bluuebunny/crossref_metadata_2025 huggingface dataset:
The risk of bleeding for antiplatelet agents in Haemodialysis patients: a Meta-analysis
Authors: Wang Qi , Xie Xiaojie , Xu Gaosi
Published: March 2020

Background

The safety of antiplatelet therapy in haemodialysis (HD) patients remains controversial. we conducted the first meta-analysis to evaluate the bleeding risk with antiplatelet agents in these populations.

Methods

The relevant literature was searched using the following electronic databases without any language restrictions: the Cochrane Library, EMBASE, Global Health, MEDLINE, PubMed, and the Chinese Biomedical Database.

Results

Seven randomized controlled trials (RCTs) and 2 prospective cohort studies, consisting of 1131 patients, were identified for detailed evaluation. The meta-analysis suggested that the use of double antiplatelet agents increased the risk of bleeding in HD patients [odds ratio (OR) = 2.78; 95% confidence interval (CI) 1.63 to 4.76; I2 = 0], and antiplatelet agents increased the risk of bleeding in 7 RCTs [odds ratio (RR) = 1.40, 95% CI 1.08 to 1.79; I2 = 23%,]; however, the use of a single antiplatelet agent was not found to significantly increase the risk of bleeding (RR = 0.88; 95% CI 0.51 to 1.50; I2 = 0).

Conclusion

The results suggested that the use of double antiplatelet agents increased the risk of bleeding in HD patients.
Monocyte to High-Density Lipoprotein Ratio (MHR) as a predictor of mortality and Major Adverse Cardiovascular Events (MACE) among ST Elevation Myocardial Infarction (STEMI) patients undergoing primary percutaneous coronary intervention: a meta-analysis
Authors: Villanueva Danielle Louis E. , Tiongson Marc Denver , Ramos John Daniel , Llanes Elmer Jasper
Published: March 2020

Background

Monocyte to High Density Lipoprotein Ratio (MHR) is a new marker that has been associated with major adverse cardiovascular outcomes among STEMI patients. We sought to strengthen the association between MHR and mortality and major adverse cardiovascular events (MACEs) among STEMI patients who underwent primary percutaneous coronary intervention.

Methods

Studies were included if they satisfied the following criteria:1) Observational Studies; 2) Adult patients with ST-elevation Myocardial Infarction (STEMI) who underwent primary percutaneous intervention (PCI); and 3) Reported data on mortality and major adverse cardiovascular events. Using MEDLINE, Clinical Key, Science Direct, Scopus, and Cochrane Central Register of Controlled Trials databases, a search for eligible studies was conducted until September 2017. Our primary outcome of interest was all-cause cardiovascular (CV) mortality. We also investigated the association between MHR and major adverse cardiovascular events (MACEs).

Results

We identified 3 studies involving 2793 STEMI patients, showing that in STEMI patients who underwent primary PCI, a high admission MHR is associated with a significantly higher in-hospital mortality [RR 4.71, (95% CI 2.36 to 9.39, p < 0.00001] and in-hospital MACE [RR 1.90, (95% CI 1.44 to 2.50), p < 0.00001]. This significant association was not observed in long term mortality or MACE.

Conclusion

A high admission MHR among STEMI patients who underwent primary PCI is associated with a higher in-hospital mortality and MACE. This novel marker can be used as an inexpensive and readily available tool for risk stratification.
The MK2 pathway is linked to G-CSF, cytokine production and metastasis in gastric cancer: a novel intercorrelation analysis approach
Authors: Qeadan Fares , Bansal Pranshu , Hanson Joshua A. , Beswick Ellen J.
Published: March 2020

Background

Gastric cancer is associated with chronic inflammation, but there is still much to understand about the tumor microenvironment and the underlying tumor-promoting mechanisms. The Map kinase-activated protein kinase 2 (MK2) pathway is a regulator of inflammatory cytokine production that we have been studying in gastrointestinal cancers. Here, we set out to determine the significance of this gene in gastric cancer along with its downstream mediators and if there were differences in the primary tumors with and without metastasis.

Methods

Human gastric cancer tissues with and without metastasis were examined for MK2 expression and cytokine profile in organ culture supernatants. Advanced statistical methods including a lower triangular correlation matrix, novel rooted correlation network, linear and logistic regression modeling along with Kruskal–Wallis testing with Sidak correction for multiple testing were applied to gain understanding of cytokines/chemokines linked to metastasis.

Results

The MK2 pathway is strongly linked with metastasis and a panel of cytokines. Gene expression was able to classify gastric cancer metastasis 85.7% of the time. A significant association with a panel of cytokines was found, including G-CSF, GM-CSF, Mip-1β, IFN-α, MCP-1, IL-1β, IL-6, and TNF-α. Mip-1β was found to have the strongest association with MK2 and metastasis after Sidak correction for multiple testing.

Conclusions

MK2 gene expression and a novel associated cytokine panel are linked to gastric cancer metastasis. G-CSF is the strongest cytokine to differentiate between metastasis and non-metastasis patients and had the lowest P value, while Mip-1β showed the strongest association with MK2 and metastasis after Sidak correction. MK2 and associated cytokines are potential biomarkers for gastric cancer metastasis. The novel intercorrelation analysis approach is a promising method for understanding the complex nature of cytokine/chemokine regulation and links to disease outcome.
Preoperative planning and surgical technique for optimizing internal fixation of posterior malleolar fractures: CT versus standard radiographs
Authors: Palmanovich Ezequiel , Ohana Nissim , Yaacobi Eyal , Segal David , Iftach Hetsroni , Sharfman Zachary T. , Vidra Matias , Atzmon Ran
Published: March 2020

Background

A proper reduction and internal fixation of posterior malleolar fractures can be challenging, as intraoperative fluoroscopy often underestimates the extent of the fracture. Our aim was to assess the value of a modified classification system for posterior malleolar fractures, which is based on computed tomography (CT) images, optimizing screw trajectory during fluoroscopic-guided surgery, and to compare it to the Lauge-Hansen classification system to the CT-based classification.

Methods

A retrospective review of all ankle fracture operations from January 2014 to December 2016 was performed. Fractures were included if a CT scan was performed within 1 week of the surgery, and the posterior malleolar fragment occupied one third or more of the antero-posterior talar surface or jeopardize the ankle stability. Eighty-five adult ankle fractures with posterior malleolar fragments were included in this study. Fractures were categorized into one of three types, namely “postero-lateral,” “postero-medial,” or “postero-central,” according to the location of the fracture fragment on axial CT image. An optimal trajectory angle for a single-lag screw fixation was measured on the CT cut between a central antero-posterior line and the line intersecting the posterior fragment perpendicular to the major fracture line. Mean trajectory angles were calculated for each fracture type. Fractures were also categorized according to the Lauge-Hansen system.

Results

The mean trajectory angle was 21° lateral for “postero-lateral” fragments, 7° lateral for “postero-central” fragments, and 28° medial for “postero-medial” fragments (p < 0.01 for comparisons among the groups). The range of trajectory angles within each group was about 10°, as compared to about 20° within each Lauge-Hansen type. There were no differences in trajectory angle among the Lauge-Hansen groups (p > 0.05 for all comparisons).

Conclusions

There are 3 distinct anatomic subgroups of posterior malleolar fragments, each with an ideal screw trajectory that needs to be used in order to achieve an optimal reduction and fixation.
Comparative clinical efficacy and safety of the proposed biosimilar ABP 710 with infliximab reference product in patients with rheumatoid arthritis
Authors: Genovese Mark C. , Sanchez-Burson Juan , Oh MyungShin , Balazs Eva , Neal Jeffrey , Everding Andrea , Hala Tomas , Wojciechowski Rafal , Fanjiang Gary , Cohen Stanley
Published: March 2020

Background

ABP 710 is being developed as a biosimilar to infliximab reference product (RP). Analytical similarity and pharmacokinetic equivalence between the two have been previously demonstrated. Here we report results from a comparative clinical study that evaluated the efficacy and safety of ABP 710 relative to the RP in patients with rheumatoid arthritis (RA).

Methods

In this multicenter, randomized, double-blind, 50-week equivalence study, patients with moderate to severe active RA despite methotrexate received 3-mg/kg infusions of ABP 710 or RP at predetermined intervals based on initial randomization and then with re-randomization at week 22. The primary endpoint was response difference (RD) of ACR20 at week 22, with clinical equivalence evaluated based on 90% CI of − 15%, 15%. Secondary endpoints included Disease Activity Score 28-joint count C-reactive protein (DAS28-CRP), ACR20, ACR50, and ACR70 across time, as well as safety and immunogenicity assessments.

Results

A total of 558 patients were randomized for the initial treatment (ABP 710 n = 279; RP n = 279). The estimated RD of ACR20 at week 22 was 9.37% with 90% CI (2.67%, 15.96%). The lower bound was within the pre-specified criteria, thus confirming non-inferiority; the upper bound exceeded the pre-specified criteria by 0.96% such that superiority could not be ruled out statistically. In a post hoc analysis with adjustment for random imbalance in baseline factors, the CI of RD was narrowed (0.75%, 13.62%). Changes from baseline in DAS28-CRP as well as ACR20, ACR50, and ACR70 response rates across time and hybrid ACR evaluations were similar for the initial and initial/re-randomized treatment groups. Adverse events and incidence of anti-drug antibodies were similar between treatment groups.

Conclusions

These efficacy and safety results support similarity with no clinically meaningful differences between ABP 710 and infliximab RP. Although we were unable to statistically confirm non-superiority, post hoc analysis was supportive of non-superiority. DAS28-CRP, ACR20, ACR50, ACR70, and hybrid ACR evaluations over the entire study were consistently comparable as were safety and immunogenicity.

Trial registration

ClinicalTrials.gov. Identifier: NCT02937701. Registered August 30, 2016.
Neuromuscular shoulder activity during exercises with different combinations of stable and unstable weight mass
Authors: Baritello Omar , Khajooei Mina , Engel Tilman , Kopinski Stephan , Quarmby Andrew , Mueller Steffen , Mayer Frank
Published: March 2020

Background

Recent shoulder injury prevention programs have utilized resistance exercises combined with different forms of instability, with the goal of eliciting functional adaptations and thereby reducing the risk of injury. However, it is still unknown how an unstable weight mass (UWM) affects the muscular activity of the shoulder stabilizers. Aim of the study was to assess neuromuscular activity of dynamic shoulder stabilizers under four conditions of stable and UWM during three shoulder exercises. It was hypothesized that a combined condition of weight with UWM would elicit greater activation due to the increased stabilization demand.

Methods

Sixteen participants (7 m/9 f) were included in this cross-sectional study and prepared with an EMG-setup for the: Mm. upper/lower trapezius (U.TA/L.TA), lateral deltoid (DE), latissimus dorsi (LD), serratus anterior (SA) and pectoralis major (PE). A maximal voluntary isometric contraction test (MVIC; 5 s.) was performed on an isokinetic dynamometer. Next, internal/external rotation (In/Ex), abduction/adduction (Ab/Ad) and diagonal flexion/extension (F/E) exercises (5 reps.) were performed with four custom-made-pipes representing different exercise conditions. First, the empty-pipe (P; 0.5 kg) and then, randomly ordered, water-filled-pipe (PW; 1 kg), weight-pipe (PG; 4.5 kg) and weight + water-filled-pipe (PWG; 4.5 kg), while EMG was recorded. Raw root-mean-square values (RMS) were normalized to MVIC (%MVIC). Differences between conditions for RMS%MVIC, scapular stabilizer (SR: U.TA/L.TA; U.TA/SA) and contraction (CR: concentric/eccentric) ratios were analyzed (paired t-test; p ≤ 0.05; Bonferroni adjusted α = 0.008).

Results

PWG showed significantly greater muscle activity for all exercises and all muscles except for PE compared to P and PW. Condition PG elicited muscular activity comparable to PWG (p > 0.008) with significantly lower activation of L.TA and SA in the In/Ex rotation. The SR ratio was significantly higher in PWG compared to P and PW. No significant differences were found for the CR ratio in all exercises and for all muscles.

Conclusion

Higher weight generated greater muscle activation whereas an UWM raised the neuromuscular activity, increasing the stabilization demands. Especially in the In/Ex rotation, an UWM increased the RMS%MVIC and SR ratio. This might improve training effects in shoulder prevention and rehabilitation programs.
The colonial cnidarian Hydractinia
Authors: Frank Uri , Nicotra Matthew L. , Schnitzler Christine E.
Published: March 2020

Hydractinia, a genus of colonial marine cnidarians, has been used as a model organism for developmental biology and comparative immunology for over a century. It was this animal where stem cells and germ cells were first studied. However, protocols for efficient genetic engineering have only recently been established by a small but interactive community of researchers. The animal grows well in the lab, spawns daily, and its relatively short life cycle allows genetic studies. The availability of genomic tools and resources opens further opportunities for research using this animal. Its accessibility to experimental manipulation, growth- and cellular-plasticity, regenerative ability, and resistance to aging and cancer place Hydractinia as an emerging model for research in many biological and environmental disciplines.
Identifying profiles of students’ school climate perceptions using PISA 2015 data
Authors: Rohatgi Anubha , Scherer Ronny
Published: March 2020

The concept of school climate has received much attention as a predictor of educational outcomes, including students’ well-being, academic achievement, and motivation. To measure this concept, international large-scale assessments often rely on students’ perceptions of its different dimensions, such as their sense of belonging, teacher support, and disciplinary climate. However, students may perceive these dimensions differently and, ultimately, create inter-individual variation—a variation that has been explained only to a limited degree in the current body of literature. The present study explores this variation for the Norwegian PISA 2015 data (N = 5313). Using the person-centered approach of latent profile analysis, we found evidence for the existence of three student profiles: (1) students with consistently positive perceptions, (2) students with moderately negative perceptions, and (3) students with extremely negative perceptions, especially concerning teachers’ fairness and bullying. These results support the hypothesis of individual differences in school climate perceptions.
Smokeless consumption of medical cannabis pharmacokinetics, safety and feasibility of the CannaHALER© a phase 1a study
Authors: Ben-Ishay Offir , Bar-On Ortal , Kluger Yoram
Published: March 2020

Background

Substantial advancements were achieved in the management of postoperative pain, however the need for further improvement remains. This study explores the pharmacokinetics and safety of the CannaHaler, a metered dose inhaler for plant material made by Kite-Systems situated in Tel-Aviv, Israel.

Methods

The study was conducted on 12 healthy adult volunteers divided into four arms (each arm/group holds 3 volunteers) with the evaporated plant material being Alaska strain provided by “Tikun Olam”. This strain is a hybrid of 70% Sativa and 30% Indika strains, consisting of 20–22% THC and 0% CBD. Each arm received a single dose and groups were divided in an ascending dose fashion: Group I-IV receiving 10, 15, 20, 25 mg of THC respectively. The volunteers inhaled a single dose of THC using the CannaHaler, device. Blood samples for Δ9 – Tetrahydrocannabinol (THC) and 9-THCCOOH were taken at base line and up to 30 min after dosing. Adverse events were monitored following the inhalation. Pharmacokinetics profile was obtained for each patient in all arms.

Results

Ascending doses of THC produced a linear increase in the maximum concentration 10, 15, 20 and 25 mg of THC. (35.43 ± 5.97, 51.47 ± 13.79, 72.37 ± 15.93, 88.63 ± 14.75 respectively) with the same linear increase in the dimension of the AUC (441.59 ± 88.49, 624 ± 123.56, 698.35 ± 174.98, 971.36 ± 310.4 respectively) both with no change in the time needed to reach such concentration. No adverse events were recorded in all of study subjects. The CannaHaler achieved high Cmax (35.43–88.63 ng/mL) values and low coefficient of variations (16.64–26.79%) in comparison to both smoking and oral preparations, thus reaching the potential of a pharmaceutical grade device for inhaled substance.

Conclusions

The current study showed that the use of Kite-Systems CannaHaler as a smokeless medical cannabis inhalation device is feasible and efficient. The low coefficient of variation together with the high Cmax values, suggest the potential use of the CannaHaler device as a pharmaceutical cannabis dosing administrator.
Palliative Care Skills and New Resources for Oncology Practices: Meeting the Palliative Care Needs of Patients With Cancer and Their Families
Authors: Back Anthony , Friedman Tara , Abrahm Janet
Published: March 2020

In its 2017 guideline, ASCO challenged members to integrate palliative care into their standard oncology practices for all patients, throughout their cancer trajectory. However, partnering with palliative care experts alone will not be enough to achieve that goal; there are too few experts now, and there will not be enough in the future to meet the needs of patients with cancer and their families. Other strategies are required. Oncologists can develop new communication skills that were not included in their fellowship curricula, skills that integrate into their visits the subjects that palliative care clinicians discuss routinely with patients referred to them. In this review, Dr. Back offers three questions matched to communication skills that can help oncologists explore key areas: (1) What is happening? (2) How do you (and I) feel? and (3) What is important? and discusses the “REMAP” strategy for making urgent medical decisions. Dr. Friedman reviews the impact of community-based palliative care resources and telehealth on care quality, patient centeredness, and reducing costs. Community-based palliative care services and telehealth are available to patients and families at home, during active treatment. Dr. Abrahm reviews how patient-reported outcomes (PROs) completed at home can enhance patients’ symptom control, quality of life, and toleration of treatment and decrease unplanned emergency visits by alerting clinicians to patients’ severe symptoms, making appropriate referrals, or suggesting patients contact their oncology team. She also provides an update on using PROs and natural language processing with clinical decision support to create sophisticated palliative care assessments and treatment options in the electronic health record during patients’ office visits.
Novel Strategies to Effectively De-escalate Curative-Intent Therapy for Patients With HPV-Associated Oropharyngeal Cancer: Current and Future Directions
Authors: Price Katharine A. R. , Nichols Anthony C. , Shen Colette J. , Rammal Almoaidbellah , Lang Pencilla , Palma David A. , Rosenberg Ari J. , Chera Bhisham S. , Agrawal Nishant
Published: March 2020

The treatment of patients with HPV-associated oropharyngeal cancer (HPV-OPC) is rapidly evolving and challenging the standard of care of definitive radiotherapy with concurrent cisplatin. There are numerous promising de-escalation strategies under investigation, including deintensified definitive chemoradiotherapy, transoral surgery followed by de-escalated adjuvant therapy, and induction chemotherapy followed by de-escalated locoregional therapy. Definitive radiotherapy alone or with cetuximab is not recommended for curative-intent treatment of patients with locally advanced HPV-OPC. The results of ongoing phase III studies are awaited to help answer key questions and address ongoing controversies to transform the treatment of patients with HPV-OPC. Strategies for de-escalation under investigation include the incorporation of immunotherapy and the use of novel biomarkers for patient selection for de-escalation.
Antibody-Drug Conjugates: Patient and Treatment Selection
Authors: Makawita Shalini , Meric-Bernstam Funda
Published: March 2020

Antibody-drug conjugates (ADCs) are a promising drug platform designed to enhance the therapeutic index and minimize the toxicity of anticancer agents. ADCs have experienced substantial progress and technological growth over the past decades; however, several challenges to patient selection and treatment remain. Methods to optimally capture all patients who may benefit from a particular ADC are still largely unknown. Although target antigen expression remains a biomarker for patient selection, the impact of intratumor heterogeneity on antigen expression, as well as the dynamic changes in expression with treatment and disease progression, are important considerations in patient selection. Better understanding of these factors, as well as minimum levels of target antigen expression required to achieve therapeutic efficacy, will enable further optimization of selection strategies. Other important considerations include understanding mechanisms of primary and acquired resistance to ADCs. Ongoing efforts in the design of its constituent parts to possess the intrinsic ability to overcome these mechanisms, including use of the “bystander effect” to enhance efficacy in heterogeneous or low target antigen-expressing tumors, as well as modulation of the chemical and immunophenotypic properties of antibodies and linker molecules to improve payload sensitivity and therapeutic efficacy, are under way. These strategies may also lead to improved safety profiles. Similarly, combination strategies using ADCs with other cytotoxic or immunomodulatory agents are also under development. Great strides have been made in ADC technology. With further refinements, this therapeutic modality has the potential to make an important clinical impact on a wider range of tumor types.
Gender Homophily in Referral Networks: Consequences for the Medicare Physician Earnings Gap
Authors: Zeltzer Dan
Published: March 2020

I assess the extent to which the gender gap in physician earnings may be driven by physicians’ preference for referring to specialists of the same gender. Analyzing administrative data on 100 million Medicare patient referrals, I provide robust evidence that doctors refer more to specialists of their own gender. I show that biased referrals are predominantly driven by physicians’ decisions rather than by endogenous sorting of physicians or patients. Because most referring doctors are male, the net impact of same-gender bias by both male and female doctors generates lower demand for female relative to male specialists, pointing to a positive externality for increased female participation in medicine. (JEL H51, I11, J16, J31, J44)
Risk factors for composite adverse outcomes of postpartum haemorrhage in a low-resource setting: a single-centre cross-sectional study in Mpilo Central Hospital, Bulawayo, Zimbabwe
Authors: Ngwenya Solwayo
Published: March 2020

Background: Primary postpartum haemorrhage continues to cause considerable global maternal morbidity and mortality. The aim of this study was to determine the risk factors for composite adverse outcomes in postpartum haemorrhage using multivariable logistic regression. The findings could potentially be used to anticipate and prevent composite adverse outcomes in postpartum haemorrhage.

Methods: This was a retrospective cross-sectional study carried out at Mpilo Central Hospital, a government tertiary referral centre, covering the period 1 July 2016 to 30 November 2019. Participants were included in the study if they had a diagnosis of postpartum haemorrhage. Those variables that had a p<0.2 from the univariate logistic regression analyses were considered for multivariable logistic regression. The association between independent variables and the dependent variable was assessed using odds ratio with 95% confidence intervals, to identify independent risk factors for composite adverse outcomes in PPH.

Results: The independent risk factors for composite adverse outcomes in postpartum haemorrhage were place of dwelling (AOR 4.57, 95% CI 1.87-11.12, p=0.01), prior history of a Caesarean section (AOR 2.57, 95% CI 1.10-6.00, p=0.03), APH (AOR 5.45, 95% CI 2.23-13.27, p<0.0001), antenatal haemoglobin level (AOR 19.64, 95% CI 1.44-268.50, p=0.03), and delivery by Caesarean section (AOR 10.21, 95% CI 4.39-23.74, p<0.0001). Blood loss was also an independent risk factor for composite adverse outcomes in postpartum haemorrhage with the following blood loss; 1001-1500 ml (AOR 9.94, 95% CI 3.68-26.88, p<0.0001), 500-1000 ml (AOR 41.27, 95% CI 11.32-150.54, p<0.0001), and 2001 ml (AOR 164.77, 95% CI 31.06-874.25, p<0.0001).

Conclusions: This study found that the independent predictors for composite adverse outcomes in PPH were rural dwelling, prior history of a Caesarean section, antenatal haemoglobin level, delivery by Caesarean section, and blood. In low- and middle-income countries, such information should help in increasing clinical vigilance and preventing maternal deaths.
Understanding the impact of a collective leadership intervention on team working and safety culture in healthcare teams: a realist evaluation protocol
Authors: De Brun Aoife , Rogers Lisa , O'Shea Marie , McAuliffe Eilish
Published: March 2020

There is accumulating evidence for the value of collective and shared approaches to leadership across sectors and settings. However, relatively little research has explored collective leadership in healthcare and thus, there is little understanding of what works for healthcare teams, why, how and to what extent. This study describes the approach that will be adopted to the realist evaluation of a collective leadership intervention with four heterogenous healthcare teams in four different settings. A realist evaluation will be conducted. Realist evaluation is a theory-based approach to evaluation. It enables the use of mixed-methods to explore the research question of interest. Development of an initial programme theory (IPT) constitutes the first phase of the approach. This IPT will be informed by interviews with members of teams identified as working collectively, an examination of extant literature using realist synthesis, and will be refined through consultation with an expert panel. A multiple case study design will be adopted to explore the impact of the intervention, including quantitative scales on teamworking, leadership and safety culture, realist interviews with key informants and observations of teams during intervention sessions. Analysis of data will be guided by the IPT to refine the theory and context-mechanism-outcome configurations. Findings from the cases will be compared to identify patterns or demi-regularities and to explore if the intervention operates differently in different contexts. This analysis and synthesis of findings across the teams will inform the development of a middle range theory that will not only add to our understanding of how collective leadership influences teamwork and patient safety, but also provide guidance for future collective leadership interventions.  Favourable ethical opinion has been received from the University College Dublin Ethics Committee. Results will be disseminated via publication in peer-review journals, national and international conferences and to stakeholders/interest groups.
Words Matter! Toward a Prosocial Call-to-Action for Online Referral: Evidence from Two Field Experiments
Authors: Jung Jaehwuen , Bapna Ravi , Golden Joseph M. , Sun Tianshu
Published: March 2020

The underlying premise of referral marketing is to target existing ostensibly delighted customers to spread awareness and influence adoption of a focal product among their friends who are also likely to benefit from adopting the product. In other words, referral programs are designed to accelerate organic word-of-mouth (WOM) exposure using financial incentives. This poses a challenge, in that it mixes an intrinsically motivated process (stemming from the desire to share a customer’s delight with a product or a service) with an extrinsic trigger in the form of a financial incentive. In this paper, we demonstrate how firms can benefit from framing calls-to-action for referral programs in such a way as to move closer to the original intent of organic, intrinsically motivated WOM marketing, and yet at the same time reap the benefits of using a financial incentive to increase referral rates. In particular, via two large-scale randomized field experiment involving 100,000 customers each, we show the efficacy of a prosocial call-to-action over some of the more commonly used calls-to-action observed in practice. Additional mechanism-level analysis confirms the importance of an altruistic element in generating a higher quality of advocacy and reducing referral frictions.
VIVIFICAÇÃO E PROBLEMATIZAÇÃO DO PRAZER NA TRADIÇÃO GREGA
Authors: Araujo Gabriela , De Araújo Hugo Filgueiras
Published: March 2020

O prazer permeia a cultura grega nas mais diversas esferas da vida cotidiana, sendo um convidado constante na sua produção, ora testemunhado em pinturas, ora em textos antigos narrando práticas cotidianas, ora em pensadores ou poetas que o exalta ou o lamenta. Sendo assim, não é estranho que ele tenha se tornado alvo de tantas questões. O presente artigo visa analisar está presença constantemente vivificada entre os gregos desde a epopeia, permeando os líricos até os trágicos, bem como a crescente problematização do prazer antes de chegar à filosofia.
DESCONSTRUINDO O CONCEITO DE BÁRBARO COM A AJUDA DE KAVÁFIS
Authors: Petrópoulos Ioánnis
Published: March 2020

A primeira parte deste artigo discute o conceito de "bárbaro" na antiga sociedade grega e em sua literatura. Como usado a partir de meados do século V a.C., o termo serve como um marcador linguístico e cultural, denotando ou implicando a barreira conceitual entre "nós" (gregos) e "eles" (o resto do mundo), portanto entre gregos e 'outros'. No entanto, em alguns casos, essa divisão pode entrar em colapso com o uso não generoso dos gregos. A segunda parte do artigo examina o poema clássico de Kavafy "À espera dos bárbaros" (1904) à luz do antigo conceito de "bárbaro". Lançando mão de uma troca dialógica de perguntas e respostas entre dois cidadãos do final do Império Romano, o poema dramatiza o diálogo mental e a relação conceitual que surge quando, como os antigos, distinguimos entre nós e o "outro bárbaro". Por que os bárbaros de Kavafy são uma "solução" e "libertação" (ambos sugeridos por λύσις)? Por que seus não-bárbaros são paradoxalmente atraídos por eles? Como já foi proposto por outros, os bárbaros de Kaváfis podem pertencer ao clima de decadência literária do final do século XIX ou à atmosfera de incerteza política e declínio no Egito colonial ou, como sugiro, no Reino da Hélade, ainda em luta contra o império Otomano. Mais amplamente definido, seus "bárbaros" podem representar o alter ego decadente de sua sociedade.
Sobre a relevância da crítica à democracia de Platão
Authors: Ribeiro Rodrigo Dantas
Published: March 2020

Neste artigo faremos uma crítica à defesa da democracia, especialmente à defesa da democracia direta, que parte da experiência grega do século V a.C. para demonstrar a eficiência e a qualidade da cidadania na antiguidade em detrimento da cidadania nos regimes representativos contemporâneos. E, também, a partir de Platão, elabo- raremos uma posição mais construtiva pela qual deveríamos avaliar o antigo regime democrático e o moderno.
Por que não Tecla? Aspectos discursivos e romanescos na representação do feminino nos Atos de Tecla
Authors: Ipiranga Junior Pedro
Published: March 2020

Os Atos de Tecla ou Atos de Paulo e Tecla têm recebido uma gama crescente de estudos na atualidade. Esse texto faria parte de uma obra maior, Acta Pauli, que teria sido acrescentada ou desmembrada em algum momento da segunda metade do séc. II d. C. É uma obra singular, cujas características mais distintivas suscitaram uma comparação, empreendida por diversos estudiosos, com exemplares do romance antigo de tema amoroso ou erótico. Além disso, como a narrativa está centrada na personagem de Tecla e veicula uma imagem da mulher pautada por certa autonomia e liderança, houve uma produção significativa de estudos sobre o discurso feminino e a agência da mulher, com abordagens teóricas distintas e posicionamentos, por vezes, conflitantes. O presente estudo tem por fim três propósitos: pôr em evidência alguns estudos que trataram da representação da mulher na Antiguidade, aludindo a alguns pontos controversos no debate; retomar a discussão sobre o gênero da obra em relação ao romance antigo; fazer uma análise circunstanciada de algumas passagens dos Atos de Tecla, levando em consideração as questões abordadas nos dois itens anteriores.
FILOSOFIA, MEDICINA E CUIDADO DO CORPO NO BANQUETE DE PLATÃO
Authors: Da Silva Felipe Gustavo Soares
Published: March 2020

O presente trabalho tem como objetivo demonstrar a presença da relação filosofia e medicina na obra O Banquete, de Platão, através da leitura do discurso do médico Erixímaco, notadamente marcado pelo conceito de amor (Ἔρως) e de harmonia                                                      (αρμονία) em relação ao corpo. A contribuição de Platão em seu Banquete é de reforçar a importância do cuidado com o corpo nas práticas de cuidado de si na antiguidade.
As origens gregas da Hermenêutica e da Alegoria
Authors: Kibuuka Brian
Published: March 2020

Este artigo aborda as origens do conceito de hermenêutica e as relações entre tal conceito e o deus Hermes. Aborda ainda a crítica à teologia homérica e hesiódica e a adoção da alegoria como estratégia interpretativa utilizada para preservar a teologia da crítica.
Apresentação da Editora Executiva
Authors: Lima Fernanda
Published: March 2020

Apresentação do volume com textos de participantes da 5a. Universidade de Verão.
Measurement of the adjustable slight roughness emulated by a spatial light modulator employing the vortex beam speckle pattern
Authors: Cui Can , Wang Zhi , Zhan Xiangkong , Wang Jian , Liu Lanlan , Li Zhiyong , Wu Chongqing
Published: March 2020

In this paper, we analyze the speckle patterns generated by the scattering of optical vortex on different roughness surfaces, compared with those produced by Gaussian light, where the roughness is emulated by a spatial light modulator and adjustable. The scheme and experiments demonstrate an improvement with the vortex beam, especially for slight roughness measurements. In addition, since the topological charge used to produce speckle patterns has a great influence on the speckle size and can be optimized to adjust it for different object measurements, we also investigate how the roughness depends on the topological charge.
Precision analysis of turbulence phase screens and their influence on the simulation of Gaussian beam propagation in turbulent atmosphere
Authors: Chen Zhibin , Zhang Dongxiao , Xiao Cheng , Qin Mengze
Published: March 2020

The slip-step method is widely used in simulating optical wave propagation in turbulent atmosphere, which treats propagation and phase perturbations caused by turbulence separately and in discrete steps along the propagation axis. The phase perturbations are represented by a series of phase screens, and hence, the precision of the phase screen concerns the accuracy of the simulation. In this paper, we first discuss the precision and computational performance of phase screens generated by the subharmonic complemented discrete Fourier transformation (DFT) (DFT-SH) method, three kinds of randomized spectral sampling techniques (sparse spectrum (SS) technique, sparse spectrum technique with uniform wave vectors (SU), randomized DFT technique), and optimization-based (OB) method; then, the simulations are implemented with the phase screens generated by these methods. Some statistical quantities of the received optical field are calculated, such as beam wander variance, long-term beam radius, short-term beam radius, and on-axis scintillation index. The statistical results show that the undersampling of phase screen in the low-frequency region causes underestimation of the values of beam wander variance, long-term beam radius, and focused beam on-axis scintillation index because these quantities are sensitive to the large-scale inhomogeneities. However, the undersampling does not affect the predicted values of the short-term beam radius and collimated beam on-axis scintillation index because these quantities are insensitive to the large-scale inhomogeneities.
Spectroscopic properties of various blood antigens/antibodies
Authors: Seyedi Seyedeh Solaleh , Parvin Parviz , Jafargholi Amir , Hashemi Nazanin , Tabatabaee Seyed Morteza , Abbasian Ali , Khorrami Ahmad
Published: March 2020

Since the traditional method generates biological waste, there is a significant demand for an easy, quick technique of blood type identification without contamination. In fact, individuals can be divided into four main blood groups whose antigens are available in red blood cell (RBC) membranes and the antibodies in the plasma. Here, UV-vis and photoluminescence (PL) spectroscopic methods are systematically used to find the spectra of blood typing antigens (A, B and AB) and antibodies i.e. A-Anti, B-Anti, AB-Anti and D reagent. The PL spectra of RBCs in different blood groups as well as the corresponding antibodies are successfully resolved for the purpose of blood typing. The unique photophysical characteristics of these biomolecules including signal intensity and peak emission wavelength in PL spectra are lucidly anticipated to accurately discriminate ABO groups. PL spectra of RBC in positive blood typing indicate larger signal and shorter emission peak wavelength corresponding to negative ones. Furthermore, the monoclonal antibody PL emissions emphasize that Anti-A benefits higher intensity and shorter peak wavelength (blue shift) than B-Anti. In the following, lucid blue shifts are obtained in terms of antibody concentrations accompanying the elevation of fluorescence signal, most likely due to the aggregation induced emission (AIE) phenomenon, quite the opposite of the aggregation-caused quenching (ACQ) that is widely observed from conventional chromophore. Those are envisaged as unique properties of each antibody to utilize in the spectral blood typing.
Cell phone digital microscopy using an oil droplet
Authors: Szydlowski Nicole Anna , Jing Haoran , Alqashmi Mohamed , Hu Ying Samuel
Published: March 2020

We introduce an accessible cell phone imaging method using small droplets of microscope immersion oil and consumer-grade oils. Oil droplets were more resistant to evaporation than water droplets, and they resolved cellular structures that were visible using a 20x/0.75 objective. We optically characterized the droplets using a cell phone screen and resolution target. We further obtained cellular resolution images of an onion epidermis and a zea stem cross-section sample. Our droplet-based method enables stable optical imaging for diagnostic and educational purposes without custom setups, specialized components, or manufacturing processes.
Optical nonreciprocity in a three-mode optomechanical system within a common reservoir
Authors: Tang Bei , Hou Bang-Pin , Zhao Xiao-Hui , Qian Yi-Bing , Lai Deng-Gao
Published: March 2020

Optical nonreciprocity in a three-mode optomechanical system within a common optical reservoir is considered. It is found that optomechanically induced nonreciprocity is generated by the interference between the incoherent coupling induced by the common reservoir and the optomechanical coupling mediated by the interactions of two optical modes with a mechanical mode. There exist two symmetric nonreciprocal regimes that respectively correspond to the forward and backward photon transmissions, and the optical nonreciprocity for the relative phase

φ

between the optomechanical couplings is in opposite direction to that for the phase

2
π
−
φ

. Additionally, it is shown that the optimal nonreciprocity as well as the nonreciprocal amplification can be achieved only by adjusting the optomechanical couplings. To compare nonreciprocity induced by incoherent coupling with that in the case of coherent coupling, we consider the optomechanically induced nonreciprocity created by interference between the optomechanical and direct couplings between the two optical modes. The nonreciprocal behaviors and their differences in these two cases are explained by using analytic findings.
Nonradiating anapole condition derived from Devaney-Wolf theorem and excited in a broken-symmetry dielectric particle
Authors: Labate Giuseppe , Ospanova Anar K. , Nemkov Nikita A. , Basharin Alexey A. , Matekovits Ladislau
Published: March 2020

In this work, we first derive the nonradiating anapole condition with a straightforward theoretical demonstration exploiting one of the Devaney-Wolf theorems for nonradiating currents. Based on the equivalent volumetric and surface electromagnetic sources, it is possible to establish a unique compact conditions directly from Maxwell’s Equations in order to ensure nonradiating anapole state. In addition, we support our theoretical findings with a numerical investigation on a broken-symmetry dielectric particle, building block of a metamaterial structure, demonstrating through a detailed multiple expansion the nonradiating anapole condition behind these peculiar destructive interactions.
OPCPA investigation with control over the temporal shape of 1.2 ps pump pulses
Authors: Mackonis Paulius , Rodin Aleksej M.
Published: March 2020

We report a study of a compact, scalable up to TW peak power OPCPA with ∼1.2 ps pump pulses delivered from a Yb:YAG laser. Passive synchronization was ensured by using a small portion of the energy to generate a stable supercontinuum in the YAG, and the rest was directed to pump the three OPCPA stages. The temporal shape of the pump pulse was controlled by the degree of depletion of fundamental radiation in a two-cascade second harmonic converter. Under optimal conditions, the energy of amplified pulses reached ∼2.1 mJ with the support of a spectral bandwidth sufficient for a transform-limited pulse width of 8.6 fs.
Tantalum pentoxide nanophotonic circuits for integrated quantum technology
Authors: Splitthoff Lukas , Wolff Martin A. , Grottke Thomas , Schuck Carsten
Published: March 2020

Nanophotonics holds great promise for integrated quantum technologies, but realizing all functionalities for processing quantum states of light in optical waveguides poses an outstanding challenge. Here we show that tantalum pentoxide-on-insulator offers significant advantages for such purpose and experimentally demonstrate crucial photonic integrated circuit components. Exploiting advanced nanophotonic design and state-of-the-art nanofabrication processes, we realize low-loss waveguiding with 1 dB/cm propagation loss, efficient optical fiber-chip interfaces with more than 100 nm bandwidth, micro-ring resonators with quality factors of 357,200 and tunable directional couplers. We further achieve active functionality with nano-electromechanical phase-shifters. Our work enables reconfigurable photonic circuit configurations in the Ta2O5 material system with highly favorable optical properties for integrated quantum photonics.
Design of diffractive lenses operating at several wavelengths
Authors: Doskolovich Leonid L. , Skidanov Roman V. , Bezus Evgeni A. , Ganchevskaya Sofiya V. , Bykov Dmitry A. , Kazanskiy Nikolay L.
Published: March 2020

We propose a method for designing diffractive lenses having a fixed-position focus at several prescribed wavelengths, which we refer to as spectral diffractive lenses (SDLs). The method is based on minimizing an objective function describing the deviation of the complex transmission functions of the spectral lens at the operating wavelengths from the complex transmission functions of diffractive lenses calculated separately for each of these wavelengths. As examples, SDLs operating at three, five, and seven different wavelengths are designed. The simulation results of the calculated lenses confirm high efficiency of the proposed method. For experimental verification of the design method, we fabricate using direct laser writing and experimentally investigate an SDL operating at five wavelengths. The presented experimental results confirm the efficiency of the proposed method in practical problems of designing SDLs. The obtained results may find applications in the design and fabrication of novel flat diffractive lenses with reduced chromatic effects.
System-theoretical modeling of terahertz time-domain spectroscopy with ultra-high repetition rate mode-locked lasers
Authors: Kolpatzeck Kevin , Liu Xuan , Tybussek Kai-Henning , Häring Lars , Zander Marlene , Rehbein Wolfgang , Moehrle Martin , Czylwik Andreas , Balzer Jan C.
Published: March 2020

Terahertz time-domain spectroscopy (THz-TDS) systems based on ultra-high repetition rate mode-locked laser diodes (MLLDs) and semiconductor photomixers show great potential in terms of a wide bandwidth, fast acquisition speed, compactness, and robustness. They come at a much lower total cost than systems using femtosecond fiber lasers. However, to date, there is no adequate mathematical description of THz-TDS using a MLLD. In this paper, we provide a simple formula based on a system-theoretical model that accurately describes the detected terahertz spectrum as a function of the optical amplitude and phase spectrum of the MLLD and the transfer function of the terahertz system. Furthermore, we give a simple yet exact relationship between the optical intensity autocorrelation and the detected terahertz spectrum. We theoretically analyze these results for typical optical spectra of MLLDs to quantify the effect of pulse chirp on the terahertz spectrum. Finally, we confirm the validity of the model with comprehensive experimental results using a single-section and a two-section MLLD in a conventional THz-TDS system.