Thalidomide Alleviates Apoptosis, Oxidative Damage and Inflammation Induced by Pemphigus Vulgaris IgG in HaCat Cells and Neonatal Mice Through MyD88.

Purpose: Thalidomide (Tha) can be used as a selective treatment for mild pemphigus vulgaris (PV). However, the specific mechanism of action remains unclear. Patients and Methods: PV IgG extracted from patients' serum was cocultured with HaCaT cells to construct a PV cell model, and different concentrations of Tha were used to screen the drug effect. The expression level of MYD88 was assessed in skin lesions of PV patients. Intracellular Ca2+ concentration, reactive oxygen species level, DSG3, PG, MYD88, apoptosis-related proteins (Caspase-3, Bcl-2, and Bax), NF-κB pathway-related proteins (IκBα, p-IκBα, p50, and p65), NLRP3, IFN-γ, TNF-α, IL-6, and IL-8 levels were measured. PV IgG was subcutaneously injected into C57BL/6 neonatal mice to construct the animal model. Immunofluorescence was used to detect IgG deposition in the mouse epidermis, whereas immunohistochemistry and TUNEL methods were used to detect the expression of MYD88 and NLRP3 as well as cell apoptosis level in the mouse epidermis. Results: Tha reversed the decrease in Dsg3 and PG caused by PV IgG. The expression of MyD88 increased in the patients' skin, PV cell model, and PV mouse model. The increase in MyD88 expression level in PV cell models and PV newborn mouse models was inhibited by Tha. Overexpression of MyD88 induced a decrease in the expression levels of Dsg3 and PG in Hacat cells. Overexpression of MyD88 inhibited Tha effects on Dsg3 and PG expressions and blocked Tha effects on Ca2+, apoptosis, Bax, Bcl-2, and Caspase-3 expressions, oxidative damage, and inflammatory response in HaCat cells. Tha alleviated acantholysis induced by PV IgG in model mice. Conclusion: Through MYD88, Tha attenuated apoptosis of HaCat cells, modulated NF-κB to hamper the oxidative damage and inflammatory response in the PV cell models, and alleviated acantholysis, IgG deposition, and epidermal cell apoptosis induced by PV IgG in model mice.

A Rare Case of Acute Infectious Purpura Fulminans Caused by Klebsiella Pneumoniae and Human Herpesvirus Type 5.

Background: Purpura fulminans (PF), a rare, life-threatening disorder, is a hematological emergency in which there is skin necrosis, disseminated intravascular coagulation (DIC), and protein C deficiency. In PF, the skin necrosis and DIC are secondary to protein C deficiency. This may progress rapidly to multiorgan failure caused by the thrombotic occlusion of small- and medium-sized blood vessels. Case Report: This article presents the case of a 22-year-old male with fever as well as necrotic and purpuric skin lesions. The ultrasound and computed tomography scans revealed infections in the skin wounds as well as venous microthrombosis and thrombosis in multiple intracranial and pulmonary vessels. The laboratory tests showed signs of sepsis, thrombocytopenia, an abnormal decrease in protein C and antithrombin III, DIC, multiple organ and system failures, gastric varices, and gastrointestinal hemorrhage. The blood, sputum, and secretions under the skin lesions were cultured and were positive for Klebsiella pneumoniae. The results of the high-throughput genetic testing of the pathogenic microorganism DNA were consistent. In addition, human herpesvirus type 5 was detected. The histopathological examination of the skin lesions revealed pathological features consistent with PF. After successful treatment by the departments of Dermatology, Emergency Critical Care Medicine, and the Intensive Care Unit, the patient was discharged after 67 days of hospitalization. Conclusion: Adults with acquired protein C and/or S deficiency states, including certain bacterial and viral infections, who drink alcohol and take varieties of non-steroidal anti-inflammatory analgesics at the same time, may develop acute infectious PF. Clinicians should be aware of this for early diagnosis and treatment.

An Analysis of the Correlation Between Clinical Indexes and Pathological Classifications in 202 Patients with Lupus Nephritis.

OBJECTIVE: To investigate the correlation between clinical indexes and pathological classifications in 202 patients with lupus nephritis (LN). METHODS: A total of 202 LN cases were retrospectively analyzed. All these patients met the four diagnostic criteria for systemic lupus erythematosus (SLE) of the American College of Rheumatology revised in 1997. The pathological diagnostic criteria of LN were in accordance with the pathological LN classification revised by the International Society of Nephrology and the Society of Kidney Pathology in 2003. The patients were scored according to the improved SLE Disease Activity Index 2000 (SLEDAI-2K), and their basic data, clinical data, laboratory data, and pathological data were collected. RESULTS: Among the 202 patients, the ratio of male to female was 1:5.73, and type IV was the most common pathological LN classification. There were differences in the urine analysis, hypertension incidence, blood cell analysis, blood lipids, renal function, plasma albumin, immunological indexes, renal pathological score among the different pathological types (P < 0.05). In the early finding of renal function damage of the patients, cystatin C sensitivity was significantly higher than that of serum creatinine and blood urea nitrogen. Multiple linear regression analysis show that there are strong correlations between AI and SLEDAI, 24hU-Pr, serum C3, serum ALB, BUN, creatinine, UA and PLT (P < 0.001); and there are correlations between AI and serum IgM, IgA, C4, TC and LDL-C (P < 0.05). CONCLUSION: There is a clear correlation between pathological classifications and clinical indexes of LN. TRIAL REGISTRATION: Shen-PJ-2018-40, Study on Clinical and Molecular Mechanism of SLE.

Transcriptome Sequencing Identifies PLAUR as an Important Player in Patients With Dermatomyositis-Associated Interstitial Lung Disease.

Dermatomyositis (DM), an inflammatory disorder, is often associated with interstitial lung disease (ILD). However, the underlying mechanism remains unclear. Our study performed RNA sequencing (RNA-seq) and integrative bioinformatics analysis of differentially expressed genes (DEGs) in patients with dermatomyositis-associated interstitial lung disease (DM-ILD) and healthy controls. A total of 2,018 DEGs were identified between DM-ILD and healthy blood samples. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis showed that DEGs were mainly involved in immune- and inflammatory-related biological processes and pathways. Disease ontology (DO) enrichment analysis identified 35 candidate key genes involved in both skin and lung diseases. Meanwhile, a total of 886 differentially expressed alternative splicing (AS) events were found between DM-ILD and healthy blood samples. After overlapping DEGs with differential AS genes, the plasminogen activator and urokinase receptor (PLAUR) involved in immune-related biological processes and complement and coagulation cascades was screened and identified as the most important gene associated with DM-ILD. The protein-protein interaction (PPI) network revealed that PLAUR had interactions with multiple candidate key genes. Moreover, we observed that there were significantly more neutrophils and less naive B cells in DM-ILD samples than in healthy samples. And the expression of PLAUR was significantly positively correlated with the abundance of neutrophils. Significant higher abundance of PLAUR in DM-ILD patients than healthy controls was validated by RT-qPCR. In conclusion, we identified PLAUR as an important player in regulating DM-ILD by neutrophil-associated immune response. These findings enrich our understanding, which may benefit DM-ILD patients.

The high expression of miR-564 in patients with systemic lupus erythematosus promotes differentiation and maturation of DC cells by negatively regulating TP53 expression in vitro.

BACKGROUND: miRNA is involved in the occurrence and progression of systemic lupus erythematosus (SLE), but the regulatory effect of miRNA on dendritic cells in SLE patients is still unclear. MATERIAL AND METHODS: Bioinformatics methods were used to analyze the differentially expressed miRNA and its target genes in SLE patients. In vitro experiments were conducted to explore the effects and mechanisms of differentially expressed miRNAs in SLE patients on the differentiation and maturation of monocyte-derived dendritic cells. RESULTS: Bioinformatics analysis showed that miR-564 was up-regulated in SLE patients, and TP53 was the core target gene of miR-564. The expression level of miR-564 showed a rising trend during the differentiation and maturation of monocytes into Mo-DC cells. The differentiation, maturation and proliferation of Mo-DC cells were significantly inhibited by transfection with miR-564 antagomir. The expression of TP53 is negatively regulated by miR-564. In rescue experiments, the proliferation and migration of DC cells were significantly restored by co-transfection of miR-564 antagomir and TP53 si-RNA. CONCLUSION: Highly expressed miR-564 promotes the maturation, proliferation of Mo-DC cells by negatively regulating the expression of TP53.

Prognostic nutritional index and the prognosis of diffuse large b-cell lymphoma: a meta-analysis.

BACKGROUND: Some studies have investigated the prognostic value exhibited by the Prognostic Nutritional Index (PNI) in patients suffering diffuse large B-cell lymphoma (DLBCL), but varying results were obtained. In order to determine the specific prognostic value more accurately, a meta-analysis was conducted in this study. METHODS: Literatures were searched from the China National Knowledge Infrastructure (CNKI), Wanfang, PubMed, Embase, the Cochrane Library, and Web of Science. Pooled hazard ratio (HR) and the 95% confidence interval (CI) were calculated to assess the association between PNI and the overall survival (OS) and the progression-free survival (PFS) of patients with DLBCL. RESULTS: Based on seven studies with a total number of 1311 patients, our meta-analysis revealed that low PNI may meant poor OS (HR = 2.14, 95% CI 1.66-2.75, p < 0.001) and poor PFS (HR = 1.75, 95% CI 1.36-2.25, p = 0.438). Subgroup analysis showed that, in Asians, low PNI was correlated to poor OS (pooled HR = 2.06 95% CI 1.59-2.66) and poor PFS (pooled HR = 1.66, 95% CI 1.28-2.15). Similar results were obtained from one European study, which is the only study performed outside of Asia from our literature search. CONCLUSION: For patients with DLBCL, low PNI may be interpreted as adverse prognosis. More data from European patients are required in this study to avoid analysis bias.

Association among helicobacter pylori infection, gastrin level and colorectal cancer in patients aged 50 years and over.

OBJECTIVES: To study the correlations among helicobacter pylori infection, gastrin and colorectal cancer in patients aged over 50 years old. METHODS: In this study, the patients diagnosed with colorectal cancer treated in the department of digestion of our hospital together with the healthy subjects undergoing colonoscopy for health examination without pathologic findings from August 2016 to July 2019 were enrolled in colorectal cancer or control group. The blood sample was taken in fasting state, and anti-H. pylori IgG and anti-CagA antibodies as well as the level of serum gastrin were measured for all the participants. In addition, the information of each participant including age, gender, obesity, smoking history, alcohol consumption, diabetes mellitus was recorded and analyzed. RESULTS: Four hundred and twenty-eight patients were enrolled in the colorectal group and 207 healthy subjects were enrolled in the control group. There were not significant differences in the positive rate of Ig G and Cag A and family history between the two groups (p>0.05), but there were significant differences in gastrin level, obesity, smoking history, alcohol consumption and diabetes mellitus between the two groups (p<0.05). In addition, the multivariable analysis showed that obesity, smoking history, alcoholism and diabetes mellitus have the strongest influence on the formation of colorectal cancer, while the level of gastrin didn't show the influence. CONCLUSIONS: No significant correlations among H. pylori infection, the level of gastrin, and the occurrence of CRC in patients with a minimum age of 50 years, suggesting elder colorectal cancer patients may have a different carcinogenic mechanism from those younger patients.

Long Noncoding RNA MALAT1 Promotes the Development of Colon Cancer by Regulating miR-101-3p/STC1 Axis.

PURPOSE: Colon cancer (CC) is a leading cause of cancer-related deaths worldwide. This study aimed to clarify the effect of long noncoding RNA (lncRNA) metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) on CC progression and the potential mechanism. METHODS: CC cell lines HCT116 and HT29 were selected for functional analysis. The expression of MALAT1, microRNA (miR)-101-3p, and stanniocalcin 1 (STC1) in CC tissues and cells were measured by quantitative reverse transcription PCR (qRT-PCR). Cell proliferation, apoptosis, migration and invasion were measured by Cell Counting Kit-8 (CCK-8), flow cytometry, wound scratch and transwell assay, respectively. The target relationships (MALAT1 and miR-101-3p, miR-101-3p and STC1) were validated by dual-luciferase reporter and RNA pull-down assay. RESULTS: The expression of MALAT1 was elevated in CC tissues compared with adjacent normal tissues and was associated with lymph node metastasis, depth of invasion and tumor-node-metastasis (TNM) stage. Up-regulation of MALAT1 promoted the proliferation, migration, and invasion and inhibited the apoptosis of CC cells; while MALAT1 knockdown exhibited opposite results. MiR-101-3p was a target of MALAT1, which was negatively regulated by MALAT1. Silencing of miR-101-3p reverses the anti-tumor effect of MALAT1 knockdown on CC cells. STC1 was a target of miR-101-3p, which was negatively regulated by miR-101-3p. Silencing of STC1 reverses the tumor promoting effects of MALAT1 up-regulation and miR-101-3p down-regulation on CC cells. CONCLUSION: MALAT1 may function as an oncogene in CC progression by affecting the miR-101-3p/STC1 axis, providing a hopeful therapeutic option for CC.

High throughput lipid profiling for subtype classification of hepatocellular carcinoma cell lines and tumor tissues.

Cell heterogeneity of tumor tissues is one of the causes of cancer recurrence after chemotherapy. Cell subtype identification in tumor tissues of specific cancer is critical for precision medicine and prognosis. As the structural and functional components of cells, lipids are closely related to the apparent morphology of cells. They are potential biomarkers of species of cancers and can be used to classify different cancer cell types, but it remains a challenge to establish a stable cell differentiation model and extend it to tumor tissue cell subtype differentiation. Here we describe a lipid profiling method based on nanostructure assisted laser desorption/ionization mass spectrometry (NALDI-MS), which could classify five hepatocellular carcinoma (HCC) cell lines and discriminate subtype of mixed cells and tumor tissues. The NALDI target was patterned with array of sample spots containing vertical silicon nanowires (Si NWs). Owing to its high ability to absorb laser energy, the vertical Si NWs can help to generate abundant lipid ions of cell extracts without need of organic matrix. Combined with statistical analysis methods, twenty-two ion peaks distributed in four MS peak clusters were selected as potential biomarkers to distinguish the subtype of the five HCC cell lines. Peak normalization was performed within each MS peak cluster to reduce the variation of peak intensity in batch to batch analysis. Compared to full-spectrum normalization method, the inner-cluster normalization method could help to distinguish cell subtype more stably and accurately. The molecular structure of these biomarkers was identified and sorted into two classes including phosphatidylcholine (PE, PI, PG, PA, PS) and glycosphingolipid (LacCer, ST). Furthermore, the established method was successfully applied to identify the major HCC cell subtype in mixed cell samples and xenograft tumor tissues as well as drug response test, showing great potential in precision medicine and prognosis.

Clinical application of obinutuzumab for treating chronic lymphocytic leukemia.

Alkylators and nucleoside analogs were the main drugs for treatingchronic lymphoblastic leukemia (CLL), which have been replaced by monoclonal antibodies, such as rituximab in the past 10 years for refractory or relapsed CLL. The first-line immunochemotherapy regimen, rituximab combined with nucleoside analogs, significantly increased CLL patients' first-reaction rate and improved progression-free survival. Despite the long-lasting remissions by the use of chemoimmunotherapy, most CLL patients will relapse eventually. The obinutuzumab (GA101), an updated CD20 antibody, that is thought to achieve a more durable response with unique molecular and functional characteristics. Obinutuzumab is a humanized, monoclonal type II CD20 antibody modified by glycoengineering. The glycoengineered Fc portion enhances the binding affinity to the FcγRIII receptor on immune effector cells, resulting in increased antibody-dependent cellular cytotoxicity and phagocytosis. In addition, the type II antibody binding characteristics of obinutuzumab to CD20 lead to an efficient induction of direct non-apoptotic cell death. This review summarizes the results of clinical studies using obinutuzumab and looks forward to its further application in treating CLL clinically.

[Advance of Research on the Immunotherapy Targeting B Cell Maration Antigen for Multiple Myeloma--Review].

Abstract　　B cell maturation antigen (BCMA) is an ideal target for precise treatment due to its highly selective expression on malignant myeloma cells. This review summarizes briefly the advances in the latest research progress on biological activity of BCMA, its significance as a biomarker and immunotherapy direcited against BCMA, such as bispecific antibodies, antibody drug conjugates, chimeric antigen receptor T cell therapy against mature B cell antigens.

PLCE1 Promotes the Invasion and Migration of Esophageal Cancer Cells by Up-Regulating the PKCα/NF-κB Pathway.

PURPOSE: To investigate the effect and mechanism of phospholipase C epsilon gene 1 (PLCE1) expression on esophageal cancer cell lines. MATERIALS AND METHODS: The esophageal carcinoma cell lines Eca109 and EC9706 and normal esophageal epithelial cell line HEEC were cultured. The expression of PLCE1, protein kinase C alpha (PKCα), and nuclear factor kappa B (NF-κB) p50/p65 homodimer in cells were comparatively analyzed. The esophageal cancer cells were divided into si-PLCE1, control siRNA (scramble), and mock groups that were transfected with specific siRNA for PLCE1, control siRNA, and blank controls, respectively. Expression of PLCE1, PKCα, p50, and p65 was detected by Western blotting. Transwell assay was used to detect migration and invasion of Eca109 and EC9706 cells. RESULTS: Compared with HEEC, the expression of PLCE1, PKCα, p50, and p65 was increased in Eca109 and EC9706 cells. The expression of PLCE1 was positively correlated with the expression of PKCα and p50 (PKCα: r=0.6328, p=0.032; p50: r=0.6754, p=0.041). PKCα expression had a positive correlation with the expression of p50 and p65 (p50: r=0.9127, p=0.000; p65: r=0.9256, p=0.000). Down-regulation of PLCE1 significantly decreased the expression of PKCα and NF-κB-related proteins (p65: p=0.002, p=0.004; p50: p=0.005, p=0.009) and inhibited the migration and invasion of Eca109 and EC9706 cells. CONCLUSION: PLCE1 activated NF-κB signaling by up-regulating PKCα, which could promote invasion and migration of esophageal cancer cells.

[Curative effect of ozone hydrotherapy for pemphigus].

OBJECTIVE: To determine clinical curative effects of ozone therapy for pemphigus vulgaris.
 Methods: Ozone hydrotherapy was used as an aid treatment for 32 patients with pemphigus vulgaris. The hydropathic compression of potassium permanganate solution for 34 patients with pemphigus vulgaris served as a control. The main treatment for both groups were glucocorticoids and immune inhibitors. The lesions of patients, bacterial infection, usage of antibiotics, patient's satisfaction, and clinical curative effect were evaluated in the 2 groups.
 Results: There was no significant difference in the curative effect and the average length of staying at hospital between the 2 groups (P>0.05). But rate for the usage of antibiotics was significantly reduced in the group of ozone hydrotherapy (P=0.039). The patients were more satisfied in using ozone hydrotherapy than the potassium permanganate solution after 7-day therapy (P>0.05).
 Conclusion: Ozone hydrotherapy is a safe and effective aid method for pemphigus vulgaris. It can reduce the usage of antibiotics.

Exploring oxygen in graphene chemical vapor deposition synthesis.

Graphene's practical applications require its reproducible production with controlled means. In particular, graphene synthesis by chemical vapor deposition on metals has been shown to be a promising way to produce large-size and high-quality graphene film at low cost. Understanding the reaction mechanisms during the synthesis process is vital for process and product controllability. There have been a great deal of studies regarding the mutual interplays between the metal, graphene, and hydrogen in graphene production, leading to significant advances in controllable graphene synthesis. Recently, oxygen has been found to play a key role in each step of graphene synthesis, especially on Cu. Taking oxygen into consideration, one can explain the divergent experimental results under similar conditions reported before and can grasp it as another powerful tool that can help to regulate the synthesis processes. The primary discoveries of the function of oxygen in graphene synthesis are summarized and discussed herein, divided into four aspects, corresponding to the elementary steps in graphene synthesis. Oxygen may also further promote graphene synthesis toward the final goal of developing wafer-scale single crystals with definite layer numbers and defects.

Glypican 3 overexpression in primary and metastatic Wilms tumors.

Glypican 3 (GPC3), a heparan sulfate proteoglycan, plays a role in cell growth and differentiation. Mutations of the GPC3 gene are responsible for Simpson-Golabi-Behmel syndrome, which is characterized by anomalies of postnatal overgrowth and an increased risk of developing pediatric malignancies, mostly Wilms tumor and liver cancer. In order to understand the possible role of GPC3 in renal development and Wilms tumor formation, we analyzed messenger RNA (mRNA) and protein levels of GPC3 in sporadic Wilms tumors and compared it to normal kidneys and other common renal epithelial tumors. By using Affymetrix HGU133 oligonucleotide gene expression microarray data from 191 renal tumors and 12 normal kidneys, we found significant overexpression of GPC3 in Wilms tumors (p < 0.01), with 3.5-fold higher expression in comparison to normal kidneys and 6.5-fold higher than any type of renal tumors. The GPC3 gene product in Wilms tumor was further evaluated by immunohistochemistry and quantified by an automated image analysis. Cytoplasmic and membranous GPC3 immunoreactivity was present in 77 % of primary Wilms tumors (23/30), 93 % of metastatic Wilms tumors (13/14), 50 % of metanephric adenomas (4/8), 33 % of congenital mesoblastic nephromas (2/6), 100 % of nephrogenic rests (11/11), and 100 % of fetal kidneys (5/5). GPC3 staining was predominantly identified in blastemal and epithelial components of Wilms tumors, similar to that of fetal non-neoplastic kidney. All adult renal tumors (n = 60) and normal kidneys (n = 15) were GPC3 negative. These findings suggest the utility of GPC3 in differential diagnosis and follow-up of Wilms tumors. Our data also indicate that GPC3 is an oncofetal protein with a potential therapeutic value.

Fabrication of CuInS2-sensitized solar cells via an improved SILAR process and its interface electron recombination.

Tetragonal CuInS2 (CIS) has been successfully deposited onto mesoporous TiO2 films by in-sequence growth of InxS and CuyS via a successive ionic layer absorption and reaction (SILAR) process and postdeposition annealing in sulfur ambiance. X-ray diffraction and Raman measurements showed that the obtained tetragonal CIS consisted of a chalcopyrite phase and Cu-Au ordering, which related with the antisite defect states. For a fixed Cu-S deposition cycle, an interface layer of ß-In2S3 formed at the TiO2/CIS interface with suitable excess deposition of In-S. In the meantime, the content of the Cu-Au ordering phase decreased to a reasonable level. These facts resulted in the retardance of electron recombination in the cells, which is proposed to be dominated by electron transfer from the conduction band of TiO2 to the unoccupied defect states in CIS via exponentially distributed surface states. As a result, a relatively high efficiency of ~0.92% (V(oc) = 0.35 V, J(sc) = 8.49 mA cm(-2), and FF = 0.31) has been obtained. Last, but not least, with an overloading of the sensitizers, a decrease in the interface area between the sensitized TiO2 and electrolytes resulted in deceleration of hole extraction from CIS to the electrolytes, leading to a decrease in the fill factor of the solar cells. It is indicated that the unoccupied states in CIS with energy levels below EF0 of the TiO2 films play an important role in the interface electron recombination at low potentials and has a great influence on the fill factor of the solar cells.

Arrays of ZnO/Zn(x)Cd(1-x)Se nanocables: band gap engineering and photovoltaic applications.

Arrays of ZnO/Zn(x)Cd(1-x)Se (0 ≤ x ≤ 1) core/shell nanocables with shells of tunable compositions have been synthesized on fluorine-doped tin oxide glass substrates via a simple ion-exchange approach. Through the effects of stoichiometry and type II heterojunction, optical absorptions of the nanocable arrays can be controllably tuned to cover almost the entire visible spectrum. Lattice parameters and band gaps of the ternary Zn(x)Cd(1-x)Se shells were found to have respectively linear and quadratic relationships with the Zn content (x). These ZnO/Zn(x)Cd(1-x)Se nanocable arrays are further demonstrated to be promising photoelectrodes for photoelectrochemical solar cells, giving a maximum power conversion efficiency up to 4.74%.

Facile solution growth of vertically aligned ZnO nanorods sensitized with aqueous CdS and CdSe quantum dots for photovoltaic applications.

Vertically aligned single crystalline ZnO nanorod arrays, approximately 3 µm in length and 50-450 nm in diameter are grown by a simple solution approach on a Zn foil substrate. CdS and CdSe colloidal quantum dots are assembled onto ZnO nanorods array using water-soluble nanocrystals capped as-synthesized with a short-chain bifuncional linker thioglycolic acid. The solar cells co-sensitized with both CdS and CdSe quantum dots demonstrate superior efficiency compared with the cells using only one type of quantum dots. A thin Al2O3 layer deposited prior to quantum dot anchoring successfully acts as a barrier inhibiting electron recombination at the Zn/ZnO/electrolyte interface, resulting in power conversion efficiency of approximately 1% with an improved fill factor of 0.55. The in situ growth of ZnO nanorod arrays in a solution containing CdSe quantum dots provides better contact between two materials resulting in enhanced open circuit voltage.

Violet-blue LEDs based on p-GaN/n-ZnO nanorods and their stability.

In this paper, we report a fabrication, characterization and stability study of p-GaN/n-ZnO nanorod heterojunction light-emitting devices (LEDs). The LEDs were assembled from arrays of n-ZnO vertical nanorods epitaxially grown on p-GaN. LEDs showed bright electroluminescence in blue (440 nm), although weaker violet (372 nm) and green-yellow (550 nm) spectral components were also observed. The device characteristics are generally stable and reproducible. The LEDs have a low turn-on voltage (∼5 V). The electroluminescence (EL) is intense enough to be noticed by the naked eye, at an injection current as low as ∼ 40 µA (2.1 × 10(-2) A cm(-2) at 7 V bias). Analysis of the materials, electrical and EL investigations point to the role of a high quality of p-n nano-heterojunction which facilitates a large rectification ratio (320) and a stable reverse current of 2.8 µA (1.4 × 10(-3) A cm(-2) at 5 V). Stability of EL characteristics was investigated in detail. EL intensity showed systematic degradation over a short duration when the LED was bias-stressed at 30 V. At smaller bias (<20 V) LEDs tend to show a stable and repeatable EL characteristic. Thus a simple low temperature solution growth method was successfully exploited to realize nanorod/film heterojunction LED devices with predictable characteristics.