Prevalence trends of anemia impairment in adolescents and young adults with HIV/AIDS.

BACKGROUND: Anemia is a common complication of HIV/AIDS, particularly in adolescents and young adults across various countries and regions. However, little is known about the changing prevalence trends of anemia impairment in this population over time. METHODS: Data on anemia in adolescents and young adults with HIV/AIDS from 1990 to 2019 were collected from the Global Burden of Disease. Prevalence was calculated by gender, region, and country for individuals aged 10-24, and trends were measured using estimating annual percentage changes (EAPC). RESULTS: Globally, the prevalence of adolescents and young adults with HIV/AIDS increased from 103.95 per 100,000 population in 1990 to 203.78 in 2019. However, anemia impairment has decreased over the past three decades, with a global percentage decreasing from 70.6% in 1990 to 34.7% in 2019, mainly presenting as mild to moderate anemia and significantly higher in females than males. The largest decreases were observed in Central Sub-Saharan Africa, North America, and Eastern Sub-Saharan Africa, with EAPCs of -2.8, -2.34, and -2.17, respectively. Tajikistan (78.76%) and Madagascar (74.65%) had the highest anemia impairment percentage in 2019, while China (16.61%) and Iceland (13.73%) had the lowest. Anemia impairment was closely related to sociodemographic index (SDI) levels, with a high proportion of impairment in low SDI regions but a stable decreasing trend (EAPC = -0.37). CONCLUSION: Continued anemia monitoring and management are crucial for patients with HIV, especially in high-prevalence regions and among females. Public health policies and interventions can improve the quality of life and reduce morbidity and mortality.

Development of a risk assessment model for cardiac injury in patients newly diagnosed with acute myeloid leukemia based on a multicenter, real-world analysis in China.

BACKGROUND: Studies have revealed that acute myeloid leukemia (AML) patients are prone to combined cardiac injury. We aimed to identify hematological risk factors associated with cardiac injury in newly diagnosed AML patients before chemotherapy and develop a personalized predictive model. METHODS: The population baseline, blood test, electrocardiogram, echocardiograph, and genetic and cytogenetic data were collected from newly diagnosed AML patients. The data were subdivided into training and validation cohorts. The independent risk factors were explored by univariate and multivariate logistic regression analysis respectively, and data dimension reduction and variable selection were performed using the least absolute shrinkage and selection operator (LASSO) regression models. The nomogram was generated and the reliability and generalizability were verified by receiver operating characteristic (ROC) curves, the area under the curve (AUC) and calibration curves in an external validation cohort. RESULTS: Finally, 499 AML patients were included. After univariate logistic regression, LASSO regression and multivariate logistic regression analysis, abnormal NT-proBNP, NPM1 mutation, WBC, and RBC were independent risk factors for cardiac injury in AML patients (all P < 0.05). The nomogram was constructed based on the above four variables with high accuracy. The area under the curve was 0.742, 0.750, and 0.706 in the training, internal validation, and external validation cohort, respectively. The calibration curve indicated that the model has good testing capability. The Kaplan-Meier curve showed that the higher the risk of combined cardiac injury in AML patients, the lower their probability of survival. CONCLUSIONS: This prediction nomogram identifies hematological risk factors associated with cardiac injury in newly diagnosed AML patients and can help hematologists identify the risk and provide precise treatment options.

Global burden of hematologic malignancies and evolution patterns over the past 30 years.

Hematologic malignancies are among the most common cancers, and understanding their incidence and death is crucial for targeting prevention, clinical practice improvement, and research resources appropriately. Here, we investigated detailed information on hematological malignancies for the period 1990-2019 from the Global Burden of Disease study. The age-standardized incidence rate (ASIR), the age-standardized death rate (ASDR), and the corresponding estimated annual percentage changes (EAPC) were calculated to assess temporal trends in 204 countries and territories over the past 30 years. Globally, incident cases of hematologic malignancies have been increasing since 1990, reaching 1343.85 thousand in 2019, but the ASDR for all types of hematologic malignancies has been declining. The ASDR for leukemia, multiple myeloma, non-Hodgkin lymphoma, and Hodgkin lymphoma were 4.26, 1.42, 3.19, and 0.34 per 100,000 population in 2019, respectively, with Hodgkin lymphoma showing the most significant decline. However, the trend varies by gender, age, region, and the country's economic situation. The burden of hematologic malignancies is generally higher in men, and this gender gap decreases after peaking at a given age. The regions with the largest increasing trend in the ASIR of leukemia, multiple myeloma, non-Hodgkin lymphoma, and Hodgkin lymphoma were Central Europe, Eastern Europe, East Asia, and Caribbean, respectively. In addition, the proportion of deaths attributed to high body-mass index continued to rise across regions, especially in regions with high socio-demographic indices (SDI). Meanwhile, the burden of leukemia from occupational exposure to benzene and formaldehyde was more widespread in areas with low SDI. Thus, hematologic malignancies remain the leading cause of the global tumor burden, with growing absolute numbers but sharp among several age-standardized measures over the past three decades. The results of the study will inform analysis of trends in the global burden of disease for specific hematologic malignancies and develop appropriate policies for these modifiable risks.

Comprehensive analysis of clinical prognostic features and tumor microenvironment landscape of CD11b+CD64+ patients with acute myeloid leukemia.

BACKGROUND: Immunophenotyping surface molecules detected in the clinic are mainly applied in diagnostic confirmation and subtyping. However, the immunomodulatory molecules CD11b and CD64, are highly associated with leukemogenesis. Hence, the prognostic value of them and their potential biological functions merit further investigation. METHODS: Flow cytometry was operated to detect immunophenotypic molecules from AML bone marrow samples. Multivariate cox regression, Kaplan-Meier analyses, and nomogram were conducted to predict survival. Transcriptomic data, lymphocyte subsets, and immunohistochemical staining were incorporated to identify potential biological functions of prognostic immunophenotype in acute myeloid leukemia (AML). RESULTS: We classified 315 newly diagnosed AML patients of our center based on the expression of CD11b and CD64. The CD11b+CD64+ populations were identified as independent risk factors for overall survival and event-free survival of AML, exhibiting specific clinicopathological features. The predictive models based on CD11b+CD64+ showed high classification performance. In addition, the CD11b+CD64+ subset, characterized by high inhibitory immune checkpoints, M2-macrophage infiltration, low anti-tumor effector cells infiltration, as well as abnormal somatic mutation landscape, presented a distinctive tumor microenvironmental landscape. The CD11b+CD64+ population showd a higher expression of BCL2, and the drug sensitivity indicated that they presented a lower half-maximal inhibitory concentration value for BCL2 inhibitor, and could benefit more from the above medicine. CONCLUSIONS: This work might be of benefit to enhanced understanding of CD11b+CD64+ in the prognosis and leukemogenesis, and yielded novel biomarkers to guide immunotherapy and targeted therapy for AML.

Differentiating Thermal Conductances at Semiconductor Nanocrystal/Ligand and Ligand/Solvent Interfaces in Colloidal Suspensions.

Infrared-pump, electronic-probe (IPEP) spectroscopy is used to measure heat flow into and out of CdSe nanocrystals suspended in an organic solvent, where the surface ligands are initially excited with an infrared pump pulse. Subsequently, the heat is transferred from the excited ligands to the nanocrystals and in parallel to the solvent. Parallel heat transfer in opposite directions uniquely enables us to differentiate the thermal conductances at the nanocrystal/ligand and ligand/solvent interfaces. Using a novel solution to the heat diffusion equation, we fit the IPEP data to find that the nanocrystal/ligand conductances range from 88 to 135 MW m-2 K-1 and are approximately 1 order of magnitude higher than the ligand/solvent conductances, which range from 7 to 26 MW m-2 K-1. Transient nonequilibrium molecular dynamics (MD) simulations of nanocrystal suspensions agree with IPEP data and show that ligands bound to the nanocrystal by bidentate bonds have more than twice the per-ligand conductance as those bound by monodentate bonds.

Distributions and Trends of the Global Burden of Colorectal Cancer Attributable to Dietary Risk Factors over the Past 30 Years.

Dietary risk has always been a major risk factor for colorectal cancer (CRC). However, the contribution of dietary risk factors to CRC at the level of region, gender, and age has not been fully characterized. Based on the Global Burden of Disease (GBD) 2019 study, the death rates, age-standardized mortality rates (ASDRs), and estimated annual percentage changes (EAPCs) were calculated to assess the trends of CRC attributable to dietary risk factors over the past 30 years. Globally, the death cases of CRC increased to 1,085,797 in 2019, and the number of deaths attributed to dietary risk factors increased to 365,752 in 2019, representing approximately one-third of all CRC-related fatalities. Overall, the ASDR attributable to dietary risks was 4.61 per 100,000 in 2019, with a slight downward trend (EAPC = -0.29). Notably, there is a rising trend in early-onset colorectal cancer mortality associated with dietary factors. To alleviate CRC burdens, it is recommended to elevate the intake of whole grains, milk, calcium, and fiber while reducing consumption of red and processed meats. The results will improve the understanding, and provide guidance on the diet of CRC in different regions, gender, and age groups worldwide.

High accurate self-calibration of photonic integrated circuit using lossless thermo-optic phase shifters.

The accurate calibration of large-scale switch networks is critical for integrated photonics, in which the integrated optical true time delay chip is typical. In this work, a novel self-calibration method without extra testing ports is proposed by introducing lossless thermo-optic phase shifters instead to calibrate the network. As a demonstration, a 5-bit delay line based on silicon nitride is fabricated and calibrated. The extinction ratio of all the switches is greater than 30.9 dB at the cross and bar states. Using this method, the 5-bit optical delay line which can be tuned in a range of 118.53 ps and reach a low delay time deviation less than ±0.4 ps.

Solubility and conformational characterization of rice glutelin after high temperature treatment.

Enhancing the solubility of rice glutelin in neutral aqueous solution is the prerequisite for the development of rice protein drinks and ingredients. Herein, glutelin was first dissolved in an aqueous solution of pH 12, and then heated at 121 °C for 20 min. The results showed that the solubility of glutelin increased from 2.55 mg/mL to 20.7 mg/mL at pH 7. The size of glutelin aggregates at pH 7 decreased from 900 nm to 400 nm after high temperature treatment (HTT), which was confirmed by atomic force microscopy. The results of small angle X-ray scattering showed that HTT induced the conformational unfolding of glutelin, and the protein in the aggregate was rod like shape as well as the mean square rotation radius decreased from 64.9 to 54.8 Å. Furthermore, Raman spectrum results also agree with the unfolding of glutelin conformation, which was mainly reflected in the changes of tyrosine and tryptophan residues, as well as the decreasing of α-helix content and increasing of ß-sheet content. After being freeze-dried, HTT glutelin has a re-solubilization capacity of 15.48 mg/mL in pH 7 aqueous solution, which was superior to that of spray dried glutelin powder (pH 7, 9.19 mg/mL).

Cardiac-Related Lesions in Newly Diagnosed Patients With Acute Leukemia: A Chinese Population-Based Real-World Study.

The relationship between newly diagnosed acute leukemia (AL) and heart-related lesions remains unclear. This study aimed to investigate baseline cardiac function and risk of cardiovascular diseases (CVDs) in patients with new-onset AL, and provide data on cardiac management strategies for patients with AL. We retrospectively collected data on baseline characteristics, echocardiography, and biochemical blood indicators (e.g., myocardial enzymes) from 408 patients, 200 with newly diagnosed AL, 103 with coronary artery disease (CAD), and 105 controls from January 1, 2015 to August 31, 2019. The creatine kinase isoenzyme myocardial band, lactate dehydrogenase, highly sensitive troponin-I, and B-type natriuretic peptide levels and left ventricular internal diameter (LVID) were significantly higher in patients with newly diagnosed AL than in the control group. The degree of cardiac damage was lower in newly diagnosed AL patients than in CAD patients. The best predictor of heart damage was LVID (AUC [area under the curve] = 0.709; 95% CI [confidence interval]: 0.637-0.781; p < 0.001), and independent prognostic risk factors were age and ejection fraction (HR [hazard ratio] = 1.636; 95% CI: 1.039-2.575; p = 0.033). The ratio of leukemia blasts among patients with AL was positively correlated with cardiac damage. Our data indicated that newly diagnosed AL patients had certain myocardial damage before treatment. Clinicians need to pay attention to these manifestations, which may be related to the prognosis.

Development of a Risk Assessment Model for Early Grade ≥ 3 Infection During the First 3 Months in Patients Newly Diagnosed With Multiple Myeloma Based on a Multicenter, Real-World Analysis in China.

Purpose: The study aimed to assess factors associated with early infection and identify patients at high risk of developing infection in multiple myeloma. Methods: The study retrospectively analyzed patients with MM seen at two medical centers between January 2013 and June 2019. One medical center reported 745 cases, of which 540 of the cases were available for analysis and were further subdivided into training cohort and internal validation cohort. 169 cases from the other medical center served as an external validation cohort. The least absolute shrinkage and selection operator (Lasso) regression model was used for data dimension reduction, feature selection, and model building. Results: Bacteria and the respiratory tract were the most common pathogen and localization of infection, respectively. In the training cohort, PS≥2, HGB<35g/L of the lower limit of normal range, ß2MG≥6.0mg/L, and GLB≥2.1 times the upper limit of normal range were identified as factors associated with early grade ≥ 3 infections by Lasso regression. An infection risk model of MM (IRMM) was established to define high-, moderate- and low-risk groups, which showed significantly different rates of infection in the training cohort (46.5% vs. 22.1% vs. 8.8%, p<0.0001), internal validation cohort (37.9% vs. 24.1% vs. 13.0%, p=0.009) and external validation cohort (40.0% vs. 29.2% vs. 8.5%, p=0.0003). IRMM displayed good calibration (p<0.05) and discrimination with AUC values of 0.76, 0.67 and 0.71 in the three cohorts, respectively. Furthermore, IRMM still showed good classification ability in immunomodulatory (IMiD) based regimens, proteasome-inhibitors (PI) based regimens and combined IMiD and PI regimens. Conclusion: In this study, we determined risk factors for early grade ≥ 3 infection and established a predictive model to help clinicians identify MM patients with high-risk infection.

Public screening for COVID-19 in Wuhan, China and beware of the antibody positive in women and tumor patients.

The novel coronavirus disease 2019 (COVID-19) has become a global health emergency. Early detection and intervention are key factors for improving outcomes in patients with COVID-19. Real-time reverse transcriptase polymerase chain reaction-based molecular assays and antibody for detecting SARS-CoV-2 in respiratory specimens are the current reference standard for COVID-19 diagnosis. Clinical implications of different specimen types for nucleic acid and antibody testing of COVID-19 in Zhongnan hospital of Wuhan University were analyzed. Compared with health groups, tumor patients had higher rate of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) (+/-) immunoglobulin M (IgM) (+) immunoglobulin G (IgG) (+). The rate of SARS-CoV-2 (-) IgM (+) IgG (-) or SARS-CoV-2 (-) IgM (-) IgG (+) in female was significantly higher than that in male. These results can help governments to take screening measures to prevent the COVID-19 pandemic again.

Identification of novel combined biomarkers in the diagnosis of multiple myeloma.

PURPOSE: Multiple myeloma (MM) is a haematological malignant disease with a clonal proliferation of plasma cells, and timely surveillance is helpful to improve the survival rate of patients with MM. However, there is a lack of simple and effective biomarkers for the diagnosis, prognosis, and residual disease evaluation of MM. MATERIAL & METHODS: In the detection cohort, we used the samples from six newly diagnosed MM patients and six control subjects. Plasma proteins were labelled with dimethyl reagents and enriched by lectin AANL6, then the deglycosylated peptides were identified by LC-MS/MS. Differentially expressed proteins were used for further exploration. In the validation cohort, we used 90 newly diagnosed patients with MM and 70 cases of unrelated diseases as controls. The diagnosis performance was analysed by ROC analysis using SPSS. RESULTS: In this study, we show, using lectin blots with AANL6, that glycosylation levels were higher in MM patients than in controls. After AANL6 enrichment, we detected 58 differentially expressed proteins using quantitative proteomics. We further validated one candidate Fibulin-1 (FBLN1). Using an Elisa assay, we showed that FBLN1 expression was increased in plasma of 90 cases of MM, and which was significantly correlated with DKK1 expression. ROC analysis showed that these two markers had a 95.7% specificity for determining the diagnosis of MM. CONCLUSION: These data suggest that the MM cases display increased glycosylation after AANL6 enrichment and that the combined expression of FBLN1 and DKK1 can be used as an effective diagnostic biomarker.

Anti-leukemia activities of selenium nanoparticles embedded in nanotube consisted of triple-helix ß-d-glucan.

Acute myeloid leukemia (AML) is a difficult therapeutic hematological tumor. It is urgent to find a non-toxic natural drug to treat AML. Herein, the selenium nanoparticles (SeNPs) embedded in nanotubes consisted of triple helix ß-(1, 3)-d-glucan (BFP) from the black fungus that were wrapped to form stable inclusion complex BFP-Se, which was self-assembled and exhibited high stability in water. In vitro, the BFP-Se significantly inhibited the proliferation of AML cells and increased the cytotoxicity on AML cells. On single-cell levels, the U937 cells were gradually swelled and lysed with BFP-Se treatment on optofluidics chips. Further, the blood and bone marrow analysis indicated the anti-leukemia effects of BFP-Se in vivo. Moreover, BFP-Se increased the total antioxidant capacity of AML cells and decreased the expression of c-Jun activation domain-binding protein 1 and thioredoxin 1. Our results suggest that this biocompatible polysaccharide nanotube containing Se nanoparticles would provide a novel strategy for AML therapy.

The novel thioredoxin reductase inhibitor A-Z2 triggers intrinsic apoptosis and shows efficacy in the treatment of acute myeloid leukemia.

Chemoresistance and high incidence of relapse in acute myeloid leukemia (AML) patients are associated with thioredoxin (Trx) overexpression. Thus, targeting the Trx system has emerged as a promising approach to treating AML. Both arsenicals and azelaic acid (AZA) are thioredoxin reductase (TrxR) inhibitors and possess antileukemic effects. In this study, to exploit agents with higher potency and lower toxicity, we got some organic arsenicals and further synthesized a series of targeted compounds by binding AZA to organic arsenicals, and then screened the most effective one, N-(4-(1, 3, 2-dithiarsinan-2-yl) phenyl)-azelamide (A-Z2). A-Z2 showed a stronger inhibitory effect against TrxR activity and in AML cell lines than did AZA or arsenicals. Additionally, A-Z2 was less toxic to healthy cells compared with traditional chemotherapeutic drugs. A-Z2 induces apoptosis by collapsing of mitochondrial membrane potential, reducing ATP level, releasing of cytochrome c and TNF-α, activating of caspase 9, 8 and 3. Analysis of the mechanism revealed that A-Z2 activates the intrinsic apoptotic pathway by directly selectively targeting TrxR/Trx and indirectly inhibiting NF-κB. A-Z2's better efficacy and safety profile against arsenicals and azelaic acid were also evident in vivo. A-Z2 had better plasma stability and biological activity in rats. A-Z2-treated mice displayed significant symptom relief and prolonged survival in a patient-derived xenograft (PDX) AML model. Herein, our study provides a novel antitumor candidate and approach for treating AML.

Prestress-loading effect on the current-voltage characteristics of a piezoelectric p-n junction together with the corresponding mechanical tuning laws.

A model is proposed to study the diffusion of non-equilibrium minority carriers under the influence of a piezo potential and to calculate the corresponding current-voltage (I-V) characteristics of a piezoelectric p-n junction exposed to mechanical loading. An effective solution to describe this non-equilibrium process has been put forward including two concepts: the influence of prestress loading on p-n junctions in a quasi-electrostatic thermal equilibrium and the perturbation of small fields superposed on the obtained quasi-electrostatic solutions. A few useful results are obtained through this loaded p-n junction model. Under a forward-bias voltage, a tensile (compressive) loading raises (reduces) the potential barrier of the space charge zone (SCZ), i.e., produces an equivalent reverse- (forward-) electric voltage on the SCZ. When a piezoelectric p-n junction is exposed to a reverse-bias voltage, the current density monotonically decreases with increasing reverse voltage and gradually approaches saturation. A bigger tensile (compressive) loading produces a smaller (larger) saturation current density. The appearance of an equivalent voltage on the SCZ induced by prestress indicates that the performance of a p-n junction with the piezo effect can be effectively tuned and controlled by mechanical loadings. Meanwhile, numerical results show that a loading location closer to the SCZ produces a stronger effect on the I-V characteristics of a piezoelectric p-n junction, implying that the tuning effect of mechanical loadings depends on how much influence of the deformation-induced electric field can reach the SCZ. Furthermore, it is also found that the deformation-induced electric field becomes weak with increasing doping because the higher doping is corresponding to the stronger electric leakage. Thus, the higher mechanical tuning performance on higher doped piezoelectric p-n junctions requires the prestress loadings to be applied closer to the interface of p- and n-zone. This study on a non-equilibrium process of piezoelectric p-n junctions has significance for piezotronics.

TGF-ß receptor inhibitor LY2109761 enhances the radiosensitivity of gastric cancer by inactivating the TGF-ß/SMAD4 signaling pathway.

Radiotherapy is used to treat gastric cancer (GC); however, radioresistance challenges the clinical outcomes of GC, and the mechanisms of radioresistance in GC remain poorly understood. Here, we report that the TGF-ß receptor inhibitor, LY2109761 (LY), is a potential radiosensitizer both in vitro and in vivo. As per the Cancer Genome Atlas database, TGF-ß overexpression is significantly related to poor overall survival in GC patients. We demonstrated that the TGF-ß/SMAD4 signaling pathway was activated in both radioresistant GC cells and radioresistant GC patients. As a TGF-ß receptor inhibitor, LY can enhance the activities of irradiation by inhibiting cell proliferation, decreasing clonogenicity and increasing apoptosis. Moreover, LY attenuated the radiation-induced migration and invasion, epithelial-mesenchymal transition (EMT), inflammatory factor activation, immunosuppression, and cancer stem cell characteristics of GC cells, thus leading to radiosensitization of the GC cells. We confirmed that LY reduced tumor growth, inhibited TGF-ß/SMAD4 pathway activation and reversed irradiation-induced EMT in a tumor xenograft model. Our findings indicate that the novel TGF-ß receptor inhibitor, LY, increases GC radiosensitivity by directly regulating the TGF-ß/SMAD4 signaling pathway. These findings provide new insight for radiotherapy in GC patients.

Influence of Doping Concentration on the Outputs of a Bent ZnO Nanowire.

In this article, the governing equation on electric potential is established by coupling both the semiconducting characteristics and the piezo-effect property of a ZnO nanowire (ZNW). Carrier redistributions are solved for different doping concentrations while considering the effect of both types of charge carriers. The reason for the semiconducting characteristics of a ZNW to induce electric leakage in energy-harvesting is illustrated in detail and a proper initial carrier concentration, n0 or p0 , is obtained as follows: for a n-type ZnO fiber and for a p-type one under the intrinsic carrier concentration ni = 1.0×1016(1/m3) , which is of significance in both the design and the practical applications of piezotronics and piezo-phototropic devices.

Compound kushen injection suppresses human acute myeloid leukaemia by regulating the Prdxs/ROS/Trx1 signalling pathway.

BACKGROUND: The increase in the levels of reactive oxygen species (ROS) in acute myeloid leukemia (AML) patients has been previously described; thus, it is important to regulate ROS levels in AML. METHODS: Flow cytometry were used to assess the in vitro effect of compound kushen injection (CKI). Quantitative proteomics were used to analyse the mechanism. The AML patient-derived xenograft (PDX) model were used to evaluate the in vivo effect of CKI. RESULTS: We found that intracellular ROS levels in AML cells were decreased, the antioxidant capacity were increased when treated with CKI. CKI inhibited the proliferation of AML cells and enhanced the cytotoxicity of AML cells, which has few toxic effects on haematopoietic stem cells (HSCs) and T cells. At the single-cell level, individual AML cells died gradually by CKI treatment on optofluidic chips. CKI promoted apoptosis and arrested cell cycle at G1/G0 phase in U937 cells. Furthermore, higher peroxiredoxin-3 (Prdx3) expression levels were identified in CKI-treated U937 cells through quantitative proteomics detection. Mechanically, the expression of Prdx3 and peroxiredoxin-2 (Prdx2) was up-regulated in CKI-treated AML cells, while thioredoxin 1 (Trx1) was reduced. Laser confocal microscopy showed that the proteins Prdx2 could be Interacted with Trx1 by CKI treatment. In vivo, the survival was longer and the disease was partially alleviated by decreased CD45+ immunophenotyping in peripheral blood in the CKI-treated group in the AML PDX model. CONCLUSIONS: Antioxidant CKI possess better clinical application against AML through the Prdxs/ROS/Trx1 signalling pathway.

Nonlinear effect of carrier drift on the performance of an n-type ZnO nanowire nanogenerator by coupling piezoelectric effect and semiconduction.

In piezoelectric semiconductors, electric fields drive carriers into motion/redistribution, and in turn the carrier motion/redistribution has an opposite effect on the electric field itself. Thus, carrier drift in a piezoelectric semiconducting structure is essentially nonlinear unless the induced fluctuation of carrier concentration is very small. In this paper, the nonlinear governing equation of carrier concentration was established by coupling both piezoelectric effect and semiconduction. A nonlinear carrier-drift effect on the performance of a ZnO nanogenerator was investigated in detail and it was elucidated that carrier motion/redistribution occurs in the ZnO nanowire (ZNW) cross section while there is no carrier motion in the axial direction. At the same time, we noted that the amplitude of boundary electric charge grows with increasing deformation, but the peaks of boundary electric charge do not appear at the cross-section endpoints. Thus, in order to effectively improve the performance of the ZNW nanogenerator, the effect of electrode configuration on the piezoelectric potential difference and output power was analyzed in detail. The electrode size for the optimal performance of a ZnO nanowire generator was proposed. This analysis that couples electromechanical fields and carrier concentration as a whole has some referential significance to piezotronics.