bluuebunny/crossref_metadata_2025 huggingface dataset:
Feasibility of an Intradialytic Combined Exercise Program Targeting Older Adults With End-Stage Renal Disease
Authors: Parent-Roberge Hugo , Deshayes Thomas A. , Fortier Catherine , Marquis Karine , Lacharité-Lemieux Christiane , Rodrigue Chantale , Dionne Isabelle J. , Agharazii Mohsen , Godin Mélanie , Riesco Eléonor
Published: June 2021

Intradialytic exercise is feasible and yields substantial clinical benefits in middle-aged patients. However, evidence is scarce in older hemodialysis patients. Objective: To assess the feasibility and clinical benefits of supervised, intradialytic exercise in older patients. Methods: Multicenter one-arm feasibility study. The main outcome was feasibility (ease of recruitment, dropout rate, adherence, affective valence, and adverse events). The secondary outcomes were physical capacity (five-repetition sit-to-stand, 60-s sit-to-stand tests, and grip strength), quality of life (36-Item Short-Form Health Survey), quality of sleep (Pittsburgh Sleep Quality Index), depressive symptoms (Beck Depression Inventory), and dialysis efficacy (Kt/V and urea reduction ratio). Results: About 79% of the screened patients agreed to participate (n = 25, 73 [66–77] years). The dropout rate was high (32%), but adherence remained high among the participants who completed the study (94%). Improvements were found in the five-repetition sit-to-stand (p < .001), 60-s sit-to-stand tests (p = .028), 36-Item Short-Form Health Survey mental component score (p = .008), depressive symptoms (p = .006), and quality of sleep (p = .035). Conclusion: Supervised intradialytic exercise seems safe and beneficial in older patients.
‘Landmark’ African vaccine trial faces impasse
Authors: Cohen Jon
Published: June 2021

Pfizer and Moderna have been unwilling to participate in key test of their mRNA vaccines.
NASA missions to test idea of a watery past for Venus
Authors: Voosen Paul
Published: June 2021

Climate models suggest Earth's sister planet was once cool, wet, and habitable.
DNA test to predict odds of severe COVID-19 draws scrutiny
Authors: Kaiser Jocelyn
Published: June 2021

Relation between genes and risk is uncertain, skeptics say.
Alzheimer's drug approved despite murky results
Authors: Servick Kelly
Published: June 2021

FDA breaks from advisers to clear aducanumab based on reduction of toxic brain plaques.
Inhibitors of bacterial H
2
S biogenesis targeting antibiotic resistance and tolerance
Authors: Shatalin Konstantin , Nuthanakanti Ashok , Kaushik Abhishek , Shishov Dmitry , Peselis Alla , Shamovsky Ilya , Pani Bibhusita , Lechpammer Mirna , Vasilyev Nikita , Shatalina Elena , Rebatchouk Dmitri , Mironov Alexander , Fedichev Peter , Serganov Alexander , Nudler Evgeny
Published: June 2021

Turning down tolerance

Persister cells, which are found in abundance in biofilms, adopt a quiescent state and survive antimicrobial treatments, seeding disease recurrence and incubating new resistance mutations. Building on work implicating the reactive small-molecule hydrogen sulfide in bacterial defense against antibiotics, Shatalin
et al.
conducted a structure-based screen for inhibitors of a bacterial hydrogen sulfide–producing enzyme and found a group of inhibitors that act through an allosteric mechanism (see the Perspective by Mah). These inhibitors potentiated bactericidal antibiotics in vitro and in mouse infection models. They also suppressed persister bacteria and disrupted biofilm formation. This strategy of taking out persister cells may be promising for treating recalcitrant infections and holding the line against drug-resistant bacteria.

Science
, abd8377, this issue p.
1169
; see also abj3062, p.
1153
Interfacial ferroelectricity by van der Waals sliding
Authors: Vizner Stern M. , Waschitz Y. , Cao W. , Nevo I. , Watanabe K. , Taniguchi T. , Sela E. , Urbakh M. , Hod O. , Ben Shalom M.
Published: June 2021

Stacking a ferroelectric

Properties of layered van der Waals structures can depend sensitively on the stacking arrangement of constituent layers. This phenomenon has been exploited to engineer superconducting, correlated insulator, and magnetic states. Two groups now show that ferroelectricity can also be engineered through stacking: Parallel-stacked bilayers of hexagonal boron nitride exhibit ferroelectric switching even though the bulk material is not ferroelectric (see the Perspective by Tsymbal). To explore these phenomena, Yasuda
et al.
used transport measurements, whereas Vizner Stern
et al.
focused on atomic force microscopy.

Science
, abd3230 and abe8177, this issue p.
1458
and p.
1462
; see also abi7296, p.
1389
Nitrogen reduction to ammonia at high efficiency and rates based on a phosphonium proton shuttle
Authors: Suryanto Bryan H. R. , Matuszek Karolina , Choi Jaecheol , Hodgetts Rebecca Y. , Du Hoang-Long , Bakker Jacinta M. , Kang Colin S. M. , Cherepanov Pavel V. , Simonov Alexandr N. , MacFarlane Douglas R.
Published: June 2021

Shuttling protons in ammonia synthesis

An electrochemical route to ammonia could substantially lower the greenhouse gas emissions associated with the current thermal Haber-Bosch process. One relatively promising option under study involves reductive formation of lithium nitride, which can be protonated to ammonia. However, the ethanol used to date as a local proton source in these studies may degrade under the reaction conditions. Suryanto
et al.
report the use of a tetraalkyl phosphonium salt in place of ethanol (see the Perspective by Westhead
et al.
). This cation can stably undergo deprotonation–reprotonation cycles and, as an added benefit, it enhances the ionic conductivity of the medium.

Science
, abg2371, this issue p.
1187
; see also abi8329, p.
1149
Embracing the relational nature of existence
Helgoland: Making Sense of the Quantum Revolution
Carlo Rovelli Translated by Erica Segre and Simon Carnell
Riverhead, 2021. 256 pp.
Authors: Frappier Melanie
Published: June 2021

An ode to quantum physics misses the chance to teach readers how to confront uncertainty
Results of the Center for Disease Control Proficiency Testing Program for the detection of hepatitis B surface antigen
Authors: Taylor R N , Fulford K M
Published: June 2021

The changes in the types and numbers of tests used by participants in the Center for Disease Control Proficiency Testing Program for the detection of hepatitis B surface antigen from the beginning of the program in 1971 until October 1975 are analyzed; the implications of these changes are discussed. Changes in the use of agar gel diffusion, rheophoresis, counterelectrophoresis, complement fixation, reverse passive latex agglutination, radioimmunoassay, and reverse passive hemagglutination tests are reviewed. The performance of the participants for 1975 is reported, and factors related to performance (type or combinations of tests used, procedures used to confirm specificity, etc.) are discussed. The increase in the use of third-generation tests in place of tests with lower sensitivity and the decrease in the use of multiple tests undoubtedly represent increased efficiency and effectiveness.
Effects of selective media and atmosphere of incubation on the isolation of group A streptococci
Authors: Murray P R , Wold A D , Schreck C A , Washington JA I I
Published: June 2021

The effects of selective media and atmosphere of incubation on the isolation of group A beta-hemolytic streptococci were evaluated. Sheep blood agar medium with gentamicin (2.5 or 5.0 mug/ml) was inferior to antibiotic-free sheep blood agar medium. This resulted from the partial restriction of group A streptococcal growth on gentamicin medium. Recovery of beta-hemolytic streptococci from specimens in air, CO2, or anaerobic incubation was evaluated. The isolation of group A streptococci was equivalent in the three incubation atmospheres; however, non-group A beta- hemolytic streptococci were isolated significantly more often from specimens incubated in an anaerobic or CO2 atmosphere than from those incubated in air. Therefore, sheep blood agar medium, stabbed with a wire loop and incubated in air, is recommended for the isolation of group A streptococci from throat swabs.
Selective medium for isolation of Treponema hyodysenteriae
Authors: Songer J G , Kinyon J M , Harris D L
Published: June 2021

Pure cultures of six pathogenic isolates of Treponema hyodysenteriae, the colonic mucosal scrapings of seven pigs with acute swine dysentery, and feces from seven unaffected pigs were diluted in phosphate-buffered saline and plated on Trypticase soy agar with 5% citrated bovine blood (TSA) and TSA with various levels of spectinomycin (TSA-S). The plates were incubated at 42 degrees C in a vented GasPak jar with a cold palladium catalyst and either 80:20 H2-CO2 by evacuation and refilling or a H2-CO2 generator envelope. Viable cell counts of the six pathogenic isolates were not altered by plating on TSA-S with 400 mug of spectinomycin per ml (TSA-S400) as compared with TSA alone. Dilutions of colonic mucosal scrapings from seven pigs with acute swine dysentery showed numbers of T. hyodysenteriae to be unchanged when plated on TSA-S400. Flora other than T. hyodysenteriae present in acute swine dysentery was inhibited, on the average, by 99.99%. Plating of dilutions of feces of unaffected pigs on TSA-S400 showed inhibition of flora that averaged more than 99.9%. Pathogenicity of T. hyodysenteriae was not altered by isolation or serial passage on TSA-S400.
Simplified serological test for antibodies to Chlamydia trachomatis
Authors: Thomas B J , Reeve P , Oriel J D
Published: June 2021

Three-hundred sixty sera from unselected patients attending two London venereal disease clinics were examined by a microimmunofluorescence test. Eleven egg-grown serotypes of Chlamydia trachomatis and the so-called "fast" strain SA2(f) were used as antigens. Of the 360 sera tested, 119 (33%) reacted to a titer of 1:16 or above with at least one antigen. Of these positive sera, over 50% cross-reacted with all 12 serotypes, and 95.5% reacted with SA2(f) in addition to other antigenic types. It is suggested that SA2(f) could be used as a single antigen for preliminary screening of a large number of sera for the presence or absence of chlamydial antibody.
Study on the usefulness of hypertonic culture media
Authors: Louria D B , Kaminski T , Kapila R , Tecson F , Smith L
Published: June 2021

Specimens from 300 patients were studied using five to nine aerobic and anaerobic culture media, including five that were hypertonic, Groups studied included fever of unknown origin, suspected endocarditis, endocarditis during therapy, bacteremia during therapy, abscess and cellulitis, presumed infectious arthritis, renal transplantation during rejection, collagen disease, sarcoidosis, lymphoma, and colitis. Isolates in hypertonic media were reverted to parent form by agar passage. In only 5% of these selected cases were organisms found in hypertonic, but not conventional, media that appeared on the basis of repeated isolation and/or serological studies to come from the patient. Nine of the 16 appeared to be of major significance. The two groups in which use of highly enriched, hypertonic media seemed most helpful were suspected endocarditis and undefined meningitis with negative cultures using standard media. The most effective of the hypertonic media used was 0.3 M sucrose in brain heart infusion with 20% horse serum. In most instances, the organism grew only in the hypertonic sucrose, and in most cases it appeared in conventional rather than aberrant form. Hypertonic media, especially 0.3 M sucrose, are of substantial helpin a small number of carefully selected cases.
Replication of murine paramyxoviruses in hamster tracheal organ culture and comparison with standard tissue culture methods
Authors: Schiff L J
Published: June 2021

Replication of Sendai virus, pneumonia virus of mice, and SV5 was investigated in tracheal organ cultures from 2- to 4-day-old and 2- and 4-week-old hamsters, and viral infectivity in tracheal explants was compared with that in tissue culture monolayers. Explants from 2- to 4-day-old hamsters produced higher titers of the three paramyxoviruses, as detected by hemadsorption with guinea pig and murine erythrocytes in primary rhesus monkey kidney cells. Tracheal cultures from 2- and 4-week-old hamsters yielded 1.5 and 2.5 log10 lower infectivity titers. Infected explants exhibited cytopathological changes that correlated well with cessation of ciliary activity. Viral titers in BHK-21, Vero, and BS-C-1 monolayer cells, the systems commonly used for isolation and propagation of murine paramyxoviruses, were lower than those in 2- to 4-day-old hamster tracheal explants. These observations suggest that hamster trachea organ culture could have practical application as an aid for primary isolation of paramyxoviruses from clinical specimens from rodents with respiratory ailments.
Rapid method for the detection and identification of mycolic acids in aerobic actinomycetes and related bacteria
Authors: Hecht S T , Causey W A
Published: June 2021

A rapid method for the identification of lipids characteristic of the genera Corynebacterium, Mycobacterium, Nocardia, and the "rhodochrous group" has been developed. Modifications of previously described methods make this procedure suitable for use in the clinical laboratory. Thin-layer chromatography is used to demonstrate the presence of the lipid characteristic of Nocardia spp. (type A) in some corynebacteria, nocardias, and members of the "rhodochrous group." Precipitation in ether and ethanol is used to demonstrate the presence of mycobacterial mycolic acids. Since this procedure can be carried out in less than 2 days and the lipids are extracted from the same batch of cells grown for diaminopimelic acid and whole-cell sugar analyses, it can readily be added to the battery of tests performed in reference laboratories that deal with aerobic actinomycetes and related bacteria.
Interference by Neisseria gonorrhoeae growth by other bacterial species
Authors: Kraus S J , Geller R C , Perkins G H , Rhoden D L
Published: June 2021

Growth of Neisseria gonorrhoeae from clinical specimens has been enhanced by the use of selective media that inhibit the simultaneous growth of other microorganisms. One explanation for this enhancement could be that certain other bacteria inhibit gonococcal growth. This hypothesis was examined by testing 167 bacterial isolates for in vitro gonococcal inhibition; 34.1% of the isolates failed to inhibit the gonococcus, but 12.0% produced weak inhibition and 53.9% strongly inhibited N. gonorrhoeae. The pattern of in vitro gonococcal inhibition was consistently the same for all the individual isolates within some species, but individual isolates within other bacterial species varied in their ability to inhibit the gonococcus. Consistently strong in vitro N. gonorrhoeae inhibitors were Citrobacter diversus, Enterobacter cloacae, Serratia marcescens, and Pseudomonas. The in vivo significance of gonococcal interference was demonstrated in the subcutaneous chamber model of N. gonorrhoeae infection.
Immune Response to Acute Otitis Media: Association Between Middle Ear Fluid Antibody and the Clearing of Clinical Infection
Authors: Sloyer John L. , Howie Virgil M. , Ploussard John H. , Schiffman Gerald , Johnston Richard B.
Published: June 2021

Clearing of the middle ear fluid in patients with acute otitis media due to
Streptococcus pneumoniae
or
Haemophilus influenzae
was significantly associated with the presence and concentration of specific antibody in the middle ear fluid at the time of diagnosis.
Semi-microtechnique for the biochemical characterization of anaerobic bacteria
Authors: Morgan J R , Liu P Y , Smith J A
Published: June 2021

A semi-micromethod is described for characterizing anaerobic bacteria by substrate utilization. Small volumes of individual substrates were placed in the wells of plastic microtiter trays. When heavy inocula and a colorimetric indicator were used, complete results were available after 30 h of incubation. Microtiter trays containing a range of substrates can be stored at -20 degrees C. The method is accurate, economical, and convenient for use in a hospital microbiology laboratory.
A study of possible biohazards in the fluorescent antibody test using adenovirus, coxsackievirus, herpesvirus, and respiratory syncytial virus as antigens
Authors: Bardell D
Published: June 2021

Infectious adenovirus type 5 and coxsackievirus type B5, both nonlipid-containing viruses, were isolated from cells fixed in acetone at 22 degrees C for 15 min, from acetone used for fixation, from the solution used for washing slides during the fluorescent antibody procedure, and after complete processing of antigen preparations with serial twofold dilutions of human antisera and fluorescein-labeled goat anti-human immunoglobulin G. Lipid-containing herpes simplex virus type 1 and respiratory syncytial virus were inactivated by acetone, and infectious virus could not be recovered at any stage in the fluorescent antibody test. Fixation in acetone at 56 degrees C destroyed the infectivity of adenovirus 5 and coxsackievirus B5 within 30 min, but no adverse effect on the antigenic determinants of either virus occurred until after 60 min, thus demonstrating that these antigens can be utilized without the hazard of infectious virus.
Serum dilution neutralization test for California group virus identification and serology
Authors: Lindsey H S , Calisher C H , Mathews J H
Published: June 2021

The serum dilution neutralization test was evaluated for serological diagnosis of California group arbovirus infections and identification of virus isolates. The technical advantages and the degree of subtype specificity of the serum dilution neutralization test over the hemagglutination inhibition test and the complement fixation test were demonstrated with paired specimens from human cases, single human survey sera, and sentinel rabbit sera. Twenty-one virus isolates from various geographical areas of the United States were also used to evaluate the efficacy of the serum dilution neutralization test for specific virus identification.
Long-chain fatty acids of peptococci and peptostreptococci
Authors: Wells C L , Field C R
Published: June 2021

The long-chain fatty acids extracted from the whole cells of 12 clinically significant species of peptococci and peptostreptococci were characterized by gas-liquid chromatography. The resulting methylated fatty acid profiles (and some unidentified compounds) of 82 strains allowed the 12 species to be separated into four groups. Fifteen strains of Peptostreptococcus anaerobius were placed in group I because they had a unique, prominent compound that occurred in the area where a C8 to C10 fatty acid would be expected. Group II, consisting of Peptostreptococcus intermedius, Peptostreptococcus micros, Peptostreptococcus parvulus, Peptococcus morbillorum, and Peptococcus constellatus, produced C14, C16:1, C18:1, and C18 fatty acids. Peptococcus prevotii, Peptococcus variabilus, Peptococcus magnus, Peptococcus asaccharolyticus, and Peptostreptococcus productus were placed in group III because they contained three to six additional, unidentified compounds that strikingly differentiated them from group II. Peptococcus saccharolyticus was the single species assigned to group IV because it yielded C14, C16, C18:1, C18, and C20 fatty acids and a prominent unidentified peak that occurred between C14 and C16 fatty acids. This study indicated that cellular long-chain fatty acids may be an important tool in clarifying the taxonomy of the peptococci and peptostreptococci.
Inoculation of API-20E from positive blood cultures
Authors: Blazevic D J , Trombley C M , Lund M E
Published: June 2021

The API-20E system (Analytab Products, Inc., Plainview, N. Y.) was inoculated from 4- to 6-h tryptic soy broth cultures that had been inoculated from positive blood cultures containing gram-negative bacilli. This method gave the same genus and species identification for 139 of 140 organisms (47 patient and 96 simulated positive cultures) when compared to the Analytab Products, Inc., recommended method of inoculation.
DNA gyrase, topoisomerase IV, and the 4-quinolones
Authors: Drlica K , Zhao X
Published: June 2021

For many years, DNA gyrase was thought to be responsible both for unlinking replicated daughter chromosomes and for controlling negative superhelical tension in bacterial DNA. However, in 1990 a homolog of gyrase, topoisomerase IV, that had a potent decatenating activity was discovered. It is now clear that topoisomerase IV, rather than gyrase, is responsible for decatenation of interlinked chromosomes. Moreover, topoisomerase IV is a target of the 4-quinolones, antibacterial agents that had previously been thought to target only gyrase. The key event in quinolone action is reversible trapping of gyrase-DNA and topoisomerase IV-DNA complexes. Complex formation with gyrase is followed by a rapid, reversible inhibition of DNA synthesis, cessation of growth, and induction of the SOS response. At higher drug concentrations, cell death occurs as double-strand DNA breaks are released from trapped gyrase and/or topoisomerase IV complexes. Repair of quinolone-induced DNA damage occurs largely via recombination pathways. In many gram-negative bacteria, resistance to moderate levels of quinolone arises from mutation of the gyrase A protein and resistance to high levels of quinolone arises from mutation of a second gyrase and/or topoisomerase IV site. For some gram-positive bacteria, the situation is reversed: primary resistance occurs through changes in topoisomerase IV while gyrase changes give additional resistance. Gyrase is also trapped on DNA by lethal gene products of certain large, low-copy-number plasmids. Thus, quinolone-topoisomerase biology is providing a model for understanding aspects of host-parasite interactions and providing ways to investigate manipulation of the bacterial chromosome by topoisomerases.
Use of rituximab in paediatric nephrology
Authors: Sinha Rajiv , Agrawal Nirav , Xue Yuanxin , Chanchlani Rahul , Pradhan Subal , Raina Rupesh , Marks Stephen D
Published: June 2021

Rituximab is a chimeric monoclonal antibody capable of depleting B cell populations by targeting the CD20 antigen expressed on the cell surface. Its use in oncology, initially in B cell lymphoma and post-transplant lymphoproliferative disorders, predates its current utility in various fields of medicine wherein it has become one of the safest and most effective antibody-based therapies. It was subsequently found to be effective for rheumatological conditions such as rheumatoid arthritis and antineutrophil cytoplasmic antibody-associated vasculitis. Over the past decade, rituximab has generated a lot of interest in nephrology and has become an emerging or accepted therapy for multiple renal conditions, including systemic lupus erythematosus, lupus nephritis, vasculitis, nephrotic syndrome and in different scenarios before and after kidney transplantation. This review outlines its current use in paediatric nephrology practice, focusing on the knowledge required for general paediatricians who may be caring for children prescribed this medication and reviewing them on a shared care basis.
Seeking shelter: homelessness and COVID-19
Authors: Baral Stefan , Bond Andrew , Boozary Andrew , Bruketa Eva , Elmi Nika , Freiheit Deirdre , Ghosh S. Monty , Goyer Marie Eve , Orkin Aaron M. , Patel Jamie , Richter Tim , Robertson Angela , Sutherland Christy , Svoboda Tomislav , Turnbull Jeffrey , Wong Alexander , Zhu Alice
Published: June 2021

Those experiencing homelessness in Canada are impacted inequitably by COVID-19 due to their increased exposure, vulnerability of environment and medical comorbidities, and their lack of access to preventive care and treatment in the context of the pandemic. In shelter environments one is unable to effectively physically distance, maintain hygiene, obtain a test, or isolate. As a result, unique strategies are required for this population to protect them and those who serve them. Recommendations are provided to reduce or prevent further negative consequences from the COVID-19 pandemic for people experiencing homelessness. These recommendations were informed by a systematic review of the literature, as well as a jurisdictional scan. Where evidence did not exist, expert consensus from key providers and those experiencing homelessness throughout Canada was included. These recommendations recognize the need for short-term interventions to mitigate the immediate risk to this community, including coordination of response, appropriate precautions and protective equipment, reducing congestion, cohorting, testing, case and contact management strategies, dealing with outbreaks, isolation centres, and immunization. Longer-term recommendations are also provided with a view to ending homelessness by addressing the root causes of homelessness and by the provision of adequate subsidized and supportive housing through a Housing First strategy. It is imperative that meaningful changes take place now in how we serve those experiencing homelessness and how we mitigate specific vulnerabilities. These recommendations call for intersectoral, collaborative engagement to work for solutions targeted towards protecting the most vulnerable within our community through both immediate actions and long-term planning to eliminate homelessness.
Detection of SARS-CoV-2 in wastewater in Halifax, Nova Scotia, Canada, using four RT-qPCR assays
Authors: Huang Yannan , Johnston Lindsay , Parra Ana , Sweeney Crystal , Hayes Emalie , Hansen Lisbeth Truelstrup , Gagnon Graham , Stoddart Amina , Jamieson Rob
Published: June 2021

Wastewater-based surveillance methods have been implemented in several countries as a tool for monitoring SARS-CoV-2 at a community scale. A variety of methods have been used for concentrating, extracting, and detecting the virus, with no clear consensus on the most effective approach. In this note, we report preliminary findings from a study that is tracking SARS-CoV-2 in wastewater in Halifax, Nova Scotia, with a specific focus on the use of four reverse transcriptase quantitative PCR (RT-qPCR) assays for detecting the virus in wastewater. We were able to detect the virus in wastewater samples during the initial rise of cases in the Halifax region in early November 2020. Levels of the targeted SARS-CoV-2 gene fragments increased and fell in response to reported cases of COVID-19. The CDC N1 and E RT-qPCR assays demonstrated greater relative sensitivity than the CDC N2 and N3 assays for detection of SARS-CoV-2 in raw sewage samples.
Bottom Attenuation Coefficient Inversion Based on the Modal Phase Difference Between Pressure and Vertical Velocity from a Single Vector Sensor
Authors: Guarino Alexandre L. , Smith Kevin B. , Godin Oleg A.
Published: June 2021

An inversion scheme based on time-warping is presented for estimating the attenuation coefficient of a sediment bottom using a single vector sensor, restricted to shallow water and using low-frequency impulsive sources. The attenuation information is extracted from the modal phase difference between pressure and vertical velocity. The method is derived from Pekeris waveguide theoretical equations and the eigen values are obtained using the normal mode model Kraken. Some changes are made to the time-warping process to mitigate the inherent interference between adjacent modes, which improves the phase extraction capabilities. Results are presented for a two-layer, homogeneous environment using the RAM propagation model for depth-dependent sound speed profile simulations. This version of RAM was updated to provide radial and vertical velocities. For additional generality, the technique is evaluated in the presence of white noise.
Side Information Fusion for Recommender Systems over Heterogeneous Information Network
Authors: Zhao Huan , Yao Quanming , Song Yangqiu , Kwok James T. , Lee Dik Lun
Published: June 2021

Collaborative filtering (CF) has been one of the most important and popular recommendation methods, which aims at predicting users’ preferences (ratings) based on their past behaviors. Recently, various types of side information beyond the explicit ratings users give to items, such as social connections among users and metadata of items, have been introduced into CF and shown to be useful for improving recommendation performance. However, previous works process different types of information separately, thus failing to capture the correlations that might exist across them. To address this problem, in this work, we study the application of heterogeneous information network (HIN), which offers a unifying and flexible representation of different types of side information, to enhance CF-based recommendation methods. However, we face challenging issues in HIN-based recommendation, i.e., how to capture similarities of complex semantics between users and items in a HIN, and how to effectively fuse these similarities to improve final recommendation performance. To address these issues, we apply metagraph to similarity computation and solve the information fusion problem with a “matrix factorization (MF) + factorization machine (FM)” framework. For the MF part, we obtain the user-item similarity matrix from each metagraph and then apply low-rank matrix approximation to obtain latent features for both users and items. For the FM part, we apply FM with Group lasso (FMG) on the features obtained from the MF part to train the recommending model and, at the same time, identify the useful metagraphs. Besides FMG, a two-stage method, we further propose an end-to-end method, hierarchical attention fusing, to fuse metagraph-based similarities for the final recommendation. Experimental results on four large real-world datasets show that the two proposed frameworks significantly outperform existing state-of-the-art methods in terms of recommendation performance.
Role of MicroRNA-155 as a Potential Biomarker for Allergic Rhinitis in Children
Authors: Hammad Noha M. , Nabil Fedaa , Elbehedy Eman M. , Sedeek Randa , Gouda Magdy I. , Arafa Mohamed A. , Elalawi Saffaa M. , El Shahawy Alia A.
Published: June 2021

Background. Allergic rhinitis (AR) is an inflammatory state categorized by a disturbance of immunoregulatory mechanisms. MicroRNA-155 (miRNA-155) has an essential role in regulating gene expression and can mediate the allergic TH2 process. Objective. In this study, we aimed to evaluate the role of miR-155 as a biomarker in AR and correlate its level with the total nasal symptom score (TNSS) and the levels of serum interleukin-4 (IL-4). Methods. This study included 90 children: 45 with pollen-induced AR and 45 healthy controls. Serum miR-155 expression levels were measured using quantitative real-time PCR. Human IL-4 ELIZA kits were used for the semiquantitative detection of the serum levels of IL-4. Receiver operating characteristic (ROC) curves were used to determine the best cutoff values for the studied parameters for the diagnosis of AR. Results. The demographic characteristics of the two groups were matched with respect to age and sex. The AR case group included 23 (51.1%) males and 22 (48.9%) females, while the control group included 24 (53.3%) males and 21 (46.7%) females. The miR-155 level was increased in the serum of children with pollen-induced AR compared with controls (mean difference = 2.8,

p
<
0.001

). A significant positive correlation between the serum expression level of miR-155 and TNSS in children with AR was detected (r = 0.494,

p
<
0.001

). However, no significant correlation was identified between the expression of miR-155 and that of IL-4. At a cutoff value of 1.09, the sensitivity of miR-155 as a biomarker for AR was 100%, and the specificity was 71.1%. Conclusion. MiR-155 expression levels were elevated in the serum of AR children. Therefore, miR-155 could be used as a biomarker in AR diagnosis.
Minimal Invasive Surgical Management of Familial Arteriovenous Malformation
Authors: Abdel-Latif Mokhtar Mamdouh , Patil Shankargouda
Published: June 2021

Introduction. Familial arteriovenous malformations are exceedingly rare. They are often noted at birth. They can also present during childhood or adolescence. Sclerotherapy has proven to have a favorable outcome. Case Presentation. The present case report describes the treatment of arteriovenous malformations on the tongue, labial mucosa, and vermilion border in siblings treated with boiling saline injections. Conclusion. Sclerotherapy using boiling saline had shown to effectively treat arteriovenous malformations in the oral region without any significant morbidity.
Two-Port CPW-Fed Dual-Band MIMO Antenna for IEEE 802.11 a/b/g Applications
Authors: Dou Yuqing , Chen Zhuoni , Bai Jing , Cai Qibo , Liu Gui
Published: June 2021

A coplanar waveguide- (CPW-) fed dual-band multiple-input multiple-output (MIMO) antenna for 2.45/5.5 GHz wireless local area network (WLAN) applications is presented in this paper. The presented MIMO antenna consists of two identical trapezoidal radiating elements which are perpendicular to each other. The size of the entire MIMO antenna is 50 × 50 × 1.59 mm3, which is printed on a FR4 substrate. The measured impedance bandwidth of the proposed antenna is 2.25–3.15 GHz and 4.89–5.95 GHz, which can cover IEEE 802.11 a/b/g frequency bands. A rectangular microstrip stub is introduced to achieve a good isolation which is less than −15 dB in both operation frequency bands. The measured peak gain is 5.59 dBi at 2.45 GHz and 5.63 dBi at 5.5 GHz. The measured antenna efficiency is 77.8% and 80.4% in the lower and higher frequency bands, respectively. The ECC values at the lower and higher frequencies are lower than 0.003 and 0.01, respectively.
Annexin A3 as a Marker Protein for Microglia in the Central Nervous System of Rats
Authors: Zhang Zengli , Li Zhengyiqi , Ma Zhi , Deng Meiling , Xing Manyu , Wu Jing , Jiang Shasha , Wang Qiang , Guo Qulian , Zou Wangyuan
Published: June 2021

The parenchymal microglia possess different morphological characteristics in cerebral physiological and pathological conditions; thus, visualizing these cells is useful as a means of further investigating parenchymal microglial function. Annexin A3 (ANXA3) is expressed in microglia, but it is unknown whether it can be used as a marker protein for microglia and its physiological function. Here, we compared the distribution and morphology of parenchymal microglia labeled by ANXA3, cluster of differentiation 11b (CD11b), and ionized calcium-binding adaptor molecule 1 (Iba1) and measured the expression of ANXA3 in nonparenchymal macrophages (meningeal and perivascular macrophages). We also investigated the spatiotemporal expression of ANXA3, CD11b, and Iba1 in vivo and in vitro and the cellular function of ANXA3 in microglia. We demonstrated that ANXA3-positive cells were abundant and evenly distributed throughout the whole brain tissue and spinal cord of adult rats. The morphology and distribution of ANXA3-labeled microglia were quite similar to those labeled by the microglial-specific markers CD11b and Iba1 in the central nervous system (CNS). ANXA3 was expressed in the cytoplasm of microglia, and its expression was significantly increased in activated microglia. ANXA3 was almost undetectable in the nonparenchymal macrophages. Meanwhile, the protein and mRNA expression levels of ANXA3 in different regions of the CNS were different from those of CD11b and Iba1. Moreover, knockdown of ANXA3 inhibited the proliferation and migration of microglia, while overexpression of ANXA3 enhanced these activities. This study confirms that ANXA3 may be a novel marker for parenchymal microglia in the CNS of adult rats and enriches our understanding of ANXA3 from expression patterns to physiological function.
Beyond Statistical Analysis in Chaos-Based CSPRNG Design
Authors: Arockiasamy John Prakash , Benjamin Lydia Elizabeth , Vaidyanathan Rhymend Uthariaraj
Published: June 2021

The design of cryptographically secure pseudorandom number generator (CSPRNG) producing unpredictable pseudorandom sequences robustly and credibly has been a nontrivial task. Almost all the chaos-based CSPRNG design approaches invariably depend only on statistical analysis. Such schemes designed to be secure are being proven to be predictable and insecure day by day. This paper proposes a design and instantiation approach to chaos-based CSPRNG using proven generic constructions of modern cryptography. The proposed design approach with proper instantiation of such generic constructions eventually results in providing best of both worlds that is the provable security guarantees of modern cryptography and passing of necessary statistical tests as that of chaos-based schemes. Also, we introduce a new coupled map lattice based on logistic-sine map for the construction of CSPRNG. The proposed pseudorandom number generator is proven using rigorous security analysis as that of modern cryptography and tested using the standard statistical testing suites. It is observed that the generated sequences pass all stringent statistical tests such as NIST, Dieharder, ENT, and TestU01 randomness test suites.
MXRA5 Is a Novel Immune-Related Biomarker That Predicts Poor Prognosis in Glioma
Authors: Sun Jin-Zhang , Zhang Jin-Hao , Li Jia-Bo , Yuan Feng , Tong Lu-Qing , Wang Xu-Ya , Chen Lu-Lu , Fan Xiao-Guang , Zhang Yi-Ming , Ren Xiao , Zhang Chen , Yu Sheng-Ping , Yang Xue-Jun
Published: June 2021

Background. Glioma is the most common primary intracranial tumor and is associated with poor prognosis. Identifying effective biomarkers for glioma is particularly important. MXRA5, a secreted glycoprotein, is involved in cell adhesion and extracellular matrix remodeling and has been reported to be expressed in many cancers. However, the role and mechanism of action of MXRA5 in gliomas remain unclear. This study was aimed at investigating the role of MXRA5 at the transcriptome level and its clinical prognostic value. Methods. In this study, RNA microarray data of 301 glioma patients from the Chinese Glioma Genome Atlas (CGGA) were collected as a training cohort and RNA-seq data of 702 glioma samples from The Cancer Genome Atlas (TCGA) were used for validation. We analyzed the clinical and molecular characteristics as well as the prognostic value of MXRA5 in glioma. In addition, the expression level of MXRA was evaluated in 28 glioma tissue samples. Results. We found that MXRA5 expression was significantly upregulated in high-grade gliomas and IDH wild-type gliomas compared to controls. Receiver operating characteristic (ROC) analysis showed that MXRA5 is a potential marker of the mesenchymal subtype of glioblastoma multiforme (GBM). We found that MXRA5 expression is highly correlated with immune checkpoint molecule expression levels and tumor-associated macrophage infiltration. High MXRA5 expression could be used as an independent indicator of poor prognosis in glioma patients. Conclusion. Our study suggests that MXRA5 expression is associated with the clinicopathologic features and poor prognosis of gliomas. MXRA5 may play an important role in the immunosuppressive microenvironment of glioma. As a secreted glycoprotein, MXRA5 is a potential circulating biomarker for glioma, deserving further investigation.
[Retracted] Improved Genetic Algorithm to Solve the Scheduling Problem of College English Courses
Authors: Xu Jing
Published: June 2021

In this paper, an improved genetic algorithm is designed to solve the above multiobjective optimization problem for the scheduling problem of college English courses. Firstly, a variable‐length decimal coding scheme satisfying the same course that can be scheduled at different times, different classrooms, and different teaching weeks per week is proposed, which fully considers the flexibility of classrooms and time arrangements of the course and makes the scheduling problem more reasonable. Secondly, a problem‐specific local search operator is designed to accelerate the convergence speed of the algorithm. Finally, under the framework of optimal individual retention, the selection operator, crossover operator, and variation operator are improved. It is experimentally demonstrated that the designed algorithm not only has a faster convergence speed but also improves the diversity of individuals to a certain extent to enhance the search space and jump out of the local optimum. Research shows that the improved genetic algorithm has improved average fitness value and time compared with traditional genetic algorithm. At the same time, the use of the largest fuzzy pattern algorithm effectively solves the conflict problem of college English lesson scheduling, thereby improving the solution of college English lesson scheduling. Through the research of this article, the management system of college English course scheduling has been made more intelligent, and the rational allocation of teaching resources and the completion of education and teaching plans have been improved.
The Correlation between Dental Stages and Skeletal Maturity Stages
Authors: Jourieh Ayah , Khan Haris , Mheissen Samer , Assali Muhammad , Alam Mohammad Khursheed
Published: June 2021

Introduction. The determination of skeletal maturity stages is very important in orthodontic treatment planning, especially skeletal discrepancies in growing individuals. A hand‐wrist radiograph is considered the most accurate approach for skeletal maturity detection. Dental calcification stages have been suggested as an alternative diagnostic method to decrease radiation exposure. The recent study is aimed at detecting the efficacy of dental calcification stages in assessing skeletal maturity during the prepubertal and pubertal growth periods. Methods. Patients’ records were collected from the Aleppo Orthodontic Center. Dental maturity stages were assessed from a panoramic radiograph using the Demirjian method, while skeletal maturity stages were determined using the Björk method. Four permanent left mandibular teeth were included (canine, 1st premolar, 2nd premolar, and 2nd molar) for the study. Results. From 517 records, 295 records (145 males and 150 females) were included. The Spearman rank‐order correlation coefficients between skeletal maturation and dental maturation were strong and statistically significant (ranging from 0.789 to 0.835). The highest correlation was between skeletal stages and the second molar (r = 0.829 and 0.88 in males and females, respectively). Receiver operating characteristic (ROC ) curve suggested a high validity of the sum of dental stages for the four teeth in identifying MP3= stage (sensitivity was 70%, specificity was 92.77%, and ROC area was 0.81) but not for MP3cap (sensitivity was 50.85%, specificity was 81.36%, and ROC area was 0.66). Conclusions. The correlation between the skeletal maturity stages and the dental calcification stages was high. The orthodontist can use the dental stages as a definite diagnostic tool for prepubertal growth period.
Abstract A48: Therapeutic reactivation of the protein phosphatase 2A (PP2A) for the treatment of KRAS-driven cancers
Authors: Sangodkar Jaya , Westermarck Jukka , Taylor Derek , Narla Goutham
Published: June 2021

There have been tremendous strides in the development of therapies for the treatment of NSCLC over the past decade. Nevertheless, the most common recurrent mutation driving the growth of NSCLC, mutant KRAS, accounting for ~25% of patients with advanced NSCLC, remains without an effective therapy. Thus, novel therapies are critically needed to improve the lives of patients suffering from KRAS-driven lung cancers. Protein phosphatase 2A (PP2A) is a serine threonine-directed tumor-suppressive phosphatase that is dysregulated and deactivated in cancer by multiple mechanisms including somatic mutation, suppression of individual subunits, increased expression of endogenous PP2A inhibitors and changes in post-translational modifications to the catalytic C subunit. Given its central role in regulating many key cellular processes and its role in human disease pathogenesis, many efforts have been developed to therapeutically target PP2A. Our group has developed first-in-class direct small-molecule activators of PP2A (SMAPs) by using the chemical scaffold of the FDA-approved tricyclic neuroleptics. We have used molecular modeling, hydroxyl radical footprinting and cryo-electron microscopy to structurally resolve the mechanism of action of SMAP-mediated growth suppression. Specifically, SMAPs protect the regulatory c-terminal tail of the catalytic subunit through changes in the methylation of the terminal leucine (L309) that induces the holoenzyme heterotrimerization and increased substrate-directed catalysis. SMAP treatment of KRAS-mutant lung cancer cells induced apoptosis and decreased the phosphorylation of PP2A targets including AKT and ERK. We found that treatment of xenograft, PDX, and GEMM mouse models of KRAS-mutant lung cancer cells with SMAPs resulted in marked tumor growth inhibition. Taken together, these studies demonstrate the potential of using SMAPs as an approach to treat KRAS-mutant NSCLC. We also established that PP2A activity defines the response of KRAS-mutant lung cancer cells across library of over 200 kinase inhibitors. In vivo studies using xenograft mouse models of KRAS-mutant lung adenocarcinoma demonstrated that SMAP in combination with MEK inhibitor resulted in tumor regression. Our studies have identified a combination of drugs that is effective in vivo for the treatment of KRAS-mutant lung cancer. Our strategy of reactivating endogenous PP2A may be applicable to the treatment of other KRAS-driven cancers and represents a first step into a new territory of developing small-molecule activators of tumor-suppressor proteins.

Citation Format: Jaya Sangodkar, Jukka Westermarck, Derek Taylor, Goutham Narla. Therapeutic reactivation of the protein phosphatase 2A (PP2A) for the treatment of KRAS-driven cancers [abstract]. In: Proceedings of the AACR Special Conference on Targeting RAS-Driven Cancers; 2018 Dec 9-12; San Diego, CA. Philadelphia (PA): AACR; Mol Cancer Res 2020;18(5_Suppl):Abstract nr A48.
Abstract A49: Specific Kras codon 12 and 13 mutations display different tumor initiation in pancreatic cancer
Authors: Martin Maria Paz Zafra , Alonso-Curbelo Direna , Wilkinson J. Erby , Schatoff Emma , Dow Lukas E.
Published: June 2021

Defining the effect of specific oncogenic mutations on tumor behavior and therapy response is essential for developing effective treatment strategies and realizing the promise of precision medicine. KRAS is the most frequently mutated oncogene in human cancers, and specific cancer types show a clear bias in the types and frequency of Kras alterations. The generation of conditional animal models, such as Lox-Stop-Lox (LSL) KrasG12D (KC model) and LSL-KrasG12Vgeo mice, has provided important tools to dissect the impact of Kras mutation in tumor development, but these models alone do not recapitulate the spectrum of Kras alterations in human cancer. To better reflect this Kras mutational landscape, we have developed a series of critical LSL-Kras mouse models that recapitulate common Kras alterations observed in colorectal (G13D), pancreatic (G12R), and lung cancer (G12C). Mice carrying each LSL-Kras variant, a pancreas-specific Cre (p48-Cre) and a far-red fluorescent Cre-reporter (mKate2), displayed drastically different morphologic features in early stages of pancreatic cell transformation, associated with dramatic changes in the degree of stromal expansion within the pancreas. Now, we are focused in exploring how such changes following Kras alterations influence progression to carcinoma and response to targeted therapies.

Citation Format: Maria Paz Zafra Martin, Direna Alonso-Curbelo, J. Erby Wilkinson, Emma Schatoff, Lukas E. Dow. Specific Kras codon 12 and 13 mutations display different tumor initiation in pancreatic cancer [abstract]. In: Proceedings of the AACR Special Conference on Targeting RAS-Driven Cancers; 2018 Dec 9-12; San Diego, CA. Philadelphia (PA): AACR; Mol Cancer Res 2020;18(5_Suppl):Abstract nr A49.