Telecom-band multiwavelength vertical emitting quantum well nanowire laser arrays.

Highly integrated optoelectronic and photonic systems underpin the development of next-generation advanced optical and quantum communication technologies, which require compact, multiwavelength laser sources at the telecom band. Here, we report on-substrate vertical emitting lasing from ordered InGaAs/InP multi-quantum well core-shell nanowire array epitaxially grown on InP substrate by selective area epitaxy. To reduce optical loss and tailor the cavity mode, a new nanowire facet engineering approach has been developed to achieve controlled quantum well nanowire dimensions with uniform morphology and high crystal quality. Owing to the strong quantum confinement effect of InGaAs quantum wells and the successful formation of a vertical Fabry-Pérot cavity between the top nanowire facet and bottom nanowire/SiO2 mask interface, stimulated emissions of the EH11a/b mode from single vertical nanowires from an on-substrate nanowire array have been demonstrated with a lasing threshold of ~28.2 µJ cm-2 per pulse and a high characteristic temperature of ~128 K. By fine-tuning the In composition of the quantum wells, room temperature, single-mode lasing is achieved in the vertical direction across a broad near-infrared spectral range, spanning from 940 nm to the telecommunication O and C bands. Our research indicates that through a carefully designed facet engineering strategy, highly ordered, uniform nanowire arrays with precise dimension control can be achieved to simultaneously deliver thousands of nanolasers with multiple wavelengths on the same substrate, paving a promising and scalable pathway towards future advanced optoelectronic and photonic systems.

A waveguide-integrated self-powered van der Waals heterostructure photodetector with high performance at the telecom wavelength.

Two-dimensional (2D) materials are attractive candidates for high-performance photodetectors due to their wide operating wavelength and potential to integrate with silicon photonics. However, due to their limited atomic thickness and short carrier lifetime, they suffer from high driving source-drain voltages, weak light-matter interactions and low carrier collection efficiency. Here, we present a high-performance van der Waals (vdWs) heterostructure-based photodetector integrated on a silicon nitride photonic platform combining p-type black phosphorus (BP) and n-type molybdenum disulfide (MoS2). Owing to the efficient carrier separation process and dark current suppression at the junction interface of the vdWs heterostructure, high photodetectivity and a fast response speed can be achieved. A fast response time (∼2.08/3.54 µs), high responsivity (11.26 mA W-1), and a high light on/off ratio (104) operating in the near-infrared telecom band are obtained at zero bias. Our research highlights the great potential of the high-efficiency waveguide-integrated vdWs heterojunction photodetector for integrated optoelectronic systems, such as high-data-rate interconnects operated at standardized telecom wavelengths.

Vertical Emitting Nanowire Vector Beam Lasers.

Due to the peculiar structured light field with spatially variant polarizations on the same wavefront, vector beams (VBs) have sparked research enthusiasm in developing advanced super-resolution imaging and optical communications techniques. A compact VB nanolaser is intriguing for VB applications in miniaturized photonic integrated circuits. However, determined by the diffraction limit of light, it is a challenge to realize a VB nanolaser in the subwavelength scale because the VB lasing modes should have laterally structured distributions. Here, we demonstrate a VB nanolaser made from a 300 nm thick InGaAs/GaAs nanowire (NW). To select the high-order VB lasing mode, a standing NW as-grown from the selective-area-epitaxial (SAE) growth process is utilized, which has a bottom donut-shaped interface with the silicon oxide growth substrate. With this donut-shaped interface as one of the reflective mirrors of the nanolaser cavity, the VB lasing mode has the lowest threshold. Experimentally, a single-mode VB lasing mode with a donut-shaped amplitude and azimuthally cylindrical polarization distribution is obtained. Together with the high yield and uniformity of the SAE-grown NWs, our work provides a straightforward and scalable path toward cost-effective co-integration of VB nanolasers on potential photonic integrated circuits.

Self-frequency-conversion nanowire lasers.

Semiconductor nanowires (NWs) could simultaneously provide gain medium and optical cavity for performing nanoscale lasers with easy integration, ultracompact footprint, and low energy consumption. Here, we report III-V semiconductor NW lasers can also be used for self-frequency conversion to extend their output wavelengths, as a result of their non-centrosymmetric crystal structure and strongly localized optical field in the NWs. From a GaAs/In0.16Ga0.84As core/shell NW lasing at 1016 nm, an extra visible laser output at 508 nm is obtained via the process of second-harmonic generation, as confirmed by the far-field polarization dependence measurements and numerical modeling. From another NW laser with a larger diameter which supports multiple fundamental lasing wavelengths, multiple self-frequency-conversion lasing modes are observed due to second-harmonic generation and sum-frequency generation. The demonstrated self-frequency conversion of NW lasers opens an avenue for extending the working wavelengths of nanoscale lasers, even to the deep ultraviolet and THz range.

Modified Glucose-Insulin-Potassium Regimen Provides Cardioprotection With Improved Tissue Perfusion in Patients Undergoing Cardiopulmonary Bypass Surgery.

Background Laboratory studies demonstrate glucose-insulin-potassium (GIK) as a potent cardioprotective intervention, but clinical trials have yielded mixed results, likely because of varying formulas and timing of GIK treatment and different clinical settings. This study sought to evaluate the effects of modified GIK regimen given perioperatively with an insulin-glucose ratio of 1:3 in patients undergoing cardiopulmonary bypass surgery. Methods and Results In this prospective, randomized, double-blinded trial with 930 patients referred for cardiac surgery with cardiopulmonary bypass, GIK (200 g/L glucose, 66.7 U/L insulin, and 80 mmol/L KCl) or placebo treatment was administered intravenously at 1 mL/kg per hour 10 minutes before anesthesia and continuously for 12.5 hours. The primary outcome was the incidence of in-hospital major adverse cardiac events including all-cause death, low cardiac output syndrome, acute myocardial infarction, cardiac arrest with successful resuscitation, congestive heart failure, and arrhythmia. GIK therapy reduced the incidence of major adverse cardiac events and enhanced cardiac function recovery without increasing perioperative blood glucose compared with the control group. Mechanistically, this treatment resulted in increased glucose uptake and less lactate excretion calculated by the differences between arterial and coronary sinus, and increased phosphorylation of insulin receptor substrate-1 and protein kinase B in the hearts of GIK-treated patients. Systemic blood lactate was also reduced in GIK-treated patients during cardiopulmonary bypass surgery. Conclusions A modified GIK regimen administered perioperatively reduces the incidence of in-hospital major adverse cardiac events in patients undergoing cardiopulmonary bypass surgery. These benefits are likely a result of enhanced systemic tissue perfusion and improved myocardial metabolism via activation of insulin signaling by GIK. Clinical Trial Registration URL: clinicaltrials.gov. Identifier: NCT01516138.

Shape Engineering of InP Nanostructures by Selective Area Epitaxy.

Greater demand for III-V nanostructures with more sophisticated geometries other than nanowires is expected because of the recent intensive investigation of nanowire networks that show great potential in all-optical logic gates, nanoelectronics, and quantum computing. Here, we demonstrate highly uniform arrays of InP nanostructures with tunable shapes, such as membrane-, prism-, and ring-like shapes, which can be simultaneously grown by selective area epitaxy. Our in-depth investigation of shape evolution confirms that the shape is essentially determined by pattern confinement and the minimization of total surface energy. After growth optimization, all of the different InP nanostructures grown under the same growth conditions show perfect wurtzite structure regardless of the geometry and strong and homogeneous photon emission. This work expands the research field in terms of producing nanostructures with the desired shapes beyond the limits of nanowires to satisfy various requirements for nanoelectronics, optoelectronics, and quantum device applications.

Association analysis identifies new risk loci for congenital heart disease in Chinese populations.

Our previous genome-wide association study (GWAS) identified two susceptibility loci for congenital heart disease (CHD) in Han Chinese. Here we identify additional loci by testing promising associations in an extended 3-stage validation consisting of 6,053 CHD cases and 7,410 controls. We find GW significant (P<5.0 × 10(-8)) evidence of 4 additional CHD susceptibility loci at 4q31.22 (rs1400558, upstream of EDNRA, Pall=1.63 × 10(-9)), 9p24.2 (rs7863990, close to SMARCA2, Pall=3.71 × 10(-14)), 12q24.13 (rs2433752, upstream of TBX3 and TBX5, Pall=1.04 × 10(-10)) and 20q12 (rs490514, in PTPRT, Pall=1.20 × 10(-13)). Moreover, the data from previous European GWAS supports that rs490514 is associated with the risk of CHD (P=3.40 × 10(-3)). These results enhance our understanding of CHD susceptibility.

Replication of the 4p16 susceptibility locus in congenital heart disease in Han Chinese populations.

Congenital heart disease (CHD) is the most common form of congenital human birth anomalies and a leading cause of perinatal and infant mortality. Some studies including our published genome-wide association study (GWAS) of CHD have indicated that genetic variants may contribute to the risk of CHD. Recently, Cordell et al. published a GWAS of multiple CHD phenotypes in European Caucasians and identified 3 susceptibility loci (rs870142, rs16835979 and rs6824295) for ostium secundum atrial septal defect (ASD) at chromosome 4p16. However, whether these loci at 4p16 confer the predisposition to CHD in Chinese population is unclear. In the current study, we first analyzed the associations between these 3 single nucleotide polymorphisms (SNPs) at 4p16 and CHD risk by using our existing genome-wide scan data and found all of the 3 SNPs showed significant associations with ASD in the same direction as that observed in Cordell's study, but not with other subtypes- ventricular septal defect (VSD) and ASD combined VSD. As these 3 SNPs were in high linkage disequilibrium (LD) in Chinese population, we selected one SNP with the lowest P value in our GWAS scan (rs16835979) to perform a replication study with additional 1,709 CHD cases with multiple phenotypes and 1,962 controls. The significant association was also observed only within the ASD subgroup, which was heterogeneous from other disease groups. In combined GWAS and replication samples, the minor allele of rs16835979 remained significant association with the risk of ASD (OR = 1.22, 95% CI = 1.08-1.38, P = 0.001). Our findings suggest that susceptibility loci of ASD identified from Cordell's European GWAS are generalizable to Chinese population, and such investigation may provide new insights into the roles of genetic variants in the etiology of different CHD phenotypes.

Highly ordered GaN-based nanowire arrays grown on patterned (100) silicon and their optical properties.

Arrays of GaN-based nanowires have been synthesized on patterned silicon without a catalyst. The spatial density, length and average radius of the nanowires can be well-controlled. The GaN core contains two semipolar facets and a controllable polar facet. The nanowire heterostructures exhibit excellent laser behavior.

A genome-wide association study identifies two risk loci for congenital heart malformations in Han Chinese populations.

Congenital heart malformation (CHM) is the most common form of congenital human birth anomaly and is the leading cause of infant mortality. Although some causative genes have been identified, little progress has been made in identifying genes in which low-penetrance susceptibility variants occur in the majority of sporadic CHM cases. To identify common genetic variants associated with sporadic non-syndromic CHM in Han Chinese populations, we performed a multistage genome-wide association study (GWAS) in a total of 4,225 CHM cases and 5,112 non-CHM controls. The GWAS stage included 945 cases and 1,246 controls and was followed by 2-stage validation with 2,160 cases and 3,866 controls. The combined analyses identified significant associations (P < 5.0 × 10⁻8) at 1p12 (rs2474937 near TBX15; odds ratio (OR) = 1.40; P = 8.44 × 10⁻¹°) and 4q31.1 (rs1531070 in MAML3; OR = 1.40; P = 4.99 × 10⁻¹²). These results extend current knowledge of genetic contributions to CHM in Han Chinese populations.

Enhanced performance of InGaN/GaN based solar cells with an In(0.05)Ga(0.95)N ultra-thin inserting layer between GaN barrier and In(0.2)Ga(0.8)N well.

The effect of ultra-thin inserting layer (UIL) on the photovoltaic performances of InGaN/GaN solar cells is investigated. With UIL implemented, the open-circuit voltage was increased from 1.4 V to 1.7 V, short-circuit current density was increased by 65% and external quantum efficiency was increased by 59%, compared to its counterparts at room temperature under 1-sun AM1.5G illumination. The improvements in electrical and photovoltaic properties are mainly attributed to the UIL which can boost the crystal quality and alleviate strain. Moreover, it can act as a transition layer for higher indium incorporation and an effective light sub-absorption layer in multiple quantum wells.

α-Lipoic acid reduces infarct size and preserves cardiac function in rat myocardial ischemia/reperfusion injury through activation of PI3K/Akt/Nrf2 pathway.

BACKGROUND: The present study investigates the effects and mechanisms of α-Lipoic acid (LA) on myocardial infarct size, cardiac function and cardiomyocyte apoptosis in rat hearts subjected to in vivo myocardial ischemia/reperfusion (MI/R) injury. METHODOLOGY/PRINCIPAL FINDINGS: Male adult rats underwent 30 minutes of ischemia followed by 3, 24, or 72 h of reperfusion. Animals were pretreated with LA or vehicle before coronary artery ligation. The level of MI/R- induced LDH and CK release, infarct size, cardiomyocyte apoptosis and cardiac functional impairment were examined and compared. Western blot analysis was performed to elucidate the mechanism of LA pretreatment. The level of inflammatory cytokine TNF-α released to serum and accumulated in injured myocardium as well as neutrophil accumulation in injured myocardium were also examined after MI/R injury. Our results reveal that LA administration significantly reduced LDH and CK release, attenuated myocardial infarct size, decreased cardiomyocytes apoptosis, and partially preserved heart function. Western blot analysis showed that LA pretreatment up-regulated Akt phosphorylation and Nrf2 nuclear translocation while producing no impact on p38MAPK activation or nitric oxide (NO) production. LA pretreatment also increased expression of HO-1, a major target of Nrf2. LA treatment inhibited neutrophil accumulation and release of TNF-α. Moreover, PI3K inhibition abolished the beneficial effects of LA. CONCLUSIONS/SIGNIFICANCE: This study indicates that LA attenuates cardiac dysfunction by reducing cardiomyoctyes necrosis, apoptosis and inflammation after MI/R. LA exerts its action by activating the PI3K/Akt pathway as well as subsequent Nrf2 nuclear translocation and induction of cytoprotective genes such as HO-1.

Immunostimulatory and anti-neoplasm effects of a novel palindrome CpG oligodeoxynucleotide in mice.

AIM: DNAs containing unmethylated CpG motifs can stimulate innate and adaptive immunity. The aim of this study was to investigate the immunostimulatory and anti-neoplasm effects of a novel CpG oligodeoxynucleotide, ODN10, in tumor-bearing mice. METHODS: B16 melanoma-bearing C57BL/6 mice were administered ip or sc with ODN10 or conventional CpG ODN1826 on the indicated days post inoculation. The animal survival rate and the inhibitory effect on tumor growth were observed in vivo. B and T lymphocyte proliferation, natural killing cell cytotoxicity and the phagocytic ability of peritoneal macrophages from the animals were determined using [(3)H]-thymidine incorporation assay, 4-h (51)Cr release assay and neutral red chromometry method, respectively. The serum levels of IL-12, IL-4 and IgE were quantified using ELISA assays. Histological examination of tumor tissues was performed after HE staining, and the expression of PCNA, CD63, and CD80 in tumor tissues was analyzed with immunohistochemistry. RESULTS: ODN10 (1, 5 and 25 mg/kg) significantly inhibited the growth and metastasis of the tumor, and significantly prolonged the survival of tumor-bearing mice, as compared with ODN1826. The immune status was suppressed in tumor-bearing mice. Both ODN10 and ODN1826 significantly reversed the suppressed immunoactivities in tumor-bearing mice, which included promoting B and T lymphocyte proliferation, enhancing NK cell and peritoneal macrophage activities, inducing IL-12 secretion and inhibiting IL-4 and IgE secretion. Further, CpG ODNs decreased PCNA and CD63 expression while induced expression of CD80. ODN10 presented more potent activity, and displayed the most prominent immunostimulatory potential. CONCLUSION: ODN10 produces prominent immunomodulatory effects on cellular immunity in tumor-bearing mice, which might help reverse the established Th2-type responses to the Th1-type responses, thus may be used as a potent anti-tumor immunotherapy agent or adjuvant.

Carboxy terminus of heat shock protein (HSP) 70-interacting protein (CHIP) inhibits HSP70 in the heart.

Heat shock protein (HSP) 70 plays a critical role in protecting the heart from various stressor-induced cell injuries; the mechanism remains to be further understood. The present study aims to elucidate the effect of a probiotics-derived protein, LGG-derived protein p75 (LGP), in alleviating the ischemia/reperfusion (I/R)-induced heart injury. We treated rats with the I/R with or without preadministration with LGP. The levels of HSP70 and carboxy terminus of HSP70-interacting protein (CHIP) in the heart tissue were assessed by enzyme-linked immunosorbent assay (ELISA) and Western blotting. The effect of CHIP on suppression of HSP70 and the effect of LGP on suppression of CHIP were investigated with an I/R rat model and a cell culture model. The results showed that I/R-induced infarction in the heart could be alleviated by pretreatment with LGP. HSP70 was detected in naïve rat heart tissue extracts. I/R treatment significantly suppressed the level of HSP70 and increased the levels of CHIP in the heart. A complex of CHIP/HSP70 was detected in heart tissue extracts. The addition of recombinant CHIP to culture inhibited HSP70 in heart cells. LGP was bound CHIP in heart cells and prevented the CHIP from binding HSP70. In summary, I/R can suppress HSP70 and increase CHIP in heart cells. CHIP can suppress HSP70 that can be prevented by pretreatment with LGP. The results imply that CHIP may be a potential target in the prevention of I/R-induced heart cell injury.

Heparanase DNA vaccine delivered by electroporation induces humoral immunity and cytoimmunity in animal models.

Electroporation (EP)-assisted DNA vaccination has been proven effective as an approach to the treatment of cancer. Although heparanase (HPA) is a potential target for patients with advanced tumor diseases, the efficacy of immunotherapeutic strategies targeting HPA has never been evaluated. In this study, humoral immunity was elicited using genetic vaccinations between C57BL/6J mice and Macaca fascicularis. The immunized serum neutralized HPA activity and attenuated the invasion of B16 cells in vitro. In addition, T lymphocytes from the splenic cells of the immunized mice induced HPA-specific cytotoxic lymphocytes (CTLs), which verified cytoimmunity. Prophylactic vaccination significantly suppressed tumor growth and metastasis in vivo and prolonged the survival rate in tumor-bearing murine models. In addition, RT-PCR and Western blot analyses of the primary tumors indicated less proliferation and angiogenesis and more apoptosis in the HPA-immunization immunotherapy groups. Simultaneously, the levels of IL-2, IL-4, and IFN-γ were not significantly greater in the HPA-immunized group than in PBS controls. Thus, we conclude that the combination of an anti-HPA antibody and a CTL response in HPA-immunization gene therapy is enough to attenuate tumor growth and metastasis. This is the first time that a DNA vaccine targeting HPA immunization assisted by EP has induced humoral immunity and cytoimmunity in vivo. This provides a basis for the continued development of DNA vaccines targeting HPA and the use of such vaccines in clinical settings.

Deletion of RBP-J in adult mice leads to the onset of aortic valve degenerative diseases.

Transcription factor RBP-J-mediated Notch signaling has been implicated in several inherited cardiovascular diseases including aortic valve diseases (AVD). But whether Notch signal plays a role in AVD in adults has been unclear. This study aims to test whether the deletion of RBP-J in adult mice would lead to AVD and to investigate the underlying mechanisms. Cre-LoxP-mediated gene deletion was employed to disrupt Notch signal in adult mice. Immunofluorescence and electron microscope observations showed that deletion of RBP-J in adult mice led to early morphological changes of AVD. The size of aortic valve was enlarged. The endothelial homeostasis was perturbed, probably due to the up-regulation of VEGFR2. The endothelial cells exhibited increased proliferation and loose endothelial junctions. The valvular mesenchyme displayed significant fibrosis, consistent with the up-regulation of TGF-ß1 and activation of endothelial-mesenchymal transition. We observed melanin-producing cells in aortic valves. The number of melanin-producing cells increased significantly, and their location changed from the mesenchyme to subendothelial layer of valve cusps in RBP-J deficient mice. These results suggest that RBP-J-mediated Notch signaling in aortic valves may be critically involved in valve homeostasis and valve diseases as well. These findings will be helpful for the understanding of the molecular mechanisms of AVD in adults.

Correction of tetralogy of fallot with combination of operative and interventional methods.

A one-stage repair was planned for an 11-year-old boy with tetralogy of Fallot. After initial attempts to wean from cardiopulmonary bypass were unsuccessful, an atrial septal defect and a ventricular septal defect were created in order to achieve hemodynamic stability. The boy recovered from the operation but had large volume of chest drainage. Transthoracic echocardiography revealed left to right shunting at both atrial and ventricular levels. Interventional catheter-directed devices were used to repair the residual shunts successfully in the catheterization laboratory.

Totally thoracoscopic surgical resection of cardiac myxoma in 12 patients.

Myxomas are the most common type of primary cardiac tumors. We report our use of totally thoracoscopic surgery in resecting cardiac myxomas in 12 cases with 10 in the left atria and 2 in the right atria. Totally thoracoscopic surgical resection of myxoma was successfully performed in all cases through three minimal incisions, with the largest incision less than 3 cm. The cardiopulmonary bypass time was 96 to 126 minutes, and the aortic cross-clamp time was 46 to 63 minutes. Postoperative ventilation assistance was 3 to 11 hours. We show that the method is safe and achieves complete tumor resection.

Spontaneous dissection of left anterior descending coronary artery: the diagnostic role of dual-source computed tomography.

Spontaneous coronary artery dissection is usually diagnosed by an urgent coronary angiography. We report a case of spontaneous coronary artery dissection of the left anterior descending coronary artery, which was diagnosed by dual-source computed tomography. Subsequent coronary angiography confirmed the result. Computed tomographic coronary angiography can be a complementary diagnostic tool for the assessment of coronary artery dissection.

Surgical treatment of severe complications caused by transcatheter closure of ventricular septal defects.

The objective was to report the surgical results following failed transcatheter intervention for closure of ventricular septal defects (VSDs). This study is a retrospective analysis of patients (n = 9) from Xijing Hospital (Xi'an, China) with failed transcatheter intervention for VSDs who subsequently underwent open heart surgery. Five patients experienced complications during transcatheter intervention, including third-degree atrioventricular block (III° AVB) (n = 2), aortic incompetence (n = 2), or tricuspid incompetence (n = 1). The devices were immediately removed in the catheterization laboratory followed by open heart surgery to repair VSDs. Four patients experienced complications after transcatheter intervention; one patient's device was displaced into the right ventricle, and 3 patients had III° AVB. These patients underwent surgery to retrieve the devices and to repair VSDs. All cardiac surgery was performed under general anesthesia and under cardiopulmonary bypass. Postoperatively, all patients recovered uneventfully with no deaths or complications. The patients with III° AVB after device implantation recovered sinus rhythm postoperatively, and tricuspid apparatus injuries were surgically repaired with valvuloplasty. Transcatheter interventional VSD closure is safe and effective, but only under the conditions of strict patient selection, proper technique, and device application. Once severe complications are observed and diagnosed, devices should be retrieved immediately, and open heart surgery should be performed to avoid further injury.