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Summary: In this paper, for the nonholonomic tractor‐trailer system with slipping and skidding, a full state‐triggering implementation of a tracking controller is proposed. Trailers are an important part, and their knowledge is crucial for the safety and control of the vehicle. Without considering system performance constraints, trailers may deviate from their expected position, leading to collisions. Therefore, there is still great interest in addressing the constraint control issues that arise in modern technologies related to network communication. Based on the backstepping method, bounded measurement errors are introduced into the continuous sampling controller considering intra‐vehicle communications. Then two neural networks are used to model unknown dynamics of the system with event sampling inputs, thereby decoupling the design of the control inputs. Finally, we prove the input‐to‐state‐like stability of a continuously sampled controller, and the given event execution control law can ensure the boundedness of measurement errors. Simulation results show the effectiveness of the proposed algorithm. [ABSTRACT FROM AUTHOR]

Rational application oi organic fertilizers is an effective approach to improve soil fertility, crop yield, and zero growth of chemical fertilizer in agricultural production. The rice variety 'Shennong9816' was planted in Shenyang, Liaoning Province, under seven different treatments: zero nitrogen fertilizer (CK), low nitrogen, 150 kg ⋅ hm-2 (LN), medium nitrogen, 240 kg ⋅ hm-2 (MN), high nitrogen, 330 kg ⋅ hm 2 (HN), medium nitrogen with replacement of chemical N by 10% organic manure (OMN10), medium nitrogen with replacement of chemical N by 20% organic manure (OMN20), and medium nitrogen with replacement of chemical N by 30% organic manure (OMN30). The effects of different treatments on photosynthetic rate, nitrogen absorption, nitrogen use efficiency, and yield were examined and the optimal fertilization scheme was determined. The results showed that the photosynthetic rate, biomass and yield were increased with the increases of nitrogen application rate, while the nitrogen use efficiency was decreased significantly. Compared with the MN treatment, the photosynthetic rate of OMN10 and OMN20 in filling stage was increased by 22.9% and 9.9%, respectively. The yield of OMN20 was increased by 3.8% compared to that of MN. The nitrogen agronomic efficiency and physiological efficiency of OMN20 were significantly improved by 8.1% and 13.3%, respectively. Moreover, the nitrogen agronomic efficiency and physiological efficiency of OMN20 were improved by 27.2% and 37.2% compared with the HN treatment. Thus, we concluded that the organic fertilizer replacement treatment could conserve soil fertility, achieve high yield and high nitrogen use efficiency, while reduce chemical nitrogen fertilizer application. The OMN20 treatment was recommended as a fertilizer application model due to its superior performance among the seven treatments. [ABSTRACT FROM AUTHOR]

This study is to investigate the mechanism and action characteristics of 6-chloro-3-methyl-4-(2-methyoxycarbonylthiophene-3-sulfonyl)-3, 4-dihydroquinoxa-lin-2-(1 H)-one (XU07011) against HIV-1 replication. XU07011 anti-HIV activity was tested by using VSVG/HIV pseudotype viral system and confirmed by HIV-1 live viruses' infectious assay. Time of addition was used to test HIV-1 reverse transcription process. RNA-dependent DNA polymerase activity and RNase H activity were tested by using enzyme linked immunoabsorbent assay and fluorescence method. Wild type and nine NNRTIs-resistant reverse transcriptase enzymatic models and cell-based pharmacological models were used to evaluate XU07011 bio-characteristics. The results showed that XU07011 inhibited HIV-1 replication with IC50 of (0.057 +/- 0.01) micromol x L(-1) which was comparable to nevirapine [IC50: (0.046 +/- 0.01) micromol x L(-1)]. Mechanism study data indicated that XU07011 blocked HIV-1 reverse transcription process through acting on reverse transcriptase RNA-dependent DNA polymerase with IC 50 of (1.1 +/- 0.3) micromol x L(-1). The compound showed no effect on RNase H activity. XU07011 exhibited better activities comparing with nevirapine on K103N mutated NNRTIs-resistant HIV-1 strains. This study could provide a theoretical basis for novel anti-HIV reagents development.

This study is to investigate the mechanism of action of lindenane disesquiterpenoid shizukaol F on HIV-1 replication. Real time quantity PCR, ELISA assay and fluorescence methods were used to test HIV-1 reverse transcription process, RNA-dependent DNA polymerase activity, and RNase H activity, respectively. It showed that shizukaol F inhibited LTR/Gag production of HIV-1 reverse transcription with an IC50 of 9.11 micromol x L(-1). This result is consistent with its inhibitory effect on HIV-1 replication (IC50 of 6.12 micromol x L(-1)). Mechanism studies showed that compound shizukaol F inhibited HIV-1 RT-RNase H with IC50 of 26.4 micromol x L(-1), but had no effect on HIV-1 RT RNA-dependent DNA polymerase activity. In conclusion, shizukaol F is a new structural type HIV-1 RNase H inhibitor. This discovery will provide a clue for new type of reverse transcriptase inhibitors development.

This study is to establish a cell-based model targeting to neuraminidase (NA) of the 2009 H1N1 influenza A virus. NA is an influenza virus structural protein with enzymatic activity of the cleavage of HA-sialic acid interaction to release new viral particles from cells. A model of HIV-1 (pNL4-3.Luc.R(-)E(-)) based pseudovirions packed with HA [hemagglutinin, A/VietNam/1203/2004 (H5N1)] and NA [A/California/04/2009 (H1N1)] was established to evaluate compounds activities on NA function. The viral release can be blocked by neuraminidase inhibitors, oseltamivir and oseltamivir carboxylate, with IC50 of (61 +/- 31) nmol L(-1) and (5.5 +/- 2.9) nmol L(-1) respectively. A point mutation of H275Y on NA leads oseltamivir-resistance. This corresponding mutation was introduced into the system which was also confirmed by oseltamivir and oseltamivir carboxylate.

Consistent non-nucleoside reverse-transcriptase inhibitors (NNRTIs) resistant HIV-1 strains occurred due to the clinical use for more than ten years of efavirenz (EFV), nevirapine (NVP), and delavirdine (DLV). In this study, we established nine cell-based pharmacological models according to most NNRTIs-resistant clinical tested strains, Resistant mutations were introduced into vector, pNL4-3.Luc.R-E-, by overlapping PCR. Then, pseudovirions were produced by co-transfection of VSV-G plasmid and pNL4-3.Luc.R-E- -mut. All nine recombinant VSVG/HIV-mut pseudovirions (VSVG/HIV-wt, VSVG/HIV(-K103N), VSVG/HIV(-Y181C), VSVG/HIV(-L100I,K103N), VSVG/HIV(-Y188L), VSVG/HIV(-K103N,Y181C), VSVG/HIV(-K103N,P225H), VSVG/HIV(-K103N,Y188L), VSVG/HIV(-K103N,G109A) and VSVG/HIV(-K103N,V108I)) had high efficient infectivity. Furthermore, they all showed resistant characteristics to EFV and NVP with IC50 changes consisting with clinical reports, not to nucleoside reverse-transcriptase inhibitors (AZT and d4T). This series safe cell-based model, which could be carried out in BSL-2 laboratory, can be used for evaluating NNRTIs candidates.

This study is to establish a cell-based pharmacological model targeting HIV-1 replication for compounds screening and to screen compounds randomly selected from compounds library by using this pseudotyped viral system. The cell-based HIV-1 replication pharmacological model was set up by HIV-1 core packed with vesicular stomatitis virus glycoprotein. The level of HIV-1 replication was presented by reporter genes expression (luciferase activity or percentage of GFP positive cells). When a compound has inhibitory effect on VSVG/HIV model, VSVG/MLV model would be used to test for specificity. Vesicular stomatitis virus glycoprotein can efficiently mediate HIV core into a wide range of host cells. Expression level of reporter genes showed dose-dependent manner with virion dilution. Among 500 compounds, three compounds dose-dependently inhibit HIV-1 replication, but not MLV replication. VSVG/HIV pseudotyped viral system can be used as a pharmacological model for HIV-1 replication inhibitor screening. Compounds 2-methylthio-5-(4-methylbenzo)amido-l,3,4-thiadiazole, N-(3-hydroxyphenyl)-2-(4-isobutylphenyl) propionamide, and N-(4-picolyl)-4-methylbenzenesulfonamide can specifically inhibit HIV-1 replication with IC50 of 1.92, 5.38, and 3.39 micromol L(-1) respectively.