bluuebunny/crossref_metadata_2025 huggingface dataset:
Different pathologic responses to neoadjuvant anti-PD-1 in primary squamous lung cancer and regional lymph nodes
Authors: Ling Yun , Li Ning , Li Lin , Guo Changyuan , Wei Jiacong , Yuan Pei , Tan Fengwei , Tao Xiuli , Wang Shuhang , Wang Zhijie , Wu Ning , Wang Jie , Ying Jianming , Gao Shugeng , He Jie
Published: December 2020

Neoadjuvant immunotherapy provides a unique opportunity for understanding therapeutic responses. We analyzed pathologic responses in surgical specimens obtained from 31 squamous non-small cell lung cancer (NSCLC) patients receiving neoadjuvant anti-PD-1 treatment. Fifteen (48.4%) patients achieved pathologic complete response (pCR) or major pathologic response (MPR). Among them, seven (46.7%) were assessed as radiological partial response and eight (53.3%) as stable disease. Among 20 patients with pathologically identified tumor beds in lymph nodes (LNs), 10 and six patients achieved pCR/MPR in primary tumors and paired LNs, respectively. pCR was achieved in 6/19 N1 nodes and 1/7 N2 nodes. Residual viable tumor (RVT) cells in 8/9 MPR specimens had 100% immune-activated phenotype, while a median of 80% of RVT cells in pathologic nonresponse specimens presented immune-excluded/desert phenotype. These findings demonstrated that assessment of pathologic responses in both primary tumor and LNs may be important as a surrogate for assessing neoadjuvant immunotherapeutic efficacy.
Re-emergence of yellow fever in the neotropics — quo vadis?
Authors: Sacchetto Livia , Drumond Betania P. , Han Barbara A. , Nogueira Mauricio L. , Vasilakis Nikos
Published: December 2020

Yellow fever virus (YFV) is the etiological agent of yellow fever (YF), an acute hemorrhagic vector-borne disease with a significant impact on public health, is endemic across tropical regions in Africa and South America. The virus is maintained in two ecologically and evolutionary distinct transmission cycles: an enzootic, sylvatic cycle, where the virus circulates between arboreal Aedes species mosquitoes and non-human primates, and a human or urban cycle, between humans and anthropophilic Aedes aegypti mosquitoes. While the urban transmission cycle has been eradicated by a highly efficacious licensed vaccine, the enzootic transmission cycle is not amenable to control interventions, leading to recurrent epizootics and spillover outbreaks into human populations. The nature of YF transmission dynamics is multifactorial and encompasses a complex system of biotic, abiotic, and anthropogenic factors rendering predictions of emergence highly speculative. The recent outbreaks in Africa and Brazil clearly remind us of the significant impact YF emergence events pose on human and animal health. The magnitude of the Brazilian outbreak and spillover in densely populated areas outside the recommended vaccination coverage areas raised the specter of human — to — human transmission and re-establishment of enzootic cycles outside the Amazon basin. Herein, we review the factors that influence the re-emergence potential of YFV in the neotropics and offer insights for a constellation of coordinated approaches to better predict and control future YF emergence events.
Preparation of GO/PAM Continuous Adsorption Medium and its Dynamic Adsorption Properties for Methylene Blue
Authors: Li Dagang , Wang Zhiwen
Published: December 2020

A continuous and structured porous adsorbent named GO/PAM was synthesised by one-step copolymerization of graphene oxide (GO) and acrylamide (AM) in amorphous region initiated by redox agent consisting of hydrogen peroxide (H2O2) and ascorbic acid (VC) at -20°C. The dynamic adsorption characteristics of methylene blue (MB) in GO/PAM structured adsorption medium were investigated. With the introduction of GO which rich in —OH and —COOH groups, the adsorption capacities were 178.65 mg/g~201.58 mg/g. Structured continuous adsorption medium was prepared by one-step polymerization of crystallization, in order to replace traditional bulk resin and ion exchange resin in the treatment of printing and dyeing wastewater.
Research on redundant control mode of coordinated controller based on dual control cores
Authors: Sun Qiao , Jia Shaokun , Zhang Jie , Zhao Kunpeng , Li Zhixiang , Yu Bo
Published: December 2020

Dual CPU redundant operation of PLC is of great significance to the reliability of industrial automation control system. In view of the problems existing in the traditional dual CPU PLC redundancy control mode based on hardware strategy, this paper proposes a dual CPU redundancy control idea based on software strategy, and describes in detail the specific scheme of Dual CPU redundancy software design using A-B ControlLogix series PLC.
Research on C30 Concrete Mix Proportion in Guangdong Province
Authors: Lai Guangxing , Yin Jianli , Ye Junhui , Chen Yujia , Xiao Wei
Published: December 2020

The reasons of C30 concrete bleeding in winter in Guangdong province were studied by collecting the concrete mix proportions of C30 concrete mixing plants in Guangdong, Fujian, Henan, Hunan, Chongqing and Shaanxi regions, the difference between the concrete mix proportions in Guangdong and other regions was investigated. Based on the representative concrete mix proportion in Guangdong province, the concrete bleeding water test was carried out, and the correlation between the amount of different cementing materials and the bleeding rate was investigated. The results showed that compared with other regions, the C30 concrete mix proportion in Guangdong has the lowest total cementitious material, which made it more prone to bleeding. The amount of slag powder and the total amount of cementitious materials have a high correlation with the bleeding rate. With the increase of the amount of slag powder and the total amount of cementitious materials, the bleeding rate decreases.
Structural Analysis and Comprehensive Evaluation of Economic Index of Distribution Network
Authors: Dong Litong , Chen Yinghua , Ge Yanqin , Xu Xuesong
Published: December 2020

With the orderly advancement of power system reform and the rapid development of incremental power distribution pilots, the investment process of power grid companies has become more and more transparent and standardized. However, in the current fierce environment, how to maintain certain economic benefits in various regional distribution networks has become a problem of concern. This paper establishes a distribution network asset economic index system from the three dimensions of investment cost, operating cost, and economic benefit. The hierarchical structure of indicators is clarified based on the interpretative structural model, and the economic level is measured based on the improved analytical hierarchy process AHP-fuzzy evaluation model. Finally, the analysis of calculation examples shows that: (1) The investment cost and operating cost of the distribution network indirectly affect the economic benefits of the power grid by affecting the electricity sales. (2) The economic levels of the distribution network in the three regions of X, Y, and Z are good, medium, and poor. The region X needs to strengthen the management of distribution network investment, and the region Y continues to improve the economy from all aspects of cost and income. The first thing in region Z is to improve the level of economic efficiency.
Graphic programming design based on embedded AI processor
Authors: Li Lin , Yin Shangxia , Li Kai
Published: December 2020

This paper designs a system platform for graphical programming. The system is based on the open source software platform developed for the second time, which can realize the layer-by-layer conversion of diagrams and source codes, allowing users to deeply understand the logical relationship of programming, and programming and the host can be downloaded. The user can complete the drag-and-drop procedure, the icon shows the basic elements of the function, and the attribute box can modify each variable and automatically build it. After the user builds a graphics program with this system, click the run button to generate Python code and save the project.
Fracture failure analysis of the pump shaft
Authors: Jiang Chengjun , Tao Kai , Wang Jifeng , Wang Wei
Published: December 2020

The failure reasons of the circulating pump shaft in the upper section of the quench tower were analyzed by means of chemical composition analysis, macroscopic observation, metallographic examination and fracture section analysis. The analysis result shows that the calcium-silicate inclusions in the surface of the pump shaft cause the microcracks and the parallel fatigue sources, which leads to the fatigue cracks propagation under alternating load and finally the shaft is fatigue fractured.
Innovation Report of Big Data on Marine Forecast on the North Line of Maritime Silk Road
Authors: Lin Bo
Published: December 2020

Since the first Arctic expedition in China in 1999, the National Marine Environment Forecasting Center of China has undertaken safety guarantee tasks for the 9 batches of Arctic scientific expedition ships (teams) and 26 merchant ships to come and back the North Line of Maritime Silk Road in China. This paper summarized their successful experience and innovation achievements in big data application, emphatically introduced the innovation of big data infrastructure construction of Maritime Silk Road marine forecasting, that is, the establishment of independent marine observation system, the exploration of international cooperation mode of marine observation, as well as the participation in global regional observation plans. Besides, marine prediction business innovation, safety guarantee service innovation, and supercomputing technology innovation were included in the scientific and technological business innovation. Moreover, the innovation achievements include aspects of polar marine prediction big data, guarantee technology big data and supercomputing. Finally, the construction and development prospect on the North Line of Maritime Silk Road were briefly prospected.
Multi-attribute evaluation and deviation analysis of regional distribution network investment effect
Authors: Wu Jianbin , Wang Zheng , Gu Zhihong , Liu Zhuo
Published: December 2020

As the input ratio of regional distribution network increases year by year, higher requirements are put forward for high quality and high reliability of power consumption. Under this background, this paper involves 11 evaluation indexes from three dimensions of reliability, economy and environmental protection, and designs the evaluation index system of investment effect of regional distribution network. The multiattribute AHP-TOPSIS-entropy weight combination evaluation method for the investment effect of regional distribution networks is constructed. And select distribution network A, B, C area for example analysis, the results show that the n-1 pass rate, power supply reliability, power consumption growth and emission reduction of clean energy generation are positively correlated with the investment effect of regional distribution network.
Automatic Identification and Importance Evaluation Technology of Power Transmission Section
Authors: Weng Yixuan , Ma Weizhe , Xie EnYan , Qi Hui , Liu Zhenxing , Huang Shuang
Published: December 2020

In theory, the cross section is the minimum cut set in the network. For the actual power grid, the transmission cross section is a collection of transmission lines between different regions, which is mainly used for power transmission to achieve the purpose of generating load balance. In this paper, a power grid zoning algorithm is proposed based on the topological structure characteristics and current operation state of the power grid, and the key transmission sections can be directly obtained without depending on the calculation of safety and stability margin. A practical system state partition model and key section sorting method are introduced, and a set of automatic identification method flow of key transmission sections of the system is established by searching for electrical betweenness. The importance of the transmission section is quantitatively evaluated from three angles: the margin from the stability limit, the hub position in the current power flow state, and the impact on the power grid after the power cut-off. The evaluation results can be used as a Reference for decision-making in the planning and reconstruction of the transmission section, safety monitoring, protection configuration, etc.
Convection Heat Transfer Analysis in a Channel with an Open Trapezoidal Cavity: Heat Source Locations effect
Authors: Mebarek-Oudina F. , Laouira H. , Aissa A. , Hussein A. K. , El Ganaoui M.
Published: December 2020

In this work, a numerical study of mixed convection inside a horizontal channel with an open trapezoidal enclosure subjected to a discrete heat source in different locations is carried out. The heat source with the length of ε = 0.75, is maintained at a constant temperature. The air flow with a fixed velocity and a cold temperature enters the channel horizontally. The other walls of the enclosure and the channel are adiabatic. The results are presented in the form of the contours of velocity, isotherms and Nusselt numbers profiles for various heat source locations, Prandtl number (Pr = 0.71) and Reynolds number (Re = 100) respectively. The distribution of the isotherms depends significantly on the position of the heat source. We noted that the best heat transfer is detected where the heat source is placed in the top of the left .
Multiple-relaxation-time Lattice Boltzmann model for flow and convective heat transfer in lid driven cavity with porous obstacle
Authors: Bourada Abderrahmane , Ouahouah Asma , Bouarnouna Kaoutar , Ragui Karim , Boutra Abdelkader , Benkahla Youb Khaled
Published: December 2020

In this work, we study numerically a problem of mixed convection in lid driven square cavity, filled with air (Pr = 0.71), whose upper wall is movable and kept at constant cold temperature TC. The cavity contains a porous obstacle of height h and width b, placed on the bottom wall maintained at a constant hot temperature TH. The side walls are adiabatic. Darcy-Brinkmann-forchheimer model is used for modelling the momentum equations in porous medium. This numerical study is based on the multiple relaxation time lattice Boltzmann method (MRT -LBM). The D2Q9 two-dimensional model is adopted to the dynamic part, while the D2Q5 model is applied for the thermal part. The objective of the study is to analyze the effect of Darcy number (10-1 ≼ Da ≼ 10-5), Richardson number (0.01 ≼ Ri ≼ 100) and the aspect ratio w = b/H (0.2 ≼ w ≼ 1) on the hydrodynamic and thermal characteristics in the cavity through the velocity and temperature as well as the average Nusselt number. The results obtained show a considerable effect of these parameters on the structure of the flow and on the heat exchange in the cavity.
Inter and intra band impurity-related absorption in (In,Ga)N/GaN QW under composition, size and impurity effects
Authors: En-nadir Redouane , El Ghazi Haddou , Jorio Anouar , Zorkani Izeddine
Published: December 2020

In this paper, we theoretically investigate the impacts of Internal well composition, size and impurity's position on the inter valence-conduction bands and intra conduction band optical absorption in GaN/(In,Ga)N/GaN hetero-structure. Based on the numerically finite element method (FEM), the impurity's related Schrödinger equation is solved for the finite potential barrier considering the dielectric constant and effective-mass mismatches between the well and its surrounding matrix. Our results show that the absorption is strongly governed by the dipole matrix element and initial and final implied states transition energies. For a fixed barrier width, the absorption spectra are found red-shifted (blue-shifted) with increasing the well width (In-concentration). It is also shown that the impurity's absorption phenomenon is more pronounced for the off-center case compared to the on-center one. We conclude that the proper control of these parameters is required to best understanding of the optical absorption for solar cell applications.
Impurity position effect on the diamagnetic susceptibility of a magneto-donor in GaAs inhomogeneous quantum dots
Authors: Janati Edrissi Sanae , Mmadi Ali , Zorkani Izeddine , Rahmani Khalid , Jorio Anouar , El Ganaoui Mohamed
Published: December 2020

Inhomogeneous Quantum Dot (IQD) semiconductor represents a newest trend in condensed matter, due to their important quantum levels and the outstanding properties. In this work, the impurity position effect on the diamagnetic susceptibility of a shallow magneto-donor, confined to move in (IQD) made out of Ga1-xAlxAs / GaAs/ Ga1-xAlxAs is reported theoretically. With the increase of the magnetic field, the diamagnetic susceptibility increases. The results using variational method reveal that diamagnetic susceptibility depends on many parameters including the impurity position, the external magnetic field and the nanostructure size. The magnetic field effect is more pronounced when the donor is placed near the extremities of the spherical layer (off-center). In addition, a maximum of diamagnetic susceptibility is observed, corresponding to a critical position value, for strong confinement regime and when the impurity is located in the spherical layer center.
Exergy performance of a new ORC configuration of a solar cogeneration system using a gas ejector
Authors: Afif Larbi , Bouaziz Nahla
Published: December 2020

In the context of sustainable development and more particularly the conversion of heat into electricity, the present work proposes a new system of cogeneration operating at low energy value. It’s an organic Rankine cycle, associated with a gas ejector and operating with different organic fluids. It should be noted that the development of the ORC technology is partly a well-adapted response to problems of energy saving and ecosystem preservation. Accordingly, this paper presents a new configuration of a cogeneration system operating at low temperature and ensuring the simultaneous production of electricity and refrigeration. The proposed system is operating under transcritical and subcritical regime using solar energy as thermal source. On the other hand, an energy and exergy study has been developed by choosing the refrigerants R124, R236fa, R1234yf and R1234ze as working fluids according to their low environmental impact and thermodynamic properties. The results of the numerical simulation carried out as part of this study have also shown the importance of integrating the ejector into the proposed machine. Indeed, we investigated the effect of the thermodynamic parameters of the ejector on the coefficient of performance and the exergy efficiency of the cogeneration system.
Stability analysis of magnetic fluids in the presence of an oblique field and mass and heat transfer
Authors: Djeghiour Rabah , Meziani Bachir
Published: December 2020

In this paper, we investigate an analysis of the stability of a basic flow of streaming magnetic fluids in the presence of an oblique magnetic field is made. We have use the linear analysis of modified Kelvin-Helmholtz instability by the addition of the influence of mass transfer and heat across the interface. Problems equations model is presented where nonlinear terms are neglected in model equations as well as the boundary conditions. In the case of a oblique magnetic field, the dispersion relation is obtained and discussed both analytically and numerically and the stability diagrams are also obtained. It is found that the effect of the field depends strongly on the choice of some physical parameters of the system. Regions of stability and instability are identified. It is found that the mass and heat transfer parameter has a destabilizing influence regardless of the mechanism of the field.
High-resolution wavemeter based on polarization modulation of fiber speckles
Authors: Wang Tianliang , Li Yi , Xu Ben , Mao Bangning , Qiu Yanqing , Meng Yanlong
Published: December 2020

For speckle pattern-based wavemeters or spectrometers, the intermodal and the chromatic dispersion of the diffusion waveguide are key factors in determining the wavelength resolution. In this study, we propose a new mechanism to modulate the fiber speckles aside from the dispersion related effect. The polarization modulation is introduced in a rectangular core fiber (RCF) by using an in-line polarization rotator (IPR). The IPR can rotate the polarization angle at different wavelengths. Interestingly, it is observed that the modulated speckle patterns appear periodically similar, and they present more variations when compared to unmodulated ones. The theoretical simulation indicates that the polarization exerts an influence on the fiber speckles by modulating the mode coupling coefficients when light is coupled into the RCF. In the demonstration experiment, we first built a precise laser frequency tuning system based on an electro-optic modulator and a microwave source. By comparing the recorded speckles with and without polarization modulation, the former speckles have lower correlations, which are evaluated using the Arc Cosine Similarity algorithm. Reconstructing the spectrum of speckles, the smallest detectable wavelength that can be detected with polarization modulation is 0.2 fm. The experimental results prove that the polarization modulation is a convenient and effective method to enhance the speckle’s wavelength sensitivity. In addition, this study paves a new way to design high-resolution wavemeters with shorter, more compact optical waveguides.
Role of antioxidant pool in management of ozone stress through soil nitrogen amendments in two cultivars of a tropical legume
Authors: Sen Gupta Gereraj , Tiwari Supriya
Published: December 2020

The present experiment was done on two different cultivars of a tropical legume, Cymopsis tetragonoloba L. Taub. (cluster bean) cvv. Pusa-Naubahar (PUSA-N) and Selection-151 (S-151). The experiment was conducted under ambient ozone (O3) conditions with inputs of three different doses of inorganic nitrogen (N1, recommended; N2, 1.5-times recommended and N3, 2-times recommended) as well as control plants. The objective of this study was to evaluate the effectiveness of soil nitrogen amendments in management of ambient ozone stress in the two cultivars of C. tetragonoloba. Our experiment showed that nitrogen amendments can be an efficient measure to manage O3 injury in plants. Stimulation of antioxidant enzyme activities under nitrogen amendments is an important feature of plants that help plants cope with ambient O3 stress. Nitrogen amendments strengthened the antioxidant machinery in a more effective way in the tolerant cultivar PUSA-N, while in the sensitive cultivar S-151, avoidance strategy marked by more reduction in stomatal conductance was more prominent. Enzymes of the Halliwell–Asada pathway, especially ascorbate peroxidase and glutathione reductase, were more responsive and synchronised in PUSA-N than S-151, under similar nitrogen amendment regimes and were responsible for the differential sensitivities of the two cultivars of C. tetragonoloba. The present study shows that 1.5-times recommended dose of soil nitrogen amendments was sufficient in partial mitigation of O3 injury and the higher nitrogen dose (2-times recommended, in our case), did not provide any extra advantage to the plant’s metabolism compared with plants treated with the lower nitrogen dose (1.5-times recommended).
Iddingsitisation of olivine and kaolinitisation of biotite in two contrasting tephra-derived soils along the Cameroon Volcanic Line (CVL)
Authors: Enang Roger Kogge , Mees Florias , Yerima Bernard Palmer Kfuban , Van Ranst Eric
Published: December 2020

Mineral transformations in soils are important processes in assessing pedogenesis. A micromorphological study, complemented by mineralogical and physicochemical analyses, was conducted for two contrasting soils developed on tephra of Mt. Manengouba, i.e. an Andosol and a Cambisol, in order to compare weathering trends based on olivine and biotite alteration. The contrasting character of the two soils is portrayed in their various properties, and is also observed in the field. The majority of the investigated soil properties proved to be effective in capturing differences between the two soils. Iddingsite, formed by pellicular alteration of olivine, occurs in both soils. Its presence is an inherited feature, as recorded by identical occurrences of affected olivine crystals as isolated grains in the groundmass of the soils and as phenocrysts in volcanic rock fragments within the Andosol profile. Kaolinitisation of biotite, producing parallel linear alteration patterns, is limited to the Cambisol and is attributed to pedogenic processes, recording a more advanced stage of weathering than for the Andosol profile. Kaolinitisation is thus more indicative in assessing pedogenesis compared with iddingsitisation in these soils.
Expansion characteristics of butanol-diesel spray and droplet
Authors: Li Fengyu , Fu Wei , Zhou Kun , Lin Qizhao
Published: December 2020

Butanol is one of the most promising alternative fuels. This study is conducted focusing on the expansion characteristics of butanol-diesel spray. In this work, a high-speed common rail system is used for generating direct spray, and single droplet of tested fuel is heated, the radial diffusion of the whole spray and the expansion of butanol-diesel droplet are observed and analysed. Results show that the addition of butanol enhances the radial development of butanol-diesel value, while the addition of butanol would bring a little negative effect on the speed of radial diffusion. Additionally, the addition of butanol makes the deformation of the mixed fuel droplets more intense.
Are crop and detailed physiological models equally ‘mechanistic’ for predicting the genetic variability of whole-plant behaviour? The nexus between mechanisms and adaptive strategies
Authors: Tardieu F , Granato I S C , Van Oosterom E J , Parent B , Hammer G L
Published: December 2020

Tailoring genotypes for the variety of environmental scenarios associated with climate change requires modelling of the genetic variability of adaptation mechanisms to environmental cues. A large number of physiological mechanisms have been described and modelled, e.g. at transcript, metabolic or hormonal levels, but they remain to be assembled into whole-plant and canopy models. A ‘bottom-up’ approach combining physiological mechanisms leads to a near-infinite number of combinations and to an unmanageable number of parameters, so more parsimonious approaches are required. We propose that natural selection has constrained the large diversity of mechanisms into consistent strategies, in such a way that not all combinations of mechanisms are possible. These constraints, and resulting feedbacks, result in integrative ‘meta-mechanisms’, e.g. response curves of traits to environmental conditions, measurable via high-throughput phenotyping, and resulting in robust and stable equations with heritable genotype-dependent parameters. Examples are provided for the responses of developmental traits to temperature, for the response of growth and yield to water deficit and evaporative demand, and for the response of tillering to light and temperature. In these examples, it was inoperative to combine upstream mechanisms into whole-plant mechanisms, whereas the evolutionary constraints on the combinations of physiological mechanisms render possible the use of genotype-specific response curves at plant or canopy levels. These can be used for a new generation of crop models capable of simulating the behaviour of thousands of genotypes. This has significant consequences for plant modelling and its use in genetics and breeding.
Ggps1 deficiency in the uterus results in dystocia by disrupting uterine contraction
Authors: Sang Yong-Juan , Wang Qiang , Zheng Feng , Hua Yue , Wang Xin-Ying , Zhang Jing-Zi , Li Kang , Wang Hai-Quan , Zhao Yue , Zhu Min-Sheng , Sun Hai-Xiang , Li Chao-Jun
Published: December 2020

Dystocia is a serious problem for pregnant women, and it increases the cesarean section rate. Although uterine dysfunction has an unknown etiology, it is responsible for cesarean delivery and clinical dystocia, resulting in neonatal morbidity and mortality; thus, there is an urgent need for novel therapeutic agents. Previous studies indicated that statins, which inhibit the mevalonate (MVA) pathway of cholesterol synthesis, can reduce the incidence of preterm birth, but the safety of statins for pregnant women has not been thoroughly evaluated. Therefore, to unambiguously examine the function of the MVA pathway in pregnancy and delivery, we employed a genetic approach by using myometrial cell-specific deletion of geranylgeranyl pyrophosphate synthase (Ggps1) mice. We found that Ggps1 deficiency in myometrial cells caused impaired uterine contractions, resulting in disrupted embryonic placing and dystocia. Studies of the underlying mechanism suggested that Ggps1 is required for uterine contractions to ensure successful parturition by regulating RhoA prenylation to activate the RhoA/Rock2/p-MLC pathway. Our work indicates that perturbing the MVA pathway might result in problems during delivery for pregnant females, but modifying protein prenylation with supplementary farnesyl pyrophosphate or geranylgeranyl pyrophosphate might be a strategy to avoid side effects.
Jejunal intussusceptions due to metastatic malignant melanoma: a case report
Authors: Correia de Sá Tiago , Ferreira Ana Isabel , Barreto Filomena , Santos Mariana
Published: December 2020

Intussusception is an infrequent cause of mechanical bowel obstruction in adults and surgical resection is warranted in most cases. Small bowel is a common site of recurrence from cutaneous melanoma but early diagnosis is still a challenge. Acute peritonitis, haemorrhage and obstruction are known clinical presentations. Wide surgical excision with free margins and accompanied mesentery is the treatment of choice and may improve the prognosis. We present a case of small bowel obstruction due to three intussusceptions by metastatic malignant melanoma submitted to surgery.
The impact of hospital safety-net status on inpatient outcomes for brain tumor craniotomy: a 10-year nationwide analysis
Authors: Tang Oliver Y , Rivera Perla Krissia M , Lim Rachel K , Weil Robert J , Toms Steven A
Published: December 2020

Background

Outcome disparities have been documented at safety-net hospitals (SNHs), which disproportionately serve vulnerable patient populations. Using a nationwide retrospective cohort, we assessed inpatient outcomes following brain tumor craniotomy at SNHs in the United States.

Methods

We identified all craniotomy procedures in the National Inpatient Sample from 2002–2011 for brain tumors: glioma, metastasis, meningioma, and vestibular schwannoma. Safety-net burden was calculated as the number of Medicaid plus uninsured admissions divided by total admissions. Hospitals in the top quartile of burden were defined as SNHs. The association between SNH status and in-hospital mortality, discharge disposition, complications, hospital-acquired conditions (HACs), length of stay (LOS), and costs were assessed. Multivariate regression adjusted for patient, hospital, and severity characteristics.

Results

304,719 admissions were analyzed. The most common subtype was glioma (43.8%). Of 1,206 unique hospitals, 242 were SNHs. SNH admissions were more likely to be non-white (P < .001), low income (P < .001), and have higher severity scores (P = .034). Mortality rates were higher at SNHs for metastasis admissions (odds ratio [OR] = 1.48, P = .025), and SNHs had higher complication rates for meningioma (OR = 1.34, P = .003) and all tumor types combined (OR = 1.17, P = .034). However, there were no differences at SNHs for discharge disposition or HACs. LOS and hospital costs were elevated at SNHs for all subtypes, culminating in a 10% and 9% increase in LOS and costs for the overall population, respectively (all P < .001).

Conclusions

SNHs demonstrated poorer inpatient outcomes for brain tumor craniotomy. Further analyses of the differences observed and potential interventions to ameliorate interhospital disparities are warranted.
Using Mobile Technologies Among Undergraduate Nursing Students for Academic Purposes in Tertiary Education
Authors: Harerimana Alexis , Mtshali Ntombifikile Gloria
Published: December 2020

Mobile devices are increasingly part of daily life, with the benefits of using the technology in nursing education widely recognized. This study explored the use of mobile devices among undergraduate nursing students for academic purposes in South Africa, using a quantitative survey. The majority of participants owned smartphones (87.6%), followed by laptops (76%) and tablets (47.1%). Mobile devices were used to perform academic tasks and communicate and collaborate with peers and teachers, as well as search and access electronic resources. Few of the first year nursing students owned laptops and tablets and used them less frequently than the students from other levels of the study. Equipping nursing students with mobile devices, such as laptops and tablets, particularly first year students, and ensuring that they have adequate skills to use them, is essential to training future nurses who are expected to work in a technology-mediated health environment.
Pulsed field ablation: a promise that came true
Authors: Anic Ante , Breskovic Toni , Sikiric Ivan
Published: December 2020

Purpose of review

Pulsed field ablation is a nonthermal ablative modality that uses short living, strong electrical field created around catheter to create microscopic pores in cell membranes (electroporation). When adequately dosed/configured it shows a preference for myocardial tissue necrosis. Thus, it holds a promise to become a ‘perfect’ energy source for cardiac ablation to treat arrhythmias. Herein, we present update on platforms in clinical development.

Recent findings

First in human series using pulsed field ablation for atrial fibrillation ablation have been completed and data published for several platforms. Acute safety outcomes are similar across the platforms with exceptionally low rate of those complications that are typically reported for thermal ablation methods (esophageal injury, pulmonary vein stenosis, phrenic nerve palsy). Promising acute data on pulmonary vein isolation had been corroborated with satisfactory 1-year clinical follow-up for a single platform, whereas reports are pending for the rest. Research efforts are being expanded to a development of focal catheters, and therefore, pulsed field ablation application for ventricular arrhythmias.

As the reports confirming its safety and efficacy build up, there seems to be no way that the promise of pulsed field ablation could end in a blind alley.
Prevalence of Dry Eye Disease in Africa: A Systematic Review and Meta-analysis
Authors: Akowuah Prince K. , Kobia-Acquah Emmanuel
Published: December 2020

SIGNIFICANCE

Dry eye disease is a significant public health problem globally. The magnitude of the dry eye disease problem in Africa is, however, unknown. This study provides important and lacking information on dry eye disease in Africa.

PURPOSE

This study aimed to estimate the prevalence of dry eye disease in Africa.

METHODS

A systematic online literature search was conducted for articles on dry eye disease in Africa. Meta-analysis was conducted to estimate the prevalence of dry eye disease in Africa and meta-regression to explore the association between dry eye and sex, age, study population, country of study, and type of study.

RESULTS

The overall prevalence estimate of dry eye disease in Africa was 42.0% (95% confidence interval [CI], 30.7 to 53.8%). The prevalence rates of dry eye disease in male and female individuals were 42.1% (95% CI, 28.5 to 56.3%) and 44.4% (95% CI, 30.2 to 59.0%), respectively; in South Africa, Ghana, Nigeria, and Egypt, the rates were 54.9% (95% CI, 39.0 to 70.4%), 38.3% (95% CI,17.7 to 61.4%), 41.4% (95% CI, 20.1 to 64.5%), and 34.9% (95% CI, 13.2 to 60.6%) respectively; and in school, hospital, and population-based studies, the rates were 51.6% (95% CI, 40.6 to 62.6%), 38.7% (95% CI, 21.9 to 57.0%), and 37.4% (95% CI, 27.4 to 48.0%). respectively. The prevalence rates of dry eye disease were 36.9% (95% CI, 26.7 to 51.1%) in a “normal” population and 44.2% (95% CI, 18.0 to 67.9%) in a population with known risk conditions. There were no associations between dry eye disease prevalence and sex (P= .88), type of study (P= .42), country of study (P= .33), study population (P= .59), and the diagnostic criteria used (P= .36).

CONCLUSIONS

There seems to be a significant dry eye disease burden in Africa. This may pose an important public health problem that requires immediate attention and action. More epidemiological studies in Africa are needed to fully understand this problem to inform policy decisions.
Severe Fireworks-Related Injuries
Authors: Jacobson Lauren , Sandvall Brinkley K. , Quistberg D. Alex , Rowhani-Rahbar Ali , Vavilala Monica S. , Friedrich Jeffrey B. , Keys Kari A.
Published: December 2020

Objectives

The relationship between fireworks and patient characteristics is not known. Our objective was to examine how severe fireworks-related injuries in children and teens compare to adults.

Methods

We conducted a retrospective case series (2005–2015) study of patients who sustained consumer fireworks-related injuries requiring hospital admission and/or operation at a single level 1 trauma/burn center. The distribution of race, use behavior, injury type, body region injured, and firework type was examined by age groups, 1 to 10 years, 11 to 17 years, and 18 years or older.

Results

Data from 294 patients 1 to 61 years of age (mean, 24 years) were examined. The majority (91%) were male. The proportion of injuries from different firework types varied by age, with rockets causing the highest proportion in children aged 1 to 10 years, homemade fireworks in those aged 11 to 17 years, and shells/mortars in adults 18 years or older. Compared with adults, children aged 1 to 10 years were more frequently American Indian/Alaska Native, Hispanic, or Asian than White. Compared with adults, children aged 1 to 10 years and 11 to 17 years were more frequently bystanders than active users. Compared with adults, children aged 1 to 10 years and 11 to 17 years had a greater proportion of burn and face injuries. Children aged 1 to 10 years had a decreased proportion of hand injuries. Three patients, 2 adults and 1 child aged 11 to 17 years, died.

Conclusions

Children, teens, and adults experience severe fireworks-related injuries differently, by demographic characteristics, injury patterns, and firework types. Tailored public health interventions could target safety messaging and injury prevention outreach efforts to reduce firework injuries among children and adolescents.
Musculoskeletal MRI of Nontraumatic Emergencies
Authors: Souza Felipe Ferreira de , Pretell-Mazzini Juan , Subhawong Ty K.
Published: December 2020

A wide range of nontraumatic musculoskeletal conditions may require emergent or urgent management to avoid adverse clinical outcomes. These entities include bone and soft tissue infections, tissue necrosis, impending pathologic fracture or fungating tumor, and pseudoaneurysms. In this review, the magnetic resonance imaging appearance of these various entities is presented and discussed with the aim of improving radiologist and clinician recognition of the importance of key imaging findings in each case.
Vitamin D and COVID-19: evidence and recommendations for supplementation
Authors: Griffin George , Hewison Martin , Hopkin Julian , Kenny Rose , Quinton Richard , Rhodes Jonathan , Subramanian Sreedhar , Thickett David
Published: December 2020

Vitamin D is a hormone that acts on many genes expressed by immune cells. Evidence linking vitamin D deficiency with COVID-19 severity is circumstantial but considerable—links with ethnicity, obesity, institutionalization; latitude and ultraviolet exposure; increased lung damage in experimental models; associations with COVID-19 severity in hospitalized patients. Vitamin D deficiency is common but readily preventable by supplementation that is very safe and cheap. A target blood level of at least 50 nmol l−1, as indicated by the US National Academy of Medicine and by the European Food Safety Authority, is supported by evidence. This would require supplementation with 800 IU/day (not 400 IU/day as currently recommended in UK) to bring most people up to target. Randomized placebo-controlled trials of vitamin D in the community are unlikely to complete until spring 2021—although we note the positive results from Spain of a randomized trial of 25-hydroxyvitamin D3 (25(OH)D3 or calcifediol) in hospitalized patients. We urge UK and other governments to recommend vitamin D supplementation at 800–1000 IU/day for all, making it clear that this is to help optimize immune health and not solely for bone and muscle health. This should be mandated for prescription in care homes, prisons and other institutions where people are likely to have been indoors for much of the summer. Adults likely to be deficient should consider taking a higher dose, e.g. 4000 IU/day for the first four weeks before reducing to 800 IU–1000 IU/day. People admitted to the hospital with COVID-19 should have their vitamin D status checked and/or supplemented and consideration should be given to testing high-dose calcifediol in the RECOVERY trial. We feel this should be pursued with great urgency. Vitamin D levels in the UK will be falling from October onwards as we head into winter. There seems nothing to lose and potentially much to gain.
Animal Maintenance Systems: Xenopus tropicalis
Authors: Shaidani Nikko-Ideen , McNamara Sean , Wlizla Marcin , Horb Marko E.
Published: December 2020

Modular recirculating animal aquaculture systems incorporate UV sterilization and biological, mechanical, and activated carbon filtration, creating a nearly self-contained stable housing environment for Xenopus tropicalis. Nonetheless, minimal water exchange is necessary to mitigate accumulation of metabolic waste, and regular weekly, monthly, and yearly maintenance is needed to ensure accurate and efficient operation. This protocol describes the methods for establishing a new recirculating system and the necessary maintenance, as well as water quality parameters, required for keeping Xenopus tropicalis.
Amadubi Rural Tourism Project in Jharkhand: Development of Project Risk Management (B)
Authors: Dutta Goutam
Published: December 2020

This case should be taught after (A) case. This case study discusses how the stakeholders of the (A) can sit together can discuss prepare first the activities of the project, draw the network diagram, develop a critical path. The discussion further proceeds when these stakeholders through the discussion develop risk sources, assigns probabilities and computes the impact and likelihood rating.
Private equity in 401(K) plans – a trillion dollar opportunity?
Authors: Sichel Robert L. , Wade William P. , Delaney Ruth E. , Zanotti Kristina M. , McGrath Michael
Published: December 2020

Purpose

To explain recent regulatory guidance for different types of stakeholders, including asset managers, fund complexes, and institutional investors.

Design/methodology/approach

Summary of recent regulatory guidance and explanation for different types of stakeholders, including asset managers, fund complexes, and institutional investors.

Findings

While the U.S. Department of Labor’s (DOL’s) letter does not open the door to direct access to Private Market Investments by 401(k) plan participants, it does provide a framework for the expanded use of private equity and, we believe, other types of Private Market Investments in managed asset allocation funds such as target date funds.

Originality/value

Practical guidance from experienced asset management and investment funds and ERISA lawyers.
Independent freestanding emergency departments and implications for the rural emergency physician workforce in Texas
Authors: Luo Qian , Chong Nicholas , Chen Candice
Published: December 2020

Objective

Independent freestanding emergency departments (IFEDs) have proliferated over the last decade, largely in Texas. We examined the IFED physician workforce composition and changes in emergency physician workforce supply across states and in rural Texas over the period of IFED proliferation following a 2009 legislation allowing the licensing of these sites.

Data Sources

IFED websites, Texas Medical Board lookup tool, National Plan & Provider Enumeration System (NPPES), Provider Enrollment and Chain/Ownership System (PECOS), Medicare Physician Shared Patient Patterns, CareSet DocGraph Hop Teaming, Healthcare Provider Database.

Study Design

Descriptive analysis of the IFED physician workforce; quasi‐experimental difference‐in‐difference analysis of Texas emergency physician movement into and out of the state; and difference‐in‐difference‐in‐difference analysis of the change in emergency physician supply between rural and urban areas in Texas compared with other states.

Data Extraction Methods

Using the NPIs obtained through Texas IFED websites and Texas Medical Board data, we examined NPPES/PECOS files, Medicare Physician Shared Patient Patterns, and CareSet DocGraph Hop Teaming for IFED physician practice locations from 2009 to 2017. We extracted all active emergency physicians from a Healthcare Provider Database, derived from a 5% Medicare claims (1999‐2017).

Principal Findings

In 2019, 545 physicians practiced in Texas IFEDs, of which 515 (94.5%) were emergency physicians. We located 533 in previous practice, of whom 522 (97.9%) previously practiced in Disproportionate Share Hospitals and 100 (18.8%) in rural areas. Following legislation to begin licensing IFEDs in 2009, there were on average 42.1 (P < .01) moving into Texas and 17.0 (P < .01) fewer moving out compared with all other states. Our results also indicated that the difference in emergency physician supply between rural and urban Texas was 1,002 (P < .01) fewer than for other states.

Conclusions

New models of health care organizations such as IFEDs have workforce implications that may further exacerbate rural and underserved workforce and access challenges.