The mechanism for the complexation and dissociation between siRNA and PMAL: a molecular dynamics simulation study based on a coarse-grained model

<p>The capacity of silencing genes makes small interfering RNA (siRNA) becomes potential candidates for curing many fatal diseases. Due to the low stability and delivery efficiency of siRNA, the design of amphiphilic carrier for siRNA delivery is vital for the practical gene therapy. In the present work, we explored how the complexation and dissociation of siRNA with poly (maleic anhydride-alt-1-decene) substituted with 3-(dimethylamino) propylamine (PMAL), which is a recent synthesised amphiphilic polymer and can be used in delivery of siRNAs and proteins, using traditional molecular dynamics simulations, together with steered molecular dynamics simulations. It was shown that the complexation of siRNA with PMALs can spontaneously occur, no matter what unit number of PMAL is. PMALs of different unit numbers form micelle-like structures and interact with siRNA surface. With the increase of unit number, PMAL becomes more flexible and interacts with siRNA from attachment to entanglement. The dissociation of PMAL from siRNA is an energy-consuming process. The free energy difference increases with the unit number of PMAL. The free energy for dissociation involves both the stretch of PMAL and the separation of PMAL from siRNA. Therefore, an optimal unit number of PMAL is critical for the delivery efficiency of siRNA when PMAL is used as carrier. In present work, when the radius of gyration of PMAL approaches to that of siRNA, PMAL gives a favoured both complexation and dissociation between siRNA and PMAL. Finally, we propose the mechanism of complexation and dissociation of PMAL with siRNA. The above simulation established a molecular insight of the interaction between siRNA and PMAL and was helpful for the design and applications of new PMAL-based polymers as siRNA delivery carriers.</p

Factors related to postoperative vitreous hemorrhage after small-gauge vitrectomy in proliferative diabetic retinopathy patients

Abstract Background The role of anticoagulation or antiplatelet on post-vitrectomy vitreous hemorrhage (POVH) in patients with proliferative diabetic retinopathy (PDR) is rarely investigated in the small-gauge vitrectomy era. We investigate the relationship between the long-term use of those medications and POVH in a group of PDR patients. Methods A retrospective cohort study was carried out in a group of PDR patients who underwent small-gauge vitrectomy in our center. The baseline data on diabetes, diabetic complications, long-term use of anticoagulants and antiplatelet agents, ocular findings, and vitrectomy details were collected. The occurrence of POVH was recorded during at least three-month follow-up. Factors related to POVH were analyzed using logistic analysis. Results During a median follow-up of 16 weeks, 5% (11/220) of patients had POVH, and 75 had received antiplatelet or anticoagulation agents before the operation. Factors related to persistent POVH were the use of antiplatelet or anticoagulation agents (5.98, 1.75–20.45, p = 0.004), the presence of myocardial revascularization (130.65, 3.53-4834.50, p = 0.008), the presence of coronary artery disease (CAD) treated with medicine (56.52, 1.99–1604.06, p = 0.018), and younger age (0.86, 0.77–0.96, p = 0.012). For those receiving preoperative antiplatelet or anticoagulation agents, the probability of developing POVH was higher in the patients whose previous therapy was adjusted compared to those with continued therapy (p = 0.02 by Log-rank test). Conclusions We identified long-term use of anticoagulation or antiplatelet medication, the presence of CAD, and younger age as three independent factors related to POVH. In PDR patients on long-term antiplatelet or anticoagulation medications, particular attention should be given to controlling intraoperative bleeding, and follow-up for POVH should be scheduled

Depressive Symptoms, Studying Stress and the Risks of NSP and LBP in High School Students.

<p>NSP = neck/shoulder pain; LBP = lower back pain; OR = ORs after univariate logistic regression.</p

The informed consent of this study.

The informed consent of this study in Chinese. (DOCX)</p

Characteristics of diabetes patients in different groups.

Characteristics of diabetes patients in different groups.</p

The ethics committee approval by the Institutional Review Board of Beijing Tongren Hospital.

The Chinese original version and English translation of the ethics committee approval. (DOCX)</p

Sociodemographic Factors, Physical Activity and the Risks of NSP and LBP in High School Students.

<p>NSP = neck/shoulder pain; LBP = lower back pain; OR = ORs after univariate logistic regression.</p

Mobile phone use and the Risks of NSP and LBP in High School Students.

<p>NSP = neck/shoulder pain; LBP = lower back pain; OR = ORs after univariate logistic regression.</p

DataSheet3_Computational design of quinone electrolytes for redox flow batteries using high-throughput machine learning and theoretical calculations.docx

Molecular design of redox-active materials with higher solubility and greater redox potential windows is instrumental in enhancing the performance of redox flow batteries Here we propose a computational procedure for a systematic evaluation of organic redox-active species by combining machine learning, quantum-mechanical, and classical density functional theory calculations. 1,517 small quinone molecules were generated from the building blocks of benzoquinone, naphthoquinone, and anthraquinone with different substituent groups. The physics-based methods were used to predict HOMO-LUMO gaps and solvation free energies that account for the redox potential differences and aqueous solubility, respectively. The high-throughput calculations were augmented with the quantitative structure-property relationship analyses and machine learning/graph network modeling to evaluate the materials’ overall behavior. The computational procedure was able to reproduce high-performance cathode electrolyte materials consistent with experimental observations and identify new electrolytes for RFBs by screening 100,000 di-substituted quinone molecules, the largest library of redox-active quinone molecules ever investigated. The efficient computational platform may facilitate a better understanding of the structure-function relationship of quinone molecules and advance the design and application of all-organic active materials for RFBs.</p

The radar chat for the patient-perceived reasons for delayed presentation among different groups.

The radar chat for the patient-perceived reasons for delayed presentation among different groups.</p