bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dosimetric impact of random spot positioning errors in intensity modulated proton therapy plans of small and large volume tumors
Authors: Arjunan Manikandan , Krishnan Ganapathy , Sharma Dayananda Shamurailatpam , M P Noufal , Patro Kartikeshwar C , Thiyagarajan Rajesh , Srinivas Chilukuri , Jalali Rakesh 
Published: February 2021

Objective
To study dosimetric impact of random spot positioning errors on the clinical pencil beam scanning proton therapy plans.

Methods and materials
IMPT plans of 10 patients who underwent proton therapy for tumors in brain or pelvic regions representing small and large volumes, respectively, were included in the study. Spot positioning errors of 1 mm, −1 mm or ±1 mm were introduced in these clinical plans by modifying the geometrical co-ordinates of proton spots using a script in the MATLAB programming environment. Positioning errors were simulated to certain numbers of (20%, 40%, 60%, 80%) randomly chosen spots in each layer of these treatment plans. Treatment plans with simulated errors were then imported back to the Raystation (Version 7) treatment planning system and the resultant dose distribution was calculated using Monte-Carlo dose calculation algorithm.
Dosimetric plan evaluation parameters for target and critical organs of nominal treatment plans delivered for clinical treatments were compared with that of positioning error simulated treatment plans. For targets, D95% and D2% were used for the analysis. Dose received by optic nerve, chiasm, brainstem, rectum, sigmoid, and bowel were analyzed using relevant plan evaluation parameters depending on the critical structure. In case of intracranial lesions, the dose received by 0.03 cm3 volume (D0.03 cm3) was analyzed for optic nerve, chiasm and brainstem. In rectum, the volume of it receiving a dose of 65 Gy(RBE) (V65) and 40 Gy(RBE) (V40) were compared between the nominal and error introduced plans. Similarly, V65 and V63 were analyzed for Sigmoid and V50 and V15 were analyzed for bowel.

Results
The maximum dose variation in PTV D95% (1.88 %) was observed in a brain plan in which the target volume was the smallest (2.7 cm3) among all 10 plans included in the study. This variation in D95% drops down to 0.3% for a sacral chordoma plan in which the PTV volume is significantly higher at 672 cm3. The maximum difference in OARs in terms of absolute dose (D0.03 cm3) was found in left optic nerve (9.81%) and the minimum difference was observed in brainstem (2.48%). Overall, the magnitude of dose errors in chordoma plans were less significant in comparison to brain plans.

Conclusion
The dosimetric impact of different error scenarios in spot positioning becomes more prominent for treatment plans involving smaller target volume compared to plans involving larger target volumes.

Advances in knowledge
Provides information on the dosimetric impact of various possible spot positioning errors and its dependence on the tumor volume in intensity modulated proton therapy.
Roadblock to Innovation: The Role of Patent Litigation in Corporate R&D
Authors: Mezzanotti Filippo 
Published: February 2021

I examine how patent enforcement affects corporate research and development (R&D), exploiting the legal changes induced by the Supreme Court decision eBay v. MercExchange. This ruling increased courts’ flexibility in remedying patent cases and effectively lowered the potential costs of patent litigation for defendants. For identification, I compare innovative activity across firms differentially exposed to patent litigation before the ruling. Across several measures, I find that the decision led to a general increase in innovation. This result confirms that the changes in enforcement induced by the ruling reduced some of the distortions caused by patent litigation. Exploring the channels, I show that patent litigation negatively affects investment because it lowers the returns from R&D and exacerbates its financing constraints.This paper was accepted by Gustavo Manso, finance.
Unspanned Global Macro Risks in Bond Returns
Authors: Zhao Feng , Zhou Guofu , Zhu Xiaoneng 
Published: February 2021

We examine the macro-spanning hypothesis for bond returns in international markets. Based on a large panel of real-time macroeconomic variables that are not subject to revisions, we find that global macro factors have predictive power for bond returns unspanned by yield factors. Furthermore, we estimate macro-finance term structure models with the unspanned global macro factors and find that the global macro factors influence the market prices of level and slope risks and induce comovements in forward term premia in global bond markets.This paper was accepted by David Simchi-Levi, finance.
Evaluation of processes, outcomes, and use of midline peripheral catheters for the purpose of blood collection
Authors: Penoyer Daleen , Bennett Melody , Geddie Patricia I. , Nugent Alyssa , Volkerson Tara 
Published: February 2021

HIGHLIGHTS Results added knowledge on use of midline catheters (MCs) for blood sampling. Using MCs for blood withdrawal resulted in low rates of hemolysis (0.69%). Dwell time was longer in those who had blood drawn from their MC. Nurse practices for blood sampling from MCs varied and learned from other nurses. Background: Blood withdrawal from midline catheters (MCs) is done clinically, but no studies were found evaluating outcomes from this procedure, nor were clinical guidelines found. Drawing blood samples from short peripheral catheters is associated with higher hemolysis rates. Methods: A prospective, observational, mixed methods study was used to evaluate outcomes from using MCs for blood withdrawal. Focus group sessions were held to evaluate nurses' practices for this procedure. Results: Data were collected over 3 months on 397 MCs in 378 patients. Hemolysis rates when the MC was used for blood withdrawal was 0.69% in 1021 tests. More than half had blood specimens drawn through the MC, and the time known for the successful withdrawal was on average 64 ± 85 hours. Mean dwell time for all MCs was 108.5 ± 98 hours, and when MCs were used for blood withdrawal, mean dwell time was 127.19 ± 109.13 hours and for MCs not used for blood withdrawal, 88.34 ± 79.86 hours (P < 0.001). In 338 patients who received therapy through their MC (n = 338), 87% completed intended therapy: 88% with blood withdrawal and 81% without blood withdrawal. Qualitative analysis from focus groups demonstrated wide variation in practice for blood sampling from MCs, and most learned techniques from their preceptors, other nurses, or patients. Conclusions: Findings indicated that blood withdrawal from one specific type of MC had low rates of hemolysis, increased dwell time, and completion of therapy. More studies are needed to determine best practices for blood sampling through various types of MCs and outcomes.
Grafos de Escenas y Estudios Literarios Digitales: Una Propuesta Computacional Crítica
Authors: Jiménez Fernández Concepción María , Calvo Tello José 
Published: February 2021

Desde que en 2005 Moretti los popularizase, los grafos se han utilizado para representar la interacción de los personajes en obras de teatro y novelas. Sin embargo, en los últimos años han aparecido algunos trabajos evaluando estos grafos, cuestionando su validez. En este trabajo, proponemos una modificación de estos grafos, obteniendo una representación de las obras dramáticas que prioriza la estructura en escenas. A diferencia de otros trabajos de HD, realizamos una evaluación crítica mediante hipótesis que aúna variables cuantitativas y cualitativas.
The role of aquaporin-4 in optic nerve head astrocytes in experimental glaucoma
Authors: Kimball Elizabeth , Schaub Julie , Quillen Sarah , Keuthan Casey , Pease Mary Ellen , Korneva Arina , Quigley Harry 
Published: February 2021

Purpose
To study aquaporin channel expression in astrocytes of the mouse optic nerve (ON) and the response to IOP elevation in mice lacking aquaporin 4 (AQP4 null).

Methods
C57BL/6 (B6) and AQP4 null mice were exposed to bead-induced IOP elevation for 3 days (3D-IOP), 1 and 6 weeks. Mouse ocular tissue sections were immunolabeled against aquaporins 1(AQP1), 4(AQP4), and 9(AQP9). Ocular tissue was imaged to identify normal AQP distribution, ON changes, and axon loss after IOP elevation. Ultrastructure examination, cell proliferation, gene expression, and transport block were also analyzed.

Results
B6 mice had abundant AQP4 expression in Müller cells, astrocytes of retina and myelinated ON (MON), but minimal AQP4in prelaminar and unmyelinated ON (UON). MON of AQP4 nulls had smaller ON area, smaller axon diameter, higher axon density, and larger proportionate axon area than B6 (all p≤0.05). Bead-injection led to comparable 3D-IOP elevation (p = 0.42) and axonal transport blockade in both strains. In B6, AQP4 distribution was unchanged after 3D-IOP. At baseline, AQP1 and AQP9 were present in retina, but not in UON and this was unaffected after IOP elevation in both strains. In 3D-IOP mice, ON astrocytes and microglia proliferated, more in B6 than AQP4 null. After 6 week IOP elevation, axon loss occurred equally in the two mouse types (24.6%, AQP4 null vs. 23.3%, B6).

Conclusion
Lack of AQP4 was neither protective nor detrimental to the effects of IOP elevation. The minimal presence of AQP4 in UON may be a vital aspect of the regionally specific phenotype of astrocytes in the mouse optic nerve head.
Anemia in tuberculosis cases: A biomarker of severity?
Authors: de Mendonça Edson Beyker , Schmaltz Carolina AranaStanis , Sant’Anna Flavia Marinho , Vizzoni Alexandre Gomes , Mendes-de-Almeida Daniela Palheiro , de Oliveira Raquel de Vasconcellos Carvalhaes , Rolla Valeria Cavalcanti 
Published: February 2021

Introduction
Anemia is a common condition at tuberculosis diagnosis, and there is evidence that its prevalence is higher in patients with tuberculosis than in those infected with Mycobacterium tuberculosis and healthy controls. Information about anemia during tuberculosis diagnosis is still scarce in the Brazilian population. The aim of this study was to describe the prevalence of anemia in patients with tuberculosis cared for at a referral center and its association with clinical forms of tuberculosis and other characteristics of these patients.

Materials and methods
This was a retrospective cross-sectional study of tuberculosis patients diagnosed from January 2015 to December 2018 at the Clinical Research Laboratory on Mycobacteria (LAPCLIN-TB) of Evandro Chagas National Institute of Infectious Diseases (INI)/Oswaldo Cruz Foundation (Fiocruz). A database of an ongoing cohort study underway at this service since 2000 provided the baseline information on tuberculosis cases extracted from a visit template. Exploratory and logistic regression analyses were performed to verify associations between anemia and demographic characteristics, socioeconomic status, clinical conditions, and laboratory results.

Results
Of the 328 cases reviewed, 70 were excluded, with258 retained. The prevalence of anemia was 61.2% (27.5% mild, 27.5% moderate and 6.2% severe). Among patients with anemia, 60.8% had normochromic normocytic anemia, and 27.8% showed hypochromic microcytic anemia. In logistic regression analysis, anemia was associated with a history of weight loss >10%, hospitalizations, coinfection with HIV, increased platelet count and microcytosis. Anemia was more frequent in the most severe clinical forms, such as meningeal and disseminated tuberculosis.

Conclusions
Anemia was highly prevalent in tuberculosis patients at diagnosis, predominantly as normochromic normocytic anemia and in mild and moderate forms. It was associated with baseline characteristics and conditions indicative of severe disease, suggesting that anemia could be a biomarker of tuberculosis severity.
Motor function is the primary driver of the associations of sarcopenia and physical frailty with adverse health outcomes in community-dwelling older adults
Authors: Buchman Aron S. , Leurgans Sue E. , Wang Tianhao , Schnaider-Beeri Michal , Agarwal Puja , Dawe Robert J. , Delbono Osvaldo , Bennett David A. 
Published: February 2021

Background
This study tested the hypothesis that sarcopenia and its constituent components, reduced lean muscle mass and impaired motor function, are associated with reduced survival and increased risk of incident disabilities.

Methods
1466 community-dwelling older adults underwent assessment of muscle mass with bioelectrical impedance analysis (BIA), grip strength, gait speed and other components of physical frailty and annual self-report assessments of disability. We used Cox proportional hazards models that controlled for age, sex, race, education and height to examine the associations of a continuous sarcopenia metric with the hazard of death and incident disabilities.

Results
Mean baseline age was about 80 years old and follow-up was 5.5 years. In a proportional hazards model controlling for age, sex, race, education and baseline sarcopenia, each 1-SD higher score on a continuous sarcopenia scale was associated with lower hazards of death (HR 0.70, 95%CI [0.62, 0.78]), incident IADL (HR 0.80,95%CI [0.70, 0.93]), incident ADL disability (HR 0.80 95%CI [71, 91]) and incident mobility disability (HR 0.81, 95%CI [0.70, 0.93]). Further analyses suggest that grip strength and gait speed rather than muscle mass drive the associations with all four adverse health outcomes. Similar findings were observed when controlling for additional measures used to assess physical frailty including BMI, fatigue and physical activity.

Conclusions
Motor function is the primary driver of the associations of sarcopenia and physical frailty with diverse adverse health outcomes. Further work is needed to identify other facets of muscle structure and motor function which together can identify adults at risk for specific adverse health outcomes.
The impact of Covid-19-related distress on general health, oral behaviour, psychosocial features, disability and pain intensity in a cohort of Italian patients with temporomandibular disorders
Authors: Asquini Giacomo , Bianchi Andrea Edoardo , Borromeo Giulia , Locatelli Matteo , Falla Deborah 
Published: February 2021

This study aimed to understand the impact of COVID-19 distress on psychological status, features of central sensitization and facial pain severity in people with temporomandibular disorders (TMDs). In this prospective cohort study, 45 adults (19 chronic, 26 acute/subacute TMD) were recruited prior to the COVID-19 outbreak. Baseline assessment took place before the outbreak while a follow-up was performed immediately after the lockdown period. Multiple variables were investigated including age, gender, perceived life quality, sleep quality, anxiety and depression, coping strategies, central sensitization, pain intensity, pain-related disability and oral behaviour. COVID Stress Scales (CSS) were applied at follow-up to measure the extent of COVID-related distress. CSS were significantly higher in those with chronic TMDs compared to those with acute/subacute TMDs (p<0.05). In people with chronic TMD, the variation in anxiety and depression from baseline to follow-up was significantly correlated with scores on the CSS (r = 0.72; p = 0.002). Variations of the central sensitization inventory (r = 0.57; p = 0.020) and graded chronic pain scale (r = 0.59; p = 0.017) were significantly correlated with scores on the CSS. These initial findings indicate that people with chronic TMD were more susceptible to COVID-19 distress with deterioration of psychological status, worsening features of central sensitization and increased chronic facial pain severity. These findings reinforce the role of stress as a possible amplifier of central sensitization, anxiety, depression, chronic pain and pain-related disability in people with TMDs.Trial Registration:ClinicalTrials.gov ID:NCT03990662.
Comparative evaluation of conventional and modified frontalis muscle flap advancement techniques in the treatment of severe congenital ptosis: A retrospective cohort study
Authors: Zhang Lei , Zhai Wenjuan , Yang Lihong , Sun Chunhua , Pan Ye , Zhao Hong 
Published: February 2021

PurposeTo introduce a modified frontalis muscle (FM) flap for use in FM flap advancement surgery and compare it with the conventional flap for correcting severe congenital ptosis.MethodsThis retrospective cohort study included 200 patients (278 eyes) with severe congenital ptosis treated with FM flap advancement at Tianjin Eye Hospital from April 2018 to October 2019. The patients were divided into two groups: 100 patients (138 eyes) in the conventional group and 100 patients (140 eyes) in the modified group. The success and complication rates were evaluated.ResultsThe final success rate was 77.5% (107/138) in the conventional group and 90.0% (126/140) in the modified group (p = 0.005). Undercorrection was observed in 31 eyes (22.5%) in the conventional group and 14 eyes (10%) in the modified group (p = 0.005). In the conventional group, angular deformity of the upper eyelid was observed in 29 eyes (21.0%), FM paralysis in 11 (8.0%), frontal hypoesthesia in 10 (7.2%), severe hematoma in 12 (8.7%), and exposure keratitis in 8 (5.8%); these complications were not observed in the modified group (p <0.001, p <0.001, p = 0.004, p <0.001, p = 0.011, respectively). There were no cases of overcorrection, entropion or ectropion in either group.ConclusionCompared with the conventional FM flap, the modified FM flap in this study yielded a higher success rate with a clear field of vision, mild trauma, and few complications. This technique is simple and convenient for correcting severe congenital ptosis.
Economic evaluation of Health Extension Program packages in Ethiopia
Authors: Assebe Lelisa Fekadu , Belete Wondesen Nigatu , Alemayehu Senait , Asfaw Elias , Godana Kora Tushune , Alemayehu Yibeltal Kiflie , Teklu Alula M. , Yigezu Amanuel 
Published: February 2021

BackgroundEthiopia launched the Health Extension Program (HEP) in 2004, aimed at ensuring equitable community-level healthcare services through Health Extension Workers. Despite the program’s being a flagship initiative, there is limited evidence on whether investment in the program represents good value for money. This study assessed the cost and cost-effectiveness of HEP interventions to inform policy decisions for resource allocation and priority setting in Ethiopia.MethodsTwenty-one health care interventions were selected under the hygiene and sanitation, family health services, and disease prevention and control sub-domains. The ingredient bottom-up and top-down costing method was employed. Cost and cost-effectiveness were assessed from the provider perspective. Health outcomes were measured using life years gained (LYG). Incremental cost per LYG in relation to the gross domestic product (GDP) per capita of Ethiopia (US$852.80) was used to ascertain the cost-effectiveness. All costs were collected in Ethiopian birr and converted to United States dollars (US$) using the average exchange rate for 2018 (US$1 = 27.67 birr). Both costs and health outcomes were discounted by 3%.ResultThe average unit cost of providing selected hygiene and sanitation, family health, and disease prevention and control services with the HEP was US$0.70, US$4.90, and US$7.40, respectively. The major cost driver was drugs and supplies, accounting for 53% and 68%, respectively, of the total cost. The average annual cost of delivering all the selected interventions was US$9,897. All interventions fall within 1 times GDP per capita per LYG, indicating that they are very cost-effective (ranges: US$22–$295 per LYG). Overall, the HEP is cost-effective by investing US$77.40 for every LYG.ConclusionThe unit cost estimates of HEP interventions are crucial for priority-setting, resource mobilization, and program planning. This study found that the program is very cost-effective in delivering community health services.
Trajectory of smoking behavior change among Chinese immigrant smokers
Authors: Lei Fang , Lee Eunice , Zheng Ying 
Published: February 2021

Background
The incidence and mortality rates of smoking-associated lung cancer are high among Chinese immigrant smokers. Coming from a country with different smoking policies, culture, and economic background than the U.S., Chinese smokers may change their smoking behaviors after immigrating to the U.S.

Objectives
This study aims to explore the trajectory of smoking behavior change among Chinese immigrant smokers migrating to the U.S.

Methods
This qualitative study was guided by the Grounded theory. Semi-structured intensive individual interviews were conducted among 10 eligible participants. A purposive theoretical sampling method was used to recruit participants through a website. Individual interviews were conducted online, via telephone, or in-person in Mandarin. Data were transcribed verbatim in Mandarin, translated into English, and triangulated with follow-up interviews and dialogues among authors to enhance trustworthiness and consistency of the study. Process coding and content analysis were used to analyze data.

Results
A total of 10 participants, 7 males and 3 females, were interviewed. Results showed the trajectory of smoking behavior change among Chinese immigrant smokers went through three phases: 1) Beginning to smoke, which included learning to smoke from others, trying to smoke and learning to smoke, and hiding their smoking behaviors from others; 2) maintaining smoking, which included setting boundary around smoking, smoking as a facilitator or barrier to social interaction, feeling pressures related to smoking behavior, and making others happy: Collective smoking and controlling smoking desire; and 3) changing smoking behaviors, which included experiencing life events that were triggers to changing smoking behavior, boredom as a reason for relapses, personal will as a key to quitting smoking, and quitting smoking for a loved one. Although some differences existed between male and female Chinese immigrant smokers’ smoking behaviors, their trajectories of smoking behavior change were generally similar.

Discussion
Findings from this study can help health care providers to extend their understanding toward smoking behavior change among Chinese immigrant smokers across different socio-cultural contexts.
Changes in contraceptive and sexual behaviours among unmarried young people in Nigeria: Evidence from nationally representative surveys
Authors: Adedini Sunday A. , Mobolaji Jacob Wale , Alabi Matthew , Fatusi Adesegun O. 
Published: February 2021

Context
Nigeria is a high-burden country in terms of young people’s health. Understanding changes in young people’s sexual and reproductive health (SRH) behaviours and the associated factors is important for framing appropriate interventions.

Objective
This study assessed changes in SRH behaviours of unmarried young people aged 15–24 and associated factors over a ten-year period in Nigeria.

Data and method
We analysed datasets from Nigeria Demographic and Health Surveys of 2008, 2013 and 2018 to assess changes in inconsistent condom use, non-use of modern contraceptives; multiple sexual partnership; and early sexual debut. Using binary logistic regression, we assessed the association of selected variables with the SRH behaviours.

Results
Over four-fifths of unmarried young people (15–24) in Nigeria engaged in at least one risky sexual behaviour in each survey year. The pattern of changes in the four risky SRH behaviours was consistent over the 10-year period, with the highest rates of each behaviour occurring in 2018 while the lowest rates were in 2013, thus indicating an increase in the proportion of respondents engaging in risky sexual behaviours over the study period. Comprehensive HIV/AIDS knowledge, male gender, older age category (20–24), residence in south-west Nigeria, urban residence, higher socio-economic status, secondary/higher education were mostly protective against the four SRH variables analysed across the different data waves.

Conclusion
Addressing the high and increasing level of risky SRH behaviours among young people in Nigeria is imperative to improve overall national health status and to ensure progress towards achieving SDG target 3.7 focusing on SRH.