bluuebunny/crossref_metadata_2025 huggingface dataset:
Two Japanese patients with stage G3b chronic kidney disease and impaired glucose metabolism after renal transplantation successfully treated with empagliflozin
Authors: Miyazaki Ryoichi , Miyagi Kyoko , Yoshida Misaki
Published: November 2020

Background

Renal transplant recipients with chronic kidney disease (CKD) often develop abnormal glucose metabolism. Although recent studies have reported the protective effects of sodium-glucose transport protein 2 (SGLT2) inhibitors on the heart and kidneys, few have assessed their effect in renal transplant patients. Moreover, to our knowledge, there have been no studies on the effects of SGLT2 inhibitors in renal transplant recipients in Japan.

Case presentation

Case 1 was a 67-year-old male renal transplant recipient with post-transplant diabetes mellitus. He was administered empagliflozin 10 mg once a day for 9 months. Over time, his HbA1c levels decreased from 6.8 to 6.0%. Case 2 was a 56-year-old male renal transplant recipient with fatty liver disease. He was administered empagliflozin 10 mg once a day for 9 months. His ALT, γ-GTP, and LDL-cholesterol levels all decreased. In both patients, body weight and the urine albumin to creatinine ratio (UACR) decreased after empagliflozin administration, but there were no changes in the estimated glomerular filtration rate. No adverse events occurred in either case.

Conclusions

Administration of empagliflozin had favorable outcomes in two patients with stage G3b CKD and abnormal glucose metabolism after renal transplantation. Further studies will be required to clarify the efficacy and safety of SGLT2 inhibitors in a larger population of patients with similar medical conditions.
Geographical distribution of hyperuricemia in mainland China: a comprehensive systematic review and meta-analysis
Authors: Huang Jiayun , Ma Zheng Feei , Zhang Yutong , Wan Zhongxiao , Li Yeshan , Zhou Hang , Chu Anna , Lee Yeong Yeh
Published: November 2020

Background

Fructose plays an important role in the complex metabolism of uric acid in the human body. However, high blood uric acid concentration, known as hyperuricemia, is the main risk factor for development of gout. Therefore, we conducted an updated meta-analysis on the prevalence and geographical distribution of hyperuricemia among the general population in mainland China using systematic literature search.

Methods

Five electronic databases were used to search for relevant articles published until 2019. All calculations were conducted using the Comprehensive Meta-Analysis (CMA) software. We included 108 eligible articles (172 studies by sex, 95 studies by regions, and 107 studies by study type) and an overall sample size of > 808,505 participants.

Results

The pooled prevalence of hyperuricemia among the general population in mainland China was 17.4% (95% CI: 15.8–19.1%). Our subgroup analysis indicated that the pooled prevalence by regions ranged from 15.5 to 24.6%. Those living Northeast region and being males had the highest prevalence (P < 0.001). In addition, some provinces in South Central, East and Northeast regions reported a high prevalence (> 20%), particularly in males. An increasing prevalence was reported since 2005–2009 until 2015–2019. No publication of bias was observed as indicated by a symmetrical funnel plot and Begg and Mazumdar rank correlation (P = 0.392).

Conclusion

Prevalence of hyperuricemia is increasing in China, and future studies should investigate the association between the prevalence of hyperuricemia and its risk factors in order to tackle the issue, particularly among the vulnerable groups. Also, our study was the first comprehensive study to investigate the overall prevalence of hyperuricemia in mainland China covering the six different regions.
Preventing postoperative prosthetic joint dislocation by repairing obturator externus in total hip arthroplasty performed via the posterior approach
Authors: Fujii Hideki , Otani Takuya , Kawaguchi Yasuhiko , Hayama Tetsuo , Abe Toshiomi , Takahashi Motoi , Saito Mitsuru
Published: November 2020

Background

In total hip arthroplasty performed via the posterior approach, repairing the posterior soft tissues is a conventional method for preventing postoperative prosthetic joint dislocation. The aim of this study was to verify whether obturator externus repair played the main role and what was the mechanism of the repair preventing the dislocation.

Methods

Included were 188 patients who underwent primary cementless total hip arthroplasty via the posterior approach. The patients were divided into a repair group (n = 94) and a non-repair group (n = 94). Patients of repair group received additional obturator externus repair while patients of non-repair group did not. The range of motion of hip joint was assessed before and after operation. Data were compared between the two groups. A p value < 0.05 was considered statistically significant.

Results

Before operation and under anesthesia, with regard to internal rotation of hip joint, the mean values of repair and non-repair groups were 24° ± 16/28° ± 15 (p = 0.2933). The mean values of the groups were 13° ± 8/15° ± 9 immediately after repair (p = 0.5672). Range of internal rotation 1 year after operation were 15° ± 8/19° ± 9 (p = 0.0139). Specifically, the values in repair group were lower than those in non-repair group. During a 5-year period of postoperative follow-up, hip joint dislocation occurred in one patient of non-repair group. No dislocation was observed in repair group.

Conclusion

When THA is performed via the posterior approach, repairing the obturator externus may decrease the risk of postoperative prosthetic joint dislocation by reinforcing the posterior soft tissues of the hip joint.

Level of evidence

Therapeutic study, Level IVa.
Predictive value of neck imaging reporting and data system (NIRADS) in CECT/CEMRI of laryngeal and oral cavity squamous cell carcinoma
Authors: Abdelrahman Ahmed S. , Ashour Manar Maamoun Mohamed , Abdelaziz Tougan Taha
Published: November 2020

Background

The neck imaging reporting and data system (NI-RADS) is a structured reporting algorithm linked with further patient management recommendations. This study was conducted to assess the overall and time point predictive value of the NI-RADS in laryngeal and oral cavity squamous cell carcinoma (SCC) using contrast-enhanced magnetic resonance imaging (CEMRI) and contrast-enhanced computed tomography (CECT).

Results

The rate of tumor recurrence was statistically different among the NI-RADS 1-3 categories with recurrence trend for higher NI-RADS scores. The overall negative predictive value (NPV) of the NI-RADS 1 and 2 were 94.3%, 74.3% respectively, and the positive predictive value (PPV) of the NI-RADS 3 was 80.8%. The overall recurrence rate of NI-RADS 3 was higher in oral cavity SCC (87.5%) compared to the laryngeal SCC (70%). The PPV of overall NI-RADS 3 in the follow-up scans (77.8%) was higher than in the first scan (70.6%). The odd ratio of tumor recurrence in NI-RADS 3 primary lesion was 19.6.

Conclusion

The predictive value of NI-RADS was significantly different among its categories. Increasing NI-RADS score is associated with increased recurrence among the treated laryngeal and oral cavity SCC. The morphological and enhancement lexicon features equally assign the NI-RADS 3 score.
Natural history of hepatic hemangiomas as a guide for surgical indication
Authors: Mogahed Mohamed M. , Zytoon Ashraf Anas , Essa Bassem , Abdellatif Wessam , Ghanem Nashwa , ElWakeel Bahaa
Published: November 2020

Background

Generally, hemangiomas are asymptomatic and most lesions are incidentally diagnosed on abdominal ultrasonography. The indications for surgery are still debated mainly due to limited data about the natural history of hepatic hemangiomas. The aim of this study is to investigate the natural history of hepatic hemangiomas, the effects of age and sex on their growth, and their tendency to increase in size or causing symptoms or complications as a guide for surgical indication. In this current study, combined retrospective and prospective analysis was conducted on 186 Egyptian adult patients having 244 hepatic hemangiomas who attended to the outpatient clinics. Follow-up was performed to observe the accurate site, size, number, rate of growth of the lesions, and their tendency to cause symptoms or complications.

Results

Ninety-one percent of patients were asymptomatic and 9% were symptomatic. During follow-up, 48% of patients showed an increase in tumor diameter, 22% decreased, and 30% were stable. The growth rate at 18–45-year group showed an increasing trend that was higher in females; it was 3.3 ± 2 mm/year for males and 3.9 ± 1.8 mm/year for females. At ˃ 45 year group, the female patients showed a decreasing trend (− 2.1 ± 1.1 mm/year) while in males showed an increasing trend that was slower than in 18–45-year group (2.6 ± 1.7 mm/year).

Conclusion

Growth pattern of liver hemangiomas is affected by age and sex. The majority of hemangiomas are asymptomatic and complications are rare. Hemangioma size alone is not an indication for surgery in asymptomatic patients. Surgical indications are limited to patients with severe symptoms, complications, or suspicious lesions. Most hemangiomas can be managed conservatively even giant hemangiomas.
Spectrophotometric quantification of dolutegravir based on redox reaction with Fe3+/1,10-phenanthroline
Authors: Naraparaju Swathi , Thirumoorthy Durai Ananda Kumar , Gurrala Sunitha , Jabeen Asra , Anumolu Pani Kumar D.
Published: November 2020

Background

A simple and sensitive spectrophotometric method was developed for the quantitative measurement of dolutegravir in pure form and pharmaceutical formulation. The present method was based on redox reaction between dolutegravir and ferric chloride, which upon complexation with 1,10-phenanthroline formed an orange-colored complex that showed absorption maximum at 520.0 nm.

Results

The developed method obeyed linearity in the concentration range of 40.00–140.00 μg/mL. The method was also validated as per International Council for Harmonization guidelines and the results were within acceptance values. The validated method was employed for the determination of dolutegravir in pharmaceutical dosage form and the percentage assay value was found to be 102.5, which is in agreement with its label claimed.

Conclusion

The developed redox-based colorimetric method could be used in the routine quality control analysis of dolutegravir present in various pharmaceutical dosage forms.
Virtual consultations: delivering outpatient clinics in paediatric surgery during the COVID-19 pandemic
Authors: Charnell A. M. , Hannon E. , Burke D. , Iredale M. R. , Sutcliffe J. R.
Published: November 2020

Background

The COVID-19 pandemic has resulted in many changes to clinical practice, including the introduction of remote clinics. Those familiar with remote clinics have reported benefits to their use, such as patient satisfaction and cost benefits; however, ongoing challenges exist, including delivering optimal patient-centred care. As a tertiary paediatric surgery unit in the UK, completing remote clinics was a new experience for most of our surgical team. We completed a service evaluation early into the COVID-19 pandemic aiming to define and address issues when delivering remote clinics in paediatric surgery. Remote clinics were observed (telephone and video), with follow-up calls to families following the consultations.

Results

Eight paediatric surgeons were observed during their remote clinics (telephone n = 6, video n = 2). Surgeons new to remote clinics felt their consultations took longer and were reluctant to discharge patients. The calls did not always occur at the appointed time, causing some upset by parents. Prescription provision and outpatient investigations led to some uncertainty within the surgical team. Families (n = 11) were called following their child’s appointment to determine how our remote clinics could be optimised. The parents all liked remote clinics, either as an intermediate until a face-to-face consultation or for continued care if appropriate.

Our findings, combined by discussions with relevant managers and departments, led to the introduction of recommendations for the surgical team. An information sheet was introduced for the families attending remote clinics, which encouraged them to take notes before and during their consultations.

Conclusions

There must be strong support from management and appropriate departments for successful integration of remote clinics. Surgical trainees and their training should be considered when implementing remote clinics. Our learning from the pandemic may support those considering integrating remote clinics in the future.
Do obese patients with primary knee osteoarthritis benefit from a single bout of moderate intensity aerobic exercise?
Authors: Shaat Reham M. , Elsaid Tamer O. , EL Baz Aymen , Monir Rehan , Machaly Shereen Aly
Published: November 2020

Background

Obesity and osteoarthritis are often concomitant. Both are accompanied by oxidative stress and stimulated inflammatory response. Exercise is considered a substantial treatment in rehabilitation of both conditions. Yet most of literature reported the benefits of regular exercising, while there is paucity about the effects of single low to moderate exercise session. This study aimed to investigate the possible potential effects of a single bout of moderate exercise in obese middle-aged individuals with knee osteoarthritis (KOA).

Results

Score of pain and Western Ontario and Mc-Master University (WOMAC) had been improved 24 h after exercise. Glutathione reductase (GR) activity increased post-exercise but decreased the next 24 h though remained higher than baseline. Blood glucose level was reduced post-exercise whereas blood lipids still uninfluenced by exercise. Markers of inflammation remained unchanged after exercise session.

Conclusion

A single bout moderate-intensity aerobic exercise is effective in improving pain and antioxidant activity among middle-aged obese patients with primary knee OA. Single bout of mild to moderate exercise may help in treatment of obese patients with KOA.

Trial registration

Clinical Trials.gov Identifier:NCT03927339
Impact of COVID-19 on Cancer Care: How the Pandemic Is Delaying Cancer Diagnosis and Treatment for American Seniors
Authors: Patt Debra , Gordan Lucio , Diaz Michael , Okon Ted , Grady Lance , Harmison Merrill , Markward Nathan , Sullivan Milena , Peng Jing , Zhou Anan
Published: November 2020

PURPOSE

While the immediate care and access disruptions associated with the COVID-19 pandemic have received growing attention in certain areas, the full range of gaps in cancer screenings and treatment is not yet well understood or well documented throughout the country comprehensively.

METHODS

This study used a large medical claims clearinghouse database representing 5%-7% of the Medicare fee-for-service population to characterize changes in the utilization of cancer care services and gain insight into the impact of COVID-19 on the US cancer population, including identification of new patients, gaps in access to care, and disruption of treatment journeys.

RESULTS

In March-July 2020, in comparison with the baseline period of March-July 2019, there is a substantial decrease in cancer screenings, visits, therapy, and surgeries, with variation by cancer type and site of service. At the peak of the pandemic in April, screenings for breast, colon, prostate, and lung cancers were lower by 85%, 75%, 74%, and 56%, respectively. Significant utilization reductions were observed in April for hospital outpatient evaluation and management (E&M) visits (−74%), new patient E&M visits (−70%), and established patient E&M visits (−60%). A decrease in billing frequency was observed for the top physician-administered oncology products, dropping in both April (−26%) and July (−31%). Mastectomies were reduced consistently in April through July, with colectomies similarly reduced in April and May and prostatectomies dipping in April and July.

CONCLUSION

The current impact of the COVID-19 pandemic on cancer care in the United States has resulted in decreases and delays in identifying new cancers and delivery of treatment. These problems, if unmitigated, will increase cancer morbidity and mortality for years to come.
2019 Presidential Address: Sameness and Difference in Ethnohistory
Authors: Shoemaker Nancy
Published: November 2020

This presidential address, presented at the annual meeting of the American Society for Ethnohistory at Penn State University in 2019, draws attention to the politics of sameness and difference with examples of how people in the past invoked sameness or difference to include or exclude, disempower or empower, or advocate for equality or inequality. The address then asks how the politics of sameness and difference intersect with scholars’ use of sameness and difference in their analyses. It recommends that ethnohistorians think carefully about their word choices, assumptions, and the kinds of questions they ask about European and Native American historical actors, because these can result in misleading inferences about sameness and difference.
Military Networks at the Extremes of Empire: The Che of Chile and the Puebloans of the United States
Authors: Sauer Jacob J.
Published: November 2020

At the northern and southern ends of the Spanish “Empire,” two cultures of similar sociopolitical complexity violently removed Spanish invaders from their ancestral territory. The Che of southern Chile militarily engaged the Spanish in the mid-sixteenth century and eventually forced the Spanish to abandon their colonization attempts. The Puebloans of the southwestern United States also forced the Spanish to flee from Puebloan territory in 1680, but by 1696, Puebloan territories returned to Spanish hegemony. This article compares some of the reasons why the Che maintained independence for more than 350 years while Puebloan independence lasted 16, examining the military power networks of the Che and Puebloans and the timing of resistance to Spanish incursion. These comparisons highlight some of the diverse reactions of foreign groups and how connections between peoples affect how individuals and communities react to outside influences.
A Study in Distant Reading: Genre and the Longue Durée in the Age of AI
Authors: Goodlad Lauren M. E.
Published: November 2020

This essay explores “distant reading,” first, as a project of studying genre at supratextual scales of analysis (from early conceptions to computationalist successors) and, second, through the prescient late Victorian literary persona with which the latter practices intersect. A Study in Scarlet, the novella that introduced Sherlock Holmes, offers the first meditation on distant reading. A split double plot that anticipates generic fissures within crime fiction broadly conceived, A Study in Scarlet creates a data-centric detective intelligence in dialogue with late Victorian statistical innovations that remain central to machine learning and artificial intelligence (AI) today. Doyle’s generically split novella shows that the charismatic detective who dominates its first part is the merely partial virtuoso of a limited form. As such, A Study in Scarlet invites us to contemplate and clarify the humanistic stakes of machine “reading” during what some AI commentators conceive as a fourth industrial revolution.
Targeting Myeloid-Derived Suppressor Cells for Premetastatic Niche Disruption After Tumor Resection
Authors: Tang Fan , Tie Yan , Hong Weiqi , Wei Yuquan , Tu Chongqi , Wei Xiawei
Published: November 2020

Surgical resection is a common therapeutic option for primary solid tumors. However, high cancer recurrence and metastatic rates after resection are the main cause of cancer related mortalities. This implies the existence of a “fertile soil” following surgery that facilitates colonization by circulating cancer cells. Myeloid-derived suppressor cells (MDSCs) are essential for premetastatic niche formation, and may persist in distant organs for up to 2 weeks after surgery. These postsurgical persistent lung MDSCs exhibit stronger immunosuppression compared with presurgical MDSCs, suggesting that surgery enhances MDSC function. Surgical stress and trauma trigger the secretion of systemic inflammatory cytokines, which enhance MDSC mobilization and proliferation. Additionally, damage associated molecular patterns (DAMPs) directly activate MDSCs through pattern recognition receptor-mediated signals. Surgery also increases vascular permeability, induces an increase in lysyl oxidase and extracellular matrix remodeling in lungs, that enhances MDSC mobilization. Postsurgical therapies that inhibit the induction of premetastatic niches by MDSCs promote the long-term survival of patients. Cyclooxygenase-2 inhibitors and β-blockade, or their combination, may minimize the impact of surgical stress on MDSCs. Anti-DAMPs and associated inflammatory signaling inhibitors also are potential therapies. Existing therapies under tumor-bearing conditions, such as MDSCs depletion with low-dose chemotherapy or tyrosine kinase inhibitors, MDSCs differentiation using all-trans retinoic acid, and STAT3 inhibition merit clinical evaluation during the perioperative period. In addition, combining low-dose epigenetic drugs with chemokine receptors, reversing immunosuppression through theEnhanced Recovery After Surgeryprotocol, repairing vascular leakage, or inhibiting extracellular matrix remodeling also may enhance the long-term survival of curative resection patients.
Changing Business Dynamism and Productivity: Shocks versus Responsiveness
Authors: Decker Ryan A. , Haltiwanger John , Jarmin Ron S. , Miranda Javier
Published: November 2020

The pace of job reallocation has declined in the United States in recent decades. We draw insight from canonical models of business dynamics in which reallocation can decline due to (i ) lower dis persion of idiosyncratic shocks faced by businesses, or (ii ) weaker marginal responsiveness of businesses to shocks. We show that shock dispersion has actually risen, while the responsiveness of business-level employment to productivity has weakened. Moreover, declining responsiveness can account for a significant fraction of the decline in the pace of job reallocation, and we find suggestive evidence this has been a drag on aggregate productivity. (JEL D24, E24, E32, J21, J23, J24, L60)
Screening and Selection: The Case of Mammograms
Authors: Einav Liran , Finkelstein Amy , Oostrom Tamar , Ostriker Abigail , Williams Heidi
Published: November 2020

We analyze selection into screening in the context of recommendations that breast cancer screening start at age 40. Combining medical claims with a clinical oncology model, we document that compliers with the recommendation are less likely to have cancer than younger women who select into screening or women who never screen. We show this selection is quantitatively important: shifting the recommendation from age 40 to 45 results in three times as many deaths if compliers were randomly selected than under the estimated patterns of selection. The results highlight the importance of considering characteristics of compliers when making and designing recommendations. (JEL I12, I18, J16)
Η Ηθική στην Τέχνη
Authors: Παπανικολάου Έλενα
Published: November 2020

Δεν διατίθεται περίληψη
"Διαφορά και Φιλοσοφία του Γίγνεσθαι στους Derida, Deleuze kai Guaattari: Ριζική Ετερότητα και Ασύμμετρη Ηθική"
Authors: Γκαραγκούνης Θάνος
Published: November 2020

Η παρούσα εργασία στοχεύει να ανοίξει ένα διάλογο με μια συγκεκριμένη οπτική, γύρω από το μετανεωτερικό πρόταγμα, κυρίως όπως εμφανίζεται μέσα από τα γραπτά 1) του Derrida 2) του Deleuze και 3) του Guattari. Η οπτική αυτή δεν μπορεί με κανένα τρόπο να είναι εξαντλητική. Περιορίζεται στην ανάδειδη της ετερότητας, του άλλου και άρα του ηθικού, όπως το επιτρέπει μια ανάγνωση των παραπάνω θεωρητικών, γύρω από δύο σημεία που έχουν καίρια θέση σε αυτές τις θεωρήσεις. Τα δύο αυτά σημεία αφορούν α) την φιλοσοφία του γίγνεσθαι και της διαφοράς έξω από την εγελιανή διαλεκτική της άρνησης και αντίθεσης και β) τη διάνοιξη της ετερότητας και του άλλου πέρα και έξω από κάθε βία- πολιτική, θεωρητική ή πρακτική. Οι σχέσεις των 1, 2 και 3 με τα α και β είναι ακριβώς το ανά χείρας εγχείρημα.
Ο ορισμός του φυσικού νόμου στο έργο του Thomas Hobbes, Λεβιάθαν
Authors: Βάσση Παναγιώτα
Published: November 2020

Δεν διατίθεται περίληψη
Η σημασία του χορού στην Αντιγόνη
Authors: Γιακουμάκη Ελένη
Published: November 2020

Δεν διατίθεται περίληψη
Η πραγματική ελευθερία κατά την Hannah Arendt
Authors: Λιανόπουλος Θεόδωρος Μ.
Published: November 2020

Δεν διατίθεται περίληψη
Jean-Jacques Rousseau: ο εαυτός και ο χρόνος
Authors: Μελιδώνης Ανέστης
Published: November 2020

Δεν διατίθεται περίληψη
Legal Values in the Focus of Comparative Law
Authors: Khabrieva T. Ya. , Kovler A.I. , Belyalova A.M.
Published: November 2020

The Institute of legislation and comparative law under the Government of the Russian Federation, as the organizer of The international Congress of comparative law in partnership with the European Commission for democracy through law (the Venice Commission of the Council of Europe), seeks to attract representatives of various legal systems, schools, and generations to cooperate. It is as a result of such cooperation that it is possible to get the most adequate picture of the modern legal world. The topic of the IX Congress was chosen as the problem of value orientations in various branches of law, since in the field of comparative legal research it is often the starting point of scientific research. The purpose of this publication is to enrich the methodology of comparative legal research, fill in theoretical developments and help in the implementation of practical tasks of jurisprudence, which are set by modern society. The materials of the collection convincingly show the importance of socially significant values for increasing the effectiveness of legal regulation in various areas of public and state life. For practicing lawyers, employees of public authorities, representatives of the scientific community, teachers, students and postgraduates of law schools and faculties, as well as for anyone interested in the value sources of law and legislation.
2020
Authors: Cantoral Uriza Ricardo
Published: November 2020

El conjunto de sorpresas que presentó este año 2020, como defunciones y contagios a causa de la pandemia, confinamiento y desconfinamiento con varias modalidades, formas improvisadas de virtualidad en la educación, deslizamiento del costo de las tecnologías del gobierno hacia la población, escenarios “de alerta roja” ante la atención médica y más ampliamente, la aplicación de normativas más exigentes para la salud de la población; todo ello nos hace reflexionar sobre un aspecto del quehacer académico, aquel que corresponde a la publicación científica.
Criterios de clasificación en niños de preescolar utilizando bloques lógicos
Authors:   Universidad Surcolombiana, Casadiego Cabrales Alix , Avendaño Casadiego Karina ,   Universidad de Tolima, Chávarro Medina Gloria ,   Universidad Surcolombiana, Avendaño Casadiego Gabriel ,   Universidad Nacional de Colombia, Guevara Salazar Leidy Ximena ,   Universidad Surcolombiana, Avendaño Rodríguez Alvaro ,   Universidad Surcolombiana
Published: November 2020

La investigación tiene como objetivo identificar la evolución de los niños en criterios de clasificación y seriación utilizando los bloques lógicos de Dienes e indagar las preferencias de construcción de los niños durante el desarrollo del juego libre. La metodología empleada fue un estudio descriptivo mediante un código de observación, construido previamente. Los resultados mostraron que el color y el tamaño son las características que los niños más rápidamente identifican y con las cuales presenta mayor familiaridad. Un poco cercano a las anteriores se encuentra la forma. El grosor es la característica menos observada. En la semana 7, empiezan a realizar seriaciones por 2 criterios simultáneos, completándose por la mayoría al final de 9 semanas. En cuanto a las preferencias de construcción los niños prefieren recrear el mundo de la fantasía de sus cuentos que los objetos de su cotidianidad.
Institutional Change and Early-Stage Start-Up Selection: Evidence from Applicants to Venture Accelerators
Authors: Assenova Valentina A.
Published: November 2020

Existing research at the nexus of institutional theory and entrepreneurship suggests that lowering institutional barriers to forming, growing, and exiting new firms can affect the types of start-ups that entrepreneurs found in a region. These institutional changes could influence entrepreneurs’ perceptions of the value of partnering with venture accelerators and potentially improve these sponsors’ capacity to select high-growth start-ups to fund and develop. This study evaluates these ideas by developing and testing three hypotheses. First, institutional reforms improve entrepreneurs’ perceived value of venture accelerators for resources that affect new venture development. Second, they reduce the average probability of being selected for new applicants, due to a surge in the number and heterogeneity of new applicants within accelerators’ local ecosystems. Third, institutional reforms increase the quality of selected cohorts for accelerator managers due to increases in the average quality and human capital of new applicants. To evaluate these hypotheses, I analyze data from 13,770 applicants to venture accelerators over multiple application cycles between 2016 and 2018 in 170 countries. I use a differences-in-differences design to estimate the effects of institutional changes on start-up selection after regulatory reforms that reduced the time and procedures to start new firms, obtain credit, and resolve bankruptcy for entrepreneurs. The findings have valuable implications for how governments, especially those in emerging and developing economies, can support high-growth entrepreneurship.
Clinical governance: quality improvement and clinical audits in practice
Authors: Curtis Amanda
Published: November 2020

Quality improvement (QI) has been employed successfully across various industries, including human healthcare, as well as the aviation and automotive industries. In the veterinary sector, practices are starting to see the many benefits that QI can offer — particularly those that come from conducting clinical audits. Clinical audits are a part of QI and aim to look at how closely clinical practice is carried out when compared with set guidelines or protocols. This article looks at the steps of clinical auditing and some of the main barriers faced when first trying to implement them into clinical practice.
Identification of cord sources in glass using CFD
Authors:   LR Crystal, Vrábel P. , Šimurka P. , Maryška M. , Vl P. , Schill P. ,   Department of Glass and Ceramics, Prague,   Glass Service
Published: November 2020

Cord appearance in the glass industry is a serious problem in high glass quality tableware production. The increased frequency of sharp cords provoked a serious analysis on cord origin and their elimination at the production line. Optical microscopy and electron microprobe analysis (EMA) were applied as direct methods for cord identification. A computational flow dynamics calculation (CFD) and process data analysis were used to verify the hypothesised source of the inhomogeneity. The hypothesis on origin of ZrO2 free cords containing high amounts of Al2O3 was postulated in relation to the refractory material composition of the forehearth. Calculations showed that the suggested mechanism at temperatures between 1200 and 1300°C was relevant. The hypothesis was supported by a change of chemical character of the cords after partial removal of the poorly resistant material. Also the average cord frequency was reduced on a production line from 53 to 17%. CFD simulations indicated that there may exist an effective mixing strategy on cord dissolution. Increasing stirrer rotation speed in a tempering part of the forehearth had a positive effect on cord disruption. The proposed stirrer set up decreased the cord frequency to less than 2%.
Fast signal quality monitoring for coherent communications enabled by CNN-based EVM estimation
Authors: Fan Yuchuan , Udalcovs Aleksejs , Pang Xiaodan , Natalino Carlos , Furdek Marija , Popov Sergei , Ozolins Oskars
Published: November 2020

We propose a fast and accurate signal quality monitoring scheme that uses convolutional neural networks for error vector magnitude (EVM) estimation in coherent optical communications. We build a regression model to extract EVM information from complex signal constellation diagrams using a small number of received symbols. For the additive-white-Gaussian-noise-impaired channel, the proposed EVM estimation scheme shows a normalized mean absolute estimation error of 3.7% for quadrature phase-shift keying, 2.2% for 16-ary quadrature amplitude modulation (16QAM), and 1.1% for 64QAM signals, requiring only 100 symbols per constellation cluster in each observation period. Therefore, it can be used as a low-complexity alternative to conventional bit-error-rate estimation, enabling solutions for intelligent optical performance monitoring.
Hybrid liquid-membrane lenses made by one fixed and one or two active optical components
Authors: Mikš Antonín , Pokorný Petr
Published: November 2020

The paper presents a methodology of calculation of the inner structure of two- and three-component hybrid liquid-membrane lenses with variable focal length that have corrected spherical aberration and coma. Specifically, the formulas for calculation of initial-design inner parameters (radii of curvatures of individual surfaces, axial thickness, and refractive indices of a material of the lens) of a thin-lens system are derived for a hybrid two-component system (doublet) made by one glass and one liquid-membrane lens, and a hybrid three-component lens (triplet) made by one glass lens and two liquid-membrane lenses, which both have variable focal length and corrected spherical aberration and coma for an object at infinity. As optimization during the optical design process requires the starting point be very close to the optimal solution, the presented approach can be successfully used for its calculation, as it is based on fundamental proven formulas of optical aberrations.
Cylindrical vector beam multiplexing for radio-over-fiber communication with dielectric metasurfaces
Authors: Wang Chaofeng , Yang Bo , Cheng Menglong , Cheng Sihang , Liu Junmin , Xiao Jiangnan , Ye Huapeng , Li Ying , Fan Dianyuan , Chen Shuqing
Published: November 2020

Radio-over-fiber (ROF) technology, loading microwave signal on light beams, has attracted considerable attention in wireless access network for its superiority in processing high-frequency microwave signals. Multiplexing for achieving high-capacity density, however, remains elusive in ROF communication because the optical microwave occupies large bandwidth. Here, we introduce a cylindrical vector beam (CVB) multiplexing for ROF communication with dielectric Pancharatnam-Berry phase-based metasurfaces (PBMs). CVBs, a structured light beam possessing spatially nonuniform polarization distribution and carrying vector mode, provide an additional multiplexing dimension for optical communication with the advantages of weak scintillation in free-space and low mode injure in few-mode-fiber. Exploiting the spin-orbit interaction of the PB phase, we construct PBMs to manipulate CVBs, which show broadband working wavelengths ranging from C- to L-band. After 3 m free-space propagation, two multiplexed CVBs carrying 100 GHz microwave are successfully demultiplexed, and the 100 GHz ROF communication with 12 Gbit/s QPSK-OFDM signals is realized. The crosstalk of the multiplexed CVBs is less than −15.13 dB, and the bit-error-rates (BERs) are below 3.26 × 10−5. With 5 km few-mode-fiber transmission, the CVBs are also demultiplexed with the BERs of 6.51 × 10−5. These results indicate that CVB is not only capable of free-space transmission but also available for few-mode-fiber transmission, which might pave new avenues for the multiplexing of ROF communications.
Limitation of bulk GeSn alloy in the application of a high-performance laser due to the high threshold
Authors: Hong Haiyang , Zhang Lu , Qian Kun , An Yuying , Li Cheng , Li Jun , Chen Songyan , Huang Wei , Wang Jianyuan , Zhang Shuhong
Published: November 2020

In this work, the gain characteristics of the GeSn alloy are systematically investigated with effective mass approximation theory, and the potential of bulk GeSn in the application of a high-performance laser is discussed. The gain could not be enhanced persistently as the mole fraction of Sn continuously increases and becomes negative as the Sn fraction beyond 18%. An Sn fraction dependent doping scheme is proposed to effectively reduce the threshold injected carrier density to the lowest of 1.10×1018 cm-3. The optimum doping type varies from n-type to p-type as the Sn fraction increases with the conversion fraction of 10%. With doping optimization, the lowest threshold current density of bulk GeSn based laser is predicted to be 1.225 kA/cm2 for a designed n-Si0.157Ge0.643Sn0.200/p-Ge0.84Sn0.16/p-Si0.157Ge0.643Sn0.200 double heterostructure laser, indicating the inadequacy of bulk GeSn alloy of being the gain material for a high-performance laser.
Performance limits of astronomical arrayed waveguide gratings on a silica platform
Authors: Stoll Andreas , Madhav Kalaga , Roth Martin
Published: November 2020

We present a numerical and experimental study of the impact of phase errors on the performance of large, high-resolution arrayed waveguide gratings (AWG) for applications in astronomy. We use a scalar diffraction model to study the transmission spectrum of an AWG under random variations of the optical waveguide lengths. We simulate phase error correction by numerically trimming the lengths of the optical waveguides to the nearest integer multiple of the central wavelength. The optical length error distribution of a custom-fabricated silica AWG is measured using frequency-domain interferometry and Monte-Carlo fitting of interferogram intensities. In the end, we give an estimate for the phase-error limited size of a waveguide array manufactured using state-of-the-art technology. We show that post-processing eliminates phase errors as a performance limiting factor for astronomical spectroscopy in the H-band.
Compact patch antenna enabled by a metasurface with stereo elements
Authors: Li Ximing , Xi Xiang , Yang Xi , Chen Ping , Wu Rui-Xin
Published: November 2020

We implemented a novel compact antenna by applying a metasurface with stereo elements (stereo-MS) as the superstrate of a patch antenna. The stereo-MS, an array of stereo patches printed on a grooved dielectric substrate, enabled the footprint miniaturization and bandwidth enhancement of the patch antenna. The overall size reduction of the stereo-MS antenna is over 38% compared with the conventional plane metasurface (plane-MS) antenna working in the same frequency range. A prototype antenna working at 5.3 GHz was designed, fabricated, and measured. Experiments demonstrated the fractional impedance bandwidth of the antenna was 44.5% at criteria |S11 |< −10 dB, covering the frequencies 4.18 to 6.56 GHz, and the average gain about 6.9 dBi in the band. Experimental results were found in very good agreement with the design, which confirms the functionality of stereo-MS in antenna minimization. Our antenna features a compact size (0.409

λ
0
2

) and low profile (3.024 mm). The stereo-MSs provide a new way for the size miniaturization of microwave and optical devices, such as antennas.
Electrical conductance of silicon photonic waveguides
Authors: Zanetto Francesco , Perino Alessandro , Petrini Matteo , Toso Fabio , Milanizadeh Maziyar , Morichetti Francesco , Melloni Andrea , Ferrari Giorgio , Sampietro Marco
Published: November 2020

Many optoelectronic devices embedded in a silicon photonic chip, like photodetectors, modulators, and attenuators, rely on waveguide doping for their operation. However, the doping level of a waveguide is not always reflecting in an equal amount of free carriers available for conduction because of the charges and trap energy states inevitably present at the

S
i

/

S
i
O

2

interface. In a silicon-on-insulator technology with

10

15

c
m

−
3

p

-doped native waveguides, this can lead to a complete depletion of the core from free carriers and to a consequently very high electrical resistance. This Letter experimentally quantifies this effect and shows how the amount of free carriers in a waveguide can be modified and restored to the original doping value with a proper control of the chip substrate potential. A similar capability is also demonstrated by means of a specific metal gate integrated above the waveguide that allows fine control of the conductance with high locality level. This paper highlights the linearity achievable in the conductance modulation that can be exploited in a number of possible applications.
Formation and stability of vortex solitons in nematic liquid crystals
Authors: Jung Pawel S. , Izdebskaya Yana V. , Shvedov Vladlen G. , Christodoulides Demetrios N. , Krolikowski Wieslaw
Published: November 2020

We study the propagation dynamics of bright optical vortex solitons in nematic liquid crystals with a nonlocal reorientational nonlinear response. We investigate the role of optical birefringence on the stability of these solitons. In agreement with recent experimental observations, we show that the birefringence-induced astigmatism can eventually destabilize these vortex solitons. However, for low and moderate birefringence, vortex solitons can propagate stably over experimentally relevant distances.
Chirped laser dispersion spectroscopy for spectroscopic chemical sensing with simultaneous range detection
Authors: Hangauer Andreas , Chen Yifeng , Wysocki Gerard
Published: November 2020

Spectroscopic chemical detection requires knowledge or determination of an optical path for accurate quantification of path-integrated concentration of species. Continuous-wave-laser-based spectroscopic systems operating in an open integrated-path remote sensing configuration are usually not equipped for optical path determination. Here we demonstrate a measurement technique capable of simultaneous spectroscopic chemical quantification and range finding. The range-finding functionality is implemented with chirped laser dispersion spectroscopy. The methodology is potentially useful for remote chemical sensing in a hard-target LIDAR configuration and for automatic calibration of gas cells with unknown or varying lengths.
Gradient in cytoplasmic pressure in germline cells controls overlying epithelial cell morphogenesis
Authors: Lamiré Laurie-Anne , Milani Pascale , Runel Gaël , Kiss Annamaria , Arias Leticia , Vergier Blandine , de Bossoreille Stève , Das Pradeep , Cluet David , Boudaoud Arezki , Grammont Muriel
Published: November 2020

It is unknown how growth in one tissue impacts morphogenesis in a neighboring tissue. To address this, we used theDrosophilaovarian follicle, in which a cluster of 15 nurse cells and a posteriorly located oocyte are surrounded by a layer of epithelial cells. It is known that as the nurse cells grow, the overlying epithelial cells flatten in a wave that begins in the anterior. Here, we demonstrate that an anterior to posterior gradient of decreasing cytoplasmic pressure is present across the nurse cells and that this gradient acts through TGFβ to control both the triggering and the progression of the wave of epithelial cell flattening. Our data indicate that intrinsic nurse cell growth is important to control proper nurse cell pressure. Finally, we reveal that nurse cell pressure and subsequent TGFβ activity in the stretched cells combine to increase follicle elongation in the anterior, which is crucial for allowing nurse cell growth and pressure control. More generally, our results reveal that during development, inner cytoplasmic pressure in individual cells has an important role in shaping their neighbors.
Acetylation-mediated remodeling of the nucleolus regulates cellular acetyl-CoA responses
Authors: Houston Ryan , Sekine Shiori , Calderon Michael J. , Seifuddin Fayaz , Wang Guanghui , Kawagishi Hiroyuki , Malide Daniela A. , Li Yuesheng , Gucek Marjan , Pirooznia Mehdi , Nelson Alissa J. , Stokes Matthew P. , Stewart-Ornstein Jacob , Mullett Steven J. , Wendell Stacy G. , Watkins Simon C. , Finkel Toren , Sekine Yusuke
Published: November 2020

The metabolite acetyl-coenzyme A (acetyl-CoA) serves as an essential element for a wide range of cellular functions including adenosine triphosphate (ATP) production, lipid synthesis, and protein acetylation. Intracellular acetyl-CoA concentrations are associated with nutrient availability, but the mechanisms by which a cell responds to fluctuations in acetyl-CoA levels remain elusive. Here, we generate a cell system to selectively manipulate the nucleo-cytoplasmic levels of acetyl-CoA using clustered regularly interspaced short palindromic repeat (CRISPR)-mediated gene editing and acetate supplementation of the culture media. Using this system and quantitative omics analyses, we demonstrate that acetyl-CoA depletion alters the integrity of the nucleolus, impairing ribosomal RNA synthesis and evoking the ribosomal protein-dependent activation of p53. This nucleolar remodeling appears to be mediated through the class IIa histone deacetylases (HDACs). Our findings highlight acetylation-mediated control of the nucleolus as an important hub linking acetyl-CoA fluctuations to cellular stress responses.
Predicting changes in protein thermodynamic stability upon point mutation with deep 3D convolutional neural networks
Authors: Li Bian , Yang Yucheng T. , Capra John A. , Gerstein Mark B.
Published: November 2020

Predicting mutation-induced changes in protein thermodynamic stability (ΔΔG) is of great interest in protein engineering, variant interpretation, and protein biophysics. We introduce ThermoNet, a deep, 3D-convolutional neural network (3D-CNN) designed for structure-based prediction of ΔΔGs upon point mutation. To leverage the image-processing power inherent in CNNs, we treat protein structures as if they were multi-channel 3D images. In particular, the inputs to ThermoNet are uniformly constructed as multi-channel voxel grids based on biophysical properties derived from raw atom coordinates. We train and evaluate ThermoNet with a curated data set that accounts for protein homology and is balanced with direct and reverse mutations; this provides a framework for addressing biases that have likely influenced many previous ΔΔG prediction methods. ThermoNet demonstrates performance comparable to the best available methods on the widely used Ssym test set. In addition, ThermoNet accurately predicts the effects of both stabilizing and destabilizing mutations, while most other methods exhibit a strong bias towards predicting destabilization. We further show that homology between Ssym and widely used training sets like S2648 and VariBench has likely led to overestimated performance in previous studies. Finally, we demonstrate the practical utility of ThermoNet in predicting the ΔΔGs for two clinically relevant proteins, p53 and myoglobin, and for pathogenic and benign missense variants from ClinVar. Overall, our results suggest that 3D-CNNs can model the complex, non-linear interactions perturbed by mutations, directly from biophysical properties of atoms.