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In this article, the adaptive fuzzy tracking control problem for a class of uncertain strict-feedback systems with unknown nonlinearities is investigated with particular emphasis on global stability. The proposed control scheme is designed by integrating the barrier Lyapunov functions (BLFs) with the techniques of fuzzy approximation and backstepping. The novel integral BLFs (iBLFs) are introduced to overcome the design difficulties induced by the virtual control coefficients and determine a priori the compact set for guaranteeing the validity of fuzzy approximation. Compared with existing approximation-based control results, the developed controller not only guarantees global stability without requiring prior information of system nonlinearities and assumptions on the time derivatives of virtual control coefficients, but also prevents the ``explosion of complexity'' issue without attaching additional filters. The simulation results further confirm the effectiveness of the theoretical findings.

In this article, the problem of adaptive tracking control is tackled for a class of high-order nonlinear systems. In contrast to existing results, the considered system contains not only unknown nonlinear functions but also unknown rational powers. By utilizing the fuzzy approximation approach together with the barrier Lyapunov functions (BLFs), we present a new adaptive tracking control strategy. Remarkably, the BLFs are employed to determine a priori the compact set for maintaining the validity of fuzzy approximation. The primary advantage of this article is that the developed controller is independent of the powers and can be capable of ensuring global stability. Finally, two illustrative examples are given to verify the effectiveness of the theoretical findings.

This article considers the funnel output tracking control for a class of high-order uncertain nonlinear systems with the powers of positive odd rational numbers, aiming to accomplish output tracking with prescribed accuracy when both the system nonlinearities and the powers of the system are unknown. For such a purpose, a robust funnel control algorithm, i.e., a continuous, static, and universal, state-feedback controller is explicitly constructed, which achieves the state errors evolving within the predesigned performance space. Benefits of the proposed funnel output tracking controller comparing with the current approaches lie in the fact that the exact knowledge of system nonlinearities, including generally required bounding functions, is not needed to be a priori . Moreover, all the powers in each high-order subsystem are permitted to be any unknown positive odd rational numbers as well. The efficacy of the developed algorithm is confirmed through two illustrative examples.

This article considers the problem of output feedback funnel control for a class of uncertain nonlinear systems with arbitrary known relative degree. By utilizing the funnel control approach with a barrier Lyapunov function, a novel adaptive output feedback controller is constructed recursively, which accomplishes the output tracking with prescribed transient behavior. The developed control scheme features that the precise knowledge of system nonlinearities, including generally required bounding functions, is not needed. A physical example is performed to verify the effectiveness of the proposed theoretical findings.

Background Sulfation of tyrosine, yielding O-sulfotyrosine, is a common but fixed post-translational modification in eukaryotes. Patients with increased circulating O-sulfotyrosine levels experience a faster decline in renal function with progression to end-stage renal disease (ESRD). In the present study, we measured serum O-sulfotyrosine levels in individuals with chronic kidney disease (CKD) and acute kidney injury (AKI) to explore its ability to differentiate AKI from CKD. Methods A total of 135 patients (20 with AKI and 115 with CKD) were recruited prospectively for liquid chromatography-mass spectrometry assessment of circulating O-sulfotyrosine. We also studied C57BL/6 mice with CKD after 5/6 nephrectomy (Nx). Blood samples were drawn from the tail vein on Day 1, 3, 5, 7, 14, 30, 60, and 90 after CKD. Serum separation and characterization of creatinine, blood urea nitrogen (BUN), and O-sulfotyrosine was performed. Thus, the time-concentration curves of the O-sulfotyrosine level demonstrate the variation of kidney dysfunction. Results The serum levels of O-sulfotyrosine were markedly increased in patients with CKD compared with AKI. Median O-sulfotyrosine levels in CKD patients versus AKI, respectively, were as follows:243.61 ng/mL(interquartile range [IQR] = 171.90–553.86) versus 126.55 ng/mL (IQR = 48.19–185.03, P = 0.004). In patients with CKD, O-sulfotyrosine levels were positively correlated with creatinine, BUN, and Cystatin C (r = 0.63, P P P P P = 0.002; β = 0.73, P P = 0.472; r = 0.11, P = 0.655; r = 0.09, P = 0.716, respectively). The receiver operating characteristic (ROC) analysis illustrated that the area under the curve was 0.80 (95% confidence interval [CI] 0.71–0.89; P P P Conclusion Serum O-sulfotyrosine levels were observed correlated with degrading renal function and in CKD patients substantially higher than those in AKI patients. Thus serum O-sulfotyrosine facilitated the differential diagnosis of AKI from CKD.

Most existing approximation-based adaptive control (AAC) approaches for unknown pure-feedback nonaffine systems retain a dilemma that all closed-loop signals are semiglobally uniformly bounded (SGUB) rather than globally uniformly bounded (GUB). To achieve the GUB stability result, this article presents a neuro-adaptive backstepping control approach by blending the mean value theorem (MVT), the barrier Lyapunov functions (BLFs), and the technique of neural approximation. Specifically, we first resort the MVT to acquire the intermediate and actual control inputs from the nonaffine structures directly. Then, neural networks (NNs) are adopted to approximate the unknown nonlinear functions, in which the compact sets for maintaining the approximation capabilities of NNs are predetermined actively through the BLFs. It is shown that, with the developed neuro-adaptive control scheme, global stability of the resulting closed-loop system is ensured. Simulations are conducted to verify and clarify the developed approach.

It has been increasingly recognized that CWIN (cell wall invertase) and sugar transporters including STP (sugar transport protein) and SWEET (sugar will eventually be exported transporters) play important roles in plant–pathogen interactions. However, the information available in the literature comes from diverse systems and often yields contradictory findings and conclusions. To solve this puzzle, we provide here a comprehensive assessment of the topic. Our analyses revealed that the regulation of plant–microbe interactions by CWIN, SWEET, and STP is conditioned by the specific pathosystems involved. The roles of CWINs in plant resistance are largely determined by the lifestyle of pathogens (biotrophs versus necrotrophs or hemibiotrophs), possibly through CWIN-mediated salicylic acid or jasmonic acid signaling and programmed cell death pathways. The up-regulation of SWEETs and STPs may enhance or reduce plant resistance, depending on the cellular sites from which pathogens acquire sugars from the host cells. Finally, plants employ unique mechanisms to defend against viral infection, in part through a sugar-based regulation of plasmodesmatal development or aperture. Our appraisal further calls for attention to be paid to the involvement of microbial sugar metabolism and transport in plant–pathogen interactions, which is an integrated but overlooked component of such interactions.

Background We investigated whether glycemic control affects the relation between endothelial dysfunction and coronary artery disease in patients with type 2 diabetes mellitus (T2DM). Methods In 102 type 2 diabetic patients with stable angina, endothelial function was evaluated using brachial artery flow-mediated dilation (FMD) with high-resolution ultrasound, and significant stenosis of major epicardial coronary arteries (≥ 50% diameter narrowing) and degree of coronary atherosclerosis (Gensini score and SYNTAX score) were determined. The status of glycemic control was assessed by blood concentration of glycated hemoglobin (HbA1c). Results The prevalence of significant coronary artery stenosis (67.9% vs. 37.0%, P = 0.002) and degree of coronary atherosclerosis (Gensini score: 48.99 ± 48.88 vs. 15.07 ± 21.03, P 0.05). Conclusion Poor glycemic control negatively influences the association of endothelial dysfunction and coronary artery disease in T2DM patients.

Background Coronary artery ectasia (CAE) is an angiographic finding of abnormal coronary dilatation. Inflammation plays a major role in all phases of atherosclerosis. We investigated the relationship between CAE and serum high-sensitivity C-reactive protein (hs-CRP) and interleukin-6 (IL-6) levels to test our hypothesis that patient age is associated with the efficacy of anti-inflammatory therapy for CAE. Methods We conducted a prospective analysis of 217 patients with CAE treated at the Department of Cardiology, Shanghai East Hospital, Ji’an Campus and the Baoshan People’s Hospital, from January 1, 2015 to July 30, 2019. Baseline data of patients, including sex; age; and history of hypertension, hyperlipidemia, and diabetes, were collected from patient medical records. Study participants were grouped by age as follows: CAE-A (n = 60, age ≤ 50 years), CAE-B (n = 83, 50 years n = 74, age > 70). Additionally, there was a control (NC) group (n = 73) with normal coronary arteries. Results All patients received oral rosuvastatin therapy (10 mg, QN quaque nocte) when they were diagnosed with CAE and maintained good follow-up, with a loss rate of 0.0% at the end of the 6-month follow-up. The NC group received regular symptom-relieving treatments and rosuvastatin therapy. Of these four groups, the inflammatory markers, hs-CRP and IL-6, were significantly higher in patients with CAE than in the NCs (p P = 0.048, P = 0.025). Logistic regression analysis showed that hs-CRP (OR = 1.782, 95% CI: 1.124–2.014, P = 0.021) and IL-6 (OR = 1.584, 95% CI: 1.112–1.986, P = 0.030) were independent predictors of CAE. The inflammatory markers were higher in the CAE-A group than in the CAE-B group and higher in the CAE-B group than in the CAE-C group. Follow-up after 6 months of rosuvastatin therapy showed a significantly greater reduction in hs-CRP and IL-6 levels in the CAE-A group than in the CAE-B group, which again were greater in the CAE-B group than in the CAE-C group. Conclusions Anti-inflammatory therapy using rosuvastatin was more effective in younger CAE patients, indicating the need for early statin therapy in CAE.

In this study, the authors consider the problem of adaptive tracking control for a class of non-linear uncertain systems in the presence of input saturation. To tackle the effects of the non-smooth saturation non-linearity, a novel approximate saturation model is constructed, which can smoothly approximate the real saturation with arbitrarily prescribed precision. By utilising dynamic surface control approach with the modified linear filters, a robust adaptive control scheme is explicitly designed via the adding an integrator technique. The proposed controller can eliminate not only the ‘explosion of complexity’ issue inherent in the backstepping design but also the coupling terms with respect to the surface errors and the boundary layer errors. In addition, the stability analysis shows that all the resulting closed-loop signals are semi-global uniformly ultimately bounded. Finally, simulation results are presented to demonstrate the performance of the developed method.

In this article, a globally stable adaptive control strategy for uncertain strict-feedback systems is proposed within predefined neural network (NN) approximation sets, despite the presence of unknown system nonlinearities. In contrast to the conventional adaptive NN control results in the literature, a primary benefit of the developed approach is that the barrier Lyapunov function is employed to predefine the compact set for maintaining the validity of NN approximation at each step, thus accomplishing the global boundedness of all the closed-loop signals. Simulation results are performed to clarify the effectiveness of the proposed methodology.

In this paper, the global output tracking is investigated for a class of uncertain nonlinear hysteretic systems with nonaffine structures. By combining the solution properties of the hysteresis model with the novel backstepping approach, a robust adaptive control algorithm is developed without constructing a hysteresis inverse. The proposed control scheme is further modified to tackle the bounded disturbances by adaptively estimating their bounds. It is rigorously proven that the designed adaptive controllers can guarantee global stability of the closed-loop system. Two numerical examples are provided to show the effectiveness of the proposed control schemes.

To the Editor: An outbreak of murine typhus caused by Rickettsia typhi was confirmed among persons attending a 51-acre drug detoxification program 2.5 km from Ruili City in Yunnan Province, People’s Republic of China. Ruili City, with an average altitude of 1,381 km, is located in southwestern China near the Myanmar border (Figure). At the time of the outbreak, the detoxification program had 1,264 inpatients and 96 staff members. The facility is divided into sections A (women), B, C, and D. Residents of each section are housed in a 4-story building; each floor contains 9 rooms (2 m2 per person). During September 4–21, 2010, a total of 76 of the 430 residents of section B were reported with fever of unknown cause. All patients were men 19–38 years of age who worked in clothing manufacture at the facility and were receiving treatment for drug addiction. Before the outbreak, rats and stray cats were frequently observed in a cafeteria in section B. No persons with similar illness were observed in the other 3 sections. Figure A) Location of Ruili City, Yunnan Province, People’s Republic of China (97°51′–98°02′E, 23°38′–24°14′S; altitude 1,381 m). B) Number of murine typhus cases reported ... To investigate the outbreak, we gathered information about demographics; past medical histories; exposures to vectors, such as ticks, mites, fleas, and lice; and symptoms. Patients frequently reported headache, dizziness, diffuse myalgia, high fever (>39°C), and shivers but did not report a rash or eschar. No patients remembered a flea or louse bite, but they frequently reported seeing rats in the area. The Chinese Center for Disease Control and Prevention (China CDC) Institutional Review Board approved the investigation. Two milliliters of blood was collected from each consenting patient. Separated serum and the remaining blood clots were stored at −70°C and transferred to the Department of Rickettsiology, National Institute of Communicable Disease Control and Prevention, China CDC, for testing. Specimens were tested by indirect immunofluorescence assay (1) to detect specific IgM and IgG against 10 common rickettsiae: Rickettsia prowazekii, R. typhi, R. heilongjiangensis, Orientia tsutsugamushi types Karp and Kato, Coxiella burnetii, Bartonella henselae, and B. quintana, Ehrlichia chaffeensis, and Anaplasma phagocytophilum. Antigens were prepared by placing the rickettsial stains in L929 cells and HL60 or and DH82 cells, respectively; collecting the culture when Gimenez stain or Wright staining showed positive results; ultrasonically crushing the culture; and purifying the bacteria by density ultracentrifugation. Positive control serum was prepared by inoculating rabbits with the above standard rickettsiae strains. We collected 76 serum samples from patients a median of 4 days (range 1–9 days) after illness onset. Thirty-five (40%) were IgM positive for R. typhi (titer >40, maximum titer 160) and 29 (38%) were IgG positive for R. typhi (titer >80, maximum titer 320). No samples were positive for the other 8 rickettsial antigens, except for 10 (13%) that had weak reactions for R. prowazakii (titer 40). Twelve convalescent-phase serum samples (median interval between acute and convalescent phases 187 days [range 181–192 days]) were IgG positive for R. typhi (titer >80) and 4 had 4-fold increases in titer; 2 reached titers of 1,280 and 2,560. DNA was extracted from acute-phase samples by using a QIAGEN DNA extraction kit (Hilden, Germany) and tested by real-time PCR that targeted the groEL gene of R. prowazekii and R. typhi (2). Twelve (16%) of the 76 samples were positive. To differentiate between R. prowazekii and R. typhi, we used a previously developed nested PCR targeting the groEL gene of R. prowazekii and R. typhi (3) and found the expected 218-bp fragments in 11 patients. BLAST analysis (http://blast.ncbi.nlm.nih.gov/Blast.cgi) showed that these sequences (200 bp) were 100% homologous with that of R. typhi strain Wilmington (GenBank accession no. {"type":"entrez-nucleotide","attrs":{"text":"AF017197","term_id":"2460083","term_text":"AF017197"}}AF017197). Initially, patients were treated with antiviral drugs and Chinese herbal medicine for suspected influenza. Subsequently, murine typhus was suspected and doxycycline was administered. All patients recovered fully. Yunnan Province’s subtropical geographic and climate characteristics are advantageous to the vectors of rickettsial diseases, such as murine typhus, scrub typhus, spotted fever, and Q fever (4–6). Three national murine typhus outbreaks involving >10,000 cases each have been reported since 1949, and each involved Yunnan Province (7). In the 1970s, an outbreak of louse-borne typhus occurred in northeastern Yunnan Province (4); since then, louse-borne typhus has been rarely reported. Murine typhus was reported from Baoshan City, east of Ruili City, in 2010. However, the currently reported murine typhus outbreak in Ruili City near the China–Myanmar border was the largest outbreak in China during the previous decade. None of the 76 patients had rash, a finding similar to that reported in previous outbreaks in Myanmar, Thailand, and other Southeast Asia regions (8–10). In addition to the 76 cases reported here, 70 additional sporadic cases of murine typhus were reported to the Ruili CDC in 2010. We conclude that murine typhus should be considered in cases of unexplained fever with nonspecific clinical manifestations in southern Yunnan Province.

The output tracking problem for a class of uncertain strict-feedback nonlinear systems with unknown Duhem hysteresis input is investigated. In order to handle the undesirable effects caused by unknown hysteresis, the properties in respect to Duhem model are used to decompose it as a nonlinear smooth term and a nonlinear bounded “disturbance-like” term, which makes it possible to deal with the unknown hysteresis without constructing inverse in the controller design. By combining robust control and dynamic surface control technique, an adaptive controller is proposed in this paper to avoid “the explosion complexity” in the standard backstepping design procedure. The negative effects caused by the unknown hysteresis can be mitigated effectively, and the semiglobal uniform ultimate boundedness of all the signals in the closed-loop system is obtained. The effectiveness of the proposed scheme is validated through a simulation example.

To explore the clinical efficacies of scleral tunnel sutureless trabeculectomy plus phacoemulsification and intraocular lens implantation in the treatment of glaucoma and cataract.A total of 49 cataract patients with glaucoma (52 eyes) from our hospital during the period of February 2009 to June 2012. Their visual acuities were0.3 and intraocular pressure was not desirable or in need of various ocular hypotensive drugs. A phaco tunnel knife was employed to prepare a 4 mm × 4 mm scleral tunnel flap with 1/2-2/3 whole layer of sclera depth. Phacoemulsification instrument was used to emulsify cataracts. Foldable intraocular lens was implanted. A trabecular cut of 2 mm × 1.5 mm was made under the scleral tunnel. Tile scleral flap was not sutured and conjunctival flap tightly closed.After a 12-month follow-up,0.5 in 42 eyes (80.8%). The intraocular pressure was 11.32 - 17.63 mm Hg (1 mm Hg = 0.133 kPa) and the mean intraocular pressure (13.59 ± 4.26) mm Hg. There was a mean pressure reduction of 11.2 mm Hg from (24.53 ± 5.71) mm Hg pre-operation. Statistical significance existed (t' = 11.073, P0.01). The filtering blebs of type I-II was 43 eyes (82.6%) and the mean central anterior chamber 3.28 mm ± 0.42 mm. There was statistical difference (t' = 20.486, P0.01) with (1.79 ± 0.31) mm at pre-operation. On 52 eyes, the mean postoperative astigmatism was (1.01 ± 0.62) D versus (1.13 ± 0.74) D at pre-operation. There was no statistical significance (F = 2.0673, P0.05). No severe complication occurred in all cases.Compared with traditional trabeculectomy and triple procedure, this improved and updated procedure lowers intraocular pressure, improves visual acuity and decreases the occurrences of complications. It is a safe, reasonable, quick and effective treatment for cataract patients with glaucoma.