A machine learning method for locating subsynchronous oscillation source of VSCs in wind farm induced by open-loop modal resonance based on measurement

In recent years, sub-synchronous oscillation incidents have been reported to happen globally, which seriously threatens the safe and stable operation of the power system. It is difficult to locate the oscillation source in practice using the parameterized model of open-loop modal resonance. Therefore, this paper aims at the problem of oscillation instability caused by the interaction between the multiple voltage source converters in the wind farm grid-connected system, proposes a method for locating the oscillation source of a wind farm using measurement data based on the transfer learning algorithm of transfer component analysis. At the same time, in order to solve the problem of the lack of oscillation data and the inability to label in the real system, a simplified simulation system was proposed to generate large batches of labeled training samples. Then, the common features of the samples from simulation system and the real system were learned through the transfer component analysis algorithm. Afterward, a classifier was trained to classify samples with common features. Finally, two grid-connected wind farms with VSC access are used to verify that the proposed method has good locating performance. This has important reference value for the practical application of power grid dispatching and operation using measurement to identify oscillation sources

Transformable DNA nanocarriers for plasma membrane targeted delivery of cytokine

Direct delivery of cytokines using nanocarriers holds great promise for cancer therapy. However, the nanometric scale of the vehicles made them susceptible to size-dependent endocytosis, reducing the plasma membrane-associated apoptosis signalling. Herein, we report a tumor microenvironment-responsive and transformable nanocarrier for cell membrane targeted delivery of cytokine. This formulation is comprised of a phospholipase A2 (PLA2) degradable liposome as a shell, and complementary DNA nanostructures (designated as nanoclews) decorated with cytokines as the cores. Utilizing the tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) as a model cytokine, we demonstrate that the TRAIL loaded DNA nanoclews are capable of transforming into nanofibers after PLA2 activation. The nanofibers with micro-scaled lengths efficiently present the loaded TRAIL to death receptors on the cancer cell membrane and amplified the apoptotic signalling with reduced TRAIL internalization

ATP-Responsive and Near-Infrared-Emissive Nanocarriers for Anticancer Drug Delivery and Real-Time Imaging

Stimuli-responsive and imaging-guided drug delivery systems hold vast promise for enhancement of therapeutic efficacy. Here we report an adenosine-5'-triphosphate (ATP)-responsive and near-infrared (NIR)-emissive conjugated polymer-based nanocarrier for the controlled release of anticancer drugs and real-time imaging. We demonstrate that the conjugated polymeric nanocarriers functionalized with phenylboronic acid tags on surface as binding sites for ATP could be converted to the water-soluble conjugated polyelectrolytes in an ATP-rich environment, which promotes the disassembly of the drug carrier and subsequent release of the cargo. In vivo studies validate that this formulation exhibits promising capability for inhibition of tumor growth. We also evaluate the metabolism process by monitoring the fluorescence signal of the conjugated polymer through the in vivo NIR imaging

Self-folded redox/acid dual-responsive nanocarriers for anticancer drug delivery

Self-folded redox/acid dual-responsive nanocarriers (RAD-NCs) are developed for physiologically triggered delivery of anticancer drug. The evidenced redox/acid responsiveness, facile decoration of ligands, and active tumor-targeting capability of RAD-NCs suggest their potential as a promising formulation for tumor-targeted chemotherapy

H2O2-Responsive Vesicles Integrated with Transcutaneous Patches for Glucose-Mediated Insulin Delivery

A self-regulated "smart" insulin administration system would be highly desirable for diabetes management. Here, a glucose-responsive insulin delivery device, which integrates H2O2-responsive polymeric vesicles (PVs) with a transcutaneous microneedle-array patch was prepared to achieve a fast response, excellent biocompatibility, and painless administration. The PVs are self-assembled from block copolymer incorporated with polyethylene glycol (PEG) and phenylboronic ester (PBE)-conjugated polyserine (designated mPEG-b-P(Ser-PBE)) and loaded with glucose oxidase (GOx) and insulin. The polymeric vesicles function as both moieties of the glucose sensing element (GOx) and the insulin release actuator to provide basal insulin release as well as promote insulin release in response to hyperglycemic states. In the current study, insulin release responds quickly to elevated glucose and its kinetics can be modulated by adjusting the concentration of GOx loaded into the microneedles. In vivo testing indicates that a single patch can regulate glucose levels effectively with reduced risk of hypoglycemia

Thrombin-Responsive Transcutaneous Patch for Auto-Anticoagulant Regulation

A thrombin-responsive closed-loop patch is developed for prolonged heparin delivery in a feedback-controlled manner. This microneedle-based patch can sense activated thrombin and subsequently releases heparin to prevent coagulation in the blood flow. This "smart" heparin patch can be transcutaneously inserted into skin without drug leakage and can sustainably regulate blood coagulation in response to thrombin

An experimental analysis of the real contact area between an electrical contact and a glass plane

The exact contact between two rough surfaces is usually estimated using statistical mathematics and surface analysis before and after contact has occurred. To date the majority of real contact and loaded surfaces has been theoretical or by numerical analyses. A method of analysing real contact area under various loads, by utilizing a con-contact laser surface profiler, allows direct measurement of contact area and deformation in terms of contact force and plane displacement between two surfaces. A laser performs a scan through a transparent flat side supported in a fixed position above the base. A test contact, mounted atop a spring and force sensor, and a screw support which moves into contact with the transparent surface. This paper presents the analysis of real contact area of various surfaces under various loads. The surfaces analysed are a pair of Au coated hemispherical contacts, one is a used Au to Au coated multi-walled carbon nanotubes surface, from a MEMS relay application, the other a new contact surface of the same configuration

ATP-Charged Nanoclusters Enable Intracellular Protein Delivery and Activity Modulation for Cancer Theranostics

Protein drugs own a large share in the market and hold great prospects for the treatment of many diseases. However, the available protein drugs are limited to the extracellular target, owing to the inefficient transduction and activity modulation of proteins targeting intracellular environment. In this study, we constructed ATP-charged platforms to overcome the above-mentioned barriers for cancer theranostics. The phenylboronic acid-modified polycations (PCD) were synthesized to assemble with enzymes and shield its activity in the blood circulation. When the PCD nanoclusters reached tumor site, they effectively transported the enzymes into the cells, followed by recovering its catalytic activity after being charged with ATP. Importantly, the cascaded enzyme systems (GOx&HRPA) selectively induced starvation therapy as well as photoacoustic imaging of tumor. Our results revealed that the intelligent nanoclusters were broadly applicable for protein transduction and enzyme activity modulation, which could accelerate the clinical translation of protein drugs toward intracellular target.ISSN:2589-004

Control strategy of UPFC based on power transfer distribution factor

In practical engineering application, trial method is widely used to determine the control value of unified power flow controller (UPFC in short). Since the calculation is based on offline typical data, the trial method is inefficient and less accurate, which could not adjust to the changing operating conditions. In order to make up for the deficiency, this paper proposes a novel UPFC control strategy based on power transfer distribution factors. First, the anticipated line tripping fault throughout the grid is scanned and the N − 1 overload lines are marked. Then, in regard to each overload condition, a certain UPFC control value is calculated based on power transfer distribution factors. The anticipated control list could be formed and updated according to online EMS data. When a line tripping fault is detected, simply by searching the control list, a condition could be matched and the UPFC could immediately be activated to eliminate the line overload. This method mentioned above could provide decision-making support to power-grid dispatching institutions. The results of a simulation example shows that the method is efficient and utilisable

Engineered Nanoplatelets for Enhanced Treatment of Multiple Myeloma and Thrombus

A platelet membrane-coated biomimetic nanocarrier, which can sequentially target bone microenvironment and myeloma cells to enhance the drug availability at the myeloma site and decrease the off-target effects, is developed for inhibiting the multiple myeloma growth and simultaneously eradicating the thrombus complication