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Mud loss occurrence is one of the costly problems during drilling operations that can increase the non-productive time if not treated promptly. This study presents a new method for analysis of drilling microchip data, which can help to locate the loss and influx zone(s). An experimental flow loop facility with an inclined test section is developed to study the effect of lost circulation or fluid influx on the circulating temperature profile. The presence of loss/influx zone is simulated using an external clamp to control the peripheral leakage or injection through a joint in the test section. Drilling microchips are dropped in multiple runs to obtain the circulating temperature profiles in the flow conduits with and without lost circulation. Similar tests are conducted in presence of fluid influx. Meanwhile, the transit times of tracers in the pipe and annulus are measured. A tracer tracking algorithm is developed considering slippage between the tracers and fluid to follow the axial location of tracers while circulating in the flow loop. The experimental observations indicate that the tracers are moving slower than the average fluid velocity and mainly travel on the lower side of the inclined annular space. The circulating temperature profiles with and without lost circulation are compared to identify the loss zone. The experimental results further show that the depth of influx can be easily recognized from the calculated temperature gradients. Measured results of drilling microchips in a field trial are analyzed to identify anomalies of temperature gradients near the bottom hole. It is realized that the amplitude of the annular temperature gradient can be evaluated to identify the abnormal changes. Novel results of deployed drilling microchips along with the presented methodology can be used to investigate the lost circulation or fluid influx while drilling. In particular, the amplitude of temperature gradients from the measured data of drilling microchips can be used as a signature to locate the loss and influx zone(s).

The well-designed electrolyte enables high-voltage Li‖Ni6Mn2Co2O2 batteries with both enhanced safety and superior reversibility.

Long noncoding RNAs (LncRNAs) play a pivotal role in gastric tumorigenesis, while exosomes facilitate the LncRNAs transferring to recipient cells. However, the roles of exosomal LncRNAs in gastric premalignant lesions (GPL) remain unclear. We analyzed the expression of LncHOXA10 and its role in GPL progression. The protective effect of all-trans retinoic acid (ATRA) on GPL was explored in vitro and in vivo. Here, we found that LncHOXA10 expression was obviously increased in serum exosomes and gastric tissues from individuals with GPL, and exosomal LncHOXA10 from patients with GPL markedly promoted the malignant progression of human gastric epithelial cell line GES-1. Furthermore, RNA-pulldown assay revealed that LncHOXA10 mainly interacted with pyruvate carboxylase (PC), an essential enzyme in various cellular metabolic pathways. In gastric tissues from patients with GPL and gastric cancer (GC), PC was also upregulated and positively correlated with LncHOXA10 expression, which predicted a poor prognosis as well. Moreover, PC silencing attenuated the malignant effects of exosomal LncHOXA10 on GES-1 cells. ATRA also ameliorated the deterioration of GPL and prevented the malignant progression of GPL by reducing exosomal LncHOXA10 and PC expression. Collectively, the LncHOXA10–PC axis participated in the early stage of GC tumorigenesis, and ATRA might be useful to prevent GPL from developing into GC because it targets this axis.

Daoming Zhang,1 Yuan Li,1 Haoyue Li,2 Tian Tang,1 Yongfa Zheng,1 Xufeng Guo,1 Ximing Xu1 1Cancer Center, Renmin Hospital of Wuhan University, Wuhan, People’s Republic of China; 2Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, People’s Republic of ChinaCorrespondence: Ximing XuCancer Center, Renmin Hospital of Wuhan University, 238 Jiefang Road, Wuhan, 430060, People’s Republic of ChinaTel +86-13707120651Email doctorxu120@aliyun.comObjective: To evaluate the value of serum complement component 1q (C1q) levels in predicting the efficacy of combined immunotherapy in patients with lung cancer.Methods: A total of 42 patients with lung cancer who received combined immunotherapy in the cancer center of Renmin Hospital of Wuhan University were included in this study. The clinical data of serum C1q and lactate dehydrogenase (LDH) levels before and three weeks after immunotherapy were collected.Results: Response evaluation showed that the number of patients with complete response (CR), partial response (PR), stable disease (SD), and progressive disease (PD) was 0 (0%), 26 (61.9%), 14 (33.3%), and 2 (4.8%), respectively. The CR/PR group (patients with CR or PR) showed higher pC1q (C1q level before immunotherapy) and iC1q (C1q level 3 weeks after immunotherapy) than the SD/PD group (patients with SD or PD). The LDH reduction (96.2%) and C1q increment (84.6%) in the CR/PR group 3 weeks after immunotherapy were higher than those of the SD/PD group, and the differences were statistically significant. Logistic regression analysis indicated that pC1q, iC1q, and LDH level trends 3 weeks after the treatment were significantly correlated to the efficacy of combined immunotherapy with odds ratios of 8.185, 5.500, and 0.031, respectively.Conclusion: High C1q levels before immunotherapy and increased C1q levels and decreased LDH levels 3 weeks afterward suggest good therapeutic effects of combined immunotherapy in patients with lung cancer. Serum C1q levels have certain clinical significance in predicting the efficacy of combined immunotherapy.Keywords: immunotherapy, efficacy prediction, complement component 1q

Retinoic acid (RA) is the most biologically active metabolite of vitamin A and is important for stomach physiological function. However, little is known about the metabolic status of RA in human gastric lesions. From 2015 to 2018, 1,392 local residents in Lujiang County were recruited into a cross-sectional survey program, which included a questionnaire interview and blood collection. We detected the mRNA and protein expression of RA metabolism-relevant factors in gastric tissues from 68 local patients with gastric lesions. The effects of all-trans retinoic acid (ATRA) supplementation were investigated in a gastric precancerous lesions (GPLs) rat model. In the cross-sectional survey, no significant differences in the level of RA precursor (

Numerous long noncoding RNAs (LncRNAs) were having recently been shown to be involved in cancer development, including gastric cancer (GC). However, the precise mechanism and treatments to target these molecules have rarely been studied. Thus, we aimed to investigate the function of LncHOXA10 in gastric tumorigenesis and targeted therapy. First, we measured the differences in LncHOXA10 and retinoic acid receptor β (RAR-β) levels in gastric cancer tissues and cell lines compared with those in noncancerous tissues and cell lines. We observed that LncHOXA10 was significantly upregulated in gastric cancer tissues and cell lines, whereas RAR-β showed the opposite trend. Subsequently, loss and gain of LncHOXA10 cell lines were constructed to determine whether LncHOXA10 plays a role in gastric tumorigenesis. The results showed that LncHOXA10 promoted the proliferation, migration, and invasion of cells, whereas apoptosis was markedly inhibited. Subsequently, mechanistic investigations revealed that LncHOXA10 can repress RAR-β expression and that all-trans retinoic acid (ATRA) can rescue the expression of RAR-β. Finally, we showed that ATRA can reverse the pro-cancerous function of LncHOXA10. We showed that LncHOXA10 may be a prognostic and therapeutic factor of gastric cancer by negatively regulating RAR-β. Furthermore, ATRA can inhibit the role of LncHOXA10 in gastric tumorigenesis.

This paper studies the fault diagnosis method of pneumatic control valve. Firstly, the faults characteristics of pneumatic control valves are analyzed according to the operating principle and status of pneumatic control valves; secondly, the expert experience of the fault diagnosis of pneumatic control valves is summarized, which is verified according to the operating mechanism; thirdly, a fault diagnosis approach for pneumatic control valves based on modified expert system is proposed, by combining particle swarm optimization (PSO) algorithm with expert rules. Finally, the availability and advantages of the proposed approach is verified by the designed valve experimental system platform. The results show that compared with the basic expert system-based method, the modified method improves the accuracy and reduces the false negative rate effectively.

We aimed to detect the expression of specific LncRNAs in exosomes isolated from the serum of patients with precancerous lesions and to study the effect of these serum exosomes on the activity of GES-1 cells in patients with precancerous lesions, as well as the activity of all-trans retinoic acid on GES-1 cells with or without the exosomes. Exosomes were extracted from the serum of patients with precancerous lesions and normal controls. Based on our previous sequencing results, quantitative real time-PCR was used to detect differentially expressed LncRNAs. Exosomes from the serum of patients with precancerous lesions were cocultured with GES-1 cells, and 5 μM all-trans retinoic acid was added as an intervention. Changes in cell viability and expression of LncHOXA10 were observed. Compared with the blank group, the proliferation activity of GES-1 cells cocultured with exosomes derived from the serum of patients with precancerous lesions was increased (P < 0.01), the proportion of cells in S phase was increased (P < 0.05). After adding 5 μM all-trans retinoic acid, the viability of cells decreased significantly (P < 0.01), the proportion of cells in S phase decreased significantly (P < 0.05). The expression of LncHOXA10 was decreased (P < 0.05). All-trans retinoic acid can conduct its chemopreventive effects by inhibiting the expression of LncHOXA10, thereby reducing the activity of LncHOXA10 in GES-1 cells cocultured with serum exosomes from patients with precancerous lesions.

Electrocardiogram is a comprehensive reflection of cardiac electrical activity on the surface of the body. It is of great research value to analyse ECG signals and diagnose heart diseases. Since the heartbeat process is a chaotic system, this study proposes a multi-fractal detrended fluctuation half-spectrum analysis method of short-term heart rate variability-y (HRV) signals from the perspective of non-linear dynamics, for patients with normal heart rate, sporadic heart rate variation and supraventricular rate, the heart rate mutation signal of patients with heart rate variation is calculated, and the statistical value distribution of multi-fractal parameter α has a certain change trend with the change of disease condition. The classification accuracy can reach >75% through box plot analysis.

Helicobacter pylori (H. pylori) infection can interfere with the absorption of most elements, and the variations of some element levels are related to the incidence of gastric cancer. However, there have been conflicting results concerning the influence of H. pylori infection on serum element levels. The present study aimed to compare the serum element concentrations of H. pylori-infected local residents with uninfected residents from Lujiang County with high gastric cancer risk in Eastern China. We used data and serum samples from the H. pylori screening-survey program which was a cross-sectional study. We took 155 samples randomly from the screening survey, identified 74 H. pylori-positive residents and 81 H. pylori-negative residents by a serological test. The serum concentrations of 15 elements (calcium, magnesium, iron, zinc, selenium, copper, molybdenum, chromium, cobalt, nickel, lead, cadmium, mercury, arsenic, and aluminum) were determined using inductively coupled plasma mass spectrometry. Serum cobalt was found at higher levels in the H. pylori-infected residents than the H. pylori-uninfected residents (0.246 vs 0.205 μg/L, P = 0.022), but no statistically significant differences in the serum levels of other elements were found. This is the first study to report the serum concentrations of 15 elements and their relationships with the infection status of H. pylori among local residents from Lujiang County with high gastric cancer risk. Although the International Agency for Research on Cancer has classified cobalt and other soluble cobalt salts as possibly carcinogenic to human beings, our results may provide a clue to the relationships between cobalt, H. pylori, and gastric cancer.

The W-shaped regenerative technology-based radiant tube, a commonly adopted indirect-heating equipment item, has been well geared into various industries. This paper effectively amplifies our previ...

Intuitively, when the breakdown voltage is satisfied, enlarging the inter-dielectric gap width (d g) is prone to filamentary dielectric barrier discharges (DBDs) due to the lengthened electron migration path and the intensified electron cascade. In this letter, we report that in specific conditions, a larger d g can also promote a homogeneous DBD. The calculated results from the two-dimensional fluid model of an atmospheric helium DBD reveal that the incomplete dissipation of glows (residual positive column) induced by the enlarged d g poses an eraser-like role, wiping out the surface charges left behind by the former discharge. Thus, the so-called memory effect cannot be well established, and the uniform DBD ensues. An experiment with similar conditions and a simplified linear stability analysis qualitatively validate the calculated results. This work also provides sufficient feasibility of regulating discharge uniformity of DBDs through manipulating the dissipative characteristic, and some methods of tailoring waveform would be useful.

The role of ginsenoside in the prevention of cancer has been well established. Ginsenoside Rg5 is one of the main components isolated from red ginseng, which has been demonstrated to have anti-tumor effects by inhibiting cell proliferation and causing DNA damage. However, the role of ginsenoside Rg5 and its molecular mechanisms remain unclear in human esophageal cancer. In the present study, Rg5 was investigated as a novel drug for the chemotherapy of esophageal cancer in in vitro experiments. Esophageal cancer Eca109 cells were exposed to various concentrations of ginsenoside Rg5 (0–32 µΜ) for 24 h. Subsequent cell proliferation assays demonstrated that treatment with ginsenoside Rg5 resulted in the dose-dependent inhibition of proliferation, while a significant increase in apoptotic rate and increased activities of caspase-3, −8 and −9 were observed. In addition, the mitochondrial membrane potential was decreased and the cytoplasmic free calcium level increased following treatment with ginsenoside Rg5. Furthermore, the expression of B-cell lymphoma 2 and phosphorylated-protein kinase B (p-Akt) decreased. The specific phosphoinositide-3 kinase (PI3K) inhibitor LY294002 promoted this effect, while insulin-like growth factor-1, a specific PI3K activator, inhibited this action. Taken together, the results suggested that ginsenoside Rg5 may have a tumor-suppressive effect on esophageal cancer by promoting apoptosis and may be associated with the downregulation of the PI3K/Akt signaling pathway.

Wellbore instability due to shale hydration and dispersion is always a challenge in oil and gas drilling engineering. Hydroxyl-terminated polyamidoamine (PAMAM-OH) dendrimers were probed as potential shale inhibitors for the first time. The inhibitive potential of candidate PAMAM-OH dendrimers was screened with particle size distribution test, bentonite inhibition test, and cuttings dispersion test. In order to reveal the underlying inhibitive mechanism, the interaction between the dendrimers and sodium bentonite (Na-Bent) was characterized using X-ray diffraction analysis, zeta potential measurement, and thermal gravimetric analysis. The results indicated that PAMAM-OH dendrimers could intercalate into bentonite particles. The intercalation can form in mono or bilayer arrangement. The deformation of bentonite increased with the intercalated number of layers and affected by the phase variety and the change in adsorbed concentration. When adopting monolayer adsorption in the interlayer, the dendrimers exhibited effective inhibition performance, while the bilayer adsorption corresponded to decreased inhibitive performance. Marked improvement in shale inhibition was realized when a routinely used shale inhibitor KCl and PAMAM-OH were combined. A stable monolayer intercalation of dendrimers was observed in the presence of KCl, suggesting a synergetic effect between PAMAM-OH dendrimers and KCl.

Dendrimers have been paid increasing attention in the area of drilling fluid recently due to their unique structure and properties. The inhibitive properties of amine terminated polyamidoamine (PAMAM) dendrimers ranging from G0 to G5 were evaluated by relative inhibition rate, shale cuttings hot-rolling dispersion test and particle size distribution measurement respectively. Meanwhile the inhibitive capacity of the polymers under various pH value conditions was studied. The interaction between sodium bentonite and PAMAM dendrimers was characterized by zeta potential measurement and X-ray diffraction (XRD). The results indicated that, G0 and G5 are superior to polyether diamine, while G1, G2, G3 and G4 perform better than KCl. PAMAM dendrimers from G0 to G5 can decrease the zeta potential of clay particles from −39 mV to about −22.6 mV at natural pH values and reverse the charge when the pH value is adjusted to 9. When intercalated into the clay interlayer in aqueous solution, the candidate PAMAM dendrimers can form monolayer arrangement at lower concentrations and reduce the interlayer spacing of hydrated clay from 1.95 nm to 1.38–1.63 nm, which is the direct evidence of inhibiting shale hydration. With the increase of concentration, mixed phase and bilayer orientation are formed in the interlayer. The multi-terminal amine groups of dendrimers can effectively bind the adjacent layers together with electrostatic attraction and hydrogen bonding, and expel the water molecules out of the interlayer, contributing to the suppression of clay swelling and dispersion. The pH value reduction of aqueous solution improves the protonation of terminal-amine group, which can intensify the interaction between the polymers and clay, inducing the decrease of hydrated interlayer spacing and the zeta potential of clay particles, thus enhancing the inhibitive properties.

Electrochemical capacitors deliver high power and have long operational lives; however, their energy densities are limited. Compared to carbon-based electrical double-layer capacitors, pseudocapacitors with an aqueous electrolyte are predicated to provide both high gravimetric and volumetric capacitance while being cost-effective and eco-friendly. However, their narrow operational potential windows limit the practical delivery of energy. In this study, we synthesized novel NbCxN1-x nanoparticles encapsulated in a uniform carbon layer. This pseudocapacitive material exhibits a high volumetric capacitance, a wide potential window stability (∼345 F cm−3, 2.1 V, in 1 M of Li2SO4), and a long cycling life (>10 000 cycles). Moreover, the symmetric cells (2.2 V, in 1 M of Li2SO4) exhibit high energy density as well as excellent cyclability and rate performances. These findings provide new opportunities for the design of aqueous energy storage devices having a wide applied potential difference and excellent performance.

Aseptic loosening is one of the main failure modes in artificial joints. Significant information about the aseptic loosening is carried by the wear debris of the joints. In this paper, the wear debris acquired from the ultrahigh molecular weight polyethylene (UHMWPE) artificial joints is prepared and a systematic research is carried out to investigate the wear mechanism of aseptic loosening using the wear debris analysis. The hip joint simulator was used to conduct the wear tests of the CoCrMo-UHMWPE artificial joint friction pairs. The scanning electron microscope (SEM) was employed to analyze the wear debris profiles. The analysis results demonstrated that the UHMWPE joints mainly produced the roundness, tuberous, lacerated, sheet, pole-liked and strip wear debris, and the wear mechanism of the joint aseptic loosening had a close relationship with the morphology of the debris types. The adhesive wear, fatigue wear and laceration under alternating stress were the main causes of the joint failure. Based on the wear debris analysis results, a new diagnosis method using the radar map fractal representation was proposed to diagnose the failure of the artificial joints.

Polyetheramines as shale hydration inhibitors in water-based drilling fluids have attracted great interests in recent years. In this paper, in order to clarify the relationship between inhibitive properties and molecular structures of polyetheramines, several inhibitive experimental methods including bentonite inhibition test, shale cuttings hot-rolling dispersion test, sedimentation volume measurement, and API filtration measurement were adopted to evaluate the inhibition variation of different polyetheramines. Furthermore, a series of analytical methods such as surface tension determination, zeta potential measurement, XRD, contact angle measurement, and water adsorption test were performed to identify the relationship between the inhibitive performance and molecular structures. The factors including molecular weight, number of amine group, and molecular chain affecting the interaction between polyetheramines and clay particles were analyzed. Polyetheramine with molecular weight of 230 and oxypropylene segment can reduce the interlayer spacing of the hydrated clay to the minimum and exhibit the best performance in comparison with others. The coordination of electrostatic adsorption with monolayer arrangement, hydrogen bonding, and hydrophobic shielding effect contributed to the top level of inhibition.

The amine terminated polyamidoamine (PAMAM) dendrimers were investigated as potential shale stabilizers for the first time. Its inhibitive properties were characterized by a bentonite inhibition test and a shale cuttings dispersion test. The interaction between PAMAM dendrimers of various generations and sodium bentonite was examined by X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, transmission electron microscopy (TEM) and thermogravimetric analysis (TGA). The hydration and dispersion of shale can be effectively inhibited with PAMAM dendrimers. The decrease of pH value in the dendrimer aqueous solution improved the inhibitive performance. For lower generations of dendrimer growth (G0 to G3), the inhibitive level decreased with the increase of generation. For higher generations (G4, G5), the inhibitive level increased with the increase of generation. Low generation PAMAM dendrimers could penetrate into the clay interlayer space, but exhibited highly oblate intercalation behaviors. G0 intercalated into the interlayer space with a monolayer conformation as concentration increased, while G1, G2, G3 and G4 intercalated into the interlayer space with monolayer arrangement at low concentrations, and mixed phase orientation at high concentrations. G5 could not fully intercalate into the interlayer space due to the steric hindrance. According to the interaction between PAMAM and clay, effective internal and external inhibition on shale hydration and dispersion could be obtained with the combination of low generation G0 and high generation G5. A new water-based drilling fluid including G0 as shale swelling inhibitor and G5 as shale dispersion inhibitor was established and exhibited excellent inhibitive properties.

In this work, the experiments were conducted to investigate the performance of a W-shaped regenerative radiant tube burner (RRTB). The effects of structure scheme of air vents in the second stage, air flow rate ratio between two stages and switching time were experimentally studied on the performance of the RRTB. It is found that the RRTB has a better performance of heat recovery. The tube wall temperature is symmetrically distributed along the tube’s length, with an M-shaped profile and good temperature uniformity. The structure schemes of air vents have a significant influence on the performance of the RRTB, including the combustion organization and NOx emission. The air flow rate ratio between two stages has an evident effect on the combustion flame length inside RRTB, the wall temperature profile, the preheated air temperature and exhaust gas temperature, and NOx emission. Changing switching time has some effect on the tube wall temperature profile, preheated air temperature and heat recovery efficiency.

High radio-frequency phase-coded waveform generation based on dispersion-compensated optoelectronic oscillator (DCOEO) is proposed and experimentally demonstrated. The carrier frequency range of the generated phase-coded microwave, which exactly varies from 4 GHz to 45 GHz, can cover Ka band for Radar applications.

A wideband frequency tunable microwave generation based on a dispersion compensated optoelectronic oscillator (OEO) is proposed and demonstrated. A frequency tuning range from 3–42 GHz is obtained simply by suppressing the phasemodulation to intensity-modulation (PM-IM) conversion caused by long single mode fiber (SMF). The phase noise is measured to be less than −110 dBc/Hz@10kHz within the whole tuning range.

Correction for ‘Enhanced luminescence and tunable magnetic properties of lanthanide coordination polymers based on fluorine substitution and phenanthroline ligand’ by Xun Feng et al., RSC Adv., 2019, 9, 16328–16338.

We present a novel photonic approach based on heterodyne between a multiple-dispersed optical pulse and a continuous optical signal to generate tunable linearly chirped microwave waveform (LCMW) with large time-bandwidth product (TBWP). The carrier frequency of the generated waveform can be changed by tuning the frequency of continuous optical wave outputted from the tunable laser source (TLS),while the TBWP of the LCMW can be changed by optically pumping the linearly chirped fiber Bragg grating (LCFBG) in the dispersive loop with different pumping powers. An extremely large equivalent dispersion will be obtained because of the dispersive loop used in the system, which leads to the generation of LCMW with long temporal duration. The capability of the presented method is verified via numeric simulation.