Search

When geothermal fluid flows to the wellhead along the wellbore, there is a thermal transfer from the high-temperature geothermal fluid to the low-temperature formation. This process can directly lead to the decrease of wellhead temperature and loss of geothermal energy. Even though previous studies have confirmed that reducing the thermal conductivity of cement could validly cut down the heat loss of geothermal fluid, the influence factors of thermal conductivity are limited. In this research, we conducted detailed studies of the influence factors of thermal conductivity and compressive strength for cement. The results show that with the increase of water-cement ratio and thermal insulation materials, thermal conductivity and compressive strength decline. Furthermore, curing temperature is another important factor to improve the thermal preservation effect, but the testing temperature has the opposite influence. Based on these results, the present study concluded that porosity, Skeleton ingredients, curing temperature, and test temperature are vital factors for thermal conductivity. This research provides theoretical guidance for increasing the wellhead temperature of geothermal fluid and enhancing the efficiency of geothermal energy.

The scientific and reasonable layout of jack-up drilling platform can improve the efficiency and safety of drilling platform operation. Through the application of analytic hierarchy process (AHP) and the establishment of comprehensive evaluation and analysis model, this paper analyzes the commonly used drilling platform layout scheme and optimizes the scheme to meet operational requirements and to improve the ability of the drilling platform operation.

High-frequency measurements can provide much more new insights for drillstring dynamics compared to traditional instruments, leading to a new realm of understanding of drillstring behaviors in great detail than before. In this paper, data acquisition tools with high-frequency sample rates and the data processing are introduced. Based on high-frequency data, progress of drilling dynamics is summarized, including new understandings of low-frequency drillstring dynamics, high-frequency torsional oscillations (HFTOs), and high-frequency axial oscillations (HFAOs) and new findings for the coupling of vibrations and motions, as well as models and simulation methods to deeply comprehend high-frequency dynamics of drillstring. High-frequency measurements have been used for enabling drillers to improve drill performance, especially for field decision making, BHA selection, and bit design, usually through the ways of minimizing vibrations to obtain high-efficient drilling conditions, the high-frequency response near bit can also be used for lithology identification during drilling. Though there still exists a gap between research perspective and drilling practice, the industry of high-frequency measurements has gotten off a good start, which has huge potential to avoid nonproductive time thereupon reducing drilling cost in the future.

High-frequency measurements can provide much more new insights for drillstring dynamics compared to traditional instruments, leading to a new realm of understanding of drillstring behaviors in great detail than before. In this paper, data acquisition tools with high-frequency sample rates and the data processing are introduced. Based on high-frequency data, progress of drilling dynamics is summarized, including new understandings of low-frequency drillstring dynamics, high-frequency torsional oscillations (HFTOs), and high-frequency axial oscillations (HFAOs) and new findings for the coupling of vibrations and motions, as well as models and simulation methods to deeply comprehend high-frequency dynamics of drillstring. High-frequency measurements have been used for enabling drillers to improve drill performance, especially for field decision making, BHA selection, and bit design, usually through the ways of minimizing vibrations to obtain high-efficient drilling conditions, the high-frequency response near bit can also be used for lithology identification during drilling. Though there still exists a gap between research perspective and drilling practice, the industry of high-frequency measurements has gotten off a good start, which has huge potential to avoid nonproductive time thereupon reducing drilling cost in the future.

Ying Qi, Renjie Yao, Wenjing Zhang, Qingqing Cui, Fengyan Zhang Department of Ophthalmology, The First Affiliated Hospital of Zhengzhou University, The Laboratory for Ophthalmology and Vision Science, Henan Eye Hospital, Zhengzhou 450052, Henan, People’s Republic of ChinaCorrespondence: Ying Qi; Fengyan ZhangDepartment of Ophthalmology, The First Affiliated Hospital of Zhengzhou University, The Laboratory for Ophthalmology and Vision Science, Henan Eye Hospital, Zhengzhou 450052, Henan, People’s Republic of ChinaTel +86-371-3758296Email qiyingoph@163.com; zhangfengyanyanke@163.comBackground/Objective: Although lots of long non-coding RNAs (lncRNAs) have been demonstrated to be involved in carcinogenesis, the functions of numerous of lncRNAs remain unknown. Bioinformatics online database showed that lncRNA LOC100132707 was highly expressed in metastatic melanoma tissues, and its expression predicted a lower overall survival rate in melanoma patients. However, LOC100132707 function in uveal melanoma (UM) progression still remains unclear. In the present study, we aimed to elucidate the role and molecular mechanisms underlying LOC100132707 in UM.Methods: RT-PCR was used to detect the levels of LOC100132707 in UM cells. Cell migration, invasion and tumorigenesis were tested by using the transwell chamber assay and in vivo assay.Results: LOC100132707 expression in metastatic UM cell line MM28 was significantly higher than that of the non-metastatic UM cell lines, MP38, MP46 and MP65, as well as the expressions of LOC100132707-related genes, including XRN1, PARP14, JAK2, DDX60, BUB1 and SAMD9L. LOC100132707 downregulation significantly repressed cell migration and invasion abilities, whereas overexpressing JAK2 rescued these effects. Consistently, upregulation of LOC100132707 induced significant increases in cell migration and invasion abilities via upregulating JAK2. In addition, silencing of LOC100132707 significantly repressed the in vivo tumor formation ability in UM cells.Conclusion: This study reveals that silence of LOC100132707 represses the migration of UM via downregulating JAK2. The LOC100132707/JAK2 axis might serve as a potent target for the prevention and treatment of UM metastasis.Keywords: long non-coding RNA, lncRNA, LOC100132707, metastasis, uveal melanoma, UM, JAK2

Ying Qi, Qingqing Cui, Wenjing Zhang, Renjie Yao, Dong Xu, Fengyan Zhang Department of Ophthalmology, The First Affiliated Hospital of Zhengzhou University, The Laboratory for Ophthalmology and Vision Science, Henan Eye Hospital, Zhengzhou 450052, Henan, People’s Republic of ChinaCorrespondence: Fengyan Zhang Department of OphthalmologyThe First Affiliated Hospital of Zhengzhou University, The Laboratory for Ophthalmology and Vision Science, Henan Eye Hospital, Zhengzhou 450052, Henan, People’s Republic of ChinaEmail zhangfengyanyanke@163.comObjective: Human uveal melanoma (UM) is a common ocular malignant tumor with a high risk of metastasis. Emerging evidence indicates that long non-coding RNAs (lncRNAs) are correlated with the development of UM. Here, we aimed to determine the biological significance of lncRNA growth arrest-specific transcript 5 (GAS5) in UM.Methods: The expression levels of GAS5 and microRNA-21 (miR-21) in UM tissues and cells were detected by qRT-PCR analysis. CCK-8 assay was performed to investigate the viability of UM cells after cell transfections, and the migration and invasion of UM cells were determined by transwell assay. The protein expression levels were detected by Western blot assay. The relationship between miR-21 and GAS5 in UM cells was confirmed by bioinformatics prediction and luciferase report assay.Results: Our experiments demonstrated that GAS5 was markedly downregulated in UM cells and clinical specimens. Overexpression of GAS5 inhibited, whereas knockdown of GAS5 promoted the viability, migration, and invasion of UM cells. The epithelial-to-mesenchymal transition (EMT) process of UM cells was also suppressed by upregulating of GAS5 and enhanced by downregulating of GAS5. Additionally, as a competitive endogenous RNA (ceRNA), GAS5 directly binded to the oncogenic miR-21 in UM cells, and overexpression of miR-21 attenuated the EMT-suppressing effect of GAS5.Conclusion: Taken together, our findings suggest that GAS5/miR-21 axis is implicated in the pathogenesis of UM and might serve as a potential therapeutic target.Keywords: GAS5, uveal melanoma, invasion, epithelial–mesenchymal transition, microRNA-21

Wellbore instability caused by the dispersion of the clay is one of the most important challenges in drilling operation of fractured formations. The synthesis of new plugging inhibitors and the research of drilling fluid systems are key steps to keep the wellbore stabilization. In this paper, the limitations of conventional drilling fluid inhibitors are discussed and a new plugging inhibitor PAS-5 is synthesized by using amine inhibitor, polyethylene glycol and asbestos fiber as the main monomers. The detailed synthesis step of the plugging inhibitor PAS-5 is illustrated and its action mechanism is explained by scanning electron microscopy. In order to express the good effect of the PAS-5, a new evaluation system is used to indicate its plugging performance. At the same time, the plugging inhibitor PAS-5 was used on-site drilling operation in the Ordos Basin. The results of research show that the synthesis process of PAS-5 is simple and the effect of plugging inhibition is obvious. Compared with conventional treatment agents? PAS-5 outperforms sulfonated asphalt FT-1 and emulsified asphalt RHJ-3 in terms of plugging inhibition performance, with a plugging rate of 90.5% and roller recovery rate of 93.7%. It also has better temperature resistance, there is almost no change in viscosity and filtrate loss when the temperature rises from room temperature to 80°C. The field application results indicated that PAS-5 meets the requirements of drilling, that the reaming time of the trips of the wells is shortened considerably, that the ROP is improved, and that the hole enlargement rate is less than 6%. During the drilling process, PAS-5 can inhibit formation hydration and seal small cracks, thus maintaining the stability of the borehole. This study synthesized a novel plugging inhibitor PAS-5 and an evaluation system was adopted to reveal its plugging performance, and achieved good application effect in on-site drilling operations.

Purpose: Previous studies have revealed that microRNA-665 (miR-665) is dysregulated in a variety of human cancers. However, little is known regarding its expression profiles and functions in retinoblastoma (RB). Therefore, the aims of our study were to evaluate miR-665 expression in RB and determine the precise roles of miR-665 in the progression of RB. Patients and methods: Herein, RT-qPCR was used to determine miR-665 expression levels in RB tissues and cell lines, and a series of functional experiments were performed to explore the influence of miR-665 on RB cell proliferation, colony formation, apoptosis, migration, and invasion as well as tumor growth. The molecular mechanisms underlying the tumor-suppressive action of miR-665 in RB were also explored. Results: We found that miR-665 was markedly reduced in RB tissues and cell lines and that lower miR-665 expression was strongly associated with tumor size, TNM stage, and differentiation in patients with RB. Exogenous expression of miR-665 suppressed cell proliferation, colony formation, migration, and invasion, and induced cell apoptosis in RB cells, while silencing miR-665 expression had the opposite effects. In addition, upregulation of miR-665 decreased the tumor growth of RB cells in vivo. High-mobility group box 1 (HMGB1) was identified as a direct target of miR-665 in RB cells, and decreasing the expression of HMGB1 simulated the regulatory effects of miR-665 overexpression in RB cells, while knockdown of HMGB1 expression counteracted the miR-665-mediated antitumor effects in RB cells. Moreover, miR-665 was shown to regulate the Wnt/β-catenin signaling pathway by targeting HMGB1 in vitro and in vivo. Conclusion: Taken together, our in vitro and in vivo results suggest that miR-665 acts as a tumor-suppressive miRNA in RB by directly targeting HMGB1 and inactivating the Wnt/β-catenin pathway. Hence, this miRNA is a candidate prognostic biomarker and therapeutic target in patients with RB.

A method for the determination of the content of olive oil in olive blend oil by headspace gas chromatography-mass spectrometry (SH-GC/MS) was established. The amount of the sample, the heating temperature, the heating time, the amount of injection, the injection mode and the chromatographic column were optimized. The characteristic compounds of olive oil were found by chemometric method. A sample of 1.0 g was placed in a 20 mL headspace flask, and heated at 180℃ for 2700 s. Then, 1.0 mL headspace gas was taken into the instrument. An HP-88 chromatographic column was used for the separation and the analysis was performed by GC/MS. The results showed that the linear range was 0-100%(olive oil content). The linear correlation coefficient (r2) was more than 0.995, and the limits of detection were 1.26%-2.13%. The deviations of olive oil contents in the olive blend oil were from -0.65% to 1.02%, with the relative deviations from -1.3% to 6.8% and the relative standard deviations from 1.18% to 4.26% (n=6). The method is simple, rapid, environment friendly, sensitive and accurate. It is suitable for the determination of the content of olive oil in olive blend oil.