Monolithically integrated 112 Gbps PAM4 optical transmitter and receiver in a 45†nm CMOS-silicon photonics process.

We demonstrate a transmitter and receiver in a silicon photonics platform for O-band optical communication that monolithically incorporates a modulator driver, traveling-wave Mach-Zehnder modulator, control circuitry, photodetector, and transimpedance amplifier (TIA) in the GlobalFoundries Fotonix (45SPCLO) platform. The transmitter and receiver show an open 112 Gbps PAM4 eye at a 4.3 pJ/bit energy efficiency, not including the laser. Extensive use of gain-peaking enables our modulator driver and TIA to achieve the high bandwidths needed in the 45 nm CMOS-silicon photonics process. Our results suggest an alternative to the frequent approach of bump-bonding BiCMOS drivers and TIAs to silicon photonics.

Common gray matter loss in the frontal cortex in patients with methamphetamine-associated psychosis and schizophrenia.

BACKGROUND AND HYPOTHESIS: Methamphetamine (MA)-associated psychosis has become a public concern. However, its mechanism is not clear. Investigating similarities and differences between MA-associated psychosis and schizophrenia in brain alterations would be informative for neuropathology. STUDY DESIGN: This study compared gray matter volumes of the brain across four participant groups: healthy controls (HC, n = 53), MA users without psychosis (MA, n = 22), patients with MA-associated psychosis (MAP, n = 34) and patients with schizophrenia (SCZ, n = 33). Clinical predictors of brain alterations, as well as association of brain alterations with psychotic symptoms and attention impairment were further investigated. STUDY RESULTS: Compared with the HC, the MAP and the SCZ showed similar gray matter reductions in the frontal cortex, particularly in prefrontal areas. Moreover, a stepwise extension of gray matter reductions was exhibited across the MA - MAP - SCZ. Duration of abstinence was associated with regional volumetric recovery in the MAP, while this amendment in brain morphometry was not accompanied with symptom's remission. Illness duration of psychosis was among the predictive factors of regional gray matter reductions in both psychotic groups. Volume reductions were found to be associated with attention impairment in the SCZ, while this association was reversed in the MAP in frontal cortex. CONCLUSIONS: This study suggested MA-associated psychosis and schizophrenia had common neuropathology in cognitive-related frontal cortices. A continuum of neuropathology between MA use and schizophrenia was tentatively implicated. Illness progressions and glial repairments could both play roles in neuropathological changes in MA-associated psychosis.

Random Gauge Field Scattering in Monolayer Graphene.

Strain-induced lattice deformation affects electron hopping between the atoms. This effectively gives rise to a gauge field which impacts on the charge transport. In graphene, such gauge field is associated with a vector potential which mimics that of a magnetic field. Understanding the impact of the gauge field on charge transport is of essential importance for emerging topics including straintronics and valleytronics in two-dimensional materials. While extensive theoretical works have been carried out over the past decade, experimental progress has been largely limited to local probe and optical studies. Experimental charge transport study has been baffled by the challenge in creating an effective and independent tuning knob of strain without compromising the quality of graphene. Here we studied high quality suspended graphene field effect transistors fabricated on flexible Polyimide substrates. Applying uniaxial strain by bending the substrate, we observed a strain-induced resistivity with power-law carrier density dependence. The power factor is found to be correlated with the surface fractal dimension of the rippled graphene, in good agreement with the random gauge field scattering theory. Both phase coherent transport and magnetotransport properties are found to be strain-dependent, which can be understood in terms of a strain-tunable disorder.

Bulk signatures of pressure-induced band inversion and topological phase transitions in Pb(1-x)Sn(x)Se.

The characteristics of topological insulators are manifested in both their surface and bulk properties, but the latter remain to be explored. Here we report bulk signatures of pressure-induced band inversion and topological phase transitions in Pb(1-x)Sn(x)Se (x=0.00, 0.15, and 0.23). The results of infrared measurements as a function of pressure indicate the closing and the reopening of the band gap as well as a maximum in the free carrier spectral weight. The enhanced density of states near the band gap in the topological phase gives rise to a steep interband absorption edge. The change of density of states also yields a maximum in the pressure dependence of the Fermi level. Thus, our conclusive results provide a consistent picture of pressure-induced topological phase transitions and highlight the bulk origin of the novel properties in topological insulators.

[Expression of TGF-ß1 and PAI-1 in premature infants with bronchopulmonary dysplasia].

OBJECTIVE: To study the expression of transforming growth factor-ß1 (TGF-ß1) and plasminogen activator inhibitor-1 (PAI-1) and its significance in premature infants with bronchopulmonary dysplasia (BPD). METHODS: A retrospective analysis was performed on the clinical data of 96 very low birth weight infants (gestational age of ≤ 32 weeks) who survived for more than 28 days and were admitted to the Neonatal Intensive Care Unit between January 2010 and December 2012. These subjects were divided into BPD group (n=21) and non-BPD group (n=75). The expression of TGF-ß1 and PAI-1 in blood was measured by ELISA. RESULTS: The levels of TGF-ß1 and PAI-1 in the BPD group increased gradually from the 7th day to the 14th day and then to the 21st day after birth, and were significantly higher than in the non-BPD group at all time points (P<0.01). The TGF-ß1 and PAI-1 levels in the non-BPD group on the 7th, 14th, and 21st days after birth were not significantly different from each other (P>0.05). CONCLUSIONS: The expression of TGF-ß1 and PAI-1 in blood is elevated in premature infants with BPD, which may be associated with the development of BPD.

Expression of TGF-β1 and PAI-1 in premature infants with bronchopulmonary dysplasia / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To study the expression of transforming growth factor-β1 (TGF-β1) and plasminogen activator inhibitor-1 (PAI-1) and its significance in premature infants with bronchopulmonary dysplasia (BPD).</p><p><b>METHODS</b>A retrospective analysis was performed on the clinical data of 96 very low birth weight infants (gestational age of ≤ 32 weeks) who survived for more than 28 days and were admitted to the Neonatal Intensive Care Unit between January 2010 and December 2012. These subjects were divided into BPD group (n=21) and non-BPD group (n=75). The expression of TGF-β1 and PAI-1 in blood was measured by ELISA.</p><p><b>RESULTS</b>The levels of TGF-β1 and PAI-1 in the BPD group increased gradually from the 7th day to the 14th day and then to the 21st day after birth, and were significantly higher than in the non-BPD group at all time points (P<0.01). The TGF-β1 and PAI-1 levels in the non-BPD group on the 7th, 14th, and 21st days after birth were not significantly different from each other (P>0.05).</p><p><b>CONCLUSIONS</b>The expression of TGF-β1 and PAI-1 in blood is elevated in premature infants with BPD, which may be associated with the development of BPD.</p>

[Survey of psychological health of parents of children with malignant tumor].

OBJECTIVE: To understand the psychological problems of parents of children with malignant tumor so as to provide them with adequate psychological healthcare service. METHODS: A questionnaire-based survey was conducted in 68 parents of children with malignant tumor using an internationally standard anxiety scale. RESULTS: The 68 parents had a mean score of 44.68+/-11.26 for the scale with 6.42+/-2.25 anxiety symptoms on average. The average anxiety score of the mothers was 58.38+/-8.85, and 53.30+/-9.17 for the fathers, showing obviously difference (P<0.05). The average anxiety score of the parents with positive attitudes for treatment was 55.07+/-8.91, and that for the parents who gave up treatment for economic reasons was 66.71+/-4.50, with also significant difference (P<0.001). CONCLUSION: The parents of children with malignancies almost invariably show anxiety symptom of different degrees, which can be attributed to their gender and economic status.