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Isolation and partial purification of fungal ligninolytic enzymes from the forest soil fungi isolated from Bhadra Wildlife Sanctuary

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Frontiers in Biology 2014年第4期9卷 291-299页

作者： shivakumar p. banakar B. THIppESWAMY Department of Bioseiences Shri J.J. T. University Vidyanagari Chudela-333 001 Jhunjhunu (Dist.) Rajasthan India Department of Studies in Microbiology Bioseience Complex Kuvempu University Jnanasahyadri Shankaraghatta-577 451 Shivamogga (Dist.) Karnataka India

Screening was done for the isolation of effective lignin degraders from the forest soil samples, by providing lignin as a carbon source through the enrichment method, which leads to the isolation of 8 effective fungal isolates among 14 isolates. Submerged fermentation was done for the production of ligninolytic enzymes with the effective microorganisms by providing Guiaicol as a carbon source. The assay of laccase, lignin peroxidise activity and specific activity was done after the incubation intervals of 2, 4, 6, 7, 8, 10 and 12 days at 27±2℃ under shake culture condition. partially purified protein content was estimated by using Lowry＇s method. pleurotus sp. and phanerochaetae chrysosporium are more effective at the 2nd and 7th days of incubation for the production of laccase and lignin peroxidases among the effective isolates.

关键词： laccase lignin peroxidase extracellular enzyme fungi forest soil

Reliability analysis of TBM disc cutters under different conditions

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Underground Space 2021年第2期6卷 142-152页

作者： Bolong Liu Haiqing Yang shivakumar Karekal School of Civil Engineering Chongqing UniversityChongqing 400045China School of Civil Mining and Environmental EngineeringUniversity of WollongongNSW 2522Australia

The reliability of disc cutters has a significant influence on the safety and working efficiency of tunnel boring machines(TBMs).To investigate the reliability of disc cutters under different geological and operational conditions,we conducted a series of novel rolling cutting tests on intact and jointed sandstone blocks using different dip angles and *** normal forces and rotational speeds of the cutterhead were also applied during the experiment.A novel reliability estimation method,based on a logistic regression model,was then proposed,and the influence of dip angle,strata,normal force,and rotational speed on the reliability of the disc cutter were *** reliability estimation method consisted of data acquisition regarding the normal force and cutter wear,feature extraction using wavelet packet transform and correlation analysis,and the estimation of the logistic regression *** obtain the spectrum and normalized wavelet energy for each frequency band,we decomposed the time domain of the normal force by the wavelet packet transform.A correlation analysis was employed to determine the feature frequency bands that were sensitive to wear *** the basis of salient feature parameters and wear loss,the logistic regression model was established to evaluate the reliability of disc *** analytical results indicated that the optimal dip angle for rock cutting was 30°.In the presence of mixed-face and single ground,the reliability of disc cutters was primarily affected by the difficulty of TBM excavation and wear loss,*** increase in normal force and rotational speed aggravated wear on the cutter,thus reducing ***,compared with Rabinowicz’s formula,the proposed method considers various geological and operational conditions,making the proposed method more applicable to estimate the reliability of disc cutters.

关键词： Tunnel boring machine Sandstone Disc cutter reliability Logistic regression model

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钻头冠部形状对破岩效果的影响

石油勘探与开发 2017年第4期44卷 630-637页

作者： HEYDARSHAHY Seyed Ali KAREKAL shivakumar School of Civil Mining and Environmental Engineering EIS Faculty University of Wollongong

用有限元方法模拟了不同形状钻头的破岩效果,研究了地层应力分布及裂缝延伸模式。按照国际钻井商协会(IADC)分类标准设计了14种钻头形状。设计了地层模型,给出了钻头尺寸、地层性质、网格划分方法和边界条件等。采用拟静态条件和质量缩... 详细信息

用有限元方法模拟了不同形状钻头的破岩效果,研究了地层应力分布及裂缝延伸模式。按照国际钻井商协会(IADC)分类标准设计了14种钻头形状。设计了地层模型,给出了钻头尺寸、地层性质、网格划分方法和边界条件等。采用拟静态条件和质量缩放法以减少模拟时间、提高模拟精度。模拟结果表明,对于9种常用钻头形状,增加锥体高度高应力区面积会增大,而保径高度与产生的应力之间没有明显关系。减小保径高度,高应力区从鼻端和中心部位转移到保径区。对于非常用钻头形状,凸形钻头产生的应力场较大,双心钻头导眼体底部应力较集中。裂缝主要产生在保径区和鼻端,锥体高度和保径高度较大的钻头产生的垂直裂缝较长。使用平形和凸形钻头时没有产生较长的垂直裂缝。双心钻头可抑制保径区的垂直裂缝,却使地层更易出现水平裂缝,有中间段扩眼器的钻头造成的井壁损伤更小。

关键词： pDC钻头钻头形状破岩效果有限元方法数值模拟

Ethnomedicinal plants used in the treatment of skin diseases in Hyderabad Karnataka region,Karnataka,India

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Asian pacific Journal of Tropical Biomedicine 2013年第11期3卷 882-886页

作者： shivakumar Singh policepatel Vidyasagar Gunagambhire Manikrao Medicinal plants and Microbiology Research Laboratory Department of Post Graduate Studies and Research in BotanyGulbarga University

Objective:To document traditional medicinal plants knowledge used in treating skin diseases at Hyderabad Karnataka ***:The information on the use of medicinal plants in the treatment of skin diseases was gathered from traditional herbal healers and other villagers through ***:A total of 60 plants species belonging to 57 genera and 34 families were found useful and herewith described them along with the method of drug preparation,mode of administration,probable dosage and duration of *** new findings on the traditional rural practices were ***:The present study revealed that the Hyderabad Kamataka rural people is primarily dependent on medicinal plants for treating skin diseases.

关键词： Ethno medicinal plants Hyderabad Karnataka Skin diseases Traditional knowledge

Role of angiogenesis in oral squamous cell carcinoma development and metastasis: an immunohistochemical study

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International Journal of Oral Science 2011年第4期3卷 216-224页

作者： shivakumar Madappa Shivamallappa Narayan Tondikulam Venkatraman Balasundari Shreedhar Leeky Mohanty Sadhana Shenoy Department of Oral pathology and Microbiology The Oxford Dental College Hospital and Research Centre

Although a few studies have shown that vascularity is increased from normal mucosa to dysplasia to carcinoma suggesting that disease progression in the oral mucosa is accompanied by angiogenesis. The role in lymph node metastasis in oral squamous cell carcinoma （OSCC） is equivocal. Role of angiogenesis in OSCC development and metastasis is evaluated in this study. This retrospective study of 50 samples consisted of 9 normal buccal mucosa, 22 leukoplakias, and 19 OSCC. polyclonal antibodies to von-Willebrand factor were used to highlight the microvessels. Images were captured and morphometric image analysis was done for microvessel density （MVD）, area, and perimeter. Highest, as well as mean values of these three parameters were compared. MVD and perimeter, but not area, are significantly different between normal mucosa and OSCC, and leukoplakia and OSCC. There were no differences between normal mucosa and leukoplakia. MVD, area, and perimeter were not significantly different between the OSCC with and without lymph node metastasis. The highest and mean values of MVD are significantly correlated. In the development of OSCC, angiogenic phenotypic change occurs in carcinomas rather than in the pre-cancerous stage, and quantification of angiogenesis in OSCC does not predict the risk of lymph node metastasis.

关键词： angiogenesis vessel density oral carcinoma metastasis image analysis leukoplakia oral mucosa

Microbiome and colorectal carcinogenesis:Linked mechanisms and racial differences

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World Journal of Gastrointestinal Oncology 2022年第2期14卷 375-395页

作者： Sofia C Tortora Vimal M Bodiwala Andrew Quinn Laura A Martello shivakumar Vignesh Department of Medicine and Division of Gastroenterology&Hepatology SUNY Downstate Health Sciences UniversityBrooklynNY 11203United States

Various studies have shown the interplay between the intestinal microbiome,environmental factors,and genetic changes in colorectal cancer(CRC)*** this review,we highlight the various gut and oral microbiota associated with CRC and colorectal adenomas,and their proposed molecular mechanisms in relation to the processes of“the hallmarks of cancer”,and differences in microbial diversity and abundance between race/*** with CRC showed increased levels of Bacteroides,prevotella,Escherichia coli,enterotoxigenic Bacteroides fragilis,Streptococcus gallolyticus,Enterococcus faecalis,Fusobacterium nucleatum(***)and Clostridium *** levels of Bacteroides have been found in African American(AA)compared to Caucasian American(CA)***-inflammatory bacteria such as *** and Enterobacter species were significantly higher in ***,AA patients have been shown to have decreased microbial diversity compared to CA *** studies have shown that using microbiome profiles in conjunction with certain risk factors such as age,race and body mass index may help predict healthy colon vs one with adenomas or *** is one of the most common bacterial infections in humans and is more prevalent in Non-Hispanic-Blacks as compared to Non-Hispanic *** condition causes increased systemic inflammation,immune dysregulation,gut microbiota dysbiosis and thereby possibly influencing colorectal ***-associated bacteria such as Fusobacterium,prevotella,Bacteroides and porphyromonas have been found in CRC tissues and in feces of CRC ***,a deeper understanding of the association between oral and gastrointestinal bacterial profile,in addition to identifying prevalent bacteria in patients with CRC and the differences observed in ethnicity/race,may play a pivotal role in predicting incidence,prognosis,and lead to the development of new treatments.

关键词： Colorectal cancer Oral microbiome Gut microbiome Hallmarks of cancer Racial/ethnic microbial diversity

Atezolizumab and bevacizumab as first line therapy in advanced hepatocellular carcinoma:practical considerations in routine clinical practice

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World Journal of Hepatology 2021年第9期13卷 1132-1142页

作者： Ankit Jain shivakumar Chitturi Geoffrey peters Desmond Yip Department of Medical Oncology The Canberra HospitalGarran 2605ACTAustralia ANU Medical School Australian National UniversityCanberra 0200ACTAustralia Gastroenterology and Hepatology Unit Canberra HospitalCanberra 2605ACTAustralia

Hepatocellular carcinoma(HCC)is the most common primary liver *** advanced HCC,sorafenib was considered the standard of care for more than ten *** the atezolizumab and bevacizumab combination has become standard of care for these patients without contraindications to either immune checkpoint inhibitors or antiangiogenic *** now review the practical aspects of the atezolizumab and bevacizumab combination,including current evidence,indications,contraindications,management of adverse events,sequencing of this combination,areas of current knowledge gaps and future areas of active clinical research of this combination for busy clinicians in clinical practice.

关键词： Hepatocellular carcinoma Atezolizumab Bevacizumab Immunotherapy Child pugh cirrhosis Anti-angiogenic therapy

Chain-Length-Dependent Hydrogen-Bonded Self-Assembly of Terminally Functionalized Discrete polyketones

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precision Chemistry 2023年第1期1卷 34-39页

作者： Kilingaru I.shivakumar Yumehiro Manabe Tomoki Yoneda Yuki Ide Yasuhide Inokuma Institute for Chemical Reaction Design and Discovery(WpI-ICReDD) Hokkaido UniversitySapporoHokkaido 001-0021Japan Division of Applied Chemistry Faculty of EngineeringHokkaido UniversitySapporoHokkaido 060-8628Japan

Here,we report the synthesis and the chain-lengthdependent self-assembling behaviors of discrete di-,tetra-,and hexaketones terminally functionalized with hydrogen-bonding carboxyl(C1,C2,and C3)and 3-acylaminopyridine groups(p1,p2,and p3).These polyketones were prepared by the coupling reactions of silylated analogues of 3,3-dimethylpentane-2,4-dione and t-butyl 2,2-dimethyl-3-oxobutanoate and the subsequent hydrolysis or amidation with ***-crystal Xray diffraction analysis revealed that C1 and C2 form helical assemblies in which the components are connected by the dimerization of terminal carboxyl groups,whereas the longer C3 showed infinite hydrogen-bonded chains mediated by 1,4-dioxane used as a crystallization ***-terminated p1 exhibited a three-dimensional hydrogen-bonded network owing to multiple NH…N(pyridine)hydrogen bonds in the solid state.p2 generated a double-helix-like fiber structure in the crystalline *** the pyridine-terminated polyketones p1−p3,only p2 showed gelation behavior in chloroform(100 mM concentration)at 25℃.The scanning electron microscopy measurement of xerogel p2 revealed the formation of rod-like structures with a thickness of approximately 0.5−3.5μ*** results demonstrate that the precise control of the polyketone chain length can significantly alter hydrogen-bonded self-assembly in the solid state and in solution even with the same terminal structures.

关键词： polyketone hydrogen bond helix self-assembly gel

Tensile properties of Veins of Damselfly Wing

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Journal of Biomaterials and Nanobiotechnology 2013年第3期4卷 247-255页

作者： Rupan Talucdher Kunigal shivakumar Center for Composite Materials Research (CCMR) Department of Mechanical Engineering North Carolina A & T State University (NC A & T SU) Greensboro USA.

Microtension test of Costa and Radius veins of damselfly wing was conducted to measure tensile strength and modulus. The specimens were classified into fresh and dry depending on when the samples were prepared and tested. Fresh samples tested immediately after extracting from the fly while the dry samples were tested one year after extraction and stored in a desiccator. Measured load-displacement response and fracture load were used to calculate modulus and strength. Field Emission Scanning Electron Microscope was used to measure the fracture morphology and cross-section of the vein. The results showed that the veins are brittle and fracture surface is flat. The average strength (232 - 285 Mpa) and modulus (14 - 17 Gpa) of the Costa and Radius veins were nearly same for both fresh and dry samples. The tensile modulus of the veins was 8% - 10% higher than the indentation (compressive) modulus and was nearly the same as that of human bones.

关键词： Damselfly Wing Microtension Test Tensile Strength Tensile Modulus Micro Air Vehicle