change 1.02, p < 0.0001) and deterioration (mean change -1.13, p < 0.001) in the severity of asthma over a 6-month period. This disease-specific, Spanish-language AQL questionnaire was shown to have sound psychometric properties which make it suitable for use in cross-sectional or longitudinal studies where it is appropriate to assess the impact of asthma on the quality of life of individual patients.     

Nonepileptic posttraumatic seizures

BACKGROUND: The aim of this experimental study was to evaluate the risk of tumor recurrence after laparoscopic cecal resection (LCR) of colonic carcinoma in the rat. METHODS: The experimental cancer consisted of one million cells (DHK/K12), incorporated in an extracellular matrix, placed and secured to the cecal serosa in 110 BD9 rats. Four weeks later, all animals were reoperated through a laparotomy to control tumor growth, and animals with diffuse carcinomatosis were excluded. Eligible animals were randomized either to laparoscopic cecal resection (group LCR, n = 10), to open resection (group OCR, n = 13), or to a control group without resection (group C, n = 13). Resection was always considered as macrocopically complete. All animals were killed 4 weeks after the resection to determine the tumor recurrence and quantify carcinomatosis. RESULTS: We noted diffuse carcinomatosis in 70% of rats in groups C and LCR versus 23% in group OCR (p = 0.038). For tumors noted as S- (not extending outside the serosa), diffuse carcinomatosis was observed in all animals of group C (3 of 3), in 6 of 8 in group LCR, and 0 of 6 in group OCR (p = 0.004). The rate of port site or incisional metastases was not significantly different between groups. CONCLUSIONS: These preliminary results demonstrated the deleterious impact of the laparoscopy for resection of large bowel malignancy. LCR increased significantly the incidence of a diffuse carcinomatosis even when performed for locally noninvasive tumors (S-).     

Improved Buffer Amplifier for Incorporation Within a Biopotential Electrode

An amplifier for an active electrode is described which requires only a two-conductor connecting cable, is current limiting for patient safety, and has essentially unity voltage gain. In addition, the output impedance is lower and the input impedance has more adjustment latitude than is possible with a conventional source follower.     

Electrocardiogram Recording with Pasteless Electrodes

Experimentation regarding various aspects of a technique for recording electrocardiographic potentials from unprepared skin, without the use of conventional paste, is described. Because of the relatively high skin-to-electrode impedances encountered without electrolytic paste, high input impedance amplifiers must be utilized for acquisition of the signal. In order to minimize susceptibility to external electrostatic and electromagnetic interference, an inherent problem with high input impedance amplifiers, buffer amplifiers were incorporated directly within the electrode housing. Of the different metals tested, stainless steel proved to be the most stable skin contact material for pasteless operation. The integrated electrode-buffer amplifiers described comply with specifications of the American Heart Association and should prove useful as a direct replacement for conventional paste-type electrodes in existing clinical EKG equipment as well as for long-term applications such as space missions and intensive-care-unit patient monitoring, where frequent attention to the electrodes is inconvenient.     

Comparative antihypertensive effects of propranolol and metoprolol in DOC-treated rats

The effects of chronic twice daily s.c. injections of dlpropranolol, metoprolol and d-propranolol on systolic blood pressure and heart rate were assessed in conscious DOC-saline hypertensive rats. Measurements were taken (tail-cuff) 4 hr after the morning injection and 16-18 hr after the afternoon injection during 11 of 19 consecutive treatment days. Only dl-propranolol and metoprolol at 5 mg/kg lowered blood pressure and heart rate significantly relative to the changes occurring in control saline-injected animals. At the lower dose of 0.2 mg/kg, both agents tended to decrease heart rate while having little or no effect on blood pressure. The overall blood pressure and heart rate changes produced by propranolol at 5 mg/kg differed significantly from those of the control group at both the 4 and 16-18 hr post-dosing intervals. Metoprolol at 5 mg/kg produced significant overall changes in blood pressure and heart rate only at the 4 hr post-doing interval. D-propranolol had no effect on either blood pressure or heart rate. The results indicate tha s.c. propranolol and metoprolol lower systolic blood pressure in conscious DOC-saline hypertensive rats only at the higher dose of 5 mg/kg and that cardioselectivity does not afford increased antihypertensive activity in this model.     

Bioconjugated PLGA-4-arm-PEG branched polymeric nanoparticles as novel tumor targeting carriers

In this study, we have developed a novel carrier, micelle-type bioconjugated PLGA-4-arm-PEG branched polymeric nanoparticles (NPs), for the detection and treatment of pancreatic cancer. These NPs contained 4-arm-PEG as corona, and PLGA as core, the particle surface was conjugated with cyclo(arginine-glycine-aspartate) (cRGD) as ligand for in vivo tumor targeting. The hydrodynamic size of the NPs was determined to be 150-180 nm and the critical micellar concentration (CMC) was estimated to be 10.5 mg l( - 1). Our in vitro study shows that these NPs by themselves had negligible cytotoxicity to human pancreatic cancer (Panc-1) and human glioblastoma (U87) cell lines. Near infrared (NIR) microscopy and flow cytometry demonstrated that the cRGD conjugated PLGA-4-arm-PEG polymeric NPs were taken up more efficiently by U87MG glioma cells, over-expressing the α(v)β(3) integrin, when compared with the non-targeted NPs. Whole body imaging showed that the cRGD conjugated PLGA-4-arm-PEG branched polymeric NPs had the highest accumulation in the pancreatic tumor site of mice at 48 h post-injection. Physical, hematological, and pathological assays indicated low in vivo toxicity of this NP formulation. These studies on the ability of these bioconjugated PLGA-4-arm-PEG polymeric NPs suggest that the prepared polymeric NPs may serve as a promising platform for detection and targeted drug delivery for pancreatic cancer.     

High contrast in vitro and in vivo photoluminescence bioimaging using near infrared to near infrared up-conversion in Tm3+ and Yb3+ doped fluoride nanophosphors

A new approach for photoluminescence imaging in vitro and in vivo has been shown utilizing near infrared to near infrared (NIR-to-NIR) up-conversion in nanophosphors. This NIR-to-NIR up-conversion process provides deeper light penetration into biological specimen and results in high contrast optical imaging due to absence of an autofluorescence background and decreased light scattering. Aqueous dispersible fluoride (NaYF4) nanocrystals (20-30 nm size) co-doped with the rare earth ions, Tm(3+) and Yb(3+), were synthesized and characterized by TEM, XRD, and photoluminescence (PL) spectroscopy. In vitro cellular uptake was shown by the PL microscopy visualizing the characteristic emission of Tm(3+) at approximately 800 nm excited with 975 nm. No apparent cytotoxicity was observed. Subsequent animal imaging studies were performed using Balb-c mice injected intravenously with up-converting nanophosphors, demonstrating the high contrast PL imaging in vivo.