Self-expansion full information optimization strategy: Convenient and efficient method for near infrared spectrum auto-analysis.

An essential step in the application of near infrared spectroscopy technology is the spectrum preprocessing. A reasonable implementation of it ensures that the effective spectral information is correctly extracted and, also that the model's accuracy is increased. However, some analysts' research still uses the manual approach of trial and error, particularly those less skilled ones. Previous papers have provided preprocessing optimization algorithms for NIR, but there are still some problems that need to be resolved, such as the unwieldy sequence determination of preprocessing method or, the fluctuated optimization outcomes or, lack of sufficient statistical information. This research suggests a spectrum auto-analysis methodology named self-expansion full information optimization strategy, a new powerful open-source technique for concurrently addressing all of these above issues simultaneously. For the first time in the field of chemometrics, this algorithm offers a reliable and effective automatic near infrared auto-modelling method based on the statistical informatics. With the aid of its built-in modules, such as information generators, spectrum processors, etc., it is able to fully search the common preprocessing techniques, which is determined by Monte Carlo cross validation. Then the final ensemble calibration model is built by employing the optimized preprocessing schemes, along with the wavelength variables screening algorithm. The optimization strategy can offer the user objective useful statistics information created throughout the modeling process to further examine the model's effectiveness. The results demonstrate that the suggested method can easily and successfully extract spectrum information and develop calibration models by putting it to the test on two groups of actual near-infrared spectral data. Additionally, this optimization strategy can also be applied to other spectrum analysis areas, such Raman spectroscopy or infrared spectroscopy, by changing a few of its parameters, and has extraordinary application value.

Development of a micro-Raman system for in vivo studying the mechanism of laser biological effects.

The laser irradiation on organism will produce a series of biological effects, which can be used for basic medical research, diagnosis and treatments of diseases. However, the mechanism of this biological effects is still unclear. As a sensitive molecular monitoring technique, Raman spectroscopy has became a very popular detection method in biomedical research especially in vivo study. In this paper, we present a compact and flexible micro-Raman system for in vivo studying the mechanism of laser biological effects. The system has the two functions of laser induction and Raman measurement, which can realize the micro-area radiation of laser and simultaneously collect the corresponding Raman spectra in vivo. The detection method provided by this home-built system is able to deepen the understanding of laser biological effects mechanism at molecular level, so it is expected that the system is significant for the treatments and diagnosis of diseases in the near future.

The clinical and immunological characteristics related to salivary gland enlargement in primary Sjögren's syndrome: a retrospective cross-sectional study.

Background: Salivary gland enlargement (SGE) is one of the common manifestations in primary Sjögren's syndrome (pSS) patients who are first referred to the hospital of stomatology. Whether the characteristics of the pSS patients with SGE differ from those of the ones without SGE remains unclear. Therefore, this study aimed at investigating the clinical and immunological characteristics related to SGE in pSS, to provide a comprehensive understanding of the clinical phenotype of pSS with SGE. Methods: In this retrospective cross-sectional study, medical records of patients diagnosed with pSS from 2016 to 2021 were evaluated. The included patients were divided into the SGE and non-SGE groups. Patient data including general clinical data, radiographic and B-ultrasound examination data, and immunological data were extracted. Intergroup differences were analyzed using the chi-square test, Fisher's exact test, and non-parametric tests with SPSS 23.0. Binary logistic regression analysis was further performed to determine the factors related to SGE in pSS. Results: Two hundred and three patients with pSS were included, including 126 and 77 patients with and without SGE, respectively. Univariate analysis showed that compared to the non-SGE group, the SGE group was younger, had dry eye symptom for a longer duration, and had a higher proportion of patients with severe conditions on salivary gland radiography (P<0.05). Regarding immunological indicators, the levels of anti-Ro52, anti-SSA (Ro60), and anti-SSB antibodies; immunoglobulin (Ig)G; IgA; and rheumatoid factor (RF) and erythrocyte sedimentation rate (ESR) were significantly higher in the SGE group (P<0.05). Binary logistic regression analysis showed that younger age and high anti-Ro52 levels were independent factors related to SGE in pSS. Conclusions: SGE is highly consistent with increased immunological indicators, reflecting disease activity. pSS patients with SGE were younger than those without. Special attention should be paid to the changes in the anti-Ro52 level since it is an independent factor related to SGE in pSS.

A meta-analysis on efficacy and safety of rituximab for neuromyelitis optica spectrum disorders.

BACKGROUND: To assess the efficacy and safety of rituximab (RTX) in the treatment of neuromyelitis optica spectrum diseases (NMOSDs), and give a guideline on clinical medication. METHODS: The databases of Pubmed, Embase, Cochrane Library, CNKI, and Wan fang were systematically searched by computer, and the search period was from the establishment of the databases until January 2022. To collect the trials of RTX in the treatment of NMOSDs, two researchers completed literature screening, quality assessment, and data extraction independently. Statistical analysis was performed using Review Manager 5.3 and Stata 15.1 software. RESULTS: There were 37 studies in the meta-analysis, including 5 randomized controlled trials (RCTs) and 32 observational studies. Meta-analysis results revealed that NMOSDs patients treated with RTX significantly reduced the annualized relapse rate (ARR) (weighted mean difference [WMD] = 1.45, 95% confidence interval [CI]: 1.24-1.66, P < .01) and the Expanded disability status scale (EDSS) scores (WMD = 1.34, 95%CI: 1.25-1.44, P < .01). RTX is more effective than azathioprine (AZA) in the treatment of NMOSDs (ARR: WMD = -0.54, 95% CI: -0.75 to -0.33; EDSS: WMD = -0.65, 95% CI: -0.83 to -0.48; P < .0001).There was no difference in ARR and EDSS scores between anti-aquapor in-4-antibody seropositive NMOSD and seronegative NMOSD patients treated with RTX (ARR: WMD = -0.01, 95% CI: -0.25 to 0.24, P = .96 > 0.05; EDSS: WMD = 0, 95% CI: -0.30 to 0.31, P = .99 > 0.05). In this study, 681 patients were recorded safety data of RTX therapy, 23% (156 patients) had adverse events, and 0.7% (5 patients) of NMOSDs discontinued due to severe adverse reactions. CONCLUSIONS: NMOSDs patients treated with RTX can significantly reduce the relapse frequency and EDSS scores, and also improve neurological dysfunction, besides the efficacy is better than azathioprine. RTX has a high incidence of adverse reactions, which are mild and with certain self limited, it should be cautious in clinical medication.

A powerful tool for near-infrared spectroscopy: Synergy adaptive moving window algorithm based on the immune support vector machine.

Traditional trial-and-error methods are time-consuming and inefficient, especially very unfriendly to inexperienced analysts, and are sometimes still used to select preprocessing methods or wavelength variables in near-infrared spectroscopy (NIR). To deal with this problem, a new optimization algorithm called synergy adaptive moving window algorithm based on the immune support vector machine (SA-MW-ISVM) is proposed in this paper. Following the principle of SA-MW-ISVM, the original problem of calibration model optimization is transformed into a mathematical optimization problem that can be processed by the proposed immune support vector machine regression algorithm. The main objective of this optimization problem is the calibration model performance; meanwhile, the constraint conditions include a reasonable spectral data value, spectral data preprocessing method, and calibration model parameters. A unique antibody structure and specific coding and decoding method are used to achieve collaborative optimization in NIR spectroscopy. The tests on four actual near-infrared datasets, including a group of gasoline and three groups of diesel fuels, have shown that the proposed SA-MW-ISVM algorithm can significantly improve the calibration performance and thus achieve accurate prediction results. In the case of gasoline, the SA-MW-ISVM algorithm can decrease the prediction error by 44.09% compared with the common benchmark partial least square (PLS). Meanwhile, in the case of diesel fuels, the SA-MW-ISVM algorithm can decrease the prediction error of cetane number, freezing temperature, and viscosity by 9.99%, 28.69%, and 43.85%, respectively, compared with the PLS. The powerful prediction performance of the SA-MW-ISVM algorithm makes it an ideal tool for modeling near-infrared spectral data or other related application fields.

Laser tweezers Raman spectroscopy combined with machine learning for diagnosis of Alzheimer's disease.

Alzheimer's disease (AD) is a common nervous system disease to affect mostly elderly people over the age of 65 years. However, the diagnosis of AD is mainly depend on the imaging examination, clinical assessments and neuropsychological tests, which may get error diagnosis results and are not able to detect early AD. Here, a rapid, non-invasive, and high accuracy diagnostic method for AD especially early AD is provided based on the laser tweezers Raman spectroscopy (LTRS) combined with machine learning algorithms. AD platelets from different 3xTg-AD transgenic rats at different stages of disease are captured to collect high signal-to-noise ratio Raman signals without contact by LTRS, which is then combined with partial least squares discriminant analysis (PLS-DA), support vector machine (SVM) and principal component analysis (PCA)-canonical discriminate function (CDA) for classification. The results show that the normal and diseased platelets at 3-, 6- and 12-month AD are successfully distinguished and the accuracy is 91%, 68% and 97% respectively, which demonstrates the suggested method can provide a precise detection for AD diagnosis at early, middle and advanced stages.

Sex- related differences in the factors associated with outcomes among patients with strokes of undetermined source: a hospital-based follow-up study.

Objective: Sex-related differences are well established among stroke patients, including the incidence and prevalence of stroke being higher among men than among women. However, the sex-related factors for differences in the outcomes of strokes of undetermined source (SUSs) have not been well described, especially in the Chinese population. We assessed the sex-related differences in the factors associated with outcomes among patients with SUSs in China.Method: Between January 2011 and December 2018, we recruited 205 patients diagnosed with SUSs from Kailuan General Hospital (China). The clinical features, risk factors, and outcome data were collected for the patients at 3 and 12 months after their strokes.Results: There were higher frequencies of hyperlipidemia (27.8% vs. 26.4%), smoking (41.4% vs. 5.6%), and alcohol consumption (21.8% vs. 0%) for male patients than for female patients. However, women were more likely than men to have hypertension (63.9% vs. 46.6%), diabetes (27.8% vs. 20.3%), and atrial fibrillation (9.7% vs. 5.3%); they were also more likely to be obese (16.7% vs. 12.0%). There were no significant differences in outcome between the sexes. Among men, severe strokes were associated with higher case fatality and disability risks at 12 months after stroke onset; hyperlipidemia was a risk factor for recurrence within 3 months of the initial stroke. Among women, severe strokes also increased the risk of disability; in women, high total cholesterol (TC) and age were associated with poor outcomes.Conclusion: The factors associated with outcomes in SUS differed by sex. For male patients, more severe stroke and hyperlipidemia were associated with poor outcomes in SUS. Risk factors for poor outcomes in female patients were stroke severity, age, and TC level. These findings suggest that taking measures to manage blood lipid levels and severe stroke among patients with SUS is important for both male and female patients and is crucial for reducing the burden of stroke in China.

Cholinesterase inhibitors and memantine for Parkinson's disease dementia and Lewy body dementia: A meta-analysis.

Recently, several randomized controlled trials on the use of cholinesterase inhibitors or memantine as treatments for cognitive impairment in Parkinson's disease (CIND-PD), Parkinson's disease with dementia (PDD) and dementia with Lewy bodies (DLB) were completed. The present study provided a meta-analysis of these studies to evaluate the efficacy of cholinesterase inhibitors and memantine on CIND-PD, PDD and DLB. The Cochrane Library, Pubmed, Embase and Web of Science databases were searched to retrieve eligible studies. As primary efficacy outcomes, cognitive function, global impression, behavioral symptoms and motor function were selected, while falling and adverse events were regarded as safety outcomes. Of note, domain-specific cognitive function was assessed as a primary efficacy outcome and falling as a safety outcome, which, to the best of our knowledge, has not been studied previously in CIND-PD, PDD and DLB. A total of 15 trials were included in the present meta-analysis. The results revealed that treatment with cholinesterase inhibitors resulted in improvements in cognitive function, the clinician's global impression, behavioral symptoms and motor function, in accordance with the results of previous studies. Furthermore, it was revealed that cholinesterase inhibitors had a significant effect on attention, processing speed, executive functions, memory and language; however, they did not improve visuospatial cognition compared with placebos. Memantine had a significant effect on attention, processing speed and executive functions. In addition, cholinesterase inhibitors and memantine did not significantly reduce falling. It was demonstrated that an increased number of adverse events occurred in the pooled cholinesterase inhibitors and memantine group, compared with that in the placebo group (risk ratio (RR)=1.09; 95% confidence interval (CI): 1.04-1.16; P=0.001); however, in the subgroup analysis, only the rivastigmine group experienced significantly more adverse events than the placebo group (85 vs. 73%; RR=1.18; 95% CI: 1.08-1.29; P=0.0001), but donepezil and memantine did not produce any significant adverse events. In conclusion, cholinesterase inhibitors and memantine have an effect not only on global cognitive function and motor function, but also on attention, processing speed, executive functions, memory and language. However, careful monitoring of the side effects of rivastigmine may be required. Further clinical trials are required to verify these conclusions.

Observation of clinical efficacy of application of enhanced recovery after surgery in perioperative period on esophageal carcinoma patients.

PURPOSE: To observe the clinical efficacy of the application of enhanced recovery after surgery (ERAS) in the perioperative period of esophageal carcinoma patients. METHODS: A total of 114 patients who were admitted to Affiliated Hospital of Jining Medical University for surgical treatment of esophageal carcinoma between June 2012 and June 2016 were enrolled and randomly divided into the intervention group and the regular group according to the difference of management procedures during the perioperative period. ERAS was carried out in 57 patients in the intervention group, while conventional management procedures were applied in 57 patients in the regular group. Thereafter, compared were the fluctuations in nutritional indicators and immunological indicators, postoperative complications, time to recovery of gastrointestinal function, length of stay (LOS) in hospital and cost of patients between the two groups. RESULTS: Seven days post-operation in the intervention group, the evaluation indexes of nutrition status, including total protein (TP), albumin (ALB), prealbumin (PA) and transferrin (TF), and of immunological functions, including immunoglobulin G (IgG), immunoglobulin A (IgA), immunoglobulin M (IgM) and total blood lymphocyte count (TLC), were significantly higher than those in the regular group. As for postoperative complications, the incidence rate of the intervention group was remarkably lower than that of the regular group; the recovery time of gastrointestinal function in the intervention group was shorter than that in the regular group; the LOS in the intervention group was also shorter than that in the regular group; the in-hospital cost in the intervention group was also lower than that in the regular group. All differences above were statistically significant (p<0.05). CONCLUSION: During the perioperative period of esophageal carcinoma patients, ERAS should be fully applied to sustain the good status, and promote the recovery of immunological functions and gastrointestinal functions; at the same time, ERAS also reduces the incidence rate of postoperative complications, LOS and in-hospital cost, and we maintain that ERAS should be performed in clinical practice.

Evaluation of changes in left ventricular structure and function in hypertensive patients with coronary artery disease after PCI using real-time three-dimensional echocardiography.

We aimed to evaluate the changes in left ventricular structure and function in hypertensive patients with coronary artery disease before and after percutaneous coronary intervention (PCI) using real-time three-dimensional echocardiography. Two hundred and eighty hypertensive patients with coronary artery disease undergoing PCI and 120 cases who did not receive PCI in our hospital were selected as the subjects of our study. All patients were administered with routine antiplatelet, anticoagulant, lipid-lowering, antihypertensive, dilating coronary artery and other medications. The left ventricular systolic function and systolic synchrony index changes before and after subjects were treated by PCI were analyzed using three-dimensional echocardiography. At 2 days before surgery, there were no significant differences in the left ventricular end-diastolic volume, left ventricular end-systolic volume (LVESV) and ejection fraction (EF) between the two patient groups (P>0.05). At 3 months and 9 months, the two key time points after PCI, the LVESV level in the PCI group was distinctly decreased, while EF was significantly increased (P<0.05). In addition, before treatment, there were no significant differences in the parameters of time from the corresponding segment of the myocardium to the minimal systolic volume in two patient groups, such as Tmsv-16SD, Tmsv-16Dif, Tmsv-12SD, Tmsv-12Dif, Tmsv-6SD and Tmsv-6Dif (P>0.05); however, the parameters of time from the corresponding segment of the myocardium to the minimal systolic volume in patients in the PCI group were significantly reduced at 3 and 9 months after surgery (P<0.05). Three-dimensional echocardiography can evaluate the critical parameters in the prognosis of hypertensive patients with coronary artery disease after PCI accurately and in real-time, which may play a significant role.

RasGRP3, a Ras guanyl releasing protein 3 that contributes to malignant proliferation and aggressiveness in human esophageal squamous cell carcinoma.

Esophageal squamous cell carcinoma (ESCC) is one of the most common cancers worldwide; however, clinical and pathological parameters have limited ability in discriminating between clinically significant and indolent ESCC. Since RasGRP3 transcript levels have prognostic value in discriminating ESCC with different clinical aggressiveness, we decided to investigate its putative oncogenic role in ESCC. We found that RasGRP3 was highly expressed in ESCC cells. Suppression of endogenous RasGRP3 expression in esophageal cell lines reduced Ras-GTP formation as well as AKT phosphorylation. RasGRP3 suppression also inhibited cell invasion and migration and reduced proliferation, demonstrating the importance of RasGRP3 for the transformed phenotype of melanoma cells. Suppression of RasGRP3 expression in these cells inhibited downstream RasGRP3 responses and suppressed cell growth and migration, confirming the functional role of RasGRP3 in the altered behaviour of these cells. This suggests that RasGRP3 may function as a Ras activator in the phosphoinositide signalling pathway and may potentially serve as a new therapeutic target.

A comparative study on the efficacy of fast-track surgery in the treatment of esophageal cancer patients combined with metabolic syndrome.

The purpose of our study was to evaluate the clinical efficacy of fast-track surgery (FTS) in the treatment of esophageal cancer patients combined with metabolic syndrome. Ninety-four esophageal cancer patients with metabolic syndrome were selected in Affiliated Hospital of Jining Medical University from March, 2016 to February, 2017. Patients were randomly divided into control group and observation group with 47 cases in each group. Patients in observation group were treated with FTS, while patients in control group were treated with traditional method. Intraoperative blood loss, the number of dissected lymph nodes, operation time, postoperative hospital stay, the cost of hospitalization, postoperative readmission rate, and incidence of postoperative complications were compared between the groups. Levels of serum inflammatory cytokines (TNF-α and hs-CRP), fat cell factor chemerin and leptin (LP) were detected by enzyme-linked immunosorbent assay (ELISA) at 1 month after surgery. Levels of serum total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C) at 1 month after surgery were compared between groups. Levels of hemoglobin (Hb), albumin (Alb), prealbumin (PAB) and transferrin (TRF) at 1 month after surgery were also compared between the two groups. Treatment of cancer quality-of-life questionnaire-esophageal cancer (OES-18) module was used to evaluate the symptoms of patients at one month after surgery. It turned out that no significant differences in intraoperative blood loss, operation time and the number of dissected lymph nodes were found between groups (p>0.05). Postoperative hospital stay, the cost of hospitalization, postoperative readmission rate and the incidence of postoperative complications were significantly lower in observation group than in control group (p<0.05). Levels of TNF-α, hs-CRP, chemerin and LP in observation group were significantly lower than those in control group at one month after surgery (p<0.05). Levels of TC, TG and LDL-C were significantly lower and HDL-C level was significantly higher in observation group than in control group at one month after surgery (p<0.05). Levels of Hb and Alb were significantly lower and levels of PAB and TRF were significantly higher in observation group than in control group at one month after surgery (p<0.05). OES-18 score of observation group was significantly better than that of control group at one month after surgery (p<0.05). As a conclusion, FTS can promote postoperative rehabilitation, shorten hospital stay, reduce economic burden and reduce the rehospitalization rate of esophageal cancer patients. At the same time, FTS can also improve the lipid metabolism, nutritional status and regulate the differentiation of adipocytes, alleviate the low inflammatory response state, which in turn promotes metabolic syndrome.

[Application of anaerobic bacteria detection in oral and maxillofacial infection].

OBJECTIVE: To investigate the distribution and drug resistance of anaerobic bacteria in the patients with oral and maxillofacial infection. METHODS: Aerobic and anaerobic bacteria cultures from 61 specimens of pus from the patients with oral and maxillofacial infection in the Department of Oral and Maxillofacial Surgery, Peking University School of Stomatology were identified. The culture type was evaluated by API 20A kit and drug resistance test was performed by Etest method. The clinical data and antibacterial agents for the treatment of the 61 cases were collected, and the final outcomes were recorded. RESULTS: The bacteria cultures were isolated from all the specimens, with aerobic bacteria only in 6 cases (9.8%), anaerobic bacteria only in 7 cases (11.5%), and both aerobic and anaerobic bacteria in 48 cases (78.7%). There were 55 infected cases (90.2%) with anaerobic bacteria, and 81 anaerobic bacteria stains were isolated. The highest bacteria isolation rate of Gram positive anaerobic bacteria could be found in Peptostreptococcus, Bifidobacterium and Pemphigus propionibacterium. No cefoxitin, amoxicillin/carat acid resistant strain was detected in the above three Gram positive anaerobic bacteria. The highest bacteria isolation rate of Gram negative anaerobic bacteria could be detected in Porphyromonas and Prevotella. No metronidazole, cefoxitin, amoxicillin/carat acid resistant strain was found in the two Gram negative anaerobic bacteria. In the study, 48 patients with oral and maxillofacial infection were treated according to the results of drug resistance testing, and the clinical cure rate was 81.3%. CONCLUSION: Mixed aerobic and anaerobic bacteria cultures are very common in most oral and maxillofacial infection patients. Anaerobic bacteria culture and drug resistance testing play an important role in clinical treatment.

[Evaluation of the rapid trehalose test for the identification of the Candida glabrata].

OBJECTIVE: To explore a rapid and cost-effective method for identification of Candida glabrata through the comparison of two different methods, using molecular methods of sequencing as gold standard. METHODS: From our clinic, 200 strains of suspected Candida glabrata were collected during the last 3 years and selected after incubation in CHROMagar Candida medium for 48 h. By comparing the results of the CHROMagar Candida medium, the identification of the rapid trehalose test for different kinds of strains were analyzed under incubation in the tubes for 3 h, 6 h, and 24 h at 37 °C and 42 °C, respectively. All the strains were identified to species level by methods of sequencing. The optimal time and temperature of the trehalose test for the identification of Candida glabrata were assessed. Two different methods, CHROMagar Candida medium and the rapid trehalose test, in identification of Candida glabrata were compared. RESULTS: In all the 200 strains, Candida glabrata ferment trehalose with 3 h incubation under 42 °C were the optimal time and temperature for fermenting trehalose. The accuracy, sensitivity, and specificity of the rapid trehalose test were 99.00% (198/200), 98.66% (147/149) and 100.00% (51/51). The accuracy rate of CHROMagar Candida medium was 79.50% (159/200), the sensitivity and specificity were only 89.93% (134/149) and 49.02% (25/51), however, compared with the domestic current popular methods, the rapid trehalose test had better time efficiency ratio. CONCLUSION: The evaluation results suggest that the rapid trehalose test has advantages in terms of operational convenience and low cost, and the results can be obtained in 3 h. Therefore, it has application value in clinical laboratory.

Highly efficient, solution processed electrofluorescent small molecule white organic light-emitting diodes with a hybrid electron injection layer.

Highly efficient, solution-processed, and all fluorescent white organic light-emitting diodes (WOLEDs) based on fluorescent small molecules have been achieved by incorporating a low-conductivity hole injection layer and an inorganic-organic hybrid electron injection layer. The light-emission layer is created by doping a fluorescent π-conjugated blue dendrimer host (the zeroth generation dendrimer, G0) with a yellow-emitting fluorescent dopant oligo(paraphenylenevinylene) derivative CN-DPASDB with a doping ratio of 100:0.15 (G0:CN-DPASDB) by weight. To suppress excessive holes, the high-conductivity hole injection layer (PEDOT:PSS AI 4083) is replaced by the low-conductivity PEDOT:PSS CH 8000. To facilitate the electron injection, a hybrid electron injection layer is introduced by doping a methanol/water-soluble conjugated polymer poly[(9,9-bis(30-(N,N-dimethylamino)propyl)-2,7-fluorene)-alt-2,7-(9,9-dioctylfluorene)] (PFNR2) with solution-processed cesium fluoride (CsF). The device achieves a maximum luminous efficiency of 17.0 cd A(-1) and a peak power efficiency of 15.6 lm W(-1) at (0.32, 0.37) with a color rendering index of 64.

Improving the stability of bulk heterojunction solar cells by incorporating pH-neutral PEDOT:PSS as the hole transport layer.

In the application of traditional bulk heterojunction polymer solar cells, to prevent the etching of ITO by the acidic poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) and thereby improve the device stability, pH-neutral PEDOT:PSS is introduced as the hole transport layer (HTL). After treating the neutral PEDOT:PSS with UV-ozone and with an oxygen plasma, the average power conversion efficiency (PCE) of the device increases from 3.44% to 6.60%. Such surface treatments reduce the energy level offset between the HTL and the active layer, which increases the open circuit voltage and enhances hole transportation, leading to the PCE improvement. Moreover, the devices with the neutral PEDOT:PSS HTL are more stable in air than those with the acidic PEDOT:PSS HTL. The PCE of the devices with the acidic PEDOT:PSS HTL decreases by 20% after 7 days and 45% after 50 days under ambient conditions, whereas the PCE of the devices with the pH-neutral PEDOT:PSS HTL decreases by only 9 and 20% after 7 and 50 days, respectively. X-ray photoelectron spectroscopy shows that the acidic PEDOT:PSS etches the indium from the indium-tin-oxide (ITO) electrode, which is responsible for the degradation of the device. In comparison, the diffusion of the indium is much slower in the devices with the pH-neutral PEDOT:PSS HTL.

All-solution processed polymer light-emitting diode displays.

Adopting the emerging technology of printed electronics in manufacturing novel ultrathin flat panel displays attracts both academic and industrial interests because of the challenge in the device physics and the potential of reducing production costs. Here we produce all-solution processed polymer light-emitting diode displays by solution-depositing the cathode and utilizing a multifunctional buffer layer between the cathode and the organic layers. The use of ink-jetted conducting nanoparticles as the cathode yields high-resolution cathode patterns without any mechanical stress on the organic layers. The buffer layer, which offers the functions of solvent-proof electron injection and proper affinity, is fabricated by mixing the water/alcohol-soluble polymer and a curable epoxy adhesive. Our 1.5-inch polymer light-emitting diode displays are fabricated without any dead pixels or dead lines. The all-solution process eliminates the need for high vacuum for thermal evaporation of the cathode, which paves the way to industrial roll-to-roll manufacturing of flat panel displays.