Counting Process Based Dimension Reduction Methods for Censored Outcomes

We propose a class of dimension reduction methods for right censored survival data using a counting process representation of the failure process. Semiparametric estimating equations are constructed to estimate the dimension reduction subspace for the failure time model. The proposed method addresses two fundamental limitations of existing approaches. First, using the counting process formulation, it does not require any estimation of the censoring distribution to compensate the bias in estimating the dimension reduction subspace. Second, the nonparametric part in the estimating equations is adaptive to the structural dimension, hence the approach circumvents the curse of dimensionality. Asymptotic normality is established for the obtained estimators. We further propose a computationally efficient approach that simplifies the estimation equation formulations and requires only a singular value decomposition to estimate the dimension reduction subspace. Numerical studies suggest that our new approaches exhibit significantly improved performance for estimating the true dimension reduction subspace. We further conduct a real data analysis on a skin cutaneous melanoma dataset from The Cancer Genome Atlas. The proposed method is implemented in the R package "orthoDr".Comment: First versio

Clinical Distribution and Drug Resistance of 224 Strains of Pseudomonas Aeruginosa

Objective: To provide evidence for a rational and effective prevention and treatment of Pseudomonas aeruginosa, the clinical characteristics and the resistance to various antibiotics of were investigated.Methods：A retrospective analysis of 224 strains of Pseudomonas aeruginosa isolated from various specimens from various clinical departments of our hospital (April 1, 2018 to June 31, 2019) were conducted. Identification and drug susceptibility test of isolated strains was performed using a fully automatic bacterial identification analyzer (MicroScan WalkAway-96 plus), and data analysis was performed using WH0NET5.6 software. Result：Among all the bacteria isolated in our hospital during the above period, Pseudomonas aeruginosa accounted for 10.09% of them all and 12.57% of Gram-negative bacilli, respectively. These isolates were mainly derived from sputum specimens (68.75%), mainly from male patients (70.54%), and mostly 61-70 (27.23%) or 51-60 (22.77%) years old. Pseudomonas aeruginosa isolates are mainly from Rehabilitation Ward, ICU, and Liver Transplantation Unit, accounted for 29.91%, 12.95% and 10.27% of all isolates, respectively. The sensitivity of Pseudomonas aeruginosa to various antibacterial drugs, in the order of high to low were carbapenems, aztreonam, quinolones, cephalosporins, piperacillin/ tazobactam, aminoglycoside, with a lowest resistance rate (2.4%) to amikacin and a highest resistance rate to imipenem (33.0%). Conclusion：The isolation rate of Pseudomonas aeruginosa was relatively stable during the study period, and among all the P. aeruginosa detected, most of them were from the respiratory secretions of elderly male patients. The resistance rate of Pseudomonas aeruginosa isolates to various antibiotics is mainly within 30%. Clinical units such as Rehabilitation Ward, ICU, and Liver Transplantation Unit have a high detection rate, therefore, these departments should be monitored in a focused manner. Our research provide a scientific basis for the rational use of antibiotics and a better control of Pseudomonas aeruginosa infection

Combined Detection of Mean Platelet Volume and Immunoglobins as a Strategy for the Diagnosis of Systemic Lupus Erythematosus

Objective:To explore the possibility of diagnosing and monitoring patients with systemic lupus erythematosus (SLE) using the combination of mean platelet volume (MPV) and routine immunoglobulin test. Method:116 patients with SLE were divided into 3 groups according to their clinical characteristics, including 29 patients with renal impairment, 44 cases of active stage and 43 cases of inactive patients. 40 healthy subjects were randomly selected as controls. Subjects were tested for routine blood test and plasma Immunoglobins, such as IgG, IgA, IgM, C3, C4, CH50, CRP. The results were analyzed and the characteristics of each group of subjects were determined, the correlation between test results and diagnosis were studied. Result: In comparison to the control group, the serum level of MPV, C3 and C4 were decreased (P<0.05), and C reactive protein level was elevated (P<0.001) in the three groups of SLE patients. The IgG level in active and inactive SLE patients was increased (P<0.0001), CH50 level was decreased in patients with inactive SLE (P<0.05), IgA level of active SLE subjects was found to be elevated (P<0.05), IgM in patients with renal impairment was decreased (P<0.05). Other than that, no other significant characteristic were found. Conclusion: The pathogenesis of SLE is a complex process involving multiple factors. The changes of MPV, IgG, IgA, IgM, C3, C4, CH50 and CRP in SLE patients are characteristic parameters. The combination of the above indicators can help to determine the diagnosis and staging of SLE. The timely diagnosis and treatment of SLE patients has important clinical significance in protecting the organ function of SLE patients and improving the prognosis

Glucose Sensing Optionally in Optical and Optoelectrical Modes Based on Au-TiO2 Schottky Nanojunctions

Abstract: In recent years, metallic nanostructures have been extensively researched in the field of plasmonic for optical and optoelectronic applications such as biochemical sensing. However, an additional optoelectronic converter or spectrometer is usually required for the sensing application. Herein, the orderly-patterned Au-TiO2 Schottky junction with an Al film that we coupled, which simultaneously works as an optical reflector and conducting layer, can achieve optical sensing of glucose by exciting surface plasmon resonance associated with the environment, and meanwhile can realize glucose detection with direct electrical-signal readout by collecting the photogenerated carriers inside the Au nanostructures and TiO2 film. When used in optical mode, the designed sensor shows a sensing sensitivity of up to 1200.0 nmRIU-1 in numerical calculation, and the measured value is 346.1 nmRIU-1. When used in optoelectrical mode, the glucose sensor under one-sun illumination obtains a sensitivity of 70.0 µAM-1cm-2 in the concentration range of 0–10 mM, with a detection limit of 0.05 µM (Signal/Noise=3). Simulation and experimental results demonstrated that the Al-film-coupled Au-TiO2 Schottky nanojunction can monitor glucose concentration optionally in optical and optoelectrical modes, which presents an alternative route to the miniaturized, portable, and multi-functioned sensors

In Vitro Antibacterial Activity of Galla Chinensis Combined with Different Antibacterial Drugs against Carbapenem-Resistant E.Coli

Objective: To evaluate the antibacterial effects of meropenem and levofloxacin respectively combined with Galla chinensis on carbapenem-resistant Escherichia coli in vitro. Methods： The protocol was designed with checkerboard method and the carbapenem-resistant E.coli was isolated in our hospital. The minimum inhibitory concentrations(MICs) of G. chinensis alone and combined with 2 antimicrobial agents against carbapenem-resistant E.coli were determined by broth dilution method and the fractional inhibitory concentration index (FICI) was calculated according to MICs results. Result： the combined use of G. chinensis and meropenem (or levofloxacin) significantly decreased both MIC50 and MIC90; After the combination of G. chinensis and meropenem, the synergistic effect was 86.7%, and the additive effect was 13.3%, no irrelevant and antagonistic effects. After combined use of G. chinensis and levofloxacin, the synergistic effect was 66.7%, and the additive effect was 33.3%. No irrelevant and antagonistic effects. Conclusion： Galla chinensis combined with meropenem or levofloxacin has synergistic and additive antibacterial effect, with certain combined antibacterial activity

Central Angiotensin II Stimulation Promotes β Amyloid Production in Sprague Dawley Rats

BACKGROUND: Stress and various stress hormones, including catecholamines and glucocorticoids, have recently been implicated in the pathogenesis of Alzheimer's disease (AD), which represents the greatest unresolved medical challenge in neurology. Angiotensin receptor blockers have shown benefits in AD and prone-to-AD animals. However, the mechanisms responsible for their efficacy remain unknown, and no studies have directly addressed the role of central angiotensin II (Ang II), a fundamental stress hormone, in the pathogenesis of AD. The present study focused on the role of central Ang II in amyloidogenesis, the critical process in AD neuropathology, and aimed to provide direct evidence for the role of this stress hormone in the pathogenesis of AD. METHODOLOGY/PRINCIPAL FINDINGS: Increased central Ang II levels during stress response were modeled by intracerebroventricular (ICV) administration of graded doses of Ang II (6 ng/hr low dose, 60 ng/hr medium dose, and 600 ng/hr high dose, all delivered at a rate of 0.25 µl/hr) to male Sprague Dawley rats (280-310 g) via osmotic pumps. After 1 week of continuous Ang II infusion, the stimulation of Ang II type 1 receptors was accompanied by the modulation of amyloid precursor protein, α-, β-and γ-secretase, and increased β amyloid production. These effects could be completely abolished by concomitant ICV infusion of losartan, indicating that central Ang II played a causative role in these alterations. CONCLUSIONS/SIGNIFICANCE: Central Ang II is essential to the stress response, and the results of this study suggest that increased central Ang II levels play an important role in amyloidogenesis during stress, and that central Ang II-directed stress prevention and treatment might represent a novel anti-AD strategy