71 research outputs found

    A SURVEY OF COLLABORATIVE FILTERING BASED ON NEAREST-NEIGHBORS

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    This paper explains the k-NN classification algorithm and its operator in RapidMiner. The Use Case of this chapter applies the k-NN operator on the Teacher Evaluation dataset. The operators explained in this chapter are: Read URL, Rename, Numerical to Binominal, Numerical to Polynominal, Set Role, Split Validation, Apply Model, and Performance. The k-Nearest Neighbor algorithm is based on learning by analogy, that is, by comparing a given test example with the training examples that are similar to it. The training examples are described by n attributes. Each example represents a point in an n-dimensional space. In this way, all of the training examples are stored in an n-dimensional pattern space. When given an unknown example, the k-nearest neighbor algorithm searches the pattern space for the k training examples that are closest to the unknown example. These k training examples are the k “nearest neighbors” of the unknown example. The “Closeness” is defined in terms of a distance metric, such as the Euclidean distance

    Robust Anti‐Tumor T Cell Response with Efficient Intratumoral Infiltration by Nanodisc Cancer Immunotherapy

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    Potent anti‐tumor T cell response and efficient intratumoral T cell infiltration are the major challenges for therapeutic cancer vaccines. To address these issues, a nanovaccine system is designed to promote anti‐tumor T cell responses, and intratumoral infiltration is examined in various murine tumor models. Subcutaneous vaccination with nanodiscs carrying human papillomavirus (HPV)‐16 E7 antigen elicits as high as ∼32% E7‐specific CD8α+ T cell responses in circulation, representing a 29‐fold improvement over the soluble peptide vaccination. Importantly, nanodisc vaccination also promotes robust intratumoral T cell infiltration and eliminates HPV16 E6/E7‐expressing TC‐1 tumors at mucosal sites, including lungs, inner lip, and intravaginal tissues. In a benchmark study with a live Listeria vaccine combined with anti‐PD‐1 IgG, nanodiscs plus anti‐PD‐1 immune checkpoint blockade elicits comparable levels of T cell responses with anti‐tumor efficacy. Furthermore, compared with Complete Freund’s Adjuvant combined with tetanus toxoid, nanodisc vaccination in HLA‐A02 mice generates >200‐fold stronger IFN‐γ+ T cell responses against a neoantigen from an HLA‐A02 melanoma patient. Overall, these results show that the nanodisc system is a promising cancer vaccine platform for inducing anti‐tumor T cell responses.Efficient infiltration of T cells in solid cancer is a major challenge for cancer immunotherapy. A nanoparticle vaccine system is developed to promote T cell infiltration into peripheral mucosal tissues and eliminate disseminated tumors. Nanodiscs are broadly applicable with a wide range of tumor antigens, thus providing a versatile and potent vaccine platform for eliciting T cell immunity.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/156420/3/adtp202000094.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/156420/2/adtp202000094-sup-0001-SuppMat.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/156420/1/adtp202000094_am.pd

    Coronary artery disease as an independent predictor of short-term and long-term outcomes in patients with type-B aortic dissection undergoing thoracic endovascular repair

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    Background and aimsPrevious studies reported a high prevalence of concomitant coronary artery disease (CAD) in patients with Type B aortic dissection (TBAD). However, there is too limited data on the impact of CAD on prognosis in patients with TBAD. The present study aimed to assess the short-term and long-term impact of CAD on patients with acute or subacute TBAD undergoing thoracic endovascular aortic repair (TEVAR).MethodsWe retrospectively evaluated 463 patients with acute or subacute TBAD undergoing TEVAR from a prospectively maintained database from 2010 to 2017. CAD was defined before TEVAR by coronary angiography. Multivariable logistic and cox regression analyses were performed to evaluate the relationship between CAD and the short-term as well as long-term outcomes.ResultsAccording to the results of coronary angiography, the 463 patients were divided into the following two groups: CAD group (N = 148), non-CAD group (N = 315). In total, 12 (2.6%) in-hospital deaths and 54 (12%) all-cause deaths following a median follow-up of 48.1 months were recorded. Multivariable analysis revealed that CAD was an independent predictor of in-hospital major adverse clinical events (MACE) (odd ratio [OR], 2.33; 95% confidence interval [CI], 1.07–5.08; p = 0.033), long-term mortality [hazard ratio (HR), 2.11, 95% CI, 1.19–3.74, P = 0.011] and long-term MACE (HR, 1.95, 95% CI, 1.26–3.02, P = 0.003). To further clarify the relationship between the severity of CAD and long-term outcomes, we categorized patients into three groups: zero-vessel disease, single-vessel disease and multi-vessel disease. The long-term mortality (9.7 vs. 14.4 vs. 21.2%, P = 0.045), and long-term MACE (16.8 vs. 22.2 vs. 40.4%, P = 0.001) increased with the number of identified stenosed coronary vessels. Multivariable analysis indicated that, multi-vessel disease was independently associated with long-term mortality (HR, 2.38, 95% CI, 1.16–4.89, P = 0.018) and long-term MACE (HR, 2.79, 95% CI, 1.65–4.73, P = 0.001), compared with zero-vessel disease.ConclusionsCAD was associated with short-term and long-term worse outcomes in patients with acute or subacute TBAD undergoing TEVAR. Furthermore, the severity of CAD was also associated with worse long-term prognosis. Therefore, CAD could be considered as a useful independent predictor for pre-TEVAR risk stratification in patients with TBAD

    AEROsol generic classification using a novel Satellite remote sensing Approach (AEROSA)

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    Numerous studies (hereafter GA: general approach studies) have been made to classify aerosols into desert dust (DD), biomass-burning (BB), clean continental (CC), and clean maritime (CM) types using only aerosol optical depth (AOD) and Ångström exponent (AE). However, AOD represents the amount of aerosol suspended in the atmospheric column while the AE is a qualitative indicator of the size distribution of the aerosol estimated using AOD measurements at different wavelengths. Therefore, these two parameters do not provide sufficient information to unambiguously classify aerosols into these four types. Evaluation of the performance of GA classification applied to AErosol Robotic NETwork (AERONET) data, at sites for situations with known aerosol types, provides many examples where the GA method does not provide correct results. For example, a thin layer of haze was classified as BB and DD outside the crop burning and dusty seasons respectively, a thick layer of haze was classified as BB, and aerosols from known crop residue burning events were classified as DD, CC, and CM by the GA method. The results also show that the classification varies with the season, for example, the same range of AOD and AE were observed during a dust event in the spring (20th March 2012) and a smog event in the autumn (2nd November 2017). The results suggest that only AOD and AE cannot precisely classify the exact nature (i.e., DD, BB, CC, and CM) of aerosol types without incorporating more optical and physical properties. An alternative approach, AEROsol generic classification using a novel Satellite remote sensing Approach (AEROSA), is proposed to provide aerosol amount and size information using AOD and AE, respectively, from the Terra-MODIS (MODerate resolution Imaging Spectroradiometer) Collection 6.1 Level 2 combined Dark Target and Deep Blue (DTB) product and AERONET Version 3 Level 2.0 data. Although AEROSA is also based on AOD and AE, it does not claim the nature of aerosol types, instead providing information on aerosol amount and size. The purpose is to introduce AEROSA for those researchers who are interested in the generic classification of aerosols based on AOD and AE, without claiming the exact aerosol types such as DD, BB, CC, and CM. AEROSA not only provides 9 generic aerosol classes for all observations but can also accommodate variations in location and season, which GA aerosol types do not.</jats:p

    Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study

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    Funder: European Society of Intensive Care Medicine; doi: http://dx.doi.org/10.13039/501100013347Funder: Flemish Society for Critical Care NursesAbstract: Purpose: Intensive care unit (ICU) patients are particularly susceptible to developing pressure injuries. Epidemiologic data is however unavailable. We aimed to provide an international picture of the extent of pressure injuries and factors associated with ICU-acquired pressure injuries in adult ICU patients. Methods: International 1-day point-prevalence study; follow-up for outcome assessment until hospital discharge (maximum 12 weeks). Factors associated with ICU-acquired pressure injury and hospital mortality were assessed by generalised linear mixed-effects regression analysis. Results: Data from 13,254 patients in 1117 ICUs (90 countries) revealed 6747 pressure injuries; 3997 (59.2%) were ICU-acquired. Overall prevalence was 26.6% (95% confidence interval [CI] 25.9–27.3). ICU-acquired prevalence was 16.2% (95% CI 15.6–16.8). Sacrum (37%) and heels (19.5%) were most affected. Factors independently associated with ICU-acquired pressure injuries were older age, male sex, being underweight, emergency surgery, higher Simplified Acute Physiology Score II, Braden score 3 days, comorbidities (chronic obstructive pulmonary disease, immunodeficiency), organ support (renal replacement, mechanical ventilation on ICU admission), and being in a low or lower-middle income-economy. Gradually increasing associations with mortality were identified for increasing severity of pressure injury: stage I (odds ratio [OR] 1.5; 95% CI 1.2–1.8), stage II (OR 1.6; 95% CI 1.4–1.9), and stage III or worse (OR 2.8; 95% CI 2.3–3.3). Conclusion: Pressure injuries are common in adult ICU patients. ICU-acquired pressure injuries are associated with mainly intrinsic factors and mortality. Optimal care standards, increased awareness, appropriate resource allocation, and further research into optimal prevention are pivotal to tackle this important patient safety threat

    Expression and Significance of Beclin-1 and Bcl- 2 in Gastric Cancer

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    Abstract: Objective To investigate the role and correlation of Beclin-1 and Bcl-2 in the occurrence and progression of gastric cancer. Methods The expression of Beclin-1 and Bcl-2 in 78 cases of gastric cancer, 30 cases of atypical hyperplasia and 20 cases of chronic non-atrophic gastritis was examined by immunohistochemical staining. Results The positive rate of Beclin-1 in gastric cancer was significantly lower than those in atypical hyperplasia and chronic non-atrophic gastritis(χ 2 =9.298,7.437, P&lt;0.05), while there was no significant difference between atypical hyperplasia and chronic non-atrophic gastritis (P&gt;0.05). The positive rate of Bcl-2 in gastric cancer was significantly higher than those in atypical hyperplasia and chronic non-atrophic gastritis(χ 2 =11.013, 15.278, P&lt;0.05), while Bcl-2 expression in atypical hyperplasia showed no significant difference with that in chronic non-atrophic gastritis (P&gt;0.05). The expression of Beclin-1 and Bcl-2 was significantly correlated with differentiation, depth of invasion and TNM staging(χ 2 =7.014~16.248, P&gt;0.05), but not correlated with sex, age, tumor size, tumor location and metastasis(P&gt;0.05). The expression of Beclin-1 was negatively correlated with Bcl-2 in gastric cancer(r=-0.396, P&lt;0.01). Conclusion Beclin-1 expression was decreased and Bcl-2 expression was increased in gastric cancer. Both were associated with the occurrence and progression of gastric cancer and they were negatively correlated. Beclin-1 and Bcl-2 may be used as important markers to predict the biological behavior of gastric cancer

    Clinical Evaluation of a Multiplex PCR Assay for Simultaneous Detection of 18 Respiratory Pathogens in Patients with Acute Respiratory Infections

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    Reliable diagnostics are necessary to identify influenza infections, and coronavirus disease 2019 (COVID-19) highlights the need to develop highly specific and sensitive viral detection methods to distinguish severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and other respiratory pathogens to prevent their further spread. In this prospective study, 1070 clinical respiratory samples were collected from patients with acute respiratory infections from January 2019 to February 2021 to evaluate the diagnostic performance of a multiplex probe amplification (MPA) assay, designed to screen 18 pathogens, mainly those causing acute respiratory infections. Ninety-six positive samples and twenty negative samples for the 18 respiratory pathogens defined by the MPA assay and reverse transcription polymerase chain reaction (RT–PCR) were further confirmed by reference next-generation sequencing (NGS). The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of the MPA assay were 95.00%, 93.75%, 98.96% and 75.00%, respectively. Additionally, the co-infection rate for these positive samples were 25% (24/95). The MPA assay demonstrated a highly concordant diagnostic performance with NGS in the diagnosis of 18 respiratory pathogens and might play an important role in clinical respiratory pathogen diagnosis

    Red light mitigates Cd toxicity in Egeria densa by restricting Cd accumulation and modulating antioxidant defense system

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    Controlling light qualities have been acknowledged as an effective method to enhance the efficiency of phytoremediation, as light has a significant impact on plant growth. This study examined the effects of light qualities on cadmium (Cd) tolerance in aquatic plant Egeria densa using a combination of biochemical and transcriptomic approaches. The study revealed that E. densa exhibits higher resistance to Cd toxicity under red light (R) compared to blue light (B), as evidenced by a significant decrease in photosynthetic inhibition and damage to organelle ultrastructure. After Cd exposure, there was a significantly reduced Cd accumulation and enhanced levels of both glutathione reductase (GR) activity and glutathione (GSH), along with an increase in jasmonic acid (JA) in R-grown E. densa compared to B. Transcriptional analysis revealed that R caused an up-regulation of Cd transporter genes such as ABCG (G-type ATP-binding cassette transporter), ABCC (C-type ATP-binding cassette transporter), and CAX2 (Cation/H+ exchanger 2), while down-regulated the expression of HIPP26 (Heavy metalassociated isoprenylated plant protein 26), resulting in reduced Cd uptake and enhanced Cd exportation and sequestration into vacuoles. Moreover, the expression of genes involved in phytochromes and JA synthesis was up-regulated in Cd treated E. densa under R. In summary, the results suggest that R could limit Cd accumulation and improve antioxidant defense to mitigate Cd toxicity in E. densa, which might be attributed to the enhanced JA and phytochromes. This study provides a foundation for using light control methods with aquatic macrophytes to remediate heavy metal contamination in aquatic systems
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