Power-efficient III-V/silicon external cavity DBR lasers

We report the design and characterization of external-cavity DBR lasers built with a III-V-semiconductor reflective-SOA with spot-size converter edge-coupled to SOI waveguides containing Bragg grating mirrors. The un-cooled lasers have wall-plug-efficiencies of up to 9.5% at powers of 6 mW. The lasers are suitable for making power efficient, hybrid WDM transmitters in a CMOS-compatible SOI optical platform.

[Investigation on differential diagnostic value of multi-index detection of pleural effusion.]

BACKGROUND

To study the roles of adenosine deaminase (ADA) , interferon gamma ( IFN-gamma) and carcinoembryonic antigen(CEA) for diagnosis of tuberculous and neoplastic pleural effusion.

METHODS

ADA , IFN-gamma and CEA activity in the serum and pleural fluid were detected in 67 patients with pleural effusion by the method of Guisti , a solid-phase enzyme-immunoassay employing the multiple antibody sandwich principle , and radioimmunoassay respectively.

RESULTS

The mean ADA and IFN-gamma concentration in the tuberculous pleural effusion differed significantly from those in the neoplastic pleural effusion ( P < 0. 001) . The mean CEA concentration in the serum and pleural fluid with the neoplastic pleural effusion differed from those with the tuberculous pleural effusion ( P < 0. 05) . The sensitivity of ADA (with a diagnostic threshold of 40 U/L) and IFN-gamma(threshold of 140 pg/ mL) for tuberculosis was 88 % and 96 % respectively , the specificity was 85. 71 % and 97. 62 % , and diagnostic index was 73. 71 % and 93. 62 %. Using the ADA (with below 40 U/L) and IFN-gamma (below 140 pg/mL) and CEA (above 15mug/L) , we achieved a specificity of 95. 95 %for diagnosis of neoplastic pleural effusion.

CONCLUSIONS

ADA , IFN-gamma and CEA are useful parameters in differential diagnosis of tuberculous and neoplastic pleural effusion.

Induction of alloimmune tolerance in heart transplantation through gene silencing of TLR adaptors

Toll-like receptors (TLRs) activate biochemical pathways that evoke activation of innate immunity, which leads to dendritic cell (DC) maturation and initiation of adaptive immune responses that provoke allograft rejection. We aimed to prolong allograft survival by selectively inhibiting expression of the common adaptors of TLR signaling, namely MyD88 and TRIF, using siRNA. In vitro we demonstrated that blocking expression of MyD88 and TRIF led to reduced DC maturation. In vivo treatment of recipients with MyD88 and TRIF siRNA significantly prolonged allograft survival in the BALB/c > C57BL6 cardiac transplant model. Moreover, the combination of MyD88 and TRIF siRNA along with a low dose of rapamycin further extended the allograft survival (88.8 ± 7.1 days). Tissue histopathology demonstrated an overall reduction in lymphocyte interstitium infiltration, vascular obstruction and hemorrhage in mice treated with MyD88 and TRIF siRNA vector plus rapamycin. Furthermore, treatment was associated with an increase in the numbers of CD4(+) CD25(+) FoxP3(+) regulatory T cells and Th2 deviation. To our knowledge, this study is the first demonstration of prolonging the survival of allogeneic heart grafts through gene silencing of TLR signaling adaptors, highlighting the therapeutic potential of siRNA in clinical transplantation.

Estimating elasticity for residential electricity demand in China

Residential demand for electricity is estimated for China using a unique household level dataset. Household electricity demand is specified as a function of local electricity price, household income, and a number of social-economic variables at household level. We find that the residential demand for electricity responds rather sensitively to its own price in China, which implies that there is significant potential to use the price instrument to conserve electricity consumption. Electricity elasticities across different heterogeneous household groups (e.g., rich versus poor and rural versus urban) are also estimated. The results show that the high income group is more price elastic than the low income group, while rural families are more price elastic than urban families. These results have important policy implications for designing an increasing block tariff.

Computational modeling of phonatory dynamics in a tubular three-dimensional model of the human larynx

Simulation of the phonatory flow-structure interaction has been conducted in a three-dimensional, tubular shaped laryngeal model that has been designed with a high level of realism with respect to the human laryngeal anatomy. A non-linear spring-based contact force model is also implemented for the purpose of representing contact in more general conditions, especially those associated with three-dimensional modeling of phonation in the presence of vocal fold pathologies. The model is used to study the effects of a moderate (20%) vocal-fold tension imbalance on the phonatory dynamics. The characteristic features of phonation for normal as well as tension-imbalanced vocal folds, such as glottal waveform, glottal jet evolution, mucosal wave-type vocal-fold motion, modal entrainment, and asymmetric glottal jet deflection have been discussed in detail and compared to established data. It is found that while a moderate level of tension asymmetry does not change the vibratory dynamics significantly, it can potentially lead to measurable deterioration in voice quality.

Sox2 targets cyclinE, p27 and survivin to regulate androgen-independent human prostate cancer cell proliferation and apoptosis

OBJECTIVES

Sox2 is a major transcription factor and the transforming growth factor-α (TGF-α)/EGFR autocrine loop is a hallmark of prostate cancer progression. In this study, we have evaluated the effects and potential mechanisms of Sox2 on cell proliferation and apoptosis, and investigated effects of TGF-α on expression of Sox2 on androgen-independent human prostate cancer cells.

MATERIALS AND METHODS

Expression of Sox2 has been determined by RT-PCR, western blot analysis and immunocytochemistry, using RNAi and over-expression strategy to study functions of Sox2 in DU145 and PC-3 cells. Changes in level of proliferation, cell cycle and apoptosis profiles were measured by MTT, colony-forming, bromodeoxyuridine incorporation assays, cell cycle and annexin V analysis.

RESULTS

Sox2 was expressed in six human prostate cancer cell lines, and its inhibition reduced cell proliferation and induced apoptosis in DU145 cells. We have shown that knock-down of Sox2 inhibited G(1) to S phase transition concomitantly with down-regulation of cyclin E and up-regulation of p27 proteins. Conversely, over-expression of Sox2 led to the opposite effect in PC-3 cells but its inhibition induced apoptosis by down-regulation of survivin in DU145 cells. We also found that TGF-α up-regulated Sox2 and survivin protein expression via the EGFR/PI3K/AKT pathway.

CONCLUSIONS

Sox2 expression is necessary for cell proliferation and evasion of apoptosis in prostate cancer cells and TGF-α could regulate Sox2 and survivin expression by activating the EGFR/PI3K/AKT pathway.

Comparative study of different surgical transposition methods for ulnar nerve entrapment at the elbow

This study compared the therapeutic effects of two techniques for surgical decompression treatment for ulnar nerve entrapment at the elbow: subcutaneous transposition and modified submuscular transposition with Z-lengthening of the pronator teres origin. A total of 278 patients with ulnar nerve entrapment (McGowan grades I - III) were randomly assigned to undergo one of these techniques. All patients were followed-up for 2 years. The effects were assessed by preoperative and postoperative cross-sectional area, motor conduction velocity, sensory conduction velocity and nerve action potential. All of these parameters improved after surgery in both groups. For patients with grade I disease, there were no significant differences between the two techniques. For patients with grade II and III disease, modified submuscular transposition was associated with significantly greater improvements compared with subcutaneous transposition. In conclusion, subcutaneous ulnar nerve transposition is recommended for grade I patients and modified submuscular ulnar nerve transposition for grade II and III patients.

Measurement of the neutron radius of 208Pb through parity violation in electron scattering

We report the first measurement of the parity-violating asymmetry A(PV) in the elastic scattering of polarized electrons from 208Pb. A(PV) is sensitive to the radius of the neutron distribution (R(n)). The result A(PV)=0.656±0.060(stat)±0.014(syst) ppm corresponds to a difference between the radii of the neutron and proton distributions R(n)-R(p)=0.33(-0.18)(+0.16) fm and provides the first electroweak observation of the neutron skin which is expected in a heavy, neutron-rich nucleus.

New precision limit on the strange vector form factors of the proton

The parity-violating cross-section asymmetry in the elastic scattering of polarized electrons from unpolarized protons has been measured at a four-momentum transfer squared Q2 = 0.624  GeV2 and beam energy E(b) = 3.48  GeV to be A(PV) = -23.80 ± 0.78(stat) ± 0.36(syst) parts per million. This result is consistent with zero contribution of strange quarks to the combination of electric and magnetic form factors G(E)(s) + 0.517G(M)(s) = 0.003 ± 0.010(stat) ± 0.004(syst) ± 0.009(ff), where the third error is due to the limits of precision on the electromagnetic form factors and radiative corrections. With this measurement, the world data on strange contributions to nucleon form factors are seen to be consistent with zero and not more than a few percent of the proton form factors.

New measurements of high-momentum nucleons and short-range structures in nuclei

We present new measurements of electron scattering from high-momentum nucleons in nuclei. These data allow an improved determination of the strength of two-nucleon correlations for several nuclei, including light nuclei where clustering effects can, for the first time, be examined. The data also include the kinematic region where three-nucleon correlations are expected to dominate.

Beam-target double-spin asymmetry A{LT} in charged pion production from deep inelastic scattering on a transversely polarized {3}He target at 1.4<Q{2}<2.7 GeV{2}

We report the first measurement of the double-spin asymmetry A{LT} for charged pion electroproduction in semi-inclusive deep-inelastic electron scattering on a transversely polarized {3}He target. The kinematics focused on the valence quark region, 0.16<x<0.35 with 1.4<Q{2}<2.7  GeV{2}. The corresponding neutron A{LT} asymmetries were extracted from the measured {3}He asymmetries and proton over {3}He cross section ratios using the effective polarization approximation. These new data probe the transverse momentum dependent parton distribution function g{1T}{q} and therefore provide access to quark spin-orbit correlations. Our results indicate a positive azimuthal asymmetry for π{-} production on {3}He and the neutron, while our π{+} asymmetries are consistent with zero.

Socioeconomic status and children with intellectual disability in China

BACKGROUND

Intellectual disability (ID) accounts for 70% of all disabilities among children in China's Second National Sampling Survey on Disability. Although studies have shown a relationship between social class and ID in children, none have investigated the association of socioeconomic variables in Chinese children with mild or severe ID.

METHODS

Data for children aged 0-6 years with and without ID were abstracted from the Second National Sampling Survey on Disability in China, conducted in 2006. Crude odds ratios showed the effect of sociodemographic factors on mild and severe ID. Adjusted odds ratios (OR(a) ) (95% confidence intervals) estimated the independent effects of these factors.

RESULTS

For both mild and severe ID, risk of having ID increased with male sex, birth to a woman aged 35 years and older, lower maternal education, mother's older age at delivery, lower income and rural residence. After age, gender and parent disability were controlled, mothers aged 35 years and older were more likely to have a child with ID: mild ID, OR(a) 1.47 (1.15-1.88); severe ID, OR(a) 1.32 (1.00-1.73). There was an approximate increasing monotonic risk of severe ID with increasing socioeconomic disadvantage: lowest income, OR(a) 3.00 (2.19-4.12); low income, OR(a) 2.28 (1.63-3.19); lower middle income, OR(a) 1.72 (1.27-2.33); middle income, OR(a) 1.73 (1.28-2.36).

CONCLUSIONS

There is a significant relationship between sociodemographic factors and ID. Similar patterns were found for both mild and severe ID. Recommendations are given for preventing ID in Chinese children.

The role of chiral local field enhancements below the resolution limit of Second Harmonic Generation microscopy

While it has been demonstrated that, above its resolution limit, Second Harmonic Generation (SHG) microscopy can map chiral local field enhancements, below that limit, structural defects were found to play a major role. Here we show that, even below the resolution limit, the contributions from chiral local field enhancements to the SHG signal can dominate over those by structural defects. We report highly homogeneous SHG micrographs of star-shaped gold nanostructures, where the SHG circular dichroism effect is clearly visible from virtually every single nanostructure. Most likely, size and geometry determine the dominant contributions to the SHG signal in nanostructured systems.

Evaluation of the significance of circulating insulin-like growth factor-1 and C-reactive protein in patients with chronic obstructive pulmonary disease

OBJECTIVES

This study in patients with chronic obstructive pulmonary disease (COPD) investigated whether acute exacerbation of COPD (AECOPD) and clinically stable COPD (CSCOPD) are associated with changes in circulating insulin-like growth factor-1 (IGF-1) and C-reactive protein (CRP) concentrations, and whether changes in IGF-1 and CRP levels are related to changes in the indicators of malnutrition and muscle wasting.

METHODS

A total of 61 patients with AECOPD, 43 patients with CSCOPD and 20 healthy age-matched controls were included in the study. Circulating IGF-1 and CRP levels, together with erythrocyte sedimentation rate and indicators of malnutrition and muscle wasting, were measured in all the study participants.

RESULTS

Circulating IGF-1 levels were significantly lower and CRP levels significantly higher in COPD patients than in controls. In addition, IGF-1 levels were significantly lower and CRP levels significantly higher in AECOPD patients than in CSCOPD patients. In COPD patients, indicators of malnutrition and muscle wasting (weight, body mass index, thigh circumference and albumin level) were significantly positively correlated with logIGF-1; thigh circumference and albumin level were significantly inversely correlated with logCRP.

CONCLUSION

Circulating IGF-1 and CRP levels may have potential as indicators of exacerbation, malnutrition and muscle wasting in patients with COPD.

Treatment of angiostrongyliasis using a combination of albendazole and dexamethasone: the results of a retrospective and comparative study

As the information available on the treatment of angiostrongyliasis with a combination of albendazole and dexamethasone is limited, the efficacy of such therapy was assessed using data collected during the 2006 outbreak of angiostrongyliasis in Beijing. In a retrospective and controlled study, 35 patients treated with albendazole-dexamethasone (given 20 mg albendazole/kg and 3 mg dexamethasone daily for 7 days) were compared with 34 controls who were treated only symptomatically (with acetaminophen or other drugs). Compared with the controls, the patients given the combination were less likely to have headaches after 7 days (P = 0·038), tended to have headaches that cleared quicker (P = 0·010), and received fewer doses of acetaminophen (P = 0·036). Since no serious adverse effects were observed, a 1-week treatment with a combination of albendazole and dexamethasone appears both safe and beneficial in the treatment of angiostrongyliasis.