Data Mining: Concepts and Techniques provides the concepts and techniques in processing gathered data or information, which will be used in various applications. Specifically, it explains data mining ...and the tools used in discovering knowledge from the collected data. This book is referred as the knowledge discovery from data (KDD). It focuses on the feasibility, usefulness, effectiveness, and scalability of techniques of large data sets. After describing data mining, this edition explains the methods of knowing, preprocessing, processing, and warehousing data. It then presents information about data warehouses, online analytical processing (OLAP), and data cube technology. Then, the methods involved in mining frequent patterns, associations, and correlations for large data sets are described. The book details the methods for data classification and introduces the concepts and methods for data clustering. The remaining chapters discuss the outlier detection and the trends, applications, and research frontiers in data mining. This book is intended for Computer Science students, application developers, business professionals, and researchers who seek information on data mining. * Presents dozens of algorithms and implementation examples, all in pseudo-code and suitable for use in real-world, large-scale data mining projects * Addresses advanced topics such as mining object-relational databases, spatial databases, multimedia databases, time-series databases, text databases, the World Wide Web, and applications in several fields * Provides a comprehensive, practical look at the concepts and techniques you need to get the most out of your data
With the dramatic increase in nanotechnologies, it has become probable that biological systems will be exposed to excess of nanoparticles (NPs). However, the impact of NPs on plants remains to be ...explored. The aim of this research was to determine the effects of ZnO NPs on tomato (
Solanum lycopersicum
L.) plants. Plant growth, photosynthetic characteristics, chlorophyll fluorescence parameters, and activities of antioxidative enzymes were measured in 35-d-old plants. The ZnO NP treatments significantly inhibited tomato root and shoot growth, decreased the content of chlorophylls
a
and
b
, and reduced photosynthetic efficiency and some other chlorophyll fluorescence parameters in a concentration-dependent manner. However, the supernatant of ZnO NP suspensions did not affect growth of tomato, despite the presence of small amounts of Zn
2+
. Taken together, these results suggest that toxic effects on tomato plants were from ZnO NPs, not from Zn
2+
released into the solution; toxicity was likely caused by reduced chlorophyll content and damaged photochemical system, which in turn limited photosynthesis and led to the reduction in biomass accumulation. Also, ZnO NPs enhanced the transcription of genes related to antioxidant capacity, suggesting that ZnO NPs could enhance the defence response by increasing activities of antioxidant enzymes.
Lasting immunity following SARS-CoV-2 infection is questioned because serum antibodies decline in convalescence. However, functional immunity is mediated by long-lived memory T and B (Bmem) cells. ...Therefore, we generated fluorescently-labeled tetramers of the spike receptor binding domain (RBD) and nucleocapsid protein (NCP) to determine the longevity and immunophenotype of SARS-CoV-2-specific Bmem cells in COVID-19 patients. A total of 36 blood samples were obtained from 25 COVID-19 patients between 4 and 242 days post-symptom onset including 11 paired samples. While serum IgG to RBD and NCP was identified in all patients, antibody levels began declining at 20 days post-symptom onset. RBD- and NCP-specific Bmem cells predominantly expressed IgM
or IgG1
and continued to rise until 150 days. RBD-specific IgG
Bmem were predominantly CD27
, and numbers significantly correlated with circulating follicular helper T cell numbers. Thus, the SARS-CoV-2 antibody response contracts in convalescence with persistence of RBD- and NCP-specific Bmem cells. Flow cytometric detection of SARS-CoV-2-specific Bmem cells enables detection of long-term immune memory following infection or vaccination for COVID-19.
Background
While treatment for atopic rhinitis is aimed mostly to relieve symptoms, only allergen‐specific immunotherapy (AIT) is targeted to modify the natural history of allergic diseases. This ...results in sustained clinical tolerance, even when treatment has stopped. The immunomodulatory effects of AIT are attributed mainly to increased regulatory T‐cell function and increased allergen‐specific IgG4, yet little is known about the effect on the memory B‐cell compartment.
Objective
We aimed to examine the effects of AIT on the IgE‐ and IgG subclass‐expressing memory B cells.
Methods
We recruited 29 patients with atopic seasonal rhinoconjunctivitis and performed a longitudinal analysis of the peripheral immune compartment before, during, and after sublingual immunotherapy (SLIT) for allergy to temperate grass pollen, predominantly to ryegrass pollen (RGP; Lolium perenne). Using flow cytometry on peripheral blood mononuclear cells and serum immunoassays, we analyzed the effects of a 4 months preseasonal treatment regimen comprising two or three courses in consecutive years on circulating IgE+ and IgG+ memory B cells and allergen‐specific Ig levels.
Results
SLIT increased RGP‐specific serum IgG2 and IgG4, as well as the frequencies of IgG2+ and IgG4+ memory B cells, whereas no effect was observed on the IgE+ memory B‐cell compartment. Furthermore, SLIT enhanced proportions of regulatory T cells specific to RGP. These changes were associated with clinical improvement.
Conclusion
Our data provide evidence for immunological effects of SLIT on B‐cell memory. Skewing responses toward IgG2 and IgG4 subclasses might be a mechanism to suppress IgE‐mediated allergic responses.
This study examines the effect of ryegrass pollen AIT on B‐cell responses in a population of 29 patients with allergic rhinitis. Successful immunotherapy for ryegrass pollen allergy increases allergen‐specific IgG2 and IgG4 serum levels, and proportions of IgG2‐ and IgG4‐expressing memory B cells. Skewing toward the anti‐inflammatory IgG2 and IgG4 subclasses might be a mechanism to suppress IgE‐mediated allergic responses.
Cancer stem cells (CSCs) are a promising target for cancer therapy, particularly for metastatic lung cancers, but how CSCs are regulated is largely unknown. We identify two proteins, SLUG (encoded by ...SNAI2 gene) and SOX9, which are associated with advanced stage lung cancers and are implicated in the regulation of CSCs. Inhibition of either SLUG or SOX9 sufficiently inhibits CSCs in human lung cancer cells and attenuates experimental lung metastasis in a xenograft mouse model. Correlation between SLUG and SOX9 levels was observed remarkably, we therefore sought to explore their mechanistic relationship and regulation. SLUG, beyond its known function as an epithelial-mesenchymal transition transcription factor, was found to regulate SOX9 by controlling its stability via a post-translational modification process. SLUG interacts directly with SOX9 and prevents it from ubiquitin-mediated proteasomal degradation. SLUG expression and binding are necessary for SOX9 promotion of lung CSCs and metastasis in a mouse model. Together, our findings provide a novel mechanistic insight into the regulation of CSCs via SLUG-SOX9 regulatory axis, which represents a potential novel target for CSC therapy that may overcome cancer chemoresistance and relapse.
In vivo cartilage is in a state of constant mechanical stimulation. It is therefore reasonable to deduce that mechanical forces play an important role in cartilage formation. Mechanical forces, such ...as compression, tension, and shear force, have been widely applied for cartilage engineering; however, relatively few review papers have summarized the influence of biomechanical signals on stem cell-based neo-cartilage formation and cartilage engineering in both molecular adaption and tissue functionality. In this review, we will discuss recent progress related to the influences of substrate elasticity on stem cell chondrogenic differentiation and elucidate the potential underlying mechanisms. Aside from active sensing and responding to the extracellular environment, stem cells also could respond to various external mechanical forces, which also influence their chondrogenic capacity; this topic will be updated along with associated signaling pathways. We expect that these different regimens of biomechanical signals can be utilized to boost stem cell-based cartilage engineering and regeneration.
Summary Objective The objectives of this study were to (1) determine the correlation between osteoarthritis (OA) and Indian hedgehog (Ihh) expression, and (2) establish the effects of Ihh on ...expression of markers of chondrocyte hypertrophy and matrix metalloprotease (MMP)-13 in human OA cartilage. Design OA cartilage and synovial fluid samples were obtained during total knee arthroplasty. Normal cartilage samples were obtained from intra-articular tumor resections, and normal synovial fluid samples were obtained from healthy volunteers and the contralateral uninjured knee of patients undergoing anterior cruciate ligament reconstruction. OA was graded using the Mankin score. Expression of Ihh in synovial fluid was determined by Western blot. Ihh, type X collagen and MMP-13 mRNA were determined by real time PCR. Protein expression of type X collagen and MMP-13 in cartilage samples was analyzed with immunohistochemistry. Chondrocyte size was measured using image analysis. Results Ihh expression was increased 2.6 fold in OA cartilage and 37% in OA synovial fluid when compared to normal control samples. Increased expression of Ihh was associated with the severity of OA and expression of markers of chondrocyte hypertrophy: type X collagen and MMP-13, and chondocyte size. Chondrocytes were more spherical with increasing severity of OA. There was a significant correlation between Mankin score and cell size ( r2 = 0.80) and Ihh intensity ( r2 = 0.89). Exogenous Ihh induced a 6.8 fold increase of type X collagen and 2.8 fold increase of MMP-13 mRNA expression in cultured chondrocytes. Conversely, knockdown of Ihh by siRNA and Hh inhibitor cyclopamine had the opposite effect. Conclusions Ihh expression correlates with OA progression and changes in chondrocyte morphology and gene expression consistent with chondrocyte hypertrophy and cartilage degradation seen in OA cartilage. Thus, Ihh may be a potential therapeutic target to prevent OA progression.
Background and Aims
Quantitative real‐time polymerase chain reaction (qRT‐PCR) has the advantages of sensitivity, specificity and repeatability, and is commonly used to investigate the expression ...levels of genes. The selection of appropriate endogenous reference genes is the pre‐condition for acquiring the desired results of qRT‐PCR. This study aimed to identify and screen the most suitable reference genes for grapevines.
Methods and Results
Three novel genes from previous transcriptomic data were selected for their stable expression either at the developmental stages of the grape berry or under the various treatments. The expression stability of these three candidate genes and six commonly used reference genes were evaluated with geNorm, NormFinder and BestKeeper algorithms in several grapevine samples. The geNorm analysis indicated that two reference genes were sufficient to normalise expression. The optimal reference gene combinations were: VvEF1‐γ and PPR2 in fruit; RRM1 and EF1‐α in leaf; EF1‐α and Actin in tendril of several cultivars. The combination of EF1‐α and VvEF1‐α was the most appropriate reference gene for fruits at different developmental stages. When all the samples were considered, the combination of RRM1 and Ubiquitin was optimal.
Conclusions
Different reference genes should be employed when qRT‐PCR is performed in different grapevine samples. The gene RRM1 is a new appropriate reference gene for grapevine.
Significance of the Study
This study provided alternatives for the optimal reference genes in qRT‐PCR, and identified one novel and appropriate reference gene (RRM1) for grapevine.
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•pH-Responsive Pickering foams are prepared using silica nanoparticles.•The particles are in situ hydrophobized by trace amount of carboxyl betaine.•The foams are stable at pH < 4 and ...unstable at pH > 10.•Multi-cycles between stable and unstable of the foams can be realized.•The responsive foams are prepared without using functional particles.
pH-Responsive Pickering foams were prepared by using negatively charged silica nanoparticles in combination with trace amount of dodecyl dimethyl carboxyl betaine as stabilizer. The foams are stable at pH ≤ 4.3 but unstable at pH ≥ 10 and can then be cycled between stable and unstable for many times by alternating the pH of the aqueous phase. It is shown that in acidic aqueous media the carboxyl betaine molecules are turned to cationic form which can adsorb at surfaces of the negatively charged silica nanoparticles with head-on configuration via electrostatic interaction, rendering particles surface activity by in situ hydrophobization, and the particles can then adsorb at air/water interface to stabilize the Pickering foams; whereas in neutral and alkaline aqueous media, the carboxyl betaine molecules are in zwitterionic form, which tend to desorb from particle surface due to weakening or removing of electrostatic interaction, triggering de-hydrophobization of the particles and defoaming of the systems. This principle makes it possible to construct stimuli-responsive aqueous foaming systems using commercial inorganic nanoparticles in combination with trace amount of conventional surfactants avoiding synthesis or preparation of complicated stimuli-responsive colloid particles.
Summary Objective Synovium-derived stem cells (SDSCs) have proven to be superior in cartilage regeneration compared with other sources of mesenchymal stem cells. We hypothesized that conventionally ...passaged SDSCs can be engineered in vitro into cartilage tissue constructs and the engineered premature tissue can be implanted to repair allogeneic full-thickness femoral condyle cartilage defects without immune rejection. Methods Synovial tissue was harvested from rabbit knee joints. Passage 3 SDSCs were mixed with fibrin glue and seeded into non-woven polyglycolic acid (PGA) mesh. After 1-month incubation with growth factor cocktails, the premature tissue was implanted into rabbit knees to repair osteochondral defects with Collagraft® as a bone substitute in the Construct group. Fibrin glue-saturated PGA/Collagraft® composites were used as a Scaffold group. The defect was left untreated as an Empty group. Results SDSCs were engineered in rotating bioreactor systems into premature cartilage, which displayed the expression of sulfated glycosaminoglycan (GAG), collagen II, collagen I, and macrophages. Six months after implantation with premature tissue, cartilage defects were full of smooth hyaline-like cartilage with no detectable collagen I and macrophages but a high expression of collagen II and GAG, which were also integrated with the surrounding native cartilage. The Scaffold and Empty groups were resurfaced with fibrous-like and fibrocartilage tissue, respectively. Conclusion Allogeneic SDSC-based premature tissue constructs are a promising stem cell-based approach for cartilage defects. Although in vitro data suggest that contaminated macrophages affected the quality of SDSC-based premature cartilage, effects of macrophages on in vivo tissue regeneration and integration necessitate further investigation.
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