VCR法采空区爆破成井技术的研究与应用

呼伦贝尔山金铅锌矿采用充填法治理历史采空区,由于采空区充填井采用普通法掘进效率低、作业条件及安全性差,采用采空区充填井安全高效施工技术成为关键。根据利文斯顿爆破漏斗理论,通过前期进行的大量试验爆破,确定最佳爆破参数,结合现场条件研究提出VCR法爆破快速成井技术方案。实践结果表明,VCR法在爆破采空区充填井上取得了良好的应用效果,成功开掘了直径2.0 m、深度17.4 m的充填井。重点对爆破参数、装药结构、堵孔方式以及施工过程中存在的问题进行分析总结,为同类矿山提供一定的参考和借鉴。

VCR采矿法深孔爆破大块率控制经验浅谈

在实际矿山爆破工程中,采用VCR采矿法进行爆破时,其爆破规模较大,易产生大块岩石,增加了二次爆破成本,增加了出矿难度,同时降低了出矿效率。根据实际工程中的爆破经验,提出了大块率的计算方法,分析了爆破过程中大块产生的多种原因,并结合草楼铁矿的具体条件,针对炮孔孔网参数进行了相应的调整,并采用高精度的毫秒延期雷管进行微差爆破。实践证明,草楼铁矿采场爆破大块率显著下降,一次爆破的爆破质量有了明显地改善,爆落岩石块度均匀,满足破碎、铲装运输要求,降低了二次爆破率和生产成本,为矿山爆破工程提供了一定的参考。

大直径深孔VCR法拉槽爆破盲炮原因分析及预防措施探讨

自20世纪中期以来,伴随矿山开采的不断增加与间柱采场试验的成功,VCR法也在国内的采矿界得到了广泛应用和普及,并受到了相关人员的高度关注。在VCR采矿法的飞速发展下,其在矿山开采当中的功能与作用也更为凸显,并获得了较好的应用效果,成为了大直径深孔矿山开采中的有效方案,并进一步推动了我国采矿技术的发展。但实践显示,在大直径深孔VCR法拉槽爆破当中,盲炮的情况时有发生,为此,本文结合对其发生原因的分析,进而提出针对性的预防措施。

基于二自由度可调机构的新型VCR发动机运动方案设计方法的研究

针对现阶段VCR发动机的设计方法存在不完整、不透明的问题,本文提出一种基于二自由度可调机构的新型VCR发动机方案的设计方法。首先使用拓扑缩图插点法对二自由度9杆及构件数低于9的机构进行型综合,并系统地为新型VCR发动机进行机构选型。其次,根据给定的设计指标,对新型VCR发动机机构进行尺度综合,提出能同时满足机构传动角和机构整周转需求的几何计算方法,确定了二自由度可调构件位置变化与压缩比变化的函数关系,实现了压缩比范围的精确控制,为VCR发动机的创新设计提供了相应的理论依据,同时还拟定出完整的设计流程。

Interaction between cisplatin,5-fluorouracil and vincristine on human hepatoma cell line (7721)

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Mechanism of all-transretinoic acid increasing retinoblastoma sensitivity to vincristine

Objective:To explore the mechanism of all-transretinoic acid(ATRA) increasing retinoblastoma(RB) sensitivity to vincristine,and the inhibiting effect of vincristine combined with ATRA treatment on the SO-RB50 cell proliferation.Methods:SO-RB50 cells were cultivated by routine culture method.Different concentrations of vincristine or ATRA were added into culture solution.After 48 h.cell counting kit-8 was used to detect the median inhibitory concentration(IC_(50)) of vincristine combined with ATRT treatment to SO-RB50 cells.SO-RB50 cells were divided into drug combination group,vincristine group,ATRA group and control group.Different drugs were added into the culture solution respectively for cell culture based on the IC_(50) value.Cell counting kit-8 was used to detect the cell proliferation every 24-h cultivation.After continuous determination for 6 d,data was processed to draw the cell growth curve.After drug use for 72 h,flow cytometry was used to detect the proportion of different cell cycles of SO-RB50 cells in each group.After drug use for 48 h,annexin V/propidium iodide method was used to detect the SO-RB50 cell apoptosis in each group.Results:The IC_(50) value of vincristine treatment on the SO-RB50 cells was 0.11 μmol/L,and ATRT was 12.84 μmol/L.The cell growth curve in control group rose gradually along with the extended culture time,but after vincristine and ATRA treatment,the cell growth curve was smooth and steady.The cell increment was the least in drug combination group and its cell growth curve was the smoothest.There was significant difference in A_(450) 48 h and 72 h after treatment(F_(grouping)=77.316,P<0.001;F_(time)=86.985,P<0.001).Compared with control group.A_(450) value in drug combination group,vincristine group,ATRA group was significantly lower(P<0.001).Compared with control group,the G_2/M phase cell proportion in vincristine group was significantly increased,while the G_0/G_1 phase cell proportion was significantly decreased:the G_0/G_1 phase cell proportion in ATRA group was significantly increased,while the S phase cell proportion was significantly decreased(F_(G0/G1)=85.878,F_s=56.455,F_(G2/M)=85.878,P<0.001).After 48 h,there was significant difference in SO-RB50 cell apoptosis rate among groups(F=11.312.P<0.05).The apoptosis rate in drug combination group was significantly higher than that of other groups(P<0.001).Condusion:ATRA can increase the sensitivity of SO-RB50 cells to vincristine.Vincristine combined with ATRA treatment can significantly increase the inhibiting effect on SO-RB50 cells,which may be related with promoting cell apoptosis and involving in cell cycle control.

Folic acid-conjugated liposomal vincristine for multidrug resistant cancer therapy

We encapsulated vincristine into folic acid-conjugated PEGylated liposomes to improve the anti-tumor efficacy on multidrug resistant cancers.It was observed that the drug delivery system we constructed exhibited maximum cytotoxicity on KBv200 cells(multidrug resistant variant)compared with any other formulations.The semi-quantitative analysis of region of interest revealed that there was a great increase in area under curve(AUC)of a near-infrared fluorescein in solid tumors due to folic acid-mediated accumulation.Folic acid-conjugated PEGylated liposomes showed a significant tumor growth inhibiting effect in vitro and in vivo.TUNEL assay revealed that folic acid-conjugated PEGylated liposomes could induce cell apoptosis much more greatly than others.This study demonstrated that it had potential application prospective for the treatment of multidrug resistant cancer.

CHEMOTHERAPY FOR ADVANCED NASOPHARYNGEAL CARCINOMA WITH METHOTREXATE, VINCRISTINE, CISPLATIN AND ADRIAMYCIN

Objective: To evaluate the efficacy and toxicity of M-VCA (methortrexate 30 mg/m2, vincristine 2 mg, cisplatin 70 mg/m2, adriamycin 30 mg/m2) combination chemotherapy for advanced nasopharyngeal carcinoma. Methods: Thirty-five patients with advanced nasopharyngeal carcinoma, including 11 patients with untreated local advanced nasopharyngeal carcinoma and 24 patients with local-regional recurrent or metastatic nasopharyngeal carcinoma, received the chemotherapy of M-VCA. The cycle was repeated on day 22 for two cycles. All patients completed the chemotherapy courses. Results: The overall response rate was 75%, with untreated local advanced nasopharyngeal carcinomas 11/11(100%), local-regional recurrent nasopharyngeal carcinomas 12/18(67%), lung metastases 8/9(89%), bone metastases 5/9(56%), and liver metastases 1/2(50%). The main side effects included mild to moderate degree alopecia, nausea/vomiting, and neutropenia. Conclusion: M-VCA is well tolerated and has good efficacy for advanced nasopharyngeal carcinoma and is worth investigating further.

Preparation and quality evaluation of vincristine sulfate-loaded PEG-PLGA nanoparticles

Objective To prepare the PEG-PLGA nanoparticles loaded with vincristine sulfate(VCR-loaded PEG-PLGA-NPs) and evaluate their quality.Methods VCR-loaded PEG-PLGA-NPs were prepared by the double emulsion solvent evaporation method.The main experimental factors,which influenced the physical and chemical properties of the nanoparticles,were investigated and optimized.Results Under optimal conditions,the VCR-loaded PEG-PLGA-NPs had an average diameter of 135.9 nm with narrow size distribution.The encapsulation efficiency was 68.2%,while the drug loading capacity was 8.34%.In vitro,VCR was released from the PEG-PLGA-NPs sustainedly for more than 13 days with the total amount of 81%.Moreover,the VCR-loaded PEG-PLGA-NPs were relatively stable,which was confirmed by the stability testing.Conclusion The VCR-loaded PEG-PLGA-NPs are a promising nano drug with controlled release,which can be applied widely.

VCR法成井技术及关键控制点

目前地下矿山溜井均采用手工钻机施工,其施工环境要求操作人员到狭隘的溜井内部作业,通风存在一定的困难,又是高空作业,而且在爆破后工人再次进入溜井内部作业前,浮石无法提前处理,安全风险非常大。为解决此问题,马坑铁矿提出了VCR法爆破成井技术施工,该施工方式的特点是在上部硐室垂直向下施工大直径深孔,利用利文斯顿爆破漏斗原理分次爆破,每次爆破高度约为2~3 m,最后一次贯通破顶爆破4~5 m左右。该天井施工方式已在矿山内大面积使用,现对VCR法成井技术及关键控制点进行总结。

The interaction between cytarabine and vincristine on HL-60 cell line in vitro

Objective： To analyze the effect of cytarabine combined with vincristine on HL-60 cell line in vitro. Methods： The median-effect equation and MTr assay were used on HL-60. Results： The cytotoxic activity of cytarabine（Ara-C） and vincristine （VCR） used alone or in combination enhanced as drug concentration increased. The order of administration did not influence the cytotoxic activity of the combined antitumor drugs. The ratio of drug concentration was a factor to influence the killing effect. The interaction of the agents was synergistic at lower concentration, and antagonistic at higher concentration. Conclusion： The combined drugs interaction（CI 〈 1 ） was synergistic at lower concentration and antagonistic at higher concentration. The ratio of drug concentration is a significant factor that can influence the killing effect.

Unilateral Ptosis in a Child with Wilm’s Tumor Induced by Vincristine

Vincristine is a chemotherapy drug belonging to the group of Vinca alkaloids which also includes vinblastine and vindesine. It is used in hematological malignancies and solid tumors. The Vinca alkaloids are neurotoxic, usually causing peripheral neuropathy, and rarely cranial neuropathies. We report a case of a 33-month-old male child diagnosed with Wilms’ tumor, who had an isolated unilateral right ptosis following vincristine, with a good improvement after stopping it.

Randomized Trial Comparing Cyclophosphamide, Methotrexate, and 5-Fluorouracil (CMF) Regimen with Rotational CMFEV Regimen (E=Epirubicin, V=Vincristine) as Adjuvant Chemotherapy in Moderate Risk Operable Breast Carcinoma

Objectives: The CMFEV (cyclophosphamide, methotrexate, 5-fluorouracil, epirubicin, vincristine) regimen is an innovative schedule, designed by our Group, aimed at administering five partially or totally no cross-resistant cytotoxic agents in breast carcinoma. It was randomly compared to CMF (cyclophosphamide, methotrexate, 5-fluorouracil) as primary treatment in operable disease and demonstrated a short-term significant increase in clinical complete response rate and a long-term significant locoregional relapse-free survival in premenopausal patients. So, it seemed worth comparing this regimen with CMF as adjuvant chemotherapy in moderate risk operable breast carcinoma. Methods: Four hundred and eighty-nine patients with stage I or II moderate risk breast carcinoma were randomized to receive CMF or CMFEV regimen for 6 cycles after surgery. Main end points were overall survival (OS), invasive disease-free survival (IDFS) and recurrence-free interval (RFI), as estimated by Kaplan-Meier analyses and log-rank tests. Results: At a median observation time of 7.3 years (range 5.4 months-10.3 years), no significant differences in OS and IDFS were observed between the two arms. Deaths from breast carcinoma were more frequent with CMF (58.5%) than with CMFEV regimen (41.7%) as well as recurrences from breast carcinoma (58.8% with CMF and 41.2% with CMFEV). These differences were not statistically significant. Conclusion: CMFEV appears more effective than CMF in preventing recurrences from primary disease in patients with moderate risk stage I-II breast carcinoma. The lack of statistical significance of the observed differences was probably due to the limited number of patients enrolled which rendered the study underpowdered.

基于爆破漏斗试验在马坑铁矿VCR成井爆破技术中的应用

高位溜井的施工一直是一个技术难题,为简易、安全、高效地施工高位溜井,马坑铁矿拟采用VCR成井爆破技术,解决高位溜井施工环境差、通风困难等施工难题。以利文斯顿爆破漏斗理论为基础,对马坑铁矿进行单孔爆破漏斗试验,试验采用2#岩石乳化炸药,药量分别为150 g和300 g。试验结果得出药包最佳埋置深度及爆破漏斗半径,根据药包比例埋深及对应的漏斗半径,经单位炸药量爆破漏斗体积公式换算,确定VCR成井技术的炮孔合理间距、装药长度及孔底堵塞长度。

孔内分段爆破降振技术在会宝岭铁矿VCR采场的应用

爆破振动可能会引起地表构筑物的损坏和人的不适反应,因此对于降振的研究备受关注。在不改变孔网参数和单次爆破总药量的前提下,装药结构和雷管段位的设计至关重要。针对会宝岭铁矿VCR采场生产爆破单次爆破量大、爆破振动大的问题,提出了一种孔内分段爆破的装药结构和雷管段位布置方式,并进行了工业试验,且对地表爆破振动进行了监测。研究结果表明:采用孔内分段爆破方式能有效降低爆破振动危害,且不影响爆破破碎块度。研究成果对具有相似困扰的地下矿山具有一定的参考意义。

Side Effects of Vincristine and L-Asparaginase in Patients with Acute Lymphoblastic Leukemia in a Mexican Pediatric Hospital

Background: The treatment used to combat acute lymphoblastic leukemia (ALL) is multidrug;therefore it is important to use active pharmacovigilance to detect, assess and analyze the likely adverse reactions which may occur during the same period. Objective: To determine the frequency of adverse reactions to chemotherapeutic drugs in children with ALL. Material and Methods: Intensive pharmacovigilance was used to record the reports of adverse reactions to vincristine, L-asparaginase and the vincristine-L-asparaginase combination in children with ALL in a paediatric hospital. For each notification, the adverse reactions were analyzed in order to verify causality. Results: Forty patients were evaluated. Twenty children were female (50.0%) and 20 were male (50%). The children had a mean age, weight and height (±standard deviation: SD) of 8.1 (±3.4) years, 31.4 (±13.9) kg and 1.3 (±0.2) m, respectively. Vincristine was administered to 19 patients, vincristine plus L-asparaginase were given to 19 patients and only 2 patients used L-asparaginase. One-hundred-ninety adverse reactions were detected in the patients, with an average (±SD) of 4.8 (±2.6). Ondansetron was the drug administered for the treating of nausea and vomiting. One hundred eighty-one (95.3%) adverse reactions were identified as “definite”, 5 (2.6%) as “probable” and 4 (2.1%) as “doubtful”. Conclusions: There is a high incidence of adverse reactions by the administration of vincristine and L-asparaginase;the reactions of highest incidence were: nausea, vomiting, neutropenia, diarrhea, constipation, mucositis, headache, and abdominal pain. It is important to promote the detection, collection, reporting, assessment and treatment of ARD’s in children. It is necessary to promote the conduct further studies on pharmacovigilance with this type of treatments and to increase the duration of the studies.

沙溪铜矿大直径深孔VCR法拉槽破顶爆破工艺现状分析与优化

VCR法拉槽破顶时返冲矸石量过大以及对边帮破坏严重,一直是矿山作业中非常头疼的事情,这一问题长期得不到解决不仅影响爆破效果,更会对后续各类作业带来很大的安全隐患和风险。通过优化爆破工艺,我们克服了已有技术中的不足之处,探索出了新的VCR法拉槽破顶爆破工艺,解决了这个难题,提高了爆破效果,改善了出矿条件,规避了各类安全隐患和风险。通过一段时间的应用后效果很好,为同行业和同类矿山提供了很好的参考和借鉴。

抽水蓄能电站“VCR法”竖井导井开挖技术

针对金寨抽水蓄能电站上、下水库进/出水口闸门井施工特点,开展竖井导井开挖“VCR法”(俗称吊炮法)的研究工作,总结出一套适用于大断面、小井深竖井开挖且更安全、更经济、更有可操作性的施工技术。

ALL患儿诱导缓解期长春新碱联合应用三唑类抗真菌药物发生毒副作用单中心分析

目的研究急性淋巴细胞白血病(ALL)儿童诱导缓解期联合应用长春新碱与三唑类药物出现的毒副作用。方法回顾性分析2010年1月1日—2013年12月31日北京儿童医院诊断为ALL患儿在诱导缓解治疗过程中长春新碱和三唑类药物联合应用出现毒副作用。将患儿分为无联合用药组、长春新碱+伊曲康唑联合组,长春新碱+伏立康唑联合组,长春新碱+氟康唑联合组,分析4组患儿相关毒副作用的发生率及治疗预后。结果共纳入ALL患儿708例,发病中位年龄为8(1~16)岁。存在长春新碱与三唑类抗真菌药物联合应用组共215例,其中联合伊曲康唑组79例,联合伏立康唑组36例,联合氟康唑组100例。无联合用药组493例。联合用药组患儿相关并发症发生率:高血压37例(17.2%),趾端麻木39例(18.1%),腱反射迟钝4例(1.8%),腹痛腹胀42例(19.5%),肠梗阻5例(2.3%),低血钠43例(20%)。联合用药组相关并发症发生率均高于无联合用药物组(P<0.05)。联合用药组中,高血压发生率、腱反射迟钝发生率及低血钠发生率:伊曲康唑组与伏立康唑组无差别(P>0.05),但大于氟康唑组(P<0.05);趾端麻木、腹痛腹胀发生率:伊曲康唑组大于伏立康唑组大于氟康唑组(P<0.05);肠梗阻发生率:伏立康唑组大于伊曲康唑组大于氟康唑组(P<0.05)。对于发生的毒副作用,给予相关的对症处理及调整药物后,相关并发症均可以得到缓解及消失。结论在ALL患儿诱导缓解治疗过程中,三唑类药物联合长春新碱用药可能加重毒副作用发生,伊曲康唑和伏立康唑相比氟康唑可能更容易加重长春新碱毒性,故建议治疗过程中避免同时使用三唑类抗真菌药物及长春新碱。

芍药苷对人胃癌SGC7901/VCR细胞增殖抑制作用及其机制研究

目的:探索芍药苷(paeoniflorin)对人胃癌SGC7901/VCR细胞增殖抑制及凋亡的影响,并研究其可能的分子机制。方法:应用不同浓度芍药苷作用SGC7901/VCR细胞48h后,采用四甲基偶氮唑蓝法(MTT)检测细胞增殖抑制率;流式细胞术(FCM)检测细胞凋亡率;免疫蛋白印迹技术(Western blot)分析Bcl-2、Bax及细胞核内NF-κBp65蛋白的表达;酶联免疫吸附试验(ELISA)进一步确定核内NF-κB的转录活性。结果:芍药苷对SGC7901/VCR细胞生长有明显的抑制作用并促进其凋亡,这种作用呈现剂量依赖性;Westernblot和ELISA均证实芍药苷对NF-κB有明确抑制作用;随着芍药苷浓度增加NF-κB和Bcl-2表达水平逐渐下调(P<0.01),但对Bax没有明显影响。结论:芍药苷可明显抑制SGC7901/VCR细胞的增殖,诱导其凋亡;其机制部分可能与阻断NF-κB通路所介导的Bcl-2分子上调有关。