Linear active disturbance rejection control of waste heat recovery systems with organic Rankine cycles

In this paper, a linear active disturbance rejection controller is proposed for a waste heat recovery system using an organic Rankine cycle process, whose model is obtained by applying the system identification technique. The disturbances imposed on the waste heat recovery system are estimated through an extended linear state observer and then compensated by a linear feedback control strategy. The proposed control strategy is applied to a 100 kW waste heat recovery system to handle the power demand variations of grid and process disturbances. The effectiveness of this controller is verified via a simulation study, and the results demonstrate that the proposed strategy can provide satisfactory tracking performance and disturbance rejection

Flexibility is a mechanical determinant of antimicrobial activity for amphipathic cationic α-helical antimicrobial peptides

AbstractAntimicrobial peptides (AMPs) are recognized as the potential substitutions for common antibiotics. Flexibility has been demonstrated to be a dominant on antimicrobial activity of an AMP, similar to the structural parameters such as hydrophobicity and hydrophobic moment as well as positive charge. To better understand the effect of flexibility on antimicrobial activity, we herein examined seventy-eight peptides derived from nine different species. Defined as a weighted average of amino acid flexibility indices over whole residue chain of AMP, flexibility index was used to scale the peptide flexibility and indicated to be a reflection of mechanical properties such as tensile and flexural rigidities. The results demonstrated that flexibility index is relevant to but different from other structural properties, may enhance activity against Escherichia coli for stiff clustered peptides or reduce activity against E. coli for flexible clustered peptides, and its optimum occurs at about −0.5. This effect of flexibility on antimicrobial activity may be involved to the antimicrobial actions, such as stable peptide-bound leaflet formation and sequent stress concentration in target cell membrane, mechanically. The present results provide a new insight in understanding antimicrobial actions and may be useful in seeking for a new structure–activity relationship for cationic and amphipathic α-helical peptides

Deep Drawing of Cylindrical Cup Using Incremental Electromagnetic Assisted Stamping with Radial Magnetic Pressure

AbstractA new forming method named incremental electromagnetic assisted stamping with radial magnetic pressure is proposed to draw a deep cylindrical cup. The method combines with traditional stamping, electromagnetic sheet forming and electromagnetic launch technology. Three types of discharge coils are imbedded in die and blank holder, respectively. The 3D finite element model is set up to predict the complex deformation process. The forming process and principle of the new method are discussed. The values of material flow, stress and thickness in different forming processes are compared. In comparison with traditional stamping, incremental electromagnetic assisted stamping with radial magnetic pressure can significantly increase the value of material at sheet end flow inward, decrease the tensile stress and thickness reduction at the easily broken position, and obtain uniform stress distribution. Therefore, deeper cylindrical cup could be manufactured by incremental electromagnetic assisted stamping with radial magnetic pressure

FurinDB: A Database of 20-Residue Furin Cleavage Site Motifs, Substrates and Their Associated Drugs

FurinDB (freely available online at http://www.nuolan.net/substrates.html) is a database of furin substrates. This database includes experimentally verified furin cleavage sites, substrates, species, experimental methods, original publications of experiments and associated drugs targeting furin substrates. The current database release contains 126 furin cleavage sites from three species: mammals, bacteria and viruses. A main feature of this database is that all furin cleavage sites are recorded as a 20-residue motif, including one core region (eight amino acids, P6–P2′) and two flanking solvent accessible regions (eight amino acids, P7–P14, and four amino acids, P3′–P6′), that represent our current understanding of the molecular biology of furin cleavage. This database is important for understanding the molecular evolution and relationships between sequence motifs, 3D structures, cellular functions and physical properties required by furin for cleavage, and for elucidating the molecular mechanisms and the progression of furin cleavage associated human diseases, including pathogenic infections, neurological disorders, tumorigenesis, tumor invasion, angiogenesis, and metastasis. FurinDB database will be a solid addition to the publicly available infrastructure for scientists in the field of molecular biology

Metamagnetic transitions and anomalous magnetoresistance in EuAg4_4As2_2 single crystal

In this paper, the magnetic and transport properties were systematically studied for EuAg$_4$As$_2$ single crystals, crystallizing in a centrosymmetric trigonal CaCu$_4$P$_2$ type structure. It was confirmed that two magnetic transitions occur at $\textit{T}$$_{N1}$ = 10 K and $\textit{T}$$_{N2}$ = 15 K, respectively. With the increasing field, the two transitions are noticeably driven to lower temperature. At low temperatures, applying a magnetic field in the $\textit{ab}$ plane induces two successive metamagnetic transitions. For both $\textit{H}$ $\parallel$ $\textit{ab}$ and $\textit{H}$ $\parallel$ $\textit{c}$, EuAg$_4$As$_2$ shows a positive, unexpected large magnetoresistance (up to 202\%) at low fields below 10 K, and a large negative magnetoresistance (up to -78\%) at high fields/intermediate temperatures. Such anomalous field dependence of magnetoresistance may have potential application in the future magnetic sensors. Finally, the magnetic phase diagrams of EuAg$_{4}$As$_{2}$ were constructed for both $\textit{H}$ $\parallel$ $\textit{ab}$ and $\textit{H}$ $\parallel$ $\textit{c}$

Giα proteins exhibit functional differences in the activation of ERK1/2, Akt and mTORC1 by growth factors in normal and breast cancer cells

Background In a classic model, Giα proteins including Gi1α, Gi2α and Gi3α are important for transducing signals from Giα protein-coupled receptors (GiαPCRs) to their downstream cascades in response to hormones and neurotransmitters. Our previous study has suggested that Gi1α, Gi2α and Gi3α are also important for the activation of the PI3K/Akt/mTORC1 pathway by epidermal growth factor (EGF) and its family members. However, a genetic role of these Giα proteins in the activation of extracellular signal-regulated protein kinase 1 and 2 (ERK1/2) by EGF is largely unknown. Further, it is not clear whether these Giα proteins are also engaged in the activation of both the Akt/mTORC1 and ERK1/2 pathways by other growth factor family members. Additionally, a role of these Giα proteins in breast cancer remains to be elucidated. Results We found that Gi1/3 deficient MEFs with the low expression level of Gi2α showed defective ERK1/2 activation by EGFs, IGF-1 and insulin, and Akt and mTORC1 activation by EGFs and FGFs. Gi1/2/3 knockdown breast cancer cells exhibited a similar defect in the activations and a defect in in vitro growth and invasion. The Giα proteins associated with RTKs, Gab1, FRS2 and Shp2 in breast cancer cells and their ablation impaired Gab1’s interactions with Shp2 in response to EGF and IGF-1, or with FRS2 and Grb2 in response to bFGF. Conclusions Giα proteins differentially regulate the activation of Akt, mTORC1 and ERK1/2 by different families of growth factors. Giα proteins are important for breast cancer cell growth and invasion.Fil: Wang, Zhanwei. University of Hawaii Cancer Center. Honolulu; Estados UnidosFil: Dela Cruz, Rica. University of Hawaii Cancer Center. Honolulu; Estados UnidosFil: Ji, Fang. Shanghai Jiao Tong University . Sahnghai; ChinaFil: Guo, Sheng. University of Hawaii Cancer Center. Honolulu; Estados Unidos. Shanghai Jiaotong University. Shangha; Estados UnidosFil: Zhang, Jianhua. Shanghai Jiaotong University. Shangha; Estados Unidos. University of Hawaii Cancer Center. Honolulu; Estados UnidosFil: Wang, Ying. David Geffen School of Medicine at UCLA. Los Angeles; Estados UnidosFil: Feng, Gen-Sheng. University of California at San Diego; Estados UnidosFil: Birnbaumer, Lutz. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. National Institutes of Health; Estados UnidosFil: Jiang, Meisheng. David Geffen School of Medicine at UCLA. Los Angeles; Estados UnidosFil: Chu, Wen Ming. University of Hawaii Cancer Center. Honolulu; Estados Unido

Effect of Chinese massage (Tui Na) on isokinetic muscle strength in patients with knee osteoarthritis

AbstractObjectiveChinese massage (Tui Na) is one of the most popular Traditional Chinese Medicine remedies for knee osteoarthritis (OA). Several studies have subjectively evaluated the effect of Chinese massage on knee OA through self-assessment questionnaires; however, very few studies have objectively assessed the effect by measuring knee muscle strength. The purpose of this study was to assess the efficacy of Chinese massage in improving knee extensor and flexor muscle strength in patients with knee OA.MethodsThirty patients with knee OA received Chinese massage therapy three times per week for 2 weeks. Patients completed pre- and post-treatment Visual Analogue Scale (VAS) pain questionnaires, and pre- and post-treatment knee muscle strength was evaluated using the Biodex Multi-Joint System 3. Isokinetic muscle strength measurements were performed at 60 degrees/s and 180 degrees/s. The peak torque (PT), peak torque/body weight (PT/BW), total work (TW), average power (AP), hamstring/quadriceps (H/Q), and range of motion (ROM) values were recorded separately for flexors and extensors.ResultsChinese massage therapy significantly improved knee pain as assessed by the VAS in patients with knee OA (P < 0.05). Post-treatment values were significantly greater than pre-treatment values in the extensor muscles for PT (right P = 0.013, left P = 0.001), PT/BW (right P = 0.008, left P = 0.001) and TW (right P = 0.036, left P = 0.004) at 60 degrees/s. The AP increased significantly after treatment in the flexor muscles in the right knee (P = 0.009) and the extensor muscles in the left knee (P = 0.001). There were no significant differences in pre- and post-treatment ROM and H/Q at 60 degrees/s and 180 degrees/s.ConclusionChinese massage therapy decreased pain and may improve extensor muscle strength in patients with knee OA, but does not appear to improve ROM