Detection of weak fault using sparse empirical wavelet transform for cyclic fault

The successful prediction of the remaining useful life of rolling element bearings depends on the capability of early fault detection. A critical step in fault diagnosis is to use the correct signal processing techniques to extract the fault signal. This paper proposes a newly developed diagnostic model using a sparse-based empirical wavelet transform (EWT) to enhance the fault signal to noise ratio. The unprocessed signal is first analyzed using the kurtogram to locate the fault frequency band and filter out the system noise. Then, the preproc signal is filtered using the EWT. The l _q -regularized sparse regression is implemented to obtain a sparse solution of the defect signal in the frequency domain. The proposed method demonstrates a significant improvement of the signal to noise ratio and is applicable for detection of cyclic fault, which includes the extraction of the fault signatures of bearings and gearboxes.

Novel Membrane Detector Based on Smart Nanogels for Ultrasensitive Detection of Trace Threat Substances

A novel membrane detector is developed by a facile strategy combining commercialized membrane and smart nanogels for ultrasensitive and highly selective real-time detection of trace threat substances. On the basis of nanogel filtration and polydopamine adhesion, the membrane detector is fabricated by simply immobilizing smart nanogels onto the multiple pores of a commercialized membrane as the nanosensors and nanovalves. This is demonstrated by incorporating Pb²⁺-responsive poly( N-isopropylacrylamide- co-acryloylamidobenzo-18-crown-6) nanogels in the straight pores of a commercialized polycarbonate membrane for ultrasensitive and highly selective real-time detection of trace Pb²⁺. When selectively recognizing the Pb²⁺ in solution, the smart nanogels in the membrane pores swell, which lead to trans-membrane flux change. Quantitative detection of Pb²⁺ concentration can be achieved by simply measuring the flow rate of the trans-membrane flow. Due to the multiple nanochannels of nanogel-immobilized pores in the membrane for Pb²⁺ sensing and flux regulating, ultrasensitive and highly selective real-time detection of trace Pb²⁺ with concentration as low as 10^-10 mol L^-1 can be achieved. The nanogel-immobilized membrane detector offers a flexible platform to create versatile new membrane detectors by incorporating diverse smart nanogels for ultrasensitive and highly selective real-time detection of different trace threat substances.

The protective effect of betulinic acid (BA) diabetic nephropathy on streptozotocin (STZ)-induced diabetic rats

The present study was designed to investigate the protective effect of betulinic acid (BA) on streptozotocin (STZ)-induced diabetic rats. The rats were intraperitoneally injected with STZ (35 mg kg^-1). 7 days later, the animals were intragastrically administered with metformin (MET, 150 mg kg^-1), BA (20 mg kg^-1) or BA (40 mg kg^-1) once daily for consecutive 30 days. The blood glucose, the contents of insulin, interleukin-6 (IL-6), interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) in serum were examined. The levels of IL-6, IL-1β, TNF-α, superoxide dismutase (SOD), catalase (CAT) and malondialdehyde (MDA) in kidney tissues were measured. Moreover, the histopathological alteration and the protein expressions of the signaling pathway were detected by hematoxylin and eosin (H&E) staining and western blotting, respectively. BA significantly decreased the levels of serum insulin, IL-6, IL-1β, TNF-α and blood glucose. In addition, BA increased the activities of SOD, CAT and reduced the contents of MDA, IL-6, IL-1β, and TNF-α in kidney tissues. BA also ameliorated the histopathological condition. Furthermore, BA attenuated the phosphorylations of p-adenosine 5'-monophosphate-activated protein kinase (AMPK), nuclear factor kappaB (NF-κB), and an inhibitor of NF-κB (IκBα) and the expressions of NF-E2-related factor 2 (Nrf2) and heme oxygenase (HO)-1. These findings demonstrated that BA exhibited a protective effect on diabetic nephropathy in STZ-induced rats possibly through the AMPK/NF-κB/Nrf2 pathway.

Neurofibromatosis type 1-associated multiple rectal neuroendocrine tumors: A case report and review of the literature

Neurofibromatosis type 1 (NF-1) is commonly associated with benign or malignant tumors in both the central and peripheral nervous systems. However, rare cases of NF-1-associated multiple rectal neuroendocrine tumors have been reported. This report describes a case of a 39 year old female with NF-1 and intermittent hematochezia as a primary symptom. Physical examination showed multiple subcutaneous nodules and café au lait spots with obvious scoliosis of the back. Imaging examinations and colonoscopy found malformation of the left external iliac vein and multiple gray-yellow nodules with varying sizes and shapes in the rectal submucosal layer. Histological and immunohistochemical results suggested multiple rectal neuroendocrine tumors, a rare disease with few appreciable symptoms and a particularly poor prognosis. The patient with NF-1 presented here had not only multiple rectal neuroendocrine neoplasms but also vascular malformations, scoliosis and other multiple system lesions. This case therefore contributes to improving clinical understanding, diagnosis and treatment of related complications for patients with NF-1 who present with associated medical conditions.

miR-487a promotes progression of gastric cancer by targeting TIA1

Gastric cancer (GC) is one of the most common malignancies as well as the third leading cause for cancer-related death. Molecular basis of GC are essential and critical for its therapeutic treatment, but still remain poorly understood. T-cell intracellular antigen-1 (TIA1) extensively involves in cancer progression, whereas its role and regulation mechanism in GC have not been revealed. In the present study, we found that TIA-1 protein level was down-regulated in GC tissues and TIA1 inhibited proliferation and promoted apoptosis of GC cells. Then, we used bioinformatics to predict miR-487a as the upstream regulator of TIA1 and we also observed an inverse correlation between miR-487a level and TIA-1 protein level in GC tissues. Next, we demonstrated that miR-487a directly targeted TIA1 via binding to its 3'-untranslated region. Furthermore, we investigated the role of miR-487a-TIA1 pathway in the growth of GC cells both in vitro and in vivo. The repression of TIA-1 by miR-487a promoted cell proliferation and suppressed cell apoptosis in vitro, and the knockdown of miR-487a had the opposite effects. Finally, we demonstrated that miR-487a promoted the development of gastric tumor growth in xenograft mice by targeting TIA-1. These effects could be partially reversed by restoring the expression of TIA-1. Overall, our results reveal that TIA1 is a tumor suppressor gene and is directly regulated by miR-487a in GC, which may offer new therapeutic targets for GC treatment.

A Simple Device Based on Smart Hollow Microgels for Facile Detection of Trace Lead(II) Ions

A simple device, which is equipped with a non-woven fabric filter medium immobilized with ion-recognizable smart hollow microgels, is developed for facile detection of trace lead(II) ions (Pb²⁺ ). The ion-recognizable smart microgels are made of poly(N-isopropylacrylamide-co-benzo-18-crown-6-acrylamide) (PNB), in which the 18-crown-6 groups act as the sensors of Pb²⁺ and the N-isopropylacrylamide groups act as the actuators. The PNB hollow microgels can isothermally change from a shrunk state to a swollen state in response to recognizing Pb²⁺ in the aqueous environment due to the electrostatic repulsion among the charged 18-crown-6/Pb²⁺ complex groups and the enhancement of hydrophilicity of the microgels. Due to the hollow structures, the PNB microgels show remarkable isothermal swelling ratio. Thus, the flux of solution pass through the non-woven fabric filter medium decreases significantly because of the remarkable reduction in the space for liquid flowing upon recognizing Pb²⁺ . The Pb²⁺ concentration can be detected quantitatively by simply and easily measuring the change of solution flux using the proposed device, which is operated without external power supply or spectroscopic measurements. The strategy proposed in this study provides a promising method for facile detection of trace Pb²⁺ in aqueous environments.

Isoflurane enhances the malignant potential of glioblastoma stem cells by promoting their viability, mobility in vitro and migratory capacity in vivo

BACKGROUND

Isoflurane is one of the most common general anaesthetics used during surgical procedures, including tumour resection. However, the effects of isoflurane on the viability and migration capacity of cancer cells, specifically in the context of brain cancer cells, remain unclear. Therefore, the aim of this study was to evaluate the influence that isoflurane has on the function of glioblastoma stem cells (GCSs) in regards to cell proliferation, survival and migration.

METHOD

U251-GSCs were exposed to isoflurane at clinically relevant concentrations and incubation times. The effects on proliferation, survival and migration capacities of the cells were evaluated in vitro. The potential risk was assessed in mice by intracranial injection of U251-GSCs pretreated with isoflurane. Furthermore, the average tumour volume and migration distance of U251-GSCs from the tumour centre were calculated.

RESULTS

Exposure of U251-GSCs to 1.2% isoflurane for 6 h resulted in increased proliferation (P<0.05) and decreased apoptosis rate (P<0.05) when compared with the control group. In addition, isoflurane exposure caused increased migration capacity in vitro (P<0.05) and the distance migrated was increased in vivo (P<0.05).

CONCLUSION

Clinically relevant concentrations and incubation times of isoflurane could promote the viability and mobility of U251-GSCs, suggesting this general anaesthetic may have detrimental effects in glioblastoma by facilitating its growth and migration.

Novel insights into ion channels in cancer stem cells (Review)

Cancer stem cells (CSCs) are immortal cells in tumor tissues that have been proposed as the driving force of tumorigenesis and tumor invasion. Previously, ion channels were revealed to contribute to cancer cell proliferation, migration and apoptosis. Recent studies have demonstrated that ion channels are present in various CSCs; however, the functions of ion channels and their mechanisms in CSCs remain unknown. The present review aimed to focus on the roles of ion channels in the regulation of CSC behavior and the CSC-like properties of cancer cells. Evaluation of the relationship between ion channels and CSCs is critically important for understanding malignancy.

Design, synthesis and biological evaluation of novel carbamodithioates as anti-proliferative agents against human cancer cells

A series of new carbamodithioates compounds has been successfully synthesized. All the carbamodithioate derivatives of SFE and SFA with benzenethiols (substituted or unsubstituted) exhibited, in general, higher percentages of inhibition than their parent compounds: SFE and SFA. A number of carbamodithioate derivatives with benzenethiols (substituted or unsubstituted) (1l, 1m, 1n, 1o, 1q, 1s, 2l, 2n, 2p, 2q, 2r and 2s) were investigated for in vitro anti-proliferative activities against five cancer cell lines: SMMC-7721, A549, A375, HCT 116 and Hela. The carbamodithioate compounds (1l, 1m, 1n, 1o, 1q and 1s) derived from SFE and the carbamodithioate compounds (2l, 2n, 2p, 2q, 2r and 2s) derived from SFA are more sensitive toward SMMC-7721and A549 cancer cells than toward other cancer cells in that their IC₅₀ values are appreciably lower. Moreover, they exhibited stronger inhibitory activities than their parent compound SFE and SFE. Further investigation indicated that these carbamodithioate derivatives inhibited colony formation of SMMC-7721 and remarkably induced the G2/M or G0/G1 phase cell cycle arrest and apoptosis in SMMC-7721 cancer cells. More important, these carbamodithioate derivatives are stable in protic solvent media than their parent compounds. By virtue of the simplicity of the preparation of these carbamodithioate derivatives and their stability, compounds 1m and 2s could be the promising candidates for replacement for their parent SFE and SFA for cancer prevention agents.

[Effects of Algal Blooms and Their Degradation on the Sediment-water Micro-interface]

Effects of algal blooms and their degradation on the sediment-water micro-interface under conditions of disturbance and darkness were investigated. The concentration of chlorophyll a in water was determined via the acetone method, profiles of oxygen near the interface were measured using a microelectrode, and profiles of nutrients and metals in sediments were measured at the millimeter level. The results showed that algal bloom degradation at the sediment-water micro-interface decreased the concentration of oxygen and affected nutrient and metal profiles, at depths over approximately 3 mm. Disturbance played an important role in algal bloom degradation and early diagenesis processes of nutrients, such as C and P, and metals, such as Fe, Ca, Mg, Al, and K. Darkness sped up algal bloom degradation and reduced the influence of disturbance. Under control conditions of no disturbance nor algae, and supplied with enough light, a layer of benthic algae appeared at the sediment surface, whose photosynthesis produced oxygen and greatly changed the microenvironment. This brought about significant differences in the concentrations of nearly all nutrients and metals in the surficial sediment compared with those of other treatments. Correlation analyses showed that the vertical variability of sediment P concentration was most strongly related to sediment Mn, followed by sediment C. The results of this high-resolution research showed that algal bloom degradation had an effect on the sediment-water micro-interface at the millimeter level.

Mechanism of Premature Apoptosis in CD1d-Restricted Natural Killier T Cells From Human Peripheral Blood During the Induction of Proliferation In Vitro

OBJECTIVE

A preliminary investigation on the proliferation and cultivation process of natural killer T cells (NKT) was carried out. We provide reference data for future NKT-related research and development.

METHODS

Peripheral blood mononuclear cells (PBMCs) were isolated from healthy people and were induced by α-galactosylceramide (α-GalCer). The phenotypic changes of the cells and the activation and apoptosis of Caspase-3 were recorded for 3-4 weeks.

RESULTS

The proliferation of the NKT cells continued for approximately 3 weeks, and then apoptosis started to occur. The activity of Caspase-3 was maintained at a high level from the second week. The responses of individual human NKT cells to α-GalCer stimulation differed significantly.

CONCLUSION

The proliferation of the NKT cells continued for approximately 3 weeks, and then apoptosis Semiconstitutively started to occur. The activity of Caspase-3 was maintained at a high level from the second week. The responses of individual human NKT cells to α-GalCer stimulation differed significantly.

Prognostic value of combined and individual expression of microRNA-1290 and its target gene nuclear factor I/X in human esophageal squamous cell carcinoma

BACKGROUND

microRNA (miR)-1290 was previously indicated to promote esophageal squamous cell carcinoma (ESCC) progression via regulating its target gene nuclear factor I/X (NFIX).

OBJECTIVE

To investigate clinical significance of miR-1290 and NFIX in ESCC.

METHODS

Quantitative real-time PCR was performed to detect miR-1290 and NFIX mRNA expression in ESCC tissues. Associations of miR-1290 and/or NFIX mRNA expression with various clinicopathological features and prognosis in ESCC patients were statistically evaluated.

RESULTS

Compared to noncancerous esophageal mucosa, miR-1290 expression was upregulated, while NFIX mRNA expression was downregulated in ESCC tissues. There was a significantly negative correlation between miR-1290 and NFIX expression in ESCC tissues (r=-0.427, P= 0.01). Interestingly, miR-1290-high and/or NFIX-low expression were all significantly associated with positive lymph node metastasis and advanced tumor-node-metastasis stage of ESCC patients (all P< 0.05). Moreover, miR-1290 upregulation and NFIX downregulation both correlated short overall and disease-free survivals of ESCC patients. Importantly, the prognostic value of combined miR-1290 and NFIX expression was more significant than those considered alone.

CONCLUSIONS

Our data suggest that the dysregulation of miR-1290-NFIX axis may play crucial roles in esophageal carcinogenesis and progression. We also confirmed miR-1290 and its target gene NFIX as independent prognostic factors for ESCC patients.

Disseminated Nocardia infection in a female patient with idiopathic thrombocytopenic purpura and long-term glucocorticoid use

Introduction:

Nocardiosis is a rare kind of opportunistic infections. Because of its insidious onset and atypical clinical manifestations, diagnosis and early treatment are often delayed.

Case presentation:

Here we present a 60-year-old Chinese female patient with systemic Nocardia infection, who had been diagnosed with idiopathic thrombocytopenic purpura previously and was misdiagnosed for up to 6 months prior to presenting at our hospital and ultimately achieved clinical cure.

Discussion:

The patient took prednisone because of ITP for several years which led to immunosuppression. Nocardia infection began from the skin rupture and then spread all over the body with multiple system involvement. The pus culture eventually found Nocardia. Sulphonamides have been the standard treatment for decades and there are several other options. Patients with severe Nocardia infection or immunosuppression are suggested a combined therapy.

Conclusion:

Nocardiosis is an infection that often resulted in delayed diagnosis because of lack of specificity of the clinical profile and the difficulty in culturing the bacteria. It should be included in the differential diagnosis of patients in which there are cutaneous, respiratory or neurological manifestations, especially in immunosuppressed individuals.

Trojan-Horse-Like Stimuli-Responsive Microcapsules

Multicompartment microcapsules, with each compartment protected by a distinct stimuli-responsive shell for versatile controlled release, are highly desired for developing new-generation microcarriers. Although many multicompartmental microcapsules have been created, most cannot combine different release styles to achieve flexible programmed sequential release. Here, one-step template synthesis of controllable Trojan-horse-like stimuli-responsive microcapsules is reported with capsule-in-capsule structures from microfluidic quadruple emulsions for diverse programmed sequential release. The nested inner and outer capsule compartments can separately encapsulate different contents, while their two stimuli-responsive hydrogel shells can individually control the content release from each capsule compartment for versatile sequential release. This is demonstrated by using three types of Trojan-horse-like stimuli-responsive microcapsules, with different combinations of release styles for flexible programmed sequential release. The proposed microcapsules provide novel advanced candidates for developing new-generation microcarriers for diverse, efficient applications.

A Novel Thermoresponsive Catalytic Membrane with Multiscale Pores Prepared via Vapor-Induced Phase Separation

A novel thermoresponsive catalytic polyethersulfone membrane with multiscale pores is developed by constructing silver nanoparticles (Ag NPs) loaded poly(N-isopropylacrylamide) (PNIPAM) nanogels on pore walls of cellular pores as thermoresponsive gates and catalysts via vapor-induced phase separation. The Ag NPs are stably immobilized on the PNIPAM nanogels by an in situ reduction method based on the versatile adhesion and reduction properties of polydopamine. The micrometer cellular pores decorated with Ag NPs loaded PNIPAM nanogels are formed throughout the membrane and act as numerous microreactors with a large pore surface. The proposed membrane exhibits both satisfactory thermoresponsive characteristics and stable catalytic properties. The effects of operation temperature and reactant concentration of feed solution on the catalytic properties are investigated systematically. The results show that the apparent kinetic rate constant of catalytic reduction of 4-nitrophenol (4-NP) in water by reductant sodium borohydride (NaBH₄ ), is ranging from 3.7 to 37.9 min^-1 at temperatures from 20 to 45 ºC and the molar ratio of NaBH₄ to 4-NP from 100:1 to 500:1. When the reactant concentration in feed solution fluctuates, the permeability or throughput of the membrane is simply adjusted by virtue of the thermoresponsive characteristics of membranes to achieve high catalytic conversion of reactant.