bluuebunny/crossref_metadata_2025 huggingface dataset:
Public-private knowledge transfer and access to medicines: a systematic review and qualitative study of perceptions and roles of scientists involved in HPV vaccine research
Authors: Jahn Rosa , Müller Olaf , Nöst Stefan , Bozorgmehr Kayvan
Published: March 2020

Background

Public research organizations and their interactions with industry partners play a crucial role for public health and access to medicines. The development and commercialization of the Human Papillomavirus (HPV) vaccines illustrate how licensing practices of public research organizations can contribute to high prices of the resulting product and affect accessibility to vulnerable populations. Efforts by the international community to improve access to medicines have recognised this issue and promote the public health-sensitive management of research conducted by public research organizations. This paper explores: how medical knowledge is exchanged between public and private actors; what role inventor scientists play in this process; and how they view the implementation of public health-sensitive knowledge exchange strategies.

Methods

We conducted a systematic qualitative literature review on medical knowledge exchange and qualitative interviews with a purposive sample of public sector scientists working on HPV vaccines. We explored the strategies by which knowledge is exchanged across institutional boundaries, how these strategies are negotiated, and the views of scientists regarding public health-sensitive knowledge exchange.

Results

We included 13 studies in the systematic review and conducted seven semi-structured interviews with high-ranking scientists. The main avenues of public-private medical knowledge exchange were publications, formal transfer of patented knowledge, problem-specific exchanges such as service agreements, informal exchanges and collaborative research. Scientists played a crucial role in these processes but appeared to be sceptical of public health-sensitive knowledge exchange strategies, as these were believed to deter corporate interest in the development of new medicines and thus risk the translation of the scientists’ research.

Conclusion

Medical scientists at public research institutions play a key role in the exchange of knowledge they generate and are concerned about the accessibility of medicines resulting from their research. Their scepticism towards implementing public health-sensitive knowledge management strategies appears to be based on a biased understanding of the costs and risks involved in drug development and a perceived lack of alternatives to private engagement. Scientists could be encouraged to exchange knowledge in a public health-sensitive manner through not-for-profit drug development mechanisms, education on industry engagement, and stronger institutional and legal backing.
Anatomic change over the course of treatment for non–small cell lung cancer patients and its impact on intensity-modulated radiation therapy and passive-scattering proton therapy deliveries
Authors: Chen Mei , Yang Jinzhong , Liao Zhongxing , Chen Jiayi , Xu Cheng , He Xiaodong , Zhang Xiaodong , Zhu Ronald X. , Li Heng
Published: March 2020

Purpose

To quantify tumor anatomic change of non-small cell lung cancer (NSCLC) patients given passive-scattering proton therapy (PSPT) and intensity-modulated radiation therapy (IMRT) through 6–7 weeks of treatment, and analyze the correlation between anatomic change and the need to adopt adaptive radiotherapy (ART).

Materials and methods

Weekly 4D CT sets of 32 patients (8/8 IMRT with/without ART, 8/8 PSPT with/without ART) acquired during treatment, were registered to the planning CT using an in-house developed deformable registration algorithm. The anatomic change was quantified as the mean variation of the region of interest (ROI) relative to the planning CT by averaging the magnitude of deformation vectors of all voxels within the ROI contour. Mean variations of GTV and CTV were compared between subgroups classified by ART status and treatment modality using the independent t-test. Logistic regression analysis was performed to clarify the effect of anatomic change on the probability of ART adoption.

Results

There was no significant difference (p = 0.679) for the time-averaged mean CTV variations from the planning CT between IMRT (7.61 ± 2.80 mm) and PSPT (7.21 ± 2.67 mm) patients. However, a significant difference (p = 0.001) was observed between ART (8.93 ± 2.19 mm) and non-ART (5.90 ± 2.33 mm) patients, when treatment modality was not considered. Mean CTV variation from the planning CT in all patients increases significantly (p < 0.001), with a changing rate of 1.77 mm per week. Findings for the GTV change was similar. The logistic regression model correctly predicted 71.9% of cases in ART adoption. The correlation is stronger in the PSPT group with a pseudo R2 value of 0.782, compared to that in the IMRT group (pseudo R2 = 0.182).

Conclusion

The magnitude of target volume variation over time could be greater than the usual treatment margin. Mean target volume variation from the planning position can be used to identify lung cancer patients that may need ART.
Long non-coding RNA HUMT hypomethylation promotes lymphangiogenesis and metastasis via activating FOXK1 transcription in triple-negative breast cancer
Authors: Zheng Shaoquan , Yang Lu , Zou Yutian , Liang Jie-ying , Liu Peng , Gao Guanfeng , Yang Anli , Tang Hailin , Xie Xiaoming
Published: March 2020

Background

Triple-negative breast cancer (TNBC) is the most malignant subtype of breast cancer with highly invasive ability and metastatic nature to the lymph nodes. Long non-coding RNAs (lncRNAs) have been widely explored in cancer tumorigenesis and progression. However, their roles in TNBC lymph node metastasis remains rarely studied.

Methods

The expression of lncRNA highly upregulated in metastatic TNBC (HUMT) in cell lines and tissues was detected by quantitative real-time PCR (qRT-PCR) and in situ hybridization (ISH). RNA immunoprecipitation (RIP) and RNA pulldown were used to verify the interaction between lncRNA and protein. Chromatin immunoprecipitation (CHIP) and dCas9-gRNA-guided chromatin immunoprecipitation (dCas9-CHIP) were conducted to identify the specific binding site of HUMT-YBX1 complex. Western blot was used to detect the downstream of HUMT.

Results

HUMT was significantly upregulated in lymph node invasive cells and predicted poorer clinical prognosis. Functional study indicated that HUMT promoted lymphangiogenesis and lymph node metastasis. Bioinformatic analysis and qRT-PCR showed that the high expression of HUMT was correlated with the hypomethylation status of its promoter region. Further, HUMT recruited Y-box binding protein 1 (YBX1) to form a novel transcription complex and activated the expression of forkhead box k1 (FOXK1), thus enhancing the expression of vascular endothelial growth factor C (VEGFC). The therapeutic value was further validated in patient-derived xenograft (PDX) models, and a combined marker panel exhibited a better prognostic value for TNBC in receiver operating characteristic (ROC) analysis.

Conclusions

Our study identified a novel TNBC lymph node metastasis-associated lncRNA, which promoted TNBC progression and indicated a novel biomarker and potential therapeutic target for TNBC lymph node metastasis.
Decontamination of ambient RNA in single-cell RNA-seq with DecontX
Authors: Yang Shiyi , Corbett Sean E. , Koga Yusuke , Wang Zhe , Johnson W Evan , Yajima Masanao , Campbell Joshua D.
Published: March 2020

Droplet-based microfluidic devices have become widely used to perform single-cell RNA sequencing (scRNA-seq). However, ambient RNA present in the cell suspension can be aberrantly counted along with a cell’s native mRNA and result in cross-contamination of transcripts between different cell populations. DecontX is a novel Bayesian method to estimate and remove contamination in individual cells. DecontX accurately predicts contamination levels in a mouse-human mixture dataset and removes aberrant expression of marker genes in PBMC datasets. We also compare the contamination levels between four different scRNA-seq protocols. Overall, DecontX can be incorporated into scRNA-seq workflows to improve downstream analyses.
Correction to: Study of the mechanism of change in flavonoid composition in the processing of Chrysanthemum morifolium (Ramat.) Tzvel. ‘Boju’
Authors: Zhang Wei , Zuo Yafeng , Xu Fengqing , Wang Tongsheng , Liu Jinsong , Wu Deling
Published: March 2020

Following publication of the original article [1], the author reported an error in the reference citation. In Results and Discussion section, Zhang et al. [2] should be cited after the first and third sentences of the first paragraph under the sub-section “Determination of main components in different processed products of Boju”. The reference has been included in the list.
Potential of Zymomonas mobilis as an electricity producer in ethanol production
Authors: Geng Bo-Yu , Cao Lian-Ying , Li Feng , Song Hao , Liu Chen-Guang , Zhao Xin-Qing , Bai Feng-Wu
Published: March 2020

Background

Microbial fuel cell (MFC) convokes microorganism to convert biomass into electricity. However, most well-known electrogenic strains cannot directly use glucose to produce valuable products. Zymomonas mobilis, a promising bacterium for ethanol production, owns special Entner–Doudoroff pathway with less ATP and biomass produced and the low-energy coupling respiration, making Z. mobilis a potential exoelectrogen.

Results

A glucose-consuming MFC is constructed by inoculating Z. mobilis. The electricity with power density 2.0 mW/m2 is derived from the difference of oxidation–reduction potential (ORP) between anode and cathode chambers. Besides, two-type electricity generation is observed as glucose-independent process and glucose-dependent process. For the sake of enhancing MFC efficiency, extracellular and intracellular strategies are implemented. Biofilm removal and addition of c-type cytochrome benefit electricity performance and Tween 80 accelerates the electricity generation. Perturbation of cellular redox balance compromises the electricity output, indicating that redox homeostasis is the principal requirement to reach ideal voltage.

Conclusion

This study identifies potential feature of electricity activity for Z. mobilis and provides multiple strategies to enhance the electricity output. Therefore, additional electricity generation will benefit the techno-economic viability of the commercial bulk production for biochemicals or biofuels in an efficient and environmentally sustainable manner.
In vivo visualization of the i-motif DNA secondary structure in the Bombyx mori testis
Authors: Tang Wenhuan , Niu Kangkang , Yu Guoxing , Jin Ying , Zhang Xian , Peng Yuling , Chen Shuna , Deng Huimin , Li Sheng , Wang Jian , Song Qisheng , Feng Qili
Published: March 2020

Background

A large number of in vitro experiments have confirmed that DNA molecules can form i-motif advanced structure when multiple cytosines exist in the sequence. However, whether these structures are present in vivo environment still lacks sufficient experimental evidence.

Results

In this paper, we report the in vivo visualization of i-motif structures in the nuclei and chromosomes of the testis of the invertebrate Bombyx mori using immunofluorescence staining with an antibody specifically recognizing the endogenous transcription factor BmILF, which binds i-motif structure with high specificity. The number of i-motif structures observed in the genome increased when the pH was changed from basic to acidic and decreased under treatment with an i-motif inhibitor, the porphyrin compound TMPyP4. The pH change affected the transcription of genes that contain i-motif sequences. Moreover, there were more i-motif structures observed in the testis cells in interphase than in any other cell cycle stage.

Conclusions

In this study, the i-motif structures in invertebrates were detected for the first time at the cell and organ levels. The formation of the structures depended on cell cycle and pH and affected gene expression.
Dietary phytochemical index and overweight/obesity in children: a cross-sectional study
Authors: Eslami Omid , Khoshgoo Mahdi , Shidfar Farzad
Published: March 2020

Objective

The aim of the present study was to examine the relationship between the dietary phytochemical index (DPI) and overweight/obesity in children. This cross-sectional study was comprised of 356 children aged 7 to 10 years-old study in the city of Tehran, Iran. The dietary intake of participants was collected using a validated food frequency questionnaire. The DPI was calculated based on the daily energy derived from phytochemical-rich foods. The definition of overweight and obesity was based on the criteria developed by the US Chronic Disease Center for prevention and health promotion.

Results

The overall prevalence of overweight/obesity was 35.1%. The mean (standard deviation) of the DPI was 14.25 (4.13), 24.12 (2.64), 35.41 (3.62) and 61.52 (16.47) in the first, second, third and fourth quartiles (Q), respectively. Subjects in the higher quartiles of DPI had a significantly higher intake of dietary fiber, vitamin C, and potassium compared to those in the lower quartiles. In the multiple regression analysis, subjects in the highest quartile of DPI had significantly lower odds of being overweight/obese compared to those in the first quartile [odds ratio and 95% confidence intervals for Q4 vs. Q1: 0.47 (0.25, 0.87); P for trend = 0.02].
Genetic barcoding reveals clonal dominance in iPSC-derived mesenchymal stromal cells
Authors: Hollmann Jonathan , Brecht Johanna , Goetzke Roman , Franzen Julia , Selich Anton , Schmidt Marco , Eipel Monika , Ostrowska Alina , Hapala Jan , Fernandez-Rebollo Eduardo , Müller-Newen Gerhard , Rothe Michael , Eggermann Thomas , Zenke Martin , Wagner Wolfgang
Published: March 2020

Background

The use of mesenchymal stromal cells (MSCs) for research and clinical application is hampered by cellular heterogeneity and replicative senescence. Generation of MSC-like cells from induced pluripotent stem cells (iPSCs) may circumvent these limitations, and such iPSC-derived MSCs (iMSCs) are already tested in clinical trials. So far, a comparison of MSCs and iMSCs was particularly addressed in bulk culture. Despite the high hopes in cellular therapy, only little is known how the composition of different subclones changes in these cell preparations during culture expansion.

Methods

In this study, we used multicolor lentiviral genetic barcoding for the marking of individual cells within cell preparations. Based on this, we could track the clonal composition of syngenic MSCs, iPSCs, and iMSCs during culture expansion. Furthermore, we analyzed DNA methylation patterns at senescence-associated genomic regions by barcoded bisulfite amplicon sequencing. The proliferation and differentiation capacities of individual subclones within MSCs and iMSCs were investigated with limiting dilution assays.

Results

Overall, the clonal composition of primary MSCs and iPSCs gradually declined during expansion. In contrast, iMSCs became oligoclonal early during differentiation, indicating that they were derived from few individual iPSCs. This dominant clonal outgrowth of iMSCs was not associated with changes in chromosomal copy number variation. Furthermore, clonal dynamics were not clearly reflected by stochastically acquired DNA methylation patterns. Limiting dilution assays revealed that iMSCs are heterogeneous in colony formation and in vitro differentiation potential, while this was even more pronounced in primary MSCs.

Conclusions

Our results indicate that the subclonal diversity of MSCs and iPSCs declines gradually during in vitro culture, whereas derivation of iMSCs may stem from few individual iPSCs. Differentiation regimen needs to be further optimized to achieve homogeneous differentiation of iPSCs towards iMSCs.
Kinetic modeling of 68Ga-PSMA-11 and validation of simplified methods for quantification in primary prostate cancer patients
Authors: Ringheim Anna , Campos Neto Guilherme de Carvalho , Anazodo Udunna , Cui Lumeng , da Cunha Marcelo Livorsi , Vitor Taise , Martins Karine Minaif , Miranda Ana Cláudia Camargo , de Barboza Marycel Figols , Fuscaldi Leonardo Lima , Lemos Gustavo Caserta , Colombo Junior José Roberto , Baroni Ronaldo Hueb
Published: March 2020

Background

The positron emission tomography (PET) ligand 68Ga-Glu-urea-Lys(Ahx)-HBED-CC (68Ga-PSMA-11) targets the prostate-specific membrane antigen (PSMA), upregulated in prostate cancer cells. Although 68Ga-PSMA-11 PET is widely used in research and clinical practice, full kinetic modeling has not yet been reported nor have simplified methods for quantification been validated. The aims of our study were to quantify 68Ga-PSMA-11 uptake in primary prostate cancer patients using compartmental modeling with arterial blood sampling and to validate the use of standardized uptake values (SUV) and image-derived blood for quantification.

Results

Fifteen patients with histologically proven primary prostate cancer underwent a 60-min dynamic 68Ga-PSMA-11 PET scan of the pelvis with axial T1 Dixon, T2, and diffusion-weighted magnetic resonance (MR) images acquired simultaneously. Time-activity curves were derived from volumes of interest in lesions, normal prostate, and muscle, and mean SUV calculated. In total, 18 positive lesions were identified on both PET and MR. Arterial blood activity was measured by automatic arterial blood sampling and manual blood samples were collected for plasma-to-blood ratio correction and for metabolite analysis. The analysis showed that 68Ga-PSMA-11 was stable in vivo. Based on the Akaike information criterion, 68Ga-PSMA-11 kinetics were best described by an irreversible two-tissue compartment model. The rate constants K1 and k3 and the net influx rate constants Ki were all significantly higher in lesions compared to normal tissue (p < 0.05). Ki derived using image-derived blood from an MR-guided method showed excellent agreement with Ki derived using arterial blood sampling (intraclass correlation coefficient = 0.99). SUV correlated significantly with Ki with the strongest correlation of scan time-window 30–45 min (rho 0.95, p < 0.001). Both Ki and SUV correlated significantly with serum prostate specific antigen (PSA) level and PSA density.

Conclusions

68Ga-PSMA-11 kinetics can be described by an irreversible two-tissue compartment model. An MR-guided method for image-derived blood provides a non-invasive alternative to blood sampling for kinetic modeling studies. SUV showed strong correlation with Ki and can be used in routine clinical settings to quantify 68Ga-PSMA-11 uptake.
P2X7 receptor mediates NLRP3 inflammasome activation in depression and diabetes
Authors: Wang Danwen , Wang Hui , Gao Haixia , Zhang Heng , Zhang Hua , Wang Qiuling , Sun Zhiling
Published: March 2020

The increasing prevalence of depression and diabetes mellitus has become a major public health problem worldwide. Studies have shown that people with diabetes are at a high risk of being diagnosed with depression, and diabetes complicates depression treatment by promoting the deterioration of glycemic control, reducing self-care ability and quality of life, and causing severe functional disability and early mortality. Moreover, health deterioration dramatically increases the financial cost of social and health care system. Thus, how to treat depression, diabetes, and diabetes complicated by depression has become one of the world’s urgent concerns. The activation of nod-like receptor family pyrin domain containing 3 (NLRP3) is closely related to mental illness. This finding provides a new perspective for studying depression. NLRP3 plays an important role in the development of diabetes. In this review, we elaborate the definition and epidemiology of depression, diabetes, and diabetic depression and introduce the functional characteristics of an NLRP3 inflammasome and upstream P2X7 receptor. Moreover, related research on NLRP3 inflammasomes and P2X7 receptors is summarized and used as a reference for confirming that the excessive activation of P2X7- NLRP3 leads to the increased release of inflammatory cytokines, such as IL-1β, in depression and diabetes. We provide insights into the P2X7–NLRP3–IL-1β pathway as an important pathological mechanism and novel therapeutic target in diabetes and depression. Given that the P2X7–NLRP3–IL-1β pathway may play an important role in diabetes confounded by comorbid depression, the possibility of intervention with baicalin is proposed.
Enhancing physical layer security via channel feedback: a survey
Authors: Dai Bin , Li Chong , Liang Yingbin , Poor H. Vincent , (Shitz) Shlomo Shamai
Published: March 2020

Physical layer security (PLS), which is based on information-theoretic principles of message confidentiality, has attracted considerable attention in recent years. This paper provides a comprehensive survey of using channel feedback (CF) to enhance the quality of PLS of various communication models. To be specific, the survey starts from the secret key-based CF scheme and its variations for the wiretap channel (WTC) and other communication models. Then, for the WTC and its generalized models, an improved feedback scheme and its variations are respectively introduced, where the improved scheme combines the secret key-based CF scheme with the Wyner-Ziv scheme for source coding with side information. It has been shown that these improved schemes perform better than the original secret key-based schemes for several cases. Next, the Schalkwijk-Kailath (SK) feedback scheme and its variations are introduced, which are optimal for the Gaussian WTC and its variations. Finally, the already existing CF schemes are summarized and the future challenges of using CF to enhance PLS are discussed.
Modelling wooden cultural heritage. The need to consider each artefact as unique as illustrated by the Cannone violin
Authors: Marcon Bertrand , Goli Giacomo , Fioravanti Marco
Published: March 2020

This research work investigates the possibility to use a hygroscopic model based on Fick’s law to predict the global moisture content variations an historical violin undergoes during a concert. To set up the model to work some input are required such as: the object geometries, the wood species used, the thicknesses, the moisture diffusion coefficients, the permeability of varnished surfaces, the anhydrous masses of the moisture exchanging parts, the sorption isotherms, information often far from being available or measurable. At a first extent, the model was run on the environmental conditions recorded during nine concerts played with the “Cannone” violin (1743) and the computed mass variations compared with the mass variations recorded during the same concerts. The model, set with simplifying conditions and with diffusion coefficients from literature, has shown a very little predictive capacity. On the other hand, the model was tuned on the experimental data using an inverse procedure for moisture diffusion coefficient identification. After the tuning the model has shown a very good predictive ability showing how Fick’s low can be profitably used to assess the mass transfer in a complex heritage object such as a violin. This paper highlights the possibility to successfully use the Fick’s law to model mass transfer in a violin but also makes evident how such models must be tuned with real measurements in order to be effective.
A case of septic pulmonary embolism caused by P. aeruginosa in a hemodialysis patient and review of the literature
Authors: Shimada Hiroki , Tanaka Mari , Takami Yohtaro , Teragaki Mariko , Maeda Kotaro , Saita Hirona , Nishikawa Seira , Taniguchi Keisuke , Iwanari Sachio , Ikeda Masaki , Takeoka Hiroya
Published: March 2020

Background

Septic pulmonary embolism (SPE) is an uncommon but serious complication resulting from infection of the blood. Gram-positive cocci, including methicillin-susceptible Staphylococcus aureus and methicillin-resistant Staphylococcus aureus, are the most common causative organisms of SPE. Few case reports have been published on SPE caused by Pseudomonas aeruginosa (P. aeruginosa), and thus, the consensus treatment of SPE caused by P. aeruginosa infections remains undetermined. Management of P. aeruginosa infection can be challenging due to its poor prognosis and antimicrobial resistance. Here, we report a case of successful combination antibiotic therapy for SPE associated with infective endocarditis (IE) caused by P. aeruginosa in a hemodialysis patient, with a review of the literature.

Case presentation

A 62-year-old man receiving maintenance hemodialysis as treatment for end-stage renal disease due to IgA nephropathy was admitted to our hospital with high fever and chills lasting 10 days. Chest computed tomography revealed multiple nodular shadows, and gram-negative rods were confirmed by blood culture obtained on admission. We suspected SPE and initiated meropenem (MEPM) treatment. P. aeruginosa was identified in blood cultures, and transesophageal echocardiography demonstrated vegetation on the tricuspid valve. Therefore, a diagnosis of SPE associated with IE caused by P. aeruginosa was made. P. aeruginosa isolates showed good susceptibility to MEPM, but no symptomatic improvement was observed. Thus, antibiotics were changed from MEPM to a combination of ceftazidime and tobramycin (TOB). The patient exhibited a favorable response to the combination therapy, although we discontinued TOB on day 23 because of tinnitus symptoms.

Conclusions

We report a rare case of SPE associated with IE caused by P. aeruginosa in a hemodialysis patient. Combination antibiotic therapy may be effective in this situation.
The burden of Japanese encephalitis, the catch-up vaccination campaign, and health service providers’ perceptions in Myanmar: 2012–2017
Authors: Win Aung Ye Naung , Wai Khin Thet , Harries Anthony D. , Kyaw Nang Thu Thu , Oo Tin , Than Wint Phyo , Lin Htar Htar , Lin Zaw
Published: March 2020

Background

Myanmar is endemic for Japanese encephalitis (JE) and has experienced several outbreaks in recent years. The vector-borne disease control (VBDC) program has collected hospital-based surveillance data since 1974. There is an urgent need to collate, analyze, and interpret the most recent information. The study aimed to describe (i) hospital-based JE cases and deaths between 2012 and 2017, (ii) a catch-up vaccination campaign in children in 2017, and (iii) health service provider perceptions about JE in one township in 2018.

Methods

This was a cross-sectional study of cases, deaths, and catch-up childhood vaccinations using secondary data from program records and a survey database of health service provider perceptions.

Results

Between 2012 and 2017, there were 872 JE cases and 79 deaths with a case fatality rate of 91 per 1000; 2016 was the year with most cases and deaths. Most cases (n = 324) and deaths (n = 37) occurred in children aged 5–9 years. Large case numbers were reported in delta and lowland regions (n = 550) and during the wet season (n = 580). The highest case fatality rates were observed in the hills and coastal regions (120 and 112 per 1000, respectively). Nationwide coverage of the catch-up JE vaccination campaign among 13.7 million eligible children was 92%, with coverage lower in the hills and coastal regions (84%) compared with delta and lowland regions and plains (94%). More vaccinations (65%) occurred through school-based campaigns with the remainder (35%) vaccinated through community-based campaigns. Structured interviews in one township showed that service providers (n = 47) had good perceptions about various aspects of JE, although perceived benefits of specific vector control measures were poor: spraying/fumigation (38%), garbage removal (36%), larvicide use (36%), and drainage of standing/stagnant water (32%).

Conclusion

The catch-up vaccination campaign was a successful response to high JE case numbers and deaths in children. However, ongoing surveillance for JE needs to continue and be strengthened to ensure comprehensive reporting of all cases, more knowledge is needed on disability in JE survivors, and all attempts must be made to ensure high percentage coverage of vaccination through routine and catch-up campaigns.
Horosphere slab separation theorems in manifolds without conjugate points
Authors: Shenawy Sameh
Published: March 2020

Let$\mathcal {W}^{n}$Wnbe the set of smooth complete simply connectedn-dimensional manifolds without conjugate points. The Euclidean space and the hyperbolic space are examples of these manifolds. Let$W\in \mathcal {W}^{n}$W∈Wnand letAandBbe two convex subsets ofW. This note aims to investigate separation and slab horosphere separation ofAandB. For example,sufficient conditions onAandBto be separated by a slab of horospheres are obtained. Existence and uniqueness of foot points and farthest points of a convex setAin$W\in \mathcal {W}$W∈Ware considered.
Mixed convection flow of nanofluid with Hall and ion-slip effects using spectral relaxation method
Authors: Ibrahim Wubshet , Anbessa Temesgen
Published: March 2020

In this article, the Hall and ion-slip effects on a mixed convection flow of an electrically conducting nanofluid over a stretching sheet in a permeable medium have been discussed. Using the similarity transformations, the partial differential equations corresponding to the momentum, energy, and concentration equations are transformed to a system of nonlinear ordinary differential equations which are solved numerically using a spectral relaxation method (SRM). The effects of significant parameters on the velocities, temperature, and concentration profiles are analyzed graphically. Moreover, the results of the skin friction coefficients, local Nusselt number, and Sherwood number are determined numerically. The results of the analysis showed that the velocity profile in the flow direction increases with an increase in mixed convection parameter λ, Hall parameter βh, and ion-slip parameter βi, and it decreases with an increase in the magnetic parameter M. Furthermore, temperature and concentration profiles decrease as the mixed convection parameter λ and buoyancy ratio Nr increase. It is also observed that the skin friction coefficients, local Nusselt number, and Sherwood number increase with an increase in the Hall parameter βh, mixed convection parameter λ, and buoyancy ratio Nr.
Fourth-order stable central difference with Richardson extrapolation method for second-order self-adjoint singularly perturbed boundary value problems
Authors: Siraj Muslima Kedir , Duressa Gemechis File , Bullo Tesfaye Aga
Published: March 2020

This study introduces a stable central difference method for solving second-order self-adjoint singularly perturbed boundary value problems. First, the solution domain is discretized. Then, the derivatives in the given boundary value problem are replaced by finite difference approximations and the numerical scheme that provides algebraic systems of equations is developed. The obtained system of algebraic equations is solved by Thomas algorithm. The consistency and stability that guarantee the convergence of the scheme are investigated. The established convergence of the scheme is further accelerated by applying the Richardson extrapolation which yields sixth order convergent. To validate the applicability of the method, two model examples are solved for different values of perturbation parameter ε and different mesh size h. The proposed method approximates the exact solution very well. Moreover, the present method is convergent and gives more accurate results than some existing numerical methods reported in the literature.
Fekete-Szegő inequalities for certain class of analytic functions connected with q-analogue of Bessel function
Authors: M. El-Deeb Sheza , Bulboacă Teodor
Published: March 2020

In this paper, we obtain Fekete-Szegő inequalities for a certain class of analytic functionsfsatisfying$1+\frac {1}{\zeta }\left [\frac {z\left (\mathcal {N}_{\nu,q}^{\lambda }f(z)\right)^{\prime }} {(1-\gamma)\mathcal {N} _{\nu,q}^{\lambda }f(z)+\gamma z\left (\mathcal {N}_{\nu,q}^{\lambda }f(z) \right)^{\prime }}-1\right ]\prec \Psi (z)$1+1ζzNν,qλf(z)′(1−γ)Nν,qλf(z)+γzNν,qλf(z)′−1≺Ψ(z). Application of our results to certain functions defined by convolution products with a normalized analytic function is given, and in particular, Fekete-Szegő inequalities for certain subclasses of functions defined through Poisson distribution are obtained.
Existence of cooperative search technique to find a Brownian target
Authors: El-Hadidy Mohamed Abd Allah
Published: March 2020

This article aims to study the existence of the cooperative search technique to find a Brownian target. We have 2n cooperative searchers coordinate their search to find a Brownian target that moves on one of n disjoint real lines. Each line has two searchers. All of these searchers start the searching process from the origin. Rather than finding the conditions that make the expected value of the first interviewing time between one of the searchers and the target is finite, we compute the approximate value of this expected value.
Multiset filters
Authors: Zakaria Amr , John Sunil Jacob , Girish K. P.
Published: March 2020

A multiset is a collection of objects in which repetition of elements is essential. This paper is an attempt to generalize the notion of filters in the multiset context. In addition, many deviations between multiset filters and ordinary filters have been presented. The relation between multiset filter and multiset ideal has been mentioned. Many properties of multiset filters, multiset ultrafilters, and convergence of multiset filters have been introduced. Also, the notions of basis and subbasis have been mentioned in the multiset context. Finally, several examples have been studied.
An algorithm for solving the bi-objective median path-shaped facility on a tree network
Authors: Aboutahoun Abdallah , El-Safty Fatma
Published: March 2020

In this paper, an algorithm for the bi-objective median path (BMP) problem on a tree network is considered. The algorithm is based on the two-phase method which can compute all Pareto solutions for the BMP problem. The first phase is applied to find supported Pareto solutions by solving the uni-objective problem D(P,λ). The second phase is used to compute the unsupported Pareto solutions by applying a k-best algorithm which computes the k-best Pareto solutions in order of their objective values.
Characterization of aged male BALB/ccenp mice as a model of dementia
Authors: Esquivel Nashelly , García Yenela , Lores Bestraida , Gutiérrez Marivy , Rodríguez Claudio
Published: March 2020

Dementia is defined as cognitive impairment in more than one cognitive area and leads to an abnormal degree of impairment in the ability to remember past events. Among mice models of dementia the most used strains are SAMP8 and C57BL/6. There is no reference to characterizing a model of dementia in naturally aged mice of the BALB/c strain, or to the minimum age at which these animals can be used. The aim of this study was the characterization of aged male BALB/ccenp mice as a model of dementia from the evaluation of behavioural, pathological and biochemical markers. One hundred and twenty mice were used and 10 of these were analysed from 8 to 9 months of age, and every 4 months, in a comparative way to young control animals from 4 to 5 months. At the age of 12–13 months there was cognitive impairment in the animals from the Y-maze and object recognition tests and this impairment was maintained at 16–17 months of age. An increase in oxidative damage to proteins in the brains of aged animals was also found in relation to young animals; as well as a decrease in the concentration of triglycerides. At the age of 16–17 months, a significant decrease in the size of the thymus and brain was obtained. We consider that it’s a very useful option to use animals 12–13 months of age where there are symptoms of cognitive deficiency, histopathological and biochemical elements characteristic of dementia.
Systematic Review of Privacy-Preserving Distributed Machine Learning From Federated Databases in Health Care
Authors: Zerka Fadila , Barakat Samir , Walsh Sean , Bogowicz Marta , Leijenaar Ralph T. H. , Jochems Arthur , Miraglio Benjamin , Townend David , Lambin Philippe
Published: March 2020

Big data for health care is one of the potential solutions to deal with the numerous challenges of health care, such as rising cost, aging population, precision medicine, universal health coverage, and the increase of noncommunicable diseases. However, data centralization for big data raises privacy and regulatory concerns.

Covered topics include (1) an introduction to privacy of patient data and distributed learning as a potential solution to preserving these data, a description of the legal context for patient data research, and a definition of machine/deep learning concepts; (2) a presentation of the adopted review protocol; (3) a presentation of the search results; and (4) a discussion of the findings, limitations of the review, and future perspectives.

Distributed learning from federated databases makes data centralization unnecessary. Distributed algorithms iteratively analyze separate databases, essentially sharing research questions and answers between databases instead of sharing the data. In other words, one can learn from separate and isolated datasets without patient data ever leaving the individual clinical institutes.

Distributed learning promises great potential to facilitate big data for medical application, in particular for international consortiums. Our purpose is to review the major implementations of distributed learning in health care.
State of the Art: Toward Improving Outcomes of Lung and Liver Tumor Biopsies in Clinical Trials—A Multidisciplinary Approach
Authors: Levy Elliot B. , Fiel Maria I. , Hamilton Stanley R. , Kleiner David E. , McCall Shannon J. , Schirmacher Peter , Travis William , Kuo Michael D. , Suh Robert D. , Tam Alda L. , Islam Shaheen U. , Ferry-Galow Katherine , Enos Rebecca A. , Doroshow James H. , Makhlouf Hala R.
Published: March 2020

PURPOSE

National Cancer Institute (NCI)–sponsored clinical trial network studies frequently require biopsy specimens for pharmacodynamic and molecular biomarker analyses, including paired pre- and post-treatment samples. The purpose of this meeting of NCI-sponsored investigators was to identify local institutional standard procedures found to ensure quantitative and qualitative specimen adequacy.

METHODS

NCI convened a conference on best biopsy practices, focusing on the clinical research community. Topics discussed were (1) criteria for specimen adequacy in the personalized medicine era, (2) team-based approaches to ensure specimen adequacy and quality control, and (3) risk considerations relevant to academic and community practitioners and their patients.

RESULTS AND RECOMMENDATIONS

Key recommendations from the convened consensus panel included (1) establishment of infrastructure for multidisciplinary biopsy teams with a formalized information capture process, (2) maintenance of standard operating procedures with regular team review, (3) optimization of tissue collection and yield methodology, (4) incorporation of needle aspiration and other newer techniques, and (5) commitment of stakeholders to use of guideline documents to increase awareness of best biopsy practices, with the goal of universally improving tumor biopsy practices.
Limits to sustained energy intake. XXX. Constraint or restraint? Manipulations of food supply show peak food intake in lactation is constrained
Authors: Zhao Zhi-Jun , Derous Davina , Gerrard Abby , Wen Jing , liu Xue , Tan Song , Hambly Catherine , Speakman John R.
Published: March 2020

Lactating mice increase food intake 4-5 fold, reaching an asymptote in late lactation. A key question is whether this asymptote reflects a physiological constraint, or a maternal investment strategy (a ‘restraint’). We exposed lactating mice to periods of food restriction, hypothesizing that if the limit reflected restraint they would compensate by breaching the asymptote when refeeding. In contrast, if it was a constraint they would by definition be unable to increase their intake on refeeding days. Using isotope methods we found that during food restriction the females shut down milk production impacting offspring growth. During refeeding food intake and milk production rose again, but not significantly above unrestricted controls. Hypothalamic transcriptome profiling showed that following restriction lactating mice did not upregulate transcription of genes in the hunger signaling network, suggesting this may impose the constraint. These data provide strong evidence that asymptotic intake in lactation reflects a physiological/physical constraint, rather than restraint. Because hypothalamic neuropeptide Y (Npy) was upregulated under both states of restriction this suggests the constraint is not imposed by limits in the capacity to upregulate hunger signaling (the saturated neural capacity hypothesis). Understanding the genetic basis of the constraint will be a key future goal and will provide us additional information on the nature of the constraining factors on reproductive output, and their potential links to life history strategies.
The histogram analysis of apparent diffusion coefficient in differential diagnosis of parotid tumor
Authors: Chen Peiqian , Dong Bing , Zhang Chunye , Tao Xiaofeng , Wang Pingzhong , Zhu Ling
Published: March 2020

Objectives:

Use apparent diffusion coefficient (ADC) histogram to investigate whether the parameters of ADC histogram can distinguish between benign and malignant tumors and further differentiate the tumor subgroups.

Methods and materials:

This study retrospectively enrolls 161 patients with parotid gland tumors. Histogram parameters including mean, inhomogeneity, skewness, kurtosis and 10th, 25th, 50th, 75th, 90th percentiles are derived from ADC mono-exponential model. Mann–Whitney U test is used to compare the differences between benign and malignant groups. Kruskal–Wallis test with post-hoc Dunn–Bonferroni method is used for subgroup classification, then receiver operating characteristic curve analysis is performed in mean ADC value to obtain the appropriate cutoff values.

Results:

Except for kurtosis and 90th percentile, there are significant differences in all other ADC parameters between benign and malignant groups. In subgroup classification of benign tumors, there are significant differences in all ADC parameters between pleomorphic adenoma and Warthin’s tumor (area under curve 0.988; sensitivity 93.8%; specificity 94.7%; all ps < 0.05). Pleomorphic adenoma has high value in mean than basal cell adenoma (area under curve 0.819; sensitivity 76.9%; specificity 76.9%; p < 0.05). Basal cell adenoma has high values in mean (area under curve 0.897; sensitivity 92.3%; specificity 78.9%; all ps < 0.05) and 10th, 25th, 50th percentiles than Warthin’s tumor. In subgroup classification of malignant tumors, low-risk parotid carcinomas have higher values than hematolymphoid tumors in mean (area under curve 0.912; sensitivity 84.6%; specificity 100%, all ps < 0.05) and 10th, 25th percentiles.

Conclusion:

ADC histogram parameters, especially mean and 10th, 25th percentiles, can potentially be an effective indicator for identifying and classifying parotid tumors.
Canopy Temperature Bias from Soil Variability Enhanced at High Temperatures
Authors: DeJonge Kendall C. , Zhang Huihui , Taghvaeian Saleh , Trout Thomas J.
Published: March 2020

Highlight

Maize canopy temperature (Tc) was evaluated among four replicates of seven irrigation treatments.

Individual replicates showed Tc bias correlated with soil electroconductivity and increasing Tc.

At high Tc values (above 35°C), Tc bias was up to 5.0°C among plots with the same irrigation schedule.

ABSTRACT. Maize canopy temperature was monitored on a continuous basis for two growing seasons in a limited-irrigation maize experiment with seven separate irrigation treatments and four replicates of each treatment. Soil electroconductivity (EC) was measured and mapped to quantify the variation in soil texture throughout the plots and was correlated with the average field capacity of the soil (R2 = 0.51). At lower canopy temperatures, indicating little or no water stress, very little difference was observed between replicates within the same treatment. However, at higher temperatures, soil texture had a greater influence on temperature, with soils having lower EC (and therefore lower water-holding capacity) showing more water stress. More specifically, at canopy temperatures above 29°C, the influence of soil texture biased the temperature by up to 2.0°C over the EC range of 16.9 to 40.2 mS m-1; at mean canopy temperatures of 35°C, this bias could be more than 5.0°C between field replicates. Results similar to the continuous infrared thermometry were found using nadir thermal images. This study demonstrates the importance of understanding the potential effects of soil variability on canopy temperature, which could have profound implications for spatially variable field-based management using thermal imaging or similar technologies. Keywords: Canopy temperature, Infrared thermometry, Limited irrigation, Soil variability.
From a posteriori to a priori solutions for a two-level system interacting with a single-photon wavepacket
Authors: Dąbrowska Anita Magdalena
Published: March 2020

We present the analytical formulas for the conditional and unconditional states of a two-level atom interacting with a single-photon wavepacket. We express thea prioristate of the system by means of the quantum trajectories related to the process of detection of photons in the output field. We give the formulas for the mean number of photons detected up to the given time, and we derive the expressions for the mean time of detection of the photons.
Efficient second harmonic generation in nanophotonic GaAs-on-insulator waveguides
Authors: Stanton Eric J. , Chiles Jeff , Nader Nima , Moody Galan , Volet Nicolas , Chang Lin , Bowers John E. , Woo Nam Sae , Mirin Richard P.
Published: March 2020

Nonlinear frequency conversion plays a crucial role in advancing the functionality of next-generation optical systems. Portable metrology references and quantum networks will demand highly efficient second-order nonlinear devices, and the intense nonlinear interactions of nanophotonic waveguides can be leveraged to meet these requirements. Here we demonstrate second harmonic generation (SHG) in GaAs-on-insulator waveguides with unprecedented efficiency of 40 W−1 for a single-pass device. This result is achieved by minimizing the propagation loss and optimizing phase-matching. We investigate surface-state absorption and design the waveguide geometry for modal phase-matching with tolerance to fabrication variation. A 2.0 µm pump is converted to a 1.0 µm signal in a length of 2.9 mm with a wide signal bandwidth of 148 GHz. Tunable and efficient operation is demonstrated over a temperature range of 45 °C with a slope of 0.24 nm/°C. Wafer-bonding between GaAs and SiO2 is optimized to minimize waveguide loss, and the devices are fabricated on 76 mm wafers with high uniformity. We expect this device to enable fully integrated self-referenced frequency combs and high-rate entangled photon pair generation.
Role of surface passivation in integrated sub-bandgap silicon photodetection
Authors: Gherabli Rivka , Grajower Meir , Shappir Joseph , Mazurski Noa , Wofsy Menachem , Inbar Naor , Khurgin Jacob B. , Levy Uriel
Published: March 2020

We study experimentally the effect of oxide removal on the sub-bandgap photodetection in silicon waveguides at the telecom wavelength regime. Depassivating the device allows for the enhancement of the quantum efficiency by about 2–3 times. Furthermore, the propagation loss within the device is significantly reduced by the oxide removal. Measuring the device 60 days after the depassivation shows slight differences. We provide a possible explanation for these observations. Clearly, passivation and depassivation play an essential role in the design and the implementation of such sub-bandgap photodetector devices for applications such as on-chip light monitoring.