bluuebunny/crossref_metadata_2025 huggingface dataset:
Severe tricuspid regurgitation as first manifestation of a primary ovarian carcinoid tumor
Authors:   Department of Cardiology and Radboudumc Centre for Pulmonary Hypertension, Radboud University Medical Centre, Nijmegen,The Netherlands., AL Duijnhouwer , ML Leijssen ,   Department of Cardiology and Radboudumc Centre for Pulmonary Hypertension, Radboud University Medical Centre, Nijmegen,The Netherlands., AP J van Dijk ,   Department of Cardiology and Radboudumc Centre for Pulmonary Hypertension, Radboud University Medical Centre, Nijmegen,The Netherlands.
Published: August 2022

A 52-year-old woman presented with a 1 year-history of reduced exercise tolerance and fatigue. Physical examination revealed a grade II/VI systolic murmur at the left sternal border. Transthoracic echocardiography showed thickened tricuspid leaflets with retraction and restricted movement, resulting in a severe tricuspid regurgitation. The characteristic pattern aroused the suspicion of a systemic or hormonal etiology. 24-Hour urine analysis revealed an increased level of 5hydroxyindoleacetic acid and abdominal computed tomography (CT) showed a large tumor in the pelvis; however, without the presence of liver metastasis. During uncomplicated trans-abdominal surgery a large mass in the ovary was removed, and pathology showed a primary ovarian carcinoid tumor. One year after the diagnosis, patient remains clinically stable without signs of right heart failure and an excellent exercise tolerance. This case report shows that isolated tricuspid valve pathology in the absence of left valvular disease may raise the suspicion for an atypical cause of valvular dysfunction, in which carcinoid tumor is included.
A Case of Hepatocellular Carcinoma in Abernethy syndrome
Authors:   University of Leicester Medical School, UK, J Peachey , L Purser ,   University of Leicester Medical School, UK, J Harding ,   University of Leicester Medical School, UK, S Jepson ,   Department of radiology, University Hospitals of Leicester, UK, N Bhardwaj ,   Department of HPB surgery, University Hospitals of Leicester, UK
Published: August 2022

Abernethy malformation is a rare type of congenital malformation of the hepatic portal system. It can take one of three forms and is classified as an extrahepatic portosystemic shunt between the portal vein and a large systemic vein, usually the inferior vena cava (IVC). Here, we present at 47-year-old male who was admitted with upper abdominal pain. His laboratory investigations showed a raised alkaline phosphatase, alanine aminotransferase and bilirubin but were otherwise within normal range. Ultrasound scan showed an indeterminate mass in the right lobe of the liver which was conformed with a CT scan. An anomalous portal vein drainage system was also identified on CT scan. Following MDT discussion, the decision for surgical exploration was made to assess the resectability and potential functional liver remnant. At exploration, resection was precluded by the complete absence of portal veins with no viable reconstruction option due to the size of the tumour and the potential of inadequate functioning residual liver following resection. Both the splenic vein and SMV were visualised intraoperatively and seen to form a short convergence before draining directly into the IVC. This abnormality is in line with type 1b abernethy malformation. Biopsies were also taken which confirmed a diagnosis of well differentiated HCC. Further treatment options including TACE and TARE have been deemed inappropriate due to the lack of portal vein as well as the size of the tumour. Considering this the patient has been referred for systemic treatment.
Prevalencia de infecciones del tracto urinario y sus factores epidemiológicos en mujeres en edad menopaúsica.
Authors: Toala Reyes Jorge Luis , Ortega Ponce Josceline Pamela , Cañarte Vélez José Clímaco , Journal of Scientific Research MQRInvestigar
Published: August 2022

Las infecciones del tracto urinario, siguen preocupando a la población a nivel mundial, debido a que son un tipo de patología que presenta un alto índice de prevalencia, ha generado un impacto económico significativo en el sistema de atención médica, afectando con un rango mayor al sexo femenino, siendo la segunda causa de visita médica de origen infeccioso, lo cual es de trascendente importancia lograr identificar aquellos factores de riesgo que pueden llegar a predisponer las reinfecciones urinarias en las mujeres en edad menopaúsica, que fue la población de estudio en esta investigación. La cual tuvo como objetivo determinar la prevalencia de infecciones del tracto urinario y sus factores epidemiológicos en mujeres ecuatorianas en edad menopaúsica. El diseño de la investigación fue de tipo narrativo documental, exploratoria de nivel informativo o explicativo, en donde se obtuvo información de artículos de investigaciones en el idioma ingles y español, de revistas indexadas y bases de datos científicas como: Pubmed, Science Research, Google académico, Dialnet y Scielo, para el desarrollo de fundamentación teórica y resultados de la investigación.  Los resultados mostraron que la mujer en edad menopaúsica tiene una alta prevalencia de padecer infecciones de las vías urinarias, debido por los cambios en el pH vaginal, disminución de colágena, lubricación deficiente, que alteran el balance de la flora bacteriana, así produciendo infección, donde el principal patógeno que ocasionó una infección del tracto urinario fue la Escherichia coli.
CINCO PILARES NORTEADORES DOS CURSOS DE LICENCIATURA EM MATEMÁTICA
Authors: Aurélio Ana Carolina Gadotti , Dos Santos Cristiane Aparecida , Jenske Grazielle , Schulz Manuela de Aviz , Horbach Jaqueline Luiza
Published: August 2022

Com o objetivo de propor uma excelente formação para professores de Matemática, questiona-se: Quais são os cinco pilares dos cursos de Licenciatura em Matemática empregados pela Uniasselvi para a formação do futuro professor?
VIOLÊNCIA OBSTÉTRICA NA PARAÍBA (BRASIL): RELATOS E EXPERIÊNCIAS DE MÃES
Authors: Santos Everson Vagner de Lucena , Guedes Nadigerlane Rodrigues de Carvalho Almeida
Published: August 2022

O presente artigo tem por objetivo analisar relatos e experiências de mães que sofreram violência obstétrica na Paraíba (Brasil). Trata-se de uma pesquisa descritiva com abordagem qualitativa desenvolvida com 12 mulheres acompanhadas pela Rede de Apoio Amorddoula no município de Patos – Paraíba. Para seleção das participantes, utilizou-se o critério de saturação teórica, foi utilizado um roteiro de entrevista em profundidade e os relatos foram analisados a partir da abordagem fenomenológica e o trabalho foi aprovado pelo Comitê de Ética em Pesquisa com seres humanos. A partir dos relatos é possível afirmar que a violência obstétrica é um importante tema de saúde pública e para a saúde da mulher e da criança no Brasil e que afeta diversas mulheres ao redor do mundo e possui suas raízes relacionadas com a violência contra a mulher no geral, perpetuando-se até na esfera de saúde. É um tema importante para a formação dos profissionais e gestores de saúde, tendo em vista a necessidade de mudança e de melhorias das práticas assistenciais e do sistema de atenção ao parto e ao nascimento. A criação de legislação para proteger as mulheres contra a violência obstétrica, o reconhecimento de seu direito a um atendimento livre de violência e o direito a autonomia sobre seus corpos devem ser garantidos. Tal problemática deve ser considerada uma violação dos direitos humanos e da mulher e deve ser cabível de pena perante à lei, desde o pagamento de multas, indenizações, processos disciplinares, afastamento de profissionais incapacitados e condenações pelos atos cometidos.
COMPARISON OF WARFARIN AND BROMADIOLONE BAITS FOR RAT CONTROL IN OIL PALM PLANTATIONS - EXPERIENCES IN THE 1990S
Authors:   The Incorporated Society of Planters
Published: August 2022

In rat population studies conducted in an oil palm plantation near Kulai, the 19-, 20- and 21-year-old plantings with low percentage fresh damage of 2-3 per cent had low to high rat population of Rattus rattus diardii (R. r. diardii) ranging from 83-542 rats per hectare. Although, the percentage of fresh damage of rat detected in the tall and older planting palms were low, the rat population on the ground was still high on per hectare basis. When single plot of warfarin and bromadiolone baits were tested to control R. r. diardii in the oil palm plantation near Kulai, three treatments were found to be effective. The treatments were ten rounds of bromadiolone bait (0.005%, 14.5 g) at one bait per palm and 50 per cent application density, five rounds of bromadiolone bait (0.005%, 14.5 g) at five baits per palm and 50 per cent application density, and nine rounds of bromadiolone bait (0.005%, 21 g) at one bait per palm and 50 per cent application density. In labour short situation, five rounds of bromadiolone bait (0.005%, 14.5 g) at five baits per palm and 50 per cent application density may be recommended, bearing in mind a higher material cost will be incurred in such application of multiple baits per palm. In another single plot of warfarin and bromadiolone baits were tested to control Rattus tiomanicus (R. tiomanicus) in an oil palm plantation near Bekok and all the four bromadiolone bait treatments gave good control and recorded no fresh damage in post-baiting assessments. In terms of total bait applied per hectare basis, the best treatment was bromadiolone bait (0.005%, 14.5 g, one bait per palm) at 5.95 kg requiring eight baiting rounds followed by bromadiolone bait (0.005%, 21g, one bait per palm) at 7.71 kg requiring eight baiting rounds per campaign. Baiting with bromadiolone bait (0.005%, 14.5 g, one bait per palm) and 50 per cent application density is recommended for the control of R. r. diardii and R. tiomanicus, especially if the rat population is in high number in oil palm plantations. In plantations facing labour shortage, baiting with bromadiolone bait (0.005%, 14.5 g, five baits per palm) at 50 per cent application density is recommended as the stopgap measure. Once control is achieved, it is recommended to reverse back to standard baiting of one bait per palm in normal routine six-monthly programmes. Keywords: Rats, oil palm plantations, baiting, warfarin, bromadiolone.
Antibacterial Assessment of Biofabricated Magnesium Oxide Nanoparticles (MgO NPs) using Conocarpus erectus Leaf Extract
Authors: Rehman Khalil ur , Shahid Ullah Khan  , Umber Zaman  , Sumbul Saeed  , Masooma Rafique  , Muneeb Ullah
Published: August 2022

Nanobiotechnology is a proficient technology that concers with nano scale materials in several scientific fields such as nanotechnology, chemistry, medicines and biotechnology. A swift and  sustainable synthesis of metal oxide nanoparticles by exhausting natural sources is the present-day trend being used instead of lethal biochemical methods. This study prsent the first report for the use of medicinal plant of Conocarpus erectus as an ecofriendly regent in the synthesis of CuO NPs using copper sulphate as a starting material. Conocarpus erectus leaf extract was used as a bioreductor as wll as a capping agent in the manufacturing of MgO NPs. The structure and morphology of prepared MgO NPs were characterized byXRD, UV, FTIR, HRTEM, SEM and EDX  analysis. The UV-Vis measurment confimrd the formation of MgO NPs by giving SPR peak at 261 nm. The attendance of various functional groups in Conocarpus erectus leaf extract liable for the  development and stabilization of MgO NPs were confirmed by FTIR analysis. XRD measurement confirmed the crystaline f.c.c structure of MgO NPs. HRTEM and SEM studies exhibited the small size, spherical shape and uniformly dispersed magnesium oxide nanoparticles. EDX profile further authorized the elemental composition of the synthesized nanoparticles. The biosynthesized MgO NPs were assessed for the embarrassment of bacteria. Furthermore, plant capped MgO NPs have high inhibition efficiency against S. aureus and E. coli with inhibition zones of 17 mm and 16 mm respectively.
Nonviolent Protesters and Provocations to Violence
Authors: Kaplan Shawn ,   Washington University Review of Philosophy
Published: August 2022

In this paper, I examine the ethics of nonviolent protest when a violent response is either foreseen or intended. One central concern is whether protesters, who foresee a violent response but persist, are provoking the violence and whether they are culpable for any eventual harms. A second concern is whether it is permissible to publicize the violent response for political advantage. I begin by distinguishing between two senses of the term provoke: a normative sense where a provocateur knowingly imposes an unjustified risk of a violent response, and a descriptive sense where the respondent feels provoked. I argue that, when the risk of a violent response is justified, the protesters are not provocateurs but akin to nonculpable, entrapping agents who create an opportunity for the regime to respond with disproportionate violence. The regime’s response can disclose its brutality or criminality, and this can be fairly publicized for political advantage. When nonviolent protesters create an unjustified risk of violence either because the injustice they oppose is insufficient to justify the risk of a violent response or because the risked harms are disproportionate with the likely political advantages derived from the protest, they are partially culpable provocateurs. However, I argue these partially culpable provocateurs can still permissibly publicize the disproportionate violence of the regime so as to shape public opinion.
Vigilantism and Political Vision
Authors: Siegel Susanna ,   Washington University Review of Philosophy
Published: August 2022

Vigilantism, commonly glossed as “taking the law into one’s own hands,” has been analyzed differently in studies of comparative politics, ethnography, history, and legal theory, but has attracted little attention from philosophers. What can “taking the law into one’s hands” amount to? How does vigilantism relate to mobs, protests, and self-defense? I distinguish between several categories of vigilantism, identify the questions they are most useful for addressing, and offer an analysis on which vigilantism is a kind of political initiative done for the sake of enacting an immediate realignment of power in a polity in accordance with a political vision. In addition to defining a special kind of political initiative, my analysis helps us understand a range of rhetorical powers related to vigilantism, including some of the ways that attributions of vigilantism can mask instances of self-defense, and attributions of self-defense can mask instances of vigilantism.
Société Mutuelle d'Autopsie, American Anthropometric Society, and the Wilder Brain Collection
Authors: Wright James R.
Published: August 2022

Context.—

In the late 19th century, mutual autopsy societies formed, first in Paris, France (1876) and later in Philadelphia, Pennsylvania. Members, who were often a who's who of anthropologists, physicians, intellectuals, and highly accomplished citizens, pledged to submit their bodies for autopsies to be performed by living society members so that their brains could be weighed and surface topography studied, with the results to be correlated with the decedents' intelligence and personal strengths during life.

Objective.—

To explore the short history of these societies, the science they produced, and their extensive newspaper coverage in the United States.

Design.—

Available primary and secondary historic sources were reviewed.

Results.—

The Société Mutuelle d'Autopsie in Paris and the American Anthropometric Society in Philadelphia had different motives, as the former was heavily influenced by French Third Republic politics and secularism. The American press provided titillating coverage of both and was particularly fascinated by scandals. In America, Burt Wilder formed a splinter group and established the Wilder Brain Collection at Cornell University. In a period where many anthropologists were making untrue claims that brain and skull measurements were largely determined by race and sex, Wilder and Franklin P. Mall of the Wistar Institute in Philadelphia independently published carefully conducted studies proving this was not the case.

Conclusions.—

Mutual autopsy societies and brain clubs conclusively established that brain weight was not an accurate predictor of intelligence but accomplished little else; they were phased out shortly after World War I but are the predecessor to modern-day brain banks.
Pediatric Perioperative Clinical Pharmacy Practice: Clinical Considerations and Management: An Opinion of the Pediatrics and Perioperative Care Practice and Research Networks of the American College of Clinical Pharmacy
Authors: Beckman Elizabeth J. , Hovey Sara , Bondi Deborah S. , Patel Gourang , Parrish Richard H.
Published: August 2022

Pediatric perioperative clinical pharmacists are uniquely positioned to provide therapeutic and medication management expertise at a particularly vulnerable transition of care from the preoperative space, through surgery, and postoperative setting. There are many direct-patient care activities that are included in the role of the pediatric perioperative pharmacist, as well as many opportunities to develop effective, optimized, and safe medication use processes. This article outlines many of the areas in which a pediatric perioperative clinical pharmacist may intervene.
Epidemiology and Outcomes of Bacterial Coinfection in Hospitalized Children With Respiratory Viral Infections: A Single Center Retrospective Chart Review
Authors: Patel Nikita , AL-Sayyed Ban , Gladfelter Taylor , Tripathi Sandeep
Published: August 2022

OBJECTIVE

Children with viral respiratory illness are often suspected of having bacterial coinfection. This study was designed to determine the impact of bacterial coinfection on hospital course and outcomes and the rate of antimicrobial misuse.

METHODS

Single-center retrospective chart review, including all hospitalized children who had a respiratory viral panel sent within 48 hours of admission from January 2015 to December 2019. Patients who had a positive respiratory, urine, blood culture within 24 hours of admission were identified. Demographics, resource utilization, and outcomes were compared between the 2 groups.

RESULTS

This study included 2192 patients. Of those, 269 patients had positive bacterial cultures. Out of these cultures from 192 patients were identified as contaminants. True bacterial coinfection was 3.5% (77/2192). Almost 1/3 of admitted patients were prescribed empiric antimicrobials. Children with bacterial coinfection tended to be younger (median age 8.4 months vs 16.3 months, p < 0.01) and had higher proportion of prematurity (23.3% vs 12.1%, p < 0.01). Children with bacterial coinfection were more likely to require ICU admission (37.6% vs 23.9%, p < 0.01) and intubation (28.5% vs 5.3 %, p < 0.01). They had higher ICU (5.7 days vs 1.9 days, p < 0.01) and hospital length of stay (4.0 days vs 2.0 days, p < 0.01), higher mortality (2.6% vs 0.2%, p = 0.02), and a higher median cost of hospital care ($3774.44 vs $2424.49.90, p < 0.01).

CONCLUSIONS

The rate of bacterial coinfection in hospitalized children with viral infections is very low, which contradicts the routine administration of empiric antimicrobials. Patients with coinfection require more hospital resources and have worse clinical outcomes.
Effect of Phenobarbital on Elevated Direct Bilirubin Concentrations in Neonates and Infants in the Neonatal Intensive Care Unit
Authors: Shin Young J. , Godin Robert , Walters Ryan A. , Niu Jianli , Kahn Doron J.
Published: August 2022

OBJECTIVE

Few studies have evaluated the effect of phenobarbital (PB) on elevated direct bilirubin (DB) plasma concentrations in neonates and infants, and none have compared its effect with a control group with matched study baseline DB values. The purpose of this study was to quantify changes in elevated DB plasma concentrations (≥2 mg/dL) in neonates and infants between a PB-treated and control group.

METHODS

A retrospective, observational, matched, cohort study was performed comparing patients between a PB-treated group and a control group with similar study baseline plasma DB values ≥2 mg/dL over an 8-week period. The percent change in DB plasma concentrations from study baseline was compared for each week of the study period.

RESULTS

During the 8-year study period, 310 patients had DB plasma concentrations ≥2 mg/dL, of which 26 remained in each group after exclusions. The PB group had increased DB concentrations and the control group had decreased DB concentrations when compared with their study baseline DB concentrations each week of the study period. By study end, the mean DB concentration increased by 11.2% in the PB group and decreased by 48.5% in the control group (p = 0.02). In multiple regression analysis, only birth weight (standardized coefficient = 0.44, p = 0.02), and gastrointestinal obstruction (standardized coefficient = −0.4, p = 0.03) were associated with significant percent change in DB concentrations.

CONCLUSIONS

This study demonstrated PB does not improve cholestasis in neonates and infants.
Variability in Serum Concentrations and Clinical Response in Artisanal Versus Pharmaceutical Cannabidiol Treatment of Pediatric Pharmacoresistant Epilepsy
Authors: Cohen Nathan T. , Bahar Burak , Conry Joan A. , Schreiber John M.
Published: August 2022

OBJECTIVE

We hypothesized that serum cannabidiol (CBD) concentrations would be higher in patients taking pharmaceutical- versus artisanal-CBD oil, and higher serum CBD concentrations would correlate with increased side effects and decreased seizure frequency.

METHODS

This was a retrospective chart review. We included patients with pharmacoresistant epilepsy, treated with artisanal-CBD or pharmaceutical-CBD (Epidiolex), and with quantitative serum CBD concentrations. We tracked epilepsy diagnosis, artisanal-CBD dosage, pharmaceutical-CBD dose, serum CBD concentration, clobazam concentration, N-desmethylclobazam concentration, seizure history (frequency of motor seizures), response to medication (percentage reduction in motor seizures), and side effects.

RESULTS

Forty-two patients met inclusion criteria. Mean serum CBD concentration was 51.1 ng/mL (artisanal group) and 124 ng/mL (pharmaceutical group) (p = 0.022). Patients receiving artisanal-CBD had no change in median overall seizures (IQR, −50% to 50%); the pharmaceutical-CBD group had median 50% reduction (IQR, −90% to no change) (p = 0.199).

CONCLUSIONS

Pharmaceutical-CBD achieves higher serum CBD concentrations than artisanal-CBD in pediatric patients with refractory epilepsy. These higher CBD concentrations are associated with increased reported adverse effects, but no detectable difference in seizure frequency.
Increasing Alprostadil Requirements in a Neonate With Cardiac Anomalies and Co-administration of Rectal and Oral Acetaminophen
Authors: Ryder Jennifer M. , Bae Esther
Published: August 2022

A patent ductus arteriosus (PDA) results from the failure of the ductus arteriosus to close within 72 hours after birth. In most neonates, a PDA can lead to significant morbidities and often warrants pharmacologic intervention for closure. Common pharmacologic interventions include indomethacin, ibuprofen, and acetaminophen. In cases of ductal-dependent congenital heart defects (CHDs), such as hypoplastic left heart syndrome, it is imperative to keep the ductus arteriosus patent to maintain adequate pulmonary or systemic circulation until surgical intervention can be performed. The only proven pharmacologic agent used for this indication is prostaglandin E1 (PGE1) commonly in the form of intravenous alprostadil. This case report describes a neonate with multiple cardiac and genetic anomalies that required increased alprostadil infusion after exposure to rectal and oral acetaminophen. The patient initially presented with a large PDA on echocardiogram (ECHO); however, after an incidental finding of a small PDA on ECHO, the administration of as needed rectal acetaminophen was discontinued out of concern for its effects on patency. After a few days of increased prostaglandin therapy and 2 reassuring ECHO results, the patient was given oral acetaminophen on an as needed basis. Within 24 hours of restarting the acetaminophen, the repeated ECHO showed a reduction in PDA and flow. In patients with ductal-dependent cardiac lesions, it is important to maintain PDA patency and, therefore, introducing a medication with antiprostaglandin properties should be avoided.
First-principles study of structure prediction and electronic properties of two-dimensional SiP2 allotropes
Authors: Zhou Jia-Jian , Zhang Yu-Wen , He Chao-Yu , Ouyang Tao , Li Jin , Tang Chao ,   School of Physics and Optoelectronics, Xiangtan University, Xiangtan 411105, China,   Hunan Key Laboratory for Micro-Nano Energy Materials and Device, Xiangtan University, Xiangtan 411105, China
Published: August 2022

Since the successful preparation of single-layer graphene in 2004, the two-dimensional (2D) materials have received widespread attention. Driven by this research upsurge, many kinds of 2D compound materials with different properties have been discovered one after another, and some of these 2D materials have a variety of allotropes, showing more abundant properties. Our computational studies focus on searching for new stable 2D SiP2 allotropes, and studying their binding energy, phonon dispersions, electronic band structures, strain-dependent bandgap modulation behaviors, piezoelectric properties, etc. In this paper, three novel 2D SiP2 allotrope structures, i.e. α-SiP2, β-SiP2, and γ-SiP2, are found by the random prediction method of crystal structure based on group theory and graph theory (RG2). Their stabilities and electronic properties are investigated by using the first-principles method based on the density functional theory. The results show that the three novel SiP2 structures are stable thermodynamically, dynamically and mechanically. Using the GW calculations, three novel SiP2 structures possess indirect band gaps of 2.62, 2.99 and 3.00 eV, respectively. Their band gaps are feasible to modulate effectively by applying strain. The band gaps of the three novel SiP2 isomers are reduced significantly when subjected to a large strainused, and the three novel SiP2 isomers exhibit indirect-to-direct bandgap transitions when experienced by a certain strain along the x-axis direction. These properties make them potential materials that are suitable for serving as nanoscale photocatalysts. Moreover, three SiP2 isomers have non-centrosymmetric crystal structures, which enable them to exhibit their piezoelectricities. Therefore, we study their piezoelectric properties by combining the Berry phase theory. Our studies show that three novel 2D SiP2 allotropes have good piezoelectric properties. The piezoelectric coefficient of the α-SiP2 isomer and the β-SiP2 isomer are both larger than that of h-BN, and they are comparable to the counterpart of MoS2. These novel structures promise to be used to fabricate nano-electromechanical devices for micro- and nano-scaled electromechanical conversion and electromechanical sensing and controlling.
Tunneling delay time in strong field ionization of atomic Ar
Authors: Zhao Meng , Quan Wei , Xiao Zhi-Lei , Xu Song-Po , Wang Zhi-Qiang , Wang Ming-Hui , Cheng Si-Jin , Wu Wen-Zhuo , Wang Yan-Lan , Lai Xuan-Yang , Liu Xiao-Jun ,   State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan 430071, China,   School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China,   Department of Physics, Hubei University, Wuhan 430062, China
Published: August 2022

“Attoclock” provides a promising experimental scheme to explore the timing of tunnel ionization of atoms and molecules in intense laser fields. In this work, we perform a systematical investigation of tunneling delay time in strong field ionization of atomic Ar, based on the “attoclock” experimental scheme. Experimentally, the laser intensity dependence of the photoelectron momentum distributions of Ar subject to strong elliptically polarized laser fields at 800 nm has been measured. Theoretically, a dedicated semiclassical model, in which the Coulomb potential effect, the nonadiabatic effect, the Stark effect, the multielectron screening and polarization effect have been well considered, is employed to simulate the ionization dynamics of Ar. By comparing the experimental and simulated results, an upper limit of 10 attoseconds for the tunneling delay time of Ar has been derived for the laser intensity ranges explored in this work. In addition, the influence of various physical effects on the extracted tunneling delay time, in the context of semiclassical model, has been analyzed. It is demonstrated that, under otherwise identical conditions, consideration of multielectron screening effect will give rise to the least change of the extracted tunneling delay time. In contrast, consideration of nonadiabatic effect will lead to the most significant change of the extracted tunneling delay time.
General Internet service assessment by latency including partial measurements
Authors: Komosny Dan
Published: August 2022

Latency is one of the key parameters of Internet services. However, it is difficult to correctly assess a service by its latency. Many latency measurements are blocked en route by routers and firewalls. For this reason, the service latency is not fully known. This work proposes a method to assess Internet services including the blocked latency measurements. Survival theory is applied to process latency values. The results show that the omission of blocked latencies from statistical processing severely underestimates the service latency. Two Internet service providers were compared as an example. Their latency difference was 9 ms using the traditional approach. The survival latency resulted in a difference of 17 ms. The method of survival latency can be used to increase revenues in e-commerce and to improve the experience of online gaming.
Model for Enhancing Performance of Network Intrusion Detection based on Hybrid Feature Selection and Unsupervised Learning Techniques
Authors: Chahira Joseph Mbugua , Kiruki Jane Kinanu
Published: August 2022

As security threats change and advance in a drastic way, relevant of the organizations implement multiple Network Intrusion Detection Systems (NIDSs) to optimize detection and to provide comprehensive view of intrusion activities. But NIDSs trigger a massive amount of alerts even for a day and overwhelmed security experts as they require high levels of human involvement in creating the system and/or maintaining it. The main goal in this work is to enhances the structural based alert correlation model to improve the quality of alerts and detection capability of NIDS by grouping alerts with common attributes based on unsupervised learning techniques. This work compares four unsupervised learning algorithms namely Self-organizing maps (SOM), K-means, Expectation and Maximization (EM) and Fuzzy C-means (FCM) to select the best cluster algorithm based on Clustering Accuracy Rate (CAR), Clustering Error (CE) and processing time. The result inferred that the proposed model based on hybrid feature selection, PCA and EM is effective in terms of Clustering Accuracy Rate (CAR) and processing time for The NSL-KDD Dataset
Instructional Leadership Practices and Students’ Academic Performance in Morogoro Municipality, Tanzania
Authors: Mtei Flora
Published: August 2022

The purpose of this study was to examine instructional leadership practices of heads of schools which enhance students’ academic performance. This study used a case study research design whereby a sample size of 90 respondents that include 80 ordinary teachers, 7 heads of schools, 1 WEO, 1 MSEO, and 1 SQAO from zone office were selected. Data were collected through questionnaires, interviews and documentary reviews. Quantitative data was analyzed by using SPSS version 25 to establish frequencies and percentages then presented by frequency tables. The qualitative data were analyzed thematically to add explanatory information to the quantitative findings. Findings of the study revealed that majority of heads of schools often develop school goals which promote high standards and expectations for all students, provide data on school progress to school community, plan and budget teaching and learning resources basing on school priority and students’ needs, set meetings for staffs’ discussions on their professional learning and practices. The study recommended that, heads of schools as instructional leaders should effectively and collaboratively define and communicate school goals, monitoring teaching and learning process, ensure adequate teaching and learning resources along with promoting teachers professional growth in order to enhance academic performance of their students.
Evaluating the Media Platforms, Devices and Challenges Associated with Online Teaching and Learning of Mathematics during the COVID-19 Pandemic
Authors: Salifu Anas Seidu , Owusu-Boateng Obeng
Published: August 2022

The study investigates the usage of online educational media platforms and devices used to access online Mathematics learning. It also identifies the challenges Mathematics pre-service teachers encountered in teaching and learning of Mathematics during the COVID-19 pandemic in the Northern Region of Ghana. The research design was descriptive cross-sectional survey with a sample of 345 Mathematics pre-service teachers selected from four (4) Colleges of Education in the Northern Region via simple random and purposive sampling techniques. Close ended questionnaire was developed by the researchers via Google forms and used as the main research instrument. Data were collected via a link sent through WhatsApp and Telegram to the pre–service teachers. The results revealed that Zoom, Telegram, WhatsApp, and Google Classrooms were the mostly used online learning platforms. Again, the devices used were desktop computers, laptops, tablets, iPads, with smartphones being the most commonly device used. The results further indicated that most challenges were; high cost of internet data subscription, lack of smart device due to its high cost, poor internet services in remote areas, pre-service teachers not seeing their lecturers face-to-face for more active interaction and real time feedback, inadequate electricity supplies to keep device always charged before online lectures and the issue of eye straining. It was recommended that   Government should assist tertiary institutions with internet facilities to improve access to online learning and teaching of Mathematics.
Self-reported Sleep Quality and Associated Factors among Undergraduate Students in a Nigerian Tertiary Institution
Authors: S. Oyewole Oyewumi , A. Adewale Adedotun , O. Oyetola Elijah
Published: August 2022

Background:  The quality and quantity of sleep is strongly related to physiological and physical health and other measures of wellbeing. Undergraduates are particularly susceptible to increasing academic and social demands that can cause sleep quality.

Aim: This study aims to determine the prevalence and distribution of self-reported sleep quality among undergraduates and the association between certain academic and non-academic related factors and quality of sleep.

Material and Method: A cross-sectional study among three hundred and twenty-seven undergraduates of the College of Health Sciences, faculty of law and faculty of art of Obafemi Awolowo University Ile-Ife who registered for the 2018/2019 academic session. A self-administered questionnaire was used to obtain sociodemographic and academic information (including the number of courses per semester, Cumulative grade point average (CGPA) and carried over course(s)). Pittsburgh Sleep Quality Index (PSQI) was used to assess sleep quality.

Results: The mean age of participants was 22 years. The prevalence of self- reported sleep quality among the participants was 35.8%. Female students (66.3%) had better sleep quality when compared with their male counterparts (61.7%). Bivariate analysis shows a statistically significant association between the course of study and the quality of sleep (p=0.003). Total average sleep hour per day (p=0.002) and known environmental factors affecting bedtime or sleep pattern (p=0.01) also showed statistically significant association with sleep quality.

Conclusion: There was a high prevalence of self-reported impaired sleep quality among the undergraduate population in which this study was conducted. The course being studied, total average sleep hours in a day and environmental factors were associated with the quality of sleep.
Patterns of Practice and Improvements in Survival Among Patients With Stage 2/3 Rectal Cancer Treated With Trimodality Therapy
Authors: Kennecke Hagen F. , Bahnson Henry T. , Lin Bruce , O’Rourke Colin , Kaplan Jennifer , Pham Huong , Suen Andrew , Simianu Vlad V.
Published: August 2022

Importance

This study quantifies the trends in trimodality therapy use and its association with pathologic stage and overall survival of patients with rectal cancer at the population level.

Objective

To describe changes between 2006 and 2016 in the sequence and use of chemotherapy/radiation therapy (C/RT), multiagent (MA) chemotherapy, and total neoadjuvant therapy (TNT) for patients with stage 2/3 rectal cancer and identify associations with pathologic stage and survival over time.

Design, Setting, and Participants

This retrospective cohort analysis included patient records from the National Cancer Database between 2006 and 2016. Of 110 372 patient records, 77 905 were excluded owing to not receiving trimodality therapy and other predefined exclusion criteria. The final analytic cohort comprised 32 467 patients records treated with trimodality therapy, with 24 297 considered in the survival analysis. Data analysis was performed between June 2020 and December 2021.

Exposures

Trimodality therapy was defined as including all of the following: definitive surgery; radiation therapy (RT), alone or in combination with chemotherapy; and neoadjuvant/adjuvant single-agent (SA) or multiagent (MA) chemotherapy independent of RT.

Main Outcomes and Measures

Using Cox multivariable survival analyses across demographics, surgery type, stage, year of diagnosis, and facility type, treatment groups were allocated as the following: group A: TNT (n = 8883 [27%]); group B: preoperative C/RT plus postoperative SA chemotherapy (n = 5967 [18%]); group C: preoperative C/RT plus postoperative MA chemotherapy (n = 12 926 [40%]); and group D: postoperative C/RT plus MA chemotherapy (n = 4689 [14%]).

Results

The final analytic cohort comprised 32 467 patients (mean [SD] age at diagnosis, 57.6 [11.6] years; 12 549 [38.7%] women and 19 918 [61.3%] men). Comparing 2016 with 2006, treatment shifted to fewer patients receiving postoperative C/RT (group D) (28% vs 8%; P < .001), and more preoperative C/RT and postoperative MA chemotherapy (group C) (24% vs 45%; P < .001) being used. While clinical stage 2 and 3 distribution remained unchanged, pathologic downstaging was observed to stages 0, 1, 2, and 3: 0.60%, 10%, 31%, and 57% vs 2.8%, 22%, 29%, and 45%, from 2006 to 2015, respectively (P < .001). More recent year of diagnosis was associated with an adjusted hazard ratio of 0.77 (95% CI, 0.67-0.87) for mortality within 36 months after diagnosis (2015 vs 2006).

Conclusions and Relevance

In this cohort study, the shift toward preoperative C/RT and lower pathologic stage was associated with improved overall survival in stage 2/3 rectal cancers.
Interface Characteristics and Dynamic Compression Behaviors of Al35Ti15Cr20Mn20Cu10 High‐Entroy Alloy/6061Al Composites Fabricated by Spark Plasma Sintering
Authors: Jin Xiaoqiang , Zhu Dezhi , Liu Shiwen , Li Xiaoqiang , Yang Chao
Published: August 2022

Lightweight high‐entropy alloys (LWHEAs) become the research hotspot and are ideal reinforcement materials for aluminum matrix composites (AMCs). The 0, 5, and 10 vol% lightweight Al35Ti15Cr20Mn20Cu10 HEA/6061Al (HEA/Al) composites are fabricated by spark plasma sintering (SPS). The HEA–Al interfacial characteristics, dynamic compression behaviors, and failure mechanism of the composites are studied. Results show that Al35Ti15Cr20Mn20Cu10 LWHEA possesses body‐centered cubic (BCC) and face‐centered cubic (FCC) dual‐phase structures. The interfacial diffusion layer of HEA/Al is characterized as α‐Al (FCC phase) dissolved by Cr, Mn, and Si atoms, with a thickness of about 0.6 1. During dynamic compression, the introduction of Al35Ti15Cr20Mn20Cu10 LWHEA particles significantly improves the strain‐rate sensitivity of 6061Al alloy. Among them, the strain‐rate sensitivity coefficient of 10 vol% HEA/Al composites is 0.02, about four times that of the aluminum alloy matrix. Different from the micro‐failure controlled by interfacial‐debonding for AMCs reinforced by ceramic particles, the failures of HEA/Al composites are dominated by the breakage of LWHEA particles and micro‐cracks formed in the matrix, while interfacial‐debonding is rarely observed in the diffusion layers. It is concluded that a strong‐binding HEA–Al interface can effectively restrain the rapid propagation of cracks in the composites suffered by impact load.
Integrated Ideal‐Bandgap Perovskite/Bulk‐Heterojunction Solar Cells with Efficiencies > 24%
Authors: Zhou Xianyong , Zhang Luozheng , Yu Jianwei , Wang Dong , Liu Chang , Chen Shi , Li Yaru , Li Yan , Zhang Meiqing , Peng Yuanjun , Tian Yanqing , Huang Jinsong , Wang Xingzhu , Guo Xugang , Xu Baomin
Published: August 2022

Here, the authors report a highly efficient integrated ideal‐bandgap perovskite/bulk‐heterojunction solar cell (IPBSC) with an inverted architecture, featuring a near infrared (NIR) polymer DTBTI‐based bulk‐heterojunction (BHJ) layer atop guanidinium bromide (GABr)‐modified FA0.7MA0.3Pb0.7Sn0.3I3 perovskite film as the photoactive layer. The IPBSC shows cascade‐like energy level alignment between the charge‐extractionlayer/perovskite/BHJ and efficient passivation effect of BHJ on perovskite. Thanks to the well‐matched energy level alignment and high‐quality ideal bandgap‐based perovskite film, an efficient charge transfer occurs between the charge‐extraction‐layer/perovskite/BHJ. Moreover, the NIR polymer DTBTI on the perovskite film leads to an improved NIR light response for the IPBSC. In addition, the O, S and N atoms in the DTBTI polymer yield a strong interaction with perovskite, which is conducive to reducing the defects of the perovskite and suppressing charge recombination. As a result, the solar cell achieves a power conversion efficiency (PCE) of 24.27% (certificated value at 23.4% with 0.283‐volt voltage loss), currently the recorded efficiency for both IPBSCs and Pb‐Sn alloyed PSCs, and which is over the highest efficiency of perovskite–organic tandem solar cell. Moreover, the thermal, humidity and long‐term operational stabilities of the IPBSCs are also significantly improved compared with the control PSCs.
Priority and Prospect of Sulfide‐Based Solid‐Electrolyte Membrane
Authors: Liu Hong , Liang Yuhao , Wang Chao , Li Dabing , Yan Xiaoqin , Nan Ce‐Wen , Fan Li‐Zhen
Published: August 2022

All‐solid‐state lithium batteries (ASSLBs) employing sulfide solid electrolytes (SEs) promise sustainable energy storage systems with energy‐dense integration and critical intrinsic safety, yet they still require cost‐effective manufacturing and the integration of thin membrane‐based SE separators into large‐format cells to achieve scalable deployment. This review, based on an overview of sulfide SE materials, is expounded on why implementing a thin membrane‐based separator is the priority for mass production of ASSLBs and critical criteria for capturing a high‐quality thin sulfide SE membrane are identified. Moreover, from the aspects of material availability, membrane processing, and cell integration, the major challenges and associated strategies are described to meet these criteria throughout the whole manufacturing chain to provide a realistic assessment of the current status of sulfide SE membranes. Finally, future directions and prospects for scalable and manufacturable sulfide SE membranes for ASSLBs are presented.
Mechanically‐Reconfigurable Edge States in an Ultrathin Valley‐Hall Topological Metamaterial
Authors: Liu Yahong , Ren Huiling , Tao Liyun , Du Lianlian , Zhou Xin , Li Meize , Song Kun , Ji Ruonan , Zhao Xiaopeng , Navarro‐Cía Miguel
Published: August 2022

Broadband topological metamaterials hold the key for designing the next generation of integrated photonic platforms and microwave devices given their protected back‐scattering‐free and unidirectional edge states, among other exotic properties. However, synthesizing such metamaterial has proven challenging. Here, a broadband bandgap (relative bandwidth of more than 43%) Valley‐Hall topological metamaterial with deep subwavelength thickness is proposed. The present topological metamaterial is composed of three layers printed circuit boards whose total thickness is 1.524 mm ≈ λ/100. The topological phase transition is achieved by introducing an asymmetry parameter δr. Three mechanically reconfigurable edge states can be obtained by varying interlayer displacement. Their robust transmission is demonstrated through two kinds of waveguide domain walls with cavities and disorders. Exploiting the proposed topological metamaterial, a six‐way power divider is constructed and measured as a proof‐of‐concept of the potential of the proposed technology for future electromagnetic devices.
Liquid Crystalline Polymer Coatings Fabricated by Initiated Chemical Vapor Deposition
Authors: Kim Myounguk , Park Jieun , Nonnenmann Stephen S. , Bradley Laura C.
Published: August 2022

Liquid crystalline polymer (LCP) coatings offer avenues for the fabrication of devices with smart surfaces incorporating responsive topography, reflectivity, or polarization from their unique anisotropic optical and mechanical properties. LCPs have most commonly been made by photopolymerization of reactive mesogens within confined cells. Here, an alternative method of preparing LCP coatings using initiated chemical vapor deposition (iCVD) is described. LCP‐iCVD copolymer coatings comprised of an acrylic cyanobiphenyl mesogenic monomer copolymerized with vinyl ether crosslinkers are prepared. Systematic experiments examine the relationship between the monomer properties, reactor conditions, and polymer deposition rate. The alignment of the mesogenic phase in the as‐synthesized coatings is also demonstrated to be controlled by the surface energy of the underlying substrate. Interestingly, the surface properties of LCP coatings measured by atomic force microscopy are shown to depend on the director orientation. The data presented in this work introduce mesogenic monomers into the library of vapor‐deposited polymer coatings.