Single mode operation of impurity-induced disordering large area vertical cavity surface emitting lasers

Vertical-cavity surface-emitting lasers (VCSELs) with suitable interdiffusion quantum wells profile by the use of selective impurity-induced disordering is proposed for high power single mode operation in large area devices. It is shown that the transverse optical confinement in the quantum well active region formed by the diffusion profile counteracts the influence of carrier spatial hole burning for VCSELs biased at high injection current. Results indicate that a single mode operation can be maintained in VCSELs with the diameter of core region equal to 50µm.published_or_final_versio

High-power single-mode operation in DFB and FP lasers using diffused quantum-well structure

Distributed feedback (DFB) and Fabry-Perot (FP) semiconductor lasers with step and periodic interdiffusion quantum-well structures are proposed for high-power single-longitudinal-mode operation. It is shown that the phase-adjustment region formed by the diffusion step (i.e., step change in optical gain and refractive index) counteracts the influence of spatial hole burning, especially for DFB lasers with large coupling-length products biased at high injection current. Furthermore, it is found that with careful design of the diffusion grating (i.e., grating period and amount of diffusion extent) of FP lasers, side-mode suppression ratio can be enhanced and threshold current density can be minimized to a satisfied level.published_or_final_versio

Vertical-cavity surface-emitting semiconductor lasers with diffusedquantum wells

A self-consistent dynamic model is developed including the current distribution, carrier diffusion rate and spatial hole burning effects to investigate the modulation response of vertical-cavity surface-emitting lasers with diffused quantum wells structure. It is found that the overall performance including relaxation oscillation frequency and modulation bandwidth is improved.published_or_final_versio

Why do battered women abuse their children? Explore and discussion

Congress Theme: New Directions in Child Protection and WellbeingOBJECTIVES: A strong association between the occurrences of imitate partner violence and child abuse is confirmed in studies. This study therefore aims to explore the associated factors of battered women being violent towards their children and its implication on the service development for the family at risk. The different characteristics among abused women without and with children at different ages will be examined. This study can enrich knowledge on child protection, especially in families with multiple types ...postprin

Fabry Perot semiconductor lasers with periodic diffused quantum wells structure

Fabry Perot semiconductor laser with periodic change in the extent of interdiffusion along the longitudinal direction of the quantum well active region is proposed to improve the discrimination between cavity modes.published_or_final_versio

The Origin of Meridians

This article explores the origin of meridians. It suggests that the origin of meridians is closely related to the imageries derived by ancient physicians experiencing the circulation of Qi in their bodies during Qigong practice. Based on the cognitive experience from Qigong practice, as well as the symbolic analogy of the flow of rivers and the irrigation system of agriculture, the meridian theory has constructed a model of Qi and blood circulation. Such model is abstract and yet concrete, dialectic and yet intuitive, definite and yet vague, integrated and yet independent, having profound influence on the overall formation of traditional Chinese medicine theories.published_or_final_versio

Performance study of an ultrasonic transducer used for wire bonding

Version of RecordPublishe

Sensors for automatic process control of wire bonding

Version of RecordPublishe

Dynamics of an ultrasonic transducer used for wire bonding

Version of RecordPublishe

Use of Doppler ultrasound renal resistive index and neutrophil gelatinase-associated lipocalin in prediction of acute kidney injury in patients with septic shock

Poster PresentationThis journal suppl. contain meeting abstracts of the 31st International Symposium on Intensive Care and Emergency MedicineINTRODUCTION: Acute kidney injury (AKI) is common in septic shock and there is no good marker to predict it. Neutrophil gelatinase-associated lipocalin (NGAL) is a novel renal biomarker showing promising results in prediction of AKI in patients across diff erent clinical settings. Another potential marker is the resistive index (RI) of renal interlobar artery (calculated as (peak systolic velocity – end diastolic velocity) / peak systolic velocity), which has been shown to be useful in identifying those who will develop AKI in patients with septic shock. The aim of this study is to evaluate the usefulness of RI and NGAL in the early detection of AKI. METHODS: A prospective, observational study in a 20-bed medical/surgical ICU of a university teaching hospital. All patients with septic shock were recruited, excluding those with chronic renal failure (serum creatinine >120 μmol/l). Within the fi rst 24 hours after the introduction of vasopressor, urine and serum were collected for NGAL measurement and RI was determined by two independent operators. The occurrence of AKI was measured at day 3, according to RIFLE criteria. RI and NGAL were compared between patients with (RIFLE-F) and without (RIFLE-0/R/I) AKI. RESULTS: During the period from August to November 2010, 20 patients (age 58 ± 16) with septic shock were recruited. Eleven patients were classifi ed as having AKI. No signifi cant diff erence in baseline characteristics such as APACHE II score and baseline creatinine was shown at enrollment. RI, serum-NGAL and urine-NGAL were all higher in patients with AKI (RI: 0.749 ± 0.0697 (mean ± SD) vs. 0.585 ± 0.0983, P <0.001; serum-NGAL: 2,182 ± 838 ng/ml (mean ± SD) vs. 1,075 ± 1,006, P = 0.015; urine-NGAL: 2,009 ± 3,370 vs. 993 ± 1,789 (median ± IQR), P = 0.025). Area under the ROC curve for RI and serum-NGAL was 0.909 (±0.088, P = 0.002) and 0.808 (±0.113, P = 0.02), respectively. For RI, using 0.65 as the cut-off , sensitivity and specifi city was 1 and 0.89, respectively. For serum-NGAL, using a cut-off of 1,200 ng/ml, it had a sensitivity of 1 and specifi city of 0.67. Inter-observer diff erence of RI was low (0.0015 ± 0.0074 (mean ± SD)). CONCLUSIONS: Doppler ultrasound renal RI is non-invasive, rapidly available and easily reproducible, and is at least as good as NGAL as a predictor of AKI in patients with septic shock.link_to_OA_fulltextThe 31st International Symposium on Intensive Care and Emergency Medicine, Brussels, Belgium. 22-25 March 2011. In Critical Care, 2011, v. 15 suppl 1, p. 539, abstract no. P10