A Primary Report 166 Cases of Abdominal or Pelvic Neuroblastoma Surgery Utilizing the International Neuroblastoma Surgical Report Form (INSRF).

BACKGROUND AND AIMS: Surgery is pivotal in the management of neuroblastoma (NB), particularly in patients with Image-Defined Risk Factors (IDRFs). The International Neuroblastoma Surgical Report Form (INSRF) was introduced to enhance surgical reporting quality and analyze the defining role of extensive surgery in NB. This study reports our experience with INSRF and explores new criteria for evaluating the extent of surgical resection. METHODS: INSRF was deployed to critically analyze 166 patients with abdominal or pelvic NB who underwent surgery at our department between October 2021 and June 2023. Patient demographics, clinical characteristics, surgical datasets, and postoperative complications were described in detail. Receiver operating characteristic (ROC) curves were used to explore a new method to evaluate the extent of resection. A questionnaire was formulated to obtain attitudes/feedback and commentary from surgical oncologists with INSRF. RESULTS: 166 neuroblastoma patients with a median disease age 36.50 months. This study collated 320 INSRF reports. Among the 166 index cases, 137 were documented by two surgeons, with a concordance rate of 16.78%. Items with high inconsistency were (i) the extent of tumor resection (29.20%), (ii) renal vein involvement (25.55%), (iii) abdominal aorta encasement (16.79%), and (iv) mesenteric infiltration (17.52%). According to INSRF, the extent of resection was complete excision in 86 (51.81%) patients, minimal residual tumor < 5 cm3 in 67 (40.36%) patients, and incomplete excision > 5 cm3 in 13 (7.83%) patients. In ROC curve analysis, the number of vessels encased by tumors > 3 had a high predictive value in determining that a tumor could not be completely resected (AUC 0.916, sensitivity 0.838, specificity 0.826) using INSRF as the gold standard reference. The questionnaires showed that surgeons agreed that the extent of resection and tumor involvement of organ/vascular structures were important, while the definition and intervention(s) of intraoperative complications were less operational and understandable. CONCLUSIONS: INSRF has significant clinical application in neuroblastoma surgery. The extent of resection can be predicted based on the number of tumor-encased blood vessels. Supplementary information should be considered with the INSRF to aid practitioner reporting. Multicenter studies are needed to explore the defining role of INSRF in NB surgical management.

Risk factors, impact and treatment of postoperative lymphatic leakage in children with abdominal neuroblastoma operated on by laparotomy.

BACKGROUND: Lymphatic leakage is one of the postoperative complications of neuroblastoma. The purpose of this study is to summarize the clinical characteristics and risk factors of lymphatic leakage and try to find effective prevention and treatment measures. METHODS: A retrospective study included 186 children with abdominal neuroblastoma, including 32 children of lymphatic leakage and 154 children of non-lymphatic leakage. The clinical information, surgical data, postoperative abdominal drainage, treatment of lymphatic leakage and prognosis of the two groups were collected and analyzed. RESULTS: The incidence of lymphatic leakage in this cohort was 14% (32 children). Through univariate analysis of lymphatic leakage group and non-lymphatic leakage group, we found that lymphatic leakage increased the complications, prolonged the time of abdominal drainage and hospitalization, and delayed postoperative chemotherapy (p < 0.05). In this cohort, the median follow-up time was 46 (95% CI: 44-48) months. The follow-up data of 7 children were partially missing. 147 children survived, of which 23 had tumor recurrence (5 children recurred in the surgical area). 37 children died, of which 32 had tumor recurrence (9 children recurred in the operation area). In univariate analysis, there was no statistical difference in overall survival (p = 0.21) and event-free survival (p = 0.057) between lymphatic leakage group and non-lymphatic leakage group, while 3-year cumulative incidence of local progression was higher in lymphatic leakage group (p = 0.015). However, through multivariate analysis, we found that lymphatic leakage did not affect event-free survival, overall survival and cumulative incidence of local progression in children with neuroblastoma. Resection of 5 or more lymphatic regions was an independent risk factor for lymphatic leakage after neuroblastoma surgery. All 32 children with lymphatic leakage were cured by conservative treatment without surgery. Of these, 75% (24/32) children were cured by fat-free diet or observation, 25% (8/32) children were cured by total parenteral nutrition. The median drain output at diagnosis in total parenteral nutrition group was higher than that in non-total parenteral nutrition group (p < 0.001). The cut-off value was 17.2 ml/kg/day. CONCLUSIONS: Lymphatic leakage does not affect the prognosis of children with neuroblastoma, but long-term drain output caused by lymphatic leakage will still adversely affect postoperative complications and follow-up treatment, which requires attention and active treatment measures. More attention should be paid to the children with 5 or more lymphatic regions resection, and the injured lymphatic vessels should be actively found and ligated after tumor resection to reduce the postoperative lymphatic leakage. Early application of total parenteral nutrition is recommended for those who have drain output at diagnosis of greater than 17.2 ml/kg/day. LEVEL OF EVIDENCE: Level III, Treatment study (Retrospective comparative study).

{[In2S7]8-}∞ Chain and Isolated HgS4 Planar Unit Constructed One-Dimensional Pentanary Sulfide K2Ba7HgIn4S16 Exhibiting Nonlinear-Optical Activity.

Hg-based chalcogenides possess diverse structures, large nonlinear-optical (NLO) responses, and suitable birefringences, making them potentially suitable for numerous crucial criteria of practical application as infrared (IR) NLO crystals. Here, a new pentanary Hg-based sulfide K2Ba7HgIn4S16 has been discovered by a high-temperature solid-state method. It crystallizes in the orthorhombic P21212 space group, and its one-dimensional structure is constructed by {[In2S7]8-}∞ chains and isolated [HgS4]6- planar quadrilateral units located bewteeen the chains, representing a novel type of chalcogenide. K2Ba7HgIn4S16 exhibits a moderate NLO effect of 0.5 × AGS at 2.1 µm and a high laser-induced damage threshold of ∼5.8 × AGS, as well as a band gap of 2.98 eV, demonstrating that K2Ba7HgIn4S16 is a potential IR NLO material. This work enriches the structural chemistry of chalcogenides and the family of Hg-based IR NLO chalcogenides.

Safety and feasibility of laparoscopic resection of abdominal neuroblastoma without image-defined risk factors: a single-center experience.

OBJECTIVE: To explore the criteria, safety and efficacy of laparoscopic surgery in pediatric neuroblastoma (NB). METHODS: A retrospective study of 87 patients with NB without image-defined risk factors (IDRFs) between December 2016 and January 2021 at Beijing Children's Hospital was conducted. Patients were divided into two groups according to the surgical procedure. RESULTS: Between the 87 patients, there were 54 (62.07%) cases in the open surgery group and 33 (37.93%) cases in the laparoscopic surgery group. There were no significant differences between the two groups regarding demographic characteristics, genomic and biological features, operating time or postoperative complications. However, in terms of intraoperative bleeding (p = 0.013) and the time to start postoperative feeding after surgery (p = 0.002), the laparoscopic group was obviously better than the open group. Furthermore, there was no significant difference in the prognosis between the two groups, and no recurrence or death was observed. CONCLUSION: For children with localized NB who have no IDRFs, laparoscopic surgery could be performed safely and effectively. Surgeons who are skilled in this can help children reduce surgical injuries, speed up postoperative recovery, and obtain the same prognosis as open surgery.

Clinical risk factors for patients with ruptured hepatoblastoma in children: a retrospective study from a single center in China.

OBJECTIVE: Hepatoblastoma (HB) tumor rupture is a high-risk criterion in the International Childhood Liver Tumors Strategy Group (SIOPEL) 3/4 protocol. However, the causes and risk factors for HB rupture are still unknown, and whether tumor rupture is an independent risk factor for HB prognosis is still controversial. The purpose of this study was to retrospectively analyze the clinical characteristics of children with HB tumor rupture and to search for clinical risk factors to conduct early prediction and intervention. METHODS: We conducted a retrospective study of 27 patients with HB rupture between July 2009 and July 2019. To further identify the risk factors for HB rupture, we included 97 nonruptured HB patients from January 2013 to January 2019. We searched for potentially useful characteristics for HB rupture by univariate and multivariate logistic regression analyses. RESULTS: There were 27 patients with HB rupture, with the median age of 31 (12, 69) months. Nineteen cases (70.37%) were spontaneous tumor rupture, 1 case (3.70%) was posttraumatic rupture, 2 cases (7.41%) were tumor rupture after the biopsy, and 5 cases (18.52%) were tumor rupture after chemotherapy. After the tumor rupture, 4 patients died of hemorrhagic shock and multiple organ dysfunction syndrome (MODS), 4 patients refused further therapy and were discharged against medical advice, and the remaining 19 patients were stable after emergency treatment. After the treatment, 14 patients survived without disease, 2 patients died, and 3 patients were lost to follow-up. The median follow-up was 48 (33, 60) months, the 3-year overall survival (OS) was 54.7%. Compared with the non-tumor rupture group by multivariate logistic regression analysis, it was found that the maximum diameter of the primary tumor > 13.4 cm, and vascular invasion were independent risk factors for tumor rupture. CONCLUSION: HB rupture is rare, but it seriously threatens the life and health of children. In the acute phase of tumor rupture, surgery, rescue chemotherapy, transcatheter arterial embolization (TAE) and other supportive care can be adopted. Large tumors and vascular invasion are risk factors for HB rupture. LEVEL OF EVIDENCE: Level IV.

Sciatic nerve block downregulates the BDNF pathway to alleviate the neonatal incision-induced exaggeration of incisional pain via decreasing microglial activation.

Sciatic nerve block is under investigation as a possible therapeutic strategy for neonatal injury-induced exaggeration of pain responses to reinjury. Spinal microglial priming, brain-derived neurotrophic factor (BDNF) and Src homology-2 domain-containing protein tyrosine phosphatase-2 (SHP2) participate in exaggerated incisional pain induced by neonatal incision. However, effects of sciatic nerve block on exacerbated incisional pain and underlying mechanisms remain unclear. Here, we demonstrated that sciatic nerve block alleviates pain hypersensitivity and microglial activation in rats subjected to neonatal incision and adult incision (nIN-IN). Chemogenetic activation or inhibition of spinal microglia attenuates or mimics effects of sciatic nerve block on pain hypersensitivity, respectively. Moreover, α-amino-3-hydroxy- 5-methy- 4-isoxazole propionate (AMPA) receptor subunit GluA1 contributes to the exaggeration of incisional pain. The inhibition of BDNF or SHP2 blocks upregulations of downstream molecules in nIN-IN rats. Knockdown of SHP2 attenuates the increase of GluA1 induced by injection of BDNF in adult rats with only neonatal incision. The inhibition of microglia or ablation of microglial BDNF attenuates upregulations of SHP2 and GluA1. Additionally, sciatic nerve block downregulates the expression of these three molecules. Upregulation of BDNF, SHP2 or AMPA receptor attenuates sciatic nerve block-induced reductions of downstream molecules and pain hypersensitivity. Microglial activation abrogates reductions of these three molecules induced by sciatic nerve block. These results suggest that decreased activation of spinal microglia contributes to beneficial effects of sciatic nerve block on the neonatal incision-induced exaggeration of incisional pain via downregulating BDNF/SHP2/GluA1-containing AMPA receptor signaling. Thus, sciatic nerve block may be a promising therapy.

Clinical parameters combined with radiomics features of PET/CT can predict recurrence in patients with high-risk pediatric neuroblastoma.

BACKGROUND: This retrospective study aimed to develop and validate a combined model based [18F]FDG PET/CT radiomics and clinical parameters for predicting recurrence in high-risk pediatric neuroblastoma patients. METHODS: Eighty-four high-risk neuroblastoma patients were retrospectively enrolled and divided into training and test sets according to the ratio of 3:2. [18F]FDG PET/CT images of the tumor were segmented by 3D Slicer software and the radiomics features were extracted. The effective features were selected by the least absolute shrinkage and selection operator to construct the radiomics score (Rad_score). And the radiomics model (R_model) was constructed based on Rad_score for prediction of recurrence. Then, univariate and multivariate analyses were used to screen out the independent clinical risk parameters and construct the clinical model (C_model). A combined model (RC_model) was developed based on the Rad_score and independent clinical risk parameters and presented as radiomics nomogram. The performance of the above three models was assessed by the area under the receiver operating characteristic curve (AUC) and decision curve analysis (DCA). RESULTS: Seven radiomics features were selected for building the R_model. The AUCs of the C_model in training and test sets were 0.744 (95% confidence interval [CI], 0.595-0.874) and 0.750 (95% CI, 0.577-0.904), respectively. The R_model yielded AUCs of 0.813 (95% CI, 0.685-0.916) and 0.869 (95% CI, 0.715-0.985) in the training and test sets, respectively. The RC_model demonstrated the largest AUCs of 0.889 (95% CI, 0.794-0.963) and 0.892 (95% CI, 0.758-0.992) in the training and test sets, respectively. DCA demonstrated that RC_model added more net benefits than either the C_model or the R_model for predicting recurrence in high-risk pediatric neuroblastoma. CONCLUSIONS: The combined model performed well for predicting recurrence in high-risk pediatric neuroblastoma, which can facilitate disease follow-up and management in clinical practice.

Design and 3D FEM Analysis of a Flexible Piezoelectric Micromechanical Ultrasonic Transducer Based on Sc-Doped AlN Film.

In this paper, a flexible piezoelectric micromachined ultrasonic transducer (PMUT) based on Scandium (Sc)-doped Aluminum Nitride (AlN) film was designed and modeled by the three-dimensional finite element method (3D-FEM). The resonant frequency of 218.1 kHz was reported. It was noticeable that a high effective electromechanical coupling coefficient (k2eff) of 1.45% was obtained when a combination of a flexible PI and a thin Si layer was used as the PMUT supporting structure layer. Compared with a pure Si supporting layer counterpart, the coupling coefficient had been improved by 110.68%. Additionally, the increase of Sc doping concentration in AlN film further enhanced the device electromechanical coupling coefficient and resulted in an improvement for transmitting/receiving sensitivity of the proposed flexible PMUT. When the doping concentration of Sc reached 30%, the emission sensitivity was as large as 1.721 µm/V, which was 2.86 times greater than that of conventional AlN film-based PMUT. The receiving sensitivity was found to be 2.11 V/KPa, which was as high as 1.23 times the performance of an undoped device. Furthermore, the bending simulation result showed that the proposed flexible PMUT device can maintain a good mechanical stability when the bending radius is greater than 1.5 mm. The simulation of sound field characteristics demonstrated that the flexible PMUT based on AlScN could receive stable sound pressure signals under the bending radius of 1.5 cm.

Current status in the discovery of dual BET/HDAC inhibitors.

The development of desired multitarget agents may provide an attractive and cost-effective complement or alternative to drug combinations. Bromodomain and extraterminal domain (BET) and histone deacetylase (HDAC), as important epigenetic modulators, are attractive targets in drug discovery and development. Considering the fact that BET and HDAC inhibitors exert a synergistic effect on cellular processes in cancer cells, the design of dual BET/HDAC inhibitors may be a rational strategy to improve the efficacy of their single-target drugs for tumor treatment. In the current review, we depict the development of dual BET/HDAC inhibitors and particularly highlight their structure-activity relationships (SARs), binding modes, and biological functions with the aim to facilitate rational drug design and develop more dual BET/HDAC inhibitors.

Current status in the discovery of dual BET/HDAC inhibitors.

The development of desired multitarget agents may provide an attractive and cost-effective complement or alternative to drug combinations. BET and HDAC, as important epigenetic modulators, are both attractive targets in drug discovery and development. Considering the fact that BET and HDAC inhibitors exert a synergistic effect on cellular processes in cancer cells, the design of dual BET/HDAC inhibitors may be a rational strategy to improve the efficacy of their single-target drugs for tumor treatment. In current review, we depict the development of dual BET/HDAC inhibitors and particularly highlight their SARs, binding modes and biological functions with the aim to facilitate rational design and develop more dual BET/HDAC inhibitors.

Serum IgG-induced microglial activation enhances neuronal cytolysis via the NO/sGC/PKG pathway in children with opsoclonus-myoclonus syndrome and neuroblastoma.

BACKGROUND: Opsoclonus-myoclonus syndrome (OMS) is a rare neurological disease. Some children with OMS also have neuroblastoma (NB). We and others have previously documented that serum IgG from children with OMS and NB induces neuronal cytolysis and activates several signaling pathways. However, the mechanisms underlying OMS remain unclear. Here, we investigated whether nitric oxide (NO) from activated microglias and its cascade contribute to neuronal cytolysis in pediatric OMS. METHODS: The activation of cultured cerebral cortical and cerebellar microglias incubated with sera or IgG isolated from sera of children with OMS and NB was measured by the expression of the activation marker, cytokines, and NO. Neuronal cytolysis was determined after exposing to IgG-treated microglia-conditioned media. Using inhibitors and activators, the effects of NO synthesis and its intracellular cascade, namely soluble guanylyl cyclase (sGC) and protein kinase G (PKG), on neuronal cytolysis were evaluated. RESULTS: Incubation with sera or IgG from children with OMS and NB increased the activation of cerebral cortical and cerebellar microglias, but not the activation of astrocytes or the cytolysis of glial cells. Moreover, the cytolysis of neurons was elevated by conditioned media from microglias incubated with IgG from children with OMS and NB. Furthermore, the expression of NO, sGC, and PKG was increased. Neuronal cytolysis was relieved by the inhibitors of NO signaling, while neuronal cytolysis was exacerbated by the activators of NO signaling but not proinflammatory cytokines. The cytolysis of neurons was suppressed by pretreatment with the microglial inhibitor minocycline, a clinically tested drug. Finally, increased microglial activation did not depend on the Fab fragment of serum IgG. CONCLUSIONS: Serum IgG from children with OMS and NB potentiates microglial activation, which induces neuronal cytolysis through the NO/sGC/PKG pathway, suggesting an applicability of microglial inhibitor as a therapeutic candidate.

Clinical characteristics and risk factors of 47 cases with ruptured neuroblastoma in children.

BACKGROUND: Neuroblastoma (NB) tumor rupture is a rare oncology emergency with a poor prognosis. We aimed to evaluate patient clinical characteristics and risk factors for ruptured NB. METHODS: A retrospective study of 47 patients with confirmed NB rupture between January 2009 and January 2019 at Beijing Children's Hospital was conducted. To identify tumor rupture risk factors in high-risk NB patients, we included 93 consecutive non-ruptured high-risk NB patients from January 2017 to January 2019. RESULTS: The median age at presentation was 29 months (adrenal and retroperitoneum origin) for 47 ruptured NB patients. Spontaneous tumor rupture occurred in 22 cases; 18 cases occurred during or after the first chemotherapy cycle, and 7 occurred after core needle biopsy. Five patients died of tumor rupture, and 17 patients' parents refused further antitumor therapy. Among the 25 remaining patients, 6 survived without disease, 5 received ongoing treatment and achieved stable disease, and 14 died. According to multivariate logistic regression analysis, a maximum primary tumor diameter > 13.20 cm and MYCN gene amplification were independent risk factors for tumor rupture within high-risk NB. CONCLUSIONS: Tumor rupture is an uncommon, life-threatening event for NB patients; these patients are most likely to have poor outcomes due to tumor recurrence or rapid progression. Several treatment modalities, including symptomatic support therapy and chemotherapy, are important for saving lives and for developing NB risk-based treatment in the future.

Phase evolution of ultra-thin Ni silicide films on CF4 plasma immersion ion implanted Si.

We present a systematic study on the effects of CF4 plasma immersion ion implantation (PIII) in Si on the phase evolution of ultra-thin Ni silicides. For 3 nm Ni, NiSi2 was formed on Si substrates with and without CF4 PIII at temperature as low as 400 °C. For 6 nm Ni, NiSi was formed on pure Si, while epitaxial NiSi2 was obtained on CF4 PIII Si. The incorporation of C and F atoms in the thin epitaxial NiSi2 significantly reduces the layer resistivity. Increasing the Ni thickness to 8 nm results in the formation of NiSi, where the thermal stability of NiSi, the NiSi/Si interface and Schottky contacts are significantly improved with CF4 PIII. We suggest that the interface energy is lowered by the F and C dopants present in the layer and at the interface, leading to phase evolution of the thin Ni silicide.

Mechanistic insights into higher alcohol synthesis from syngas on Rh/Cu single-atom alloy catalysts.

Low cost Cu-based catalysts are attractive options in catalyzing higher alcohol synthesis (HAS) from syngas. Introducing isolated Rh single atoms into the surfaces of these Cu catalysts has the potential to dramatically improve the performance of these Cu-based catalysts. In this work, extensive density functional theory (DFT) calculations were performed with periodic slab models to systematically investigate the possibility of using Rh/Cu single-atom alloys (SAAs) as HAS catalysts. The mechanism of ethanol synthesis from syngas on the representative Rh/Cu(111) and Rh/Cu(100) surfaces was elucidated. All possible formation pathways of the C1 and C2 fragments leading to the ethanol main product, as well as the methane and methanol by-products were considered. Our calculations show that for ethanol formation, the C-C bond coupling is easier over the Rh/Cu SAA catalysts than pure Cu catalysts, suggesting that Rh/Cu SAA catalysts are more favorable for the formation of higher alcohols.

Duodenum-preserving pancreas head resection in the treatment of pediatric benign and low-grade malignant pancreatic tumors.

BACKGROUND: To investigate the safety, feasibility, and complications of using duodenum-preserving pancreas head resection (DPPHR) to treat pediatric benign and low-grade malignant pancreatic head tumors. METHODS: Patients with pancreatic head tumors that underwent resection were retrospectively analyzed for perioperative factors and postoperative complications. RESULTS: Thirty-five patients with a median age of 10 years at diagnosis were identified. Patients were divided by procedures into the DPPHR (n = 22), local enucleation (n = 7) and pylorus-preserving pancreatoduodenectomy (PPPD, n = 6) groups. No significant difference was found in operation time between the DPPHR and PPPD groups (P > 0.05). Significantly, longer drainage time, duration of somatostatin use and hospital stay were observed in the DPPHR group than in the PPPD group (P < 0.05). The incidences of short-term complications were not significantly different among the three groups (P > 0.05). The incidence of long-term complications was markedly lower in both the DPPHR and local enucleation groups than in the PPPD group (P < 0.05). CONCLUSION: DPPHR might be a safe treatment option for pediatric patients with benign and low-grade malignant pancreatic head tumors. The incidence of long-term complications was significantly lower with DPPHR. However, perioperative management might be challenging for surgeons.

Notch-4 silencing inhibits prostate cancer growth and EMT via the NF-κB pathway.

Epithelial-mesenchymal transition (EMT) is implicated in the metastasis of human prostate cancer (PCa). Notch signaling has been established as a regulator of EMT. Notch-4 has emerged as a mammary proto-oncogene and a target in several cancers. However, the role and the mechanism of action of Notch-4 in PCa are still unclear. In the present study, we first observed a marked increase in Notch-4 expression in the PCa cell lines DU145, PC3 and LnCAP compared with the non-malignant prostate epithelial cell line RWPE1. Knocking down the expression of Notch-4 suppressed the viability and proliferation in the PCa cell lines DU145 and PC3. Also, further study showed that a decline in Notch-4 significantly promoted apoptosis in PC3 cells. Notch-4 silencing also resulted in decreased cell migration and invasion and affected the expression of EMT markers. We hypothesized that Notch-4 ablation suppresses the activity of NF-κB, so we used PMA to stimulate NF-κB p50 and p65 activation in PC3 cells. The results indicate that PMA treatment impaired the action of Notch-4 ablation in the biology of PC3 cells including cell growth, apoptosis, migration, invasion and EMT. The results of the present study show that RNAi targeting against Notch-4 expression suppresses PCa progression.

Surface-plasmon mediated photoluminescence enhancement of Pt-coated ZnO nanowires by inserting an atomic-layer-deposited Al2O3 spacer layer.

Surface-plasmon mediated photoluminescence emission enhancement has been investigated for ZnO nanowire (NW)/Pt nanoparticle (NP) nanostructures by inserting an Al2O3 spacer layer. The thickness of the Al2O3 spacer layer and of the Pt NPs capped on the ZnO NWs are well controlled by atomic layer deposition. It is found that the photoluminescence property of the ZnO NW/Al2O3/Pt hybrid structure is highly tunable with respect to the thickness of the inserted Al2O3 spacer layer. The highest enhancement (∼14 times) of the near band emission of ZnO NWs is obtained with an optimized Al2O3 spacer layer thickness of 10 nm leading to a ultraviolet-visible emission ratio of 271.2 compared to 18.8 for bare ZnO NWs. The enhancement of emission is influenced by a Förster-type non-radiative energy transfer process of the exciton energy from ZnO NWs to Pt NPs as well as the coupling effect between excitons of ZnO NWs and surface plasmons of Pt NPs. The highly versatile and tunable photoluminescence properties of Pt-coated ZnO NWs achieved by introducing an Al2O3 spacer layer demonstrate their potential application in highly efficient optoelectronic devices.

Photoluminescence enhancement of ZnO nanowire arrays by atomic layer deposition of ZrO2 layers and thermal annealing.

The effects of shell thickness and rapid thermal annealing on photoluminescence properties of one-dimensional ZnO/ZrO2 core/shell nanowires (NWs) are studied in this work. The ZnO/ZrO2 core/shell structures were synthesized by coating thin ZrO2 layers on the surface of ZnO NWs using atomic layer deposition. The morphological and structural characterization studies reveal that the ZrO2 shells have a polycrystalline structure, which are uniformly and conformally coated on the high quality single-crystal ZnO NWs. As compared with bare ZnO NWs, the ZnO/ZrO2 core/shell structures show a remarkable and continuous enhancement of ultraviolet (UV) emission in intensity with increasing ZrO2 shell thickness up to 10 nm. The great improvement mechanism of the UV emission arises from the surface passivation and the efficient carrier confinement effect of the type-I core/shell system. Moreover, it is observed that the UV emission of ZnO/ZrO2 core/shell structures after thermal annealing increases with increasing annealing temperature. The dominant surface exciton (SX) emission in the bare ZnO NWs and the ZnO/ZrO2 core/shell nanostructures has been detected in the low temperature photoluminescence spectra. A blue shift of the NBE emission peak as well as the varied decay rate of the SX emission intensity are also found in the ZnO NWs after the growth of ZrO2 shells and further thermal treatment. Our results suggest that the ZnO/ZrO2 core/shell nanostructures could be widely implemented in the optical and electronic devices in the future.

Preparation of Vinyl Arenes by Nickel-Catalyzed Reductive Coupling of Aryl Halides with Vinyl Bromides.

This work emphasizes the synthesis of substituted vinyl arenes by reductive coupling of aryl halides with vinyl bromides under mild and easy-to-operate nickel-catalyzed reaction conditions. A broad range of aryl halides, including heteroaromatics, and vinyl bromides were employed to yielding products in moderate to excellent yields with high functional-group tolerance. The nickel-catalytic system displays good chemoselectivity between the two C(sp2 )-halide coupling partners, thus demonstrating a mechanistic pathway distinct from other stepwise protocols.