bluuebunny/crossref_metadata_2025 huggingface dataset:
Surfactant Formulation for Foam Mobility Control and Gas Shut-Off in Harsh Operational and Reservoir Conditions
Authors: Cui Leyu , Salabert Géraldine , Di-Costanzo Océane , Dur Christian , Passade-Boupat Nicolas
Published: November 2020

Surfactants in literature have been reviewed and evaluated as foaming agents, but few of them fit our harsh operational and reservoir conditions. Therefore, surfactant formulations were tuned with guide of micelle electrostatic model and Winsor type phase behavior. The novel formulations are compatible with high temperature (94 ℃) and wide salinity (50 - 290 g/L). Moreover, one of the formulations can generate relatively weak foam at high residual oil saturation (Sor), but strong foam at low Sor. This auto-selection of foam by Sor allows to block the swept and clean zone, but not lockdown the virgin oil reserve and flooding front. At the end of foam flooding, almost 100% residual oil was recovered. Additionally, the operational conditions, such as injecting brines, anti-corrosions, demulsifiers, etc., are often subjected to be changed. Therefore, a rapid bulk-foam test is proposed to re-verify the compatibility of the formulation with the new operational condition.
The Innovative Production Enhancement Strategy of using High GOR Crude in HP/HT Reservoir to Lift Upper Reservoirs’ Production, Case Study in Iraq
Authors: Tang Xueqing , Cheng Zhongliang , Wang Ruifeng , Lu Hui
Published: November 2020

Halfaya oilfield in Iraq, discovered in 1976, contains multiple vertically stacked reservoirs. Currently main oil reservoirs are under primary development. The remaining deepest high GOR, HP/HT carbonate reservoir with original pressure gradient of 0.867 psi/ft has been drilled, tested, but undeveloped. An innovative production strategy has been put forward highlighting that high GOR crude can be injected into the upper oil reservoirs with partially pressure depletion, as energy-conservation measure, in view of its high wellhead pressure and good productivity during drill stem tests, therefore to achieve production enhancement and synergy among reservoirs.

In-house studies indicate high GOR crude can be miscible with all oils from eight zones. Field results show that injection processes can bring dead wells back production, yielding the prolific output. Also, water cut can be reduced immediately and field water cut rising trend can be mitigated.

The innovative injection processes are illustrated as follows:

New development wells should be deployed at updip positions to penetrate the all the hydrocarbon reservoirs with the thick pay. Run tubing string with packer. Packer is used for isolation of upper oil zones and HP/HT environment. Huff and puff process. After perforation, high GOR crude travels up the tubing string, via surface choke and a manifold with flow meter, then enter the annulus. Choke regulates the injection rate. For low-permeability (<0.1md) carbonate reservoir, e.g., Sadi reservoir, huff and puff processes are applied post multistage fracturing treatment. High GOR flood is preferred in majorly producing reservoirs with high productivity and relatively low GOR, e.g. Mishrif reservoir. Injected high GOR crude (API=32.7) can dilute remaining oil (API=19.1-23.0), reduce its viscosity, and therefore achieve production enhancement. During primary development, asphaltene deposit occurred and chemical inhibitor has been applied. After oil blending, the risk of asphaltene deposit could be minimized. First perforate lower-pressure oil zones and then open the HP/HT zone for work safety.

The production enhancement strategy and processes in this paper could be of strong reference value to similar stacked reservoirs.
Exploiting the Presence of Leaky Subsurface Transmission Lines to Locate Oil Banks
Authors: Felix Servin Jesus Manuel
Published: November 2020

Subsurface waveguides and transmission lines are often considered a challenge to surface seismic and electromagnetic (EM) because they channel energy away from the area of interest. That same property can be used to increase the range of investigation in cross-hole EM surveys. This study describes an approach that exploits subsurface transmission lines to locate oil banks in hydrocarbon reservoirs.

3D EM numerical simulations in the time domain were conducted to demonstrate that EM signals propagated through leaky transmission lines in the form of a resistive layer bounded by hydrocarbon reservoirs are affected by the fluid saturation of the reservoirs. In addition, oil banks of different sizes were placed in the bottom reservoir along the path between the wellbores to investigate their effect on the received signal. The travel time and amplitude of the received signal was compared for multiple scenarios and subsurface conditions.

The results confirm that changes in the saturation of the bounding reservoirs have an effect on the received signal. A decrease in water saturation results in a significant reduction in signal amplitude. A shift of the waveform toward the left is also observed as water saturation decreases. In addition, we prove that our approach is sensitive to the presence of oil banks in swept reservoirs. When both reservoirs are water-saturated, including an oil bank in the bottom reservoir decreases signal amplitude and shifts the waveform toward the left. These effects increase with the length of the oil bank but are noticeable for features smaller than one wavelength. However, little to no sensitivity was observed for the location of the bank. Meaning that, for a given length, it would be challenging to determine where the bank is because different locations yield the same waveform.

This study confirms that EM signals propagating through leaky transmission lines are affected by the EM properties and thus saturation changes of the bounding layers. In the case of resistive seals bounded by hydrocarbon reservoirs this means that, the received waveform will depend on the saturation of the bounding reservoirs. Moreover, we have demonstrated that our approach has potential to locate oil banks in swept reservoirs. Our results present a potentially new research direction in the area of oil reservoir monitoring and add valuable knowledge towards our understanding of how naturally occurring waveguides and transmission lines can be used to improve subsurface characterization.
The effect of anti-cancer and anti-tuberculosis treatments in lung cancer patients with active tuberculosis: a retrospective analysis
Authors: CHAI MEI , Shi Qingming
Published: November 2020

Background: Lung tuberculosis (TB) and lung cancer have a complex relationship. Data concerning TB treatment in lung cancer patients are still incomplete. The aim of this study was to investigate the effects of anti-cancer and anti-tuberculosis treatments in lung cancer patients with active lung TB. Methods: In a retrospective cohort study, lung cancer patients with active lung TB were identified between January 2013 and December 2016. Age- and sex-matched lung cancer patients without tuberculosis were selected as control subjects. Anti-cancer and anti-tuberculosis treatments were administered according to the national guidelines. The clinical courses and responses of lung cancer patients with and without active lung TB were examined and compared. Results: A total of 31 consecutive lung cancer patients were diagnosed with active lung TB. Fifty-one lung cancer patients without TB were enrolled as control subjects. Most patients in the two groups were elderly, had advanced non-small cell lung cancer and had tumor burdens. The anti-cancer treatment completion rate and response rate were not different between two group (87.1% in TB treatment patients vs. 92.2% in lung cancer patients; 77.4% in TB treatment patients vs. 88.2% in lung cancer patients, respectively). The anti-tuberculosis treatment completion rate and success rate was 87.1% and 80.7%. The median survival times were not different between two groups (52 weeks in TB treatment patients vs. 57 weeks in lung cancer patients). The change in Karnofsky performance score was also not different between two groups. The most common side effect in TB treatment patients was liver injury (61.3%). The most serious side effect in TB treatment patients was leukocyte deficiency (9.7% in Grade 3). Both of side effects mentioned above were not different between two groups. Conclusion: Both anti-cancer and anti-tuberculosis treatments can be safely and effectively administered in lung cancer patients with active lung TB. Attention should be paid to the risk of tuberculosis in lung cancer patients in TB high-burden countries. Keywords Lung cancer, tuberculosis, prognosis.
Subjective sleep quality and association with depression syndrome, chronic diseases and health-related physical fitness in the middle-aged and elderly
Authors: Hsu Min-Fang , Lee Kang-Yun , Lin Tsung-Ching , Liu Wen-Te , Ho Shu-Chuan
Published: November 2020

Background: As a complex phenomenon, sleep quality is difficult to objectively define and measure, and multiple factors related to sleep quality, such as age, lifestyle, physical activity, and physical fitness, feature prominently in older adult populations. The aim of the present study was to evaluate subjective sleep quality using the Pittsburgh Sleep Quality Index (PSQI) and to associate sleep quality with health-related physical fitness factors, depressive symptoms, and the number of chronic diseases in the middle-aged and elderly.Methods: We enrolled a total of 283 middle-aged and elderly participants from a rehabilitation clinic or health examination department. The PSQI was used to evaluate sleep quality. The health-related fitness assessment included anthropometric and physical fitness parameters. Depressive symptoms were measured with the Center for Epidemiologic Studies Depression Scale (CES-D) short form. Data were analyzed with SPSS 18.0, and descriptive statistics and logistic regression analysis were used for the analyses.Results: Overall, 27.9% of participants in this study demonstrated poor sleep quality (with a PSQI score of >5), 10.2% of study participants frequently used sleep medication to help them fall asleep, and 6.0% reported having significant depressive symptoms (with a CES-D score of ≥10). There are two major findings: (1) depression symptoms, the number of chronic diseases, self-rated health, and arthritis were significantly associated with a poor sleep quality, and (2) the 2-min step test was associated with longer sleep latency. These results confirmed that the 2-min step was associated with a longer sleep latency among the health-related physical fitness items.Conclusions: Our study found that depressive syndrome, chronic disease numbers, a poor self-rated health status, and arthritis were the main risk factors that influenced subjective sleep quality.
Adolescent access to health services in fragile and conflict-affected contexts: the case of the Gaza Strip
Authors: Hamad Bassam Abu , Jones Nicola , Gercama Ingrid
Published: November 2020

Background: Enjoyment of physical and mental health is not only recognized as a human right but also as an integral part of development, as reflected in Sustainable Development Goal (SDG) 3 – to ensure healthy lives and promote well-being for all at all ages. The rapid physical, psychosocial and behavioural changes that take place during adolescence have a strong influence on the rest of a person’s life course, so investments in adolescent health services constitute a unique opportunity to reap lifelong and inter-generational dividends. Yet the evidence base on adolescents’ access to health services, particularly in conflict-affected contexts, remains thin. This article explores adolescents’ access to health services in the Gaza Strip, and their experiences and perceptions of those services. Methods: The article draws on mixed-methods research in the Gaza Strip in 2016 and 2017 involving 240 adolescents and 65 service providers, combining a QuickTapSurvey,™ key informant interviews, peer-to-peer research and individual in-depth interviews. Results: The findings underscore that gender norms—especially those pertaining to adolescent girls’ sexual purity––shape adolescent health in multiple ways. Girls face increasing restrictions on their mobility and social interactions, leaving them with limited opportunities for leisure or exercise, socializing with peers or seeking health (including mental health) services. Adolescent boys in Gaza do not face the same restrictions, but given the multiple political, economic and familial stressors, they are at high risk of substance abuse and involvement in peer violence. Moreover, our findings suggest that a range of socioeconomic, cultural and structural barriers prevent adolescents in Gaza from accessing quality and appropriate health care. Study participants cited the main challenges as an absence of preventive adolescent health initiatives and limited information on sexual and reproductive health, as well as drug shortages, high treatment costs, and negative interactions with service providers. Conclusions: The article highlights the importance of (1) designing and implementing conflict-sensitive and age- and gender-appropriate adolescent services and information; (2) promoting preventive services targeted at adolescents; and (3) improving service provider awareness of adolescents’ specific health needs in all contexts.
Comparison of Open and Intracorporeal Modified Ureterosigmoidostomy (Mainz Ⅱ) After Laparoscopic Radical Cystectomy with Bladder Cancer
Authors: Zheng Duo , Liu Junyao , Wu Gongjin , Yang Shujun , Luo Chuang , Du Tianci , Luo Yao , Bao Junsheng , Tian Junqiang , Wang Zhiping , Shang Panfeng , Yue Zhongjin
Published: November 2020

Objective: To compare perioperative and oncologic outcomes of open modified ureterosigmoidostomy urinary diversion (OMUUD) and intracorporeal modified ureterosigmoidostomy urinary diversion (IMUUD) following laparoscopic radical cystectomy (LRC).Patients and Methods: We retrospectively reviewed our single institutional collected database patients undergoing LRC from October 2011 to October 2019.The perioperative characteristics were compared between OMUUD and IMUUD, and overall survival (OS) and progression-free survival (PFS) were evaluated by Kaplan-Meier method. Results: Overall 84 patients were included. OMUUD and IMUUD were performed in 63 (75%) and 21 (25%) patients respectively. IMUUD patients demonstrated shorter postoperative length of stay (16.24±3.91 d vs. 18.98±7.41 d, P=0.033), similar operation time (498.57±121.44 vs. 462.24±99.71, P=0.175), similar estimated blood loss ［400(200-475) ml vs. 400(200-700) ml, P=0.095］,similar overall complication rate within 30-d (19.05% vs. 25.40%, P=0.848) and 90-d (23.81% vs. 17.46%, P=0.748). Complete urinary control rate of 87.3% (55/63) at OMUUD group. In IMUUD with a complete urinary control rate of 90.5% (19/21).There was no significant in OS (χ2=0.015, P=0.901) and PFS (χ2=0.107, P=0.743) between two groups.Conclusion: IMUUD postoperative recovery is faster, other perioperative outcomes and oncology results are not significantly different with OMUUD. It is indicated that IMUUD can be utilized safely and effectively in the urinary diversion after LRC.
Water-promoted Synthesis of Stereoselective Oxazoline-fused Saccharides and Construction for 1, 2-cis Glycosylamines of Multi-modifications of Polyhydroxyl groups
Authors: Dong Sanfeng , Zhao Yitian , Shi Yulong , Xu Zhijian , Shen Jingshan , Jia Qi , Li Yiming , Chen Kaixian , Li Bo , Zhu Weiliang
Published: November 2020

The multi-modifications of polyhydroxyl groups and the stereoselective formation of 1,2-cis glycosidic bonds are difficult in glycochemistry. Herein we disclosed a concise synthesis of the oxazoline-fused saccharides (oxazolinoses) from acetyl saccharides and benzonitriles under acidic conditions promoted by the stoichiometric water. The oxazolinoses can be easily converted into 1,2-cis glycosylamines with differentiated modifications at 2,3-positions on the saccharide ring in few steps and the 1-NH2 can further be simply transformed to the 1-OH. Oxazolinoses can also be directly used to synthesize complex chiral molecules such as schisandrins. Saccharides screening have shown that the oxazolinoses could be synthesized from various monosaccharides and oligosaccharides. Accordingly, 1-α- or 1-β-1,2-cis glycosylamines can be obtained from different oxazolinoses which are 1,2-cis stereoselectivity controlled by neighboring group participation. The density functional theory (DFT) calculations have revealed the origin of the stereoselectivity and the key role of water.
The Impact of Rheohaemapheresis on the Proprotein Convertase Subtilisin Kexin 9 (PCSK9) in Age-Related Macular Degeneration
Authors: Blaha Vladimír , Langrová Hana , Blaha Milan , Studnička Jan , Stěpanov Alexander , Andrýs Ctirad , Loefflerová Veronika , Lánská Miriam , Vejražková Eva , Dulíček Petr
Published: November 2020

Background. Age-related macular degeneration (AMD) is a progressive chronic disease with resulting visual impairment or even blindness with limited therapeutic options. Because hyperlipidemia is a significant risk factor for AMD development we investigated long-term effects of rheohaemapheresis in the dry form of age-related macular degeneration on the lipid related parameters including PCSK9.Methods. This study evaluates 31 patients with age-related macular degeneration (AMD), treated with rheohaemapheresis. The followed-up period was 7 years. Average age was 69.1 ± 4.9 years. Each treated patient received a series of 8 sessions of rheohaemapheresis. 2 additional procedures within 1-week procedures were performed to boost the effect after the 2-year period. We measured the drusenoid pigment epithelium detachment (DPED), best-corrected visual acuity (BCVA), electroretinography (ERG), lipid, inflammatory, endothelial dysfunction and rheologically important parameters. Results. Rheohaemapheresis treatment in AMD patients was associated with a significant decrease of total cholesterol, LDL-C, HDL-C, apoprotein B, and lipoprotein (a) levels, biomarkers of inflammation, endothelial dysfunction (CD40L, MCP-1) and rheologically important parameters, and serum PCSK9 (P<0.001). The patients were further divided into 2 groups based on the ophtalmological examination. Successfully treated patients (n=10, with at least a 5-year follow-up) had significantly lower baseline LDL-C and ApoB (P<0.05) and their serum PCSK9 significantly decreased after rheohaemapheresis (P<0.001) in comparison to the patients where treatment failured (n=4). Conclusion. Over the long term, rheohaemapheresis reduced the DPED, improved the function of photoreceptors, and prevented the decline of BCVA. BCVA improvement was accompanied by lowering of LDL-C and PCSK9 and improvement of endothelial dysfunction. We suggest that rheohaemapheresis and other novel anti-PCSK9 therapies may be used synergistically to reduce severity, slow down or even induce regression of AMD.
Clinical and Genetic Characteristics of Hypophosphatasia in Chinese Children
Authors: Liu Meijuan , Liu Min , Liang Xuejun , Wu Di , Li Wenjing , Su Chang , Cao Bingyan , Chen Jiajia , Gong Chunxiu
Published: November 2020

Background: Hypophosphatasia (HPP) is a rare inherited disorder, which is caused by loss-of-function mutations in the ALPL gene. HPP is a heterogeneous disease that has a wide spectrum of phenotypes. Few studies were carried out in the Chinese population with HPP, especially in children. Methods: The clinical and genetic characteristics of 10 Chinese children with HPP who were referred to the Beijing Children’s Hospital were described. We also reviewed previously reported HPP cases of children in China.Results: A total of 33 cases were identified, which included 2 perinatal lethal, 10 infantile, 10 childhood, and 11 odonto types of HPP. The male to female ratio was 24:9. The average age at onset was 0.69 years (ranged from 2 hours after birth to 14 years), while the average age at clinical diagnosis was 3.87 years (ranged from 2 hours after birth to 19 years). Serum alkaline phosphatase (ALP) levels were significantly decreased in patients with severe forms of HPP (perinatal lethal/infantile HPP) when compared with those with the mild forms of HPP (childhood/odonto HPP, P<0.01). Although serum phosphate levels were not significantly different (P>0.05), serum calcium levels were elevated, and serum intact parathyroid hormone (i-PTH) levels were decreased in patients with severe forms of HPP in comparison with those with the mild forms of HPP (P all <0.01). Genetic analyses identified 40 mutations in 31 HPP cases, including 28 missense mutations, 9 frameshift mutations, 2 splice junction alterations, and 1 regulatory mutation. Of which, 5 novel mutations were identified in our present study: 2 frameshift mutation (p.Arg138GlyfsTer27, p.Leu511Profs*272); 2 missense mutations (p.Ala176Val, p.Phe268Leu), and 1 splice junction alterations (c.297+5G>A). Compound heterozygous mutations accounted for 89.29% of all variants. No mutational “hot-spot” was found. Most mutations of ALPL were located in exons 5, 7, 10 and 3. Notably, subjects that carrying single heterozygous mutations showed milder phenotypes of HPP, while subjects with nonsense mutations were associated with a severe phenotype.Conclusions: HPP is a rare disease with often delayed diagnosis, and the incidence of HPP in China may be seriously underestimated. The present study expands the phenotypic and genotypic spectrum and our understanding of HPP in Chinese children.These findings will be useful for clinical assessment and shorten the diagnostics of pediatric HPP in China.
Comparing neoadjuvant long-course chemoradiotherapy with short-course radiotherapy in rectal cancer
Authors: Wang Jian , Long Yiwen , Liu Kun , Pei Qian , Zhu Hong
Published: November 2020

Background:The purpose of this study was to compare short-course radiotherapy (SC) or neoadjuvant long-course chemoradiotherapy (LC) treatment for locally advanced rectal cancer patients.Methods:Patients with a diagnosis of locally advanced rectal cancer (LARC) who had undergone neoadjuvant radiotherapy before surgery between 2013 and 2018 at the medical center in China were included in this study. All patients’ MRI confirmed T2N+M0 or T3-4N0-3M0 clinical stages. Patients in the SC group received pelvic radiotherapy with a dose of 5×5 Gy (with or without chemotherapy at any time), followed by immediate or delayed surgery. Patients in the LC group received a dose of 50-50.4 Gy in 25-28 fractions, concomitantly with FOLFOX or capecitabine-based chemotherapy, followed by surgery 4-6 weeks later. All clinical data were retrospectively collected, and long-term follow-up was completed and recorded at the same time.Results:A total of 170 were eligible to participate in this study, 32 patients in the SC group, and 138 in the LC group. The median follow-up time of living patients was 39 months. The disease-free survival (DFS) and overall survival (OS) rates in the SC group and LC group at 3 years, were, 84.9% versus 72.4% (P= 0.273) and 96.2% versus 87.2% (P= 0.510), respectively. The complete pathological response (pCR) rates in the SC group and LC group were, 25% versus 18.1% (the difference was not statistically significant, P=0.375), respectively. However, the SC group had better node(N) downstaging compared to the LC group (P=0.011).Conclusions:There were no differences observed in DFS and OS between short-course radiotherapy and long-course chemoradiation, and both can be used as treatment options for patients with locally advanced rectal cancer.
Experimental and Numerical Investigation on the Thermal and Mechanical Behaviours of Thermal Barrier coatings Exposed to CMAS Corrosion
Authors: Li Dongxu , Jiang Peng , Gao Renheng , Sun Fan , Jin Xiaochao , Fan Xueling
Published: November 2020

Calcium-magnesium-alumino-silicate (CMAS) corrosion is one of the most critical failure mechanisms of thermal barrier coating (TBC). CMAS attack significantly alters the temperature and stress fields in TBCs, resulting in their delamination or spallation. In this work, the dynamic evolution process of suspension plasma sprayed (SPS) TBC under CMAS attack is investigated. The CMAS corrosion leads to the formation of reaction layer and subsequent bending of TBC. Based on the observations, a corrosion model is proposed to describe the generation and evolution of the reaction layer and bending of TBC. Then, numerical simulations are performed to investigate the corrosion process of free-standing TBC and the complete TBC system under CMAS attack, respectively. Results show that the CMAS corrosion has a significant influence on the stress field, such as the peak stress, while it has little influence on the steady state temperature field. It should be noted that the peak of stress increases with holding time which increases the risk of the rupture of TBC. There is a parabolic relationship between the stress and reaction layer thickness in the holding stage. Furthermore, in the traditional failure zone, such as the interface of top coat and bond coat, the stress obviously change during CMAS corrosion.
Perianal and Perineal Rhabdomyosarcomas - A Retrospective Multicenter Study of 35 Cases
Authors: Guo Yaoyu , Hu Bang , Huang Dandan , Wang Xinhua , Li Juan , Zhang Di , Li Xueying , Chen Gong , Ren Donglin
Published: November 2020

BackgroundPerianal/perineal rhabdomyosarcoma (PRMS) is rare, easy to be misdiagnosed and has poor prognosis. This study was designed to analyze the clinical, diagnostic, pathological and prognostic features of PRMS, and to explore its therapeutic modality.MethodsClinical data of PRMS patients in the Sixth Affiliated Hospital and the Cancer Center of Sun Yat-sen University and related Chinese literatures published between 1987 and 2018 were described and analyzed. Chi-square test was used to test the differences between groups. The Kaplan-Meier methods were used to estimate and compare survival rates.Results35 patients, 20 identified in the Chinese literatures and 15 of our center from 1997 to 2019, were included in this study. 34 cases presented as perianal mass and one presented as inguinal mass. 20 patients complained about pain and 16 cases were misdiagnosed as perianal abscess, in which pain was found related to misdiagnosis (p＜0.05). The average time from symptoms to pathological diagnosis was 3.1 months. 13 cases were categorized into IRS group III/IV and 20 cases into stages 3/4. 14 Cases were diagnosed as embryonal rhabdomyosarcoma pathologically and 9 as alveolar rhabdomyosarcoma. Five patients survived for more than two years, three of them survived for more than five years. The overall survival rates of two years and five years were 32% and 24% respectively, in which misdiagnosis contributes to poor prognosis (p＜0.05). MRI showed that PRMS was closely related to external anal sphincter in 10 cases. Conclusion﻿PRMS is easy to be misdiagnosed, which could lead to worse outcome. Patients with painful perianal mass should be evaluated to exclude PRMS. MRI shows PRMS is closely related to external anal sphincter. Comprehensive therapy including radical operation and chemotherapy is recommended.
Reconstructing Surface Eruptive Sequence of 2018 Small Phreatic Eruption of Iwo-Yama Volcano, Kirishima Volcanic Complex, Japan by Infrasound Cross-correlation Analysis
Authors: Muramatsu Dan , Matsushima Takeshi , Ichihara Mie
Published: November 2020

The Iwo-yama volcano of the Kirishima Volcanic Complex in Japan had a small phreatic eruption in April 2018, which formed multiple vents. The activity was recorded by two infrasound sensors and two monitoring cameras which had been installed within 1 km of the vents. This study identified infrasonic signals from the multiple vents by a cross-correlation analysis between the two infrasound sensors. The analysis successfully revealed the signals from two main eruption craters and constrained the infrasound onsets at the individual vents in the two craters. We combined the results with the images from the cameras and reconstructed the sequence of the small phreatic eruption of Iwo-yama. Notably, the intense eruption accompanying remarkable infrasound delayed several hours to the eruption onset at each of the two craters. This study provides a sequence of the activities of the multiple vents in a phreatic eruption, which will be useful for understanding the phreatic eruption mechanism and hazard assessments.
Optimal Long-Term Power Sector Planning for Pakistan Through Modelling of Base and Alternate Scenarios
Authors: Wahid Hafsa , Aman Mohsin , Arfeen Asad , Tunio M. A.
Published: November 2020

The authors have requested that this preprint be removed from Research Square.
Longitudinal MRI Study After Carbon Ion and Photon Irradiation: Shorter Latency Time for Myelopathy is Not Associated With Differential Morphological Changes
Authors: Welzel Thomas , Bendinger Alina Leandra , Glowa Christin , Babushkina Inna , Jugold Manfred , Peschke Peter , Debus Jürgen , Karger Christian P. , Saager Maria
Published: November 2020

Background Radiation-induced myelopathy is a severe and irreversible complication that occurs after a long symptom-free latency time if the spinal cord was exposed to a significant irradiation dose during tumor treatment. As carbon ions are increasingly investigated for tumor treatment in clinical trials, their effect on normal tissue needs further investigation to assure safety of patient treatments. Magnetic resonance imaging (MRI)-visible morphological alterations could serve as predictive markers for medicinal interventions to avoid severe side effects. Thus, MRI-visible morphological alterations in the rat spinal cord after high dose photon and carbon ion irradiation and their latency times were investigated.MethodsRats whose spinal cords were irradiated with iso-effective high photon (n = 8) or carbon ion (n = 8) doses as well as sham-treated control animals (n=6) underwent frequent MRI measurements until they developed radiation-induced myelopathy (paresis II). MR images were analyzed for morphological alterations and animals were regularly tested for neurological deficits. In addition, histological analysis was performed of animals suffering from paresis II compared to controls.ResultsFor both beam modalities, first morphological alterations occurred outside the spinal cord (bone marrow conversion, contrast agent accumulation in the musculature ventral and dorsal to the spinal cord) followed by morphological alterations inside the spinal cord (edema, syrinx, contrast agent accumulation) and eventually neurological alterations (paresis I and II). Latency times were significantly shorter after carbon ions as compared to photon irradiation.Conclusions Irradiation of the rat spinal cord with photon or carbon ion doses that lead to 100% myelopathy induced a comparable fixed sequence of MRI-visible morphological alterations and neurological distortions. However, at least in the animal model used in this study, the observed MRI-visible morphological alterations in the spinal cord are not suited as predictive markers to identify animals that will develop myelopathy as the time between MRI-visible alterations and the occurrence of myelopathy is too short to intervene with protective or mitigative drugs.
Recurrent outbreaks of Ebola Virus Disease in Africa: A Meta-analysis of case fatality rates
Authors: Kawuki Joseph , Musa Taha Hussein , Yu Xiaojin
Published: November 2020

Background: In the last decade, Africa has witnessed several outbreaks of Ebola virus disease (EVD), each presenting with varying case fatality rate (CFR) and other socio-economic impacts. This study aims to summarise the CFR and identify potential factors that influenced the severity of EVD outbreaks in Africa.Methods: This was a systematic review and meta-analysis of EVD outbreaks published between January 2010 and March 2020, using Web of Science, Scopus and PubMed databases. Only English articles and reports, including the number of cases and deaths during the outbreak in Africa, were considered. Quality of the included articles was assessed using the Murad’s quality assessment tool. The analysis was conducted using Stata (version 12), pooled effect sizes were calculated using the random-effects model and heterogeneity was tested for using the I2 statistic.Result: Thirteen studies with 32,300 cases and 13,727 deaths were identified whose pooled CFR was 60% (95% CI: 47-73%). The most EVD-affected countries were DRC with 5 outbreaks and a pooled CFR of 65% (95% CI: 59-71%), followed by Uganda with 3 outbreaks and CFR= 83% (95% CI: 60-99%). Zaire ebolavirus caused the most outbreaks (10), with a CFR= 58% (95% CI: 45-71%). Besides, outbreaks with less than 1000 cases reported a higher CFR rate compared to those with more cases.Conclusion: The study has revealed a considerably high CFR caused by the recurrent EVD outbreaks in Africa. It also notes an implementation gap of the prevention and control strategies, and thus identifies a need to strengthen the surveillance systems and response mechanisms to enable early detection and prompt control of future outbreaks.
Laboratory Predictors for COVID-19 ICU Admissions in a Caribbean Territory.
Authors: Gopaul Chavin , Ventour Dale , Thomas Davlin
Published: November 2020

Introduction. Understanding the symptoms associated with COVID-19 cases that require intensive care unit (ICU) attention is important in management of the life threatening case of the disease. Method : This study was carried out with the aim of determining the laboratory indicators of ICU admission. Data from 126 COVID-19 patients (ICU patients, n = 18, Non-ICU, n = 98) were analyzed from a Caribbean Territory.Results: The median age for the non-ICU patients was 59.0 (IQR = 23.5) years while the ICU patients had a median age of 62.5 (IQR = 17.5). The univariate analysis indicted that laboratory indicators that were significantly associated with ICU admission included WBC (P = 0.037), lymphocyte (P = 0.016), LDH (P = 0.002), AST (P = 0.005) and CRP (P = 0.0001). However, multivariate analysis that included WBC, neutrophil, lymphocyte, PLT, AST, LDH, ALT, and CRP indicated that only AST was associated with high odds of patients being admitted to ICU (OR .002, 95% CI 0.000-.004, P = 0.017). Statistically significant area under the curve (AUC) were obtained for Neutrophil (AUC = 0.704, P = 0.007), CRP (AUC = 0.81, p= 0.00) and LDH (AUC=0.766, P= 0.00) and AST (AUC= 0.729, P= 0.003). Conclusion: The findings indicate that neutrophils, AST and LDH’s ROC curves are good tests while CRP curve is a very good test. However, lymphocyte curve is a poor test for determining COVID-19 patient for ICU admission. Neutrophil, AST, LDH and CRP are suitable predictors of COVID-19 patients that should receive ICU care
Distribution of sources of household air pollution: a cross-sectional study in Cameroon
Authors: Baame Esong Miranda , Goura André Pascal , Mbatchou Bertrand Hugo Ngahane , Walage Berenice , Simo Herman Styve Yomi , Medjou Romarique Mboumo , Sonkoue Martial Pianta , Djouda Cyrielle Douanla , Ngnewa Rose Suzie Fowoh , Guiagain Milaine Sandra Teugueu , Agokeng Brice-Donald Kemnang , Homla Olivia Tania Megaptche , Pope Dan , Ateudjieu Jerome
Published: November 2020

Background: Household air pollution (HAP) is a recognised risk factor for many diseases, including respiratory diseases, cardiovascular/circulatory disorders, adverse pregnancy outcomes and cataracts. Population exposure to biomass fuels, including wood, varies among countries and from one fuel source to the other. This study aimed to investigate the different sources of HAP in peri-urban and rural communities in Cameroon. Methods: A cross-sectional survey was conducted in a representative sample of households from the Dschang Health District (DHD) region. This included 848 homes in which a range of fuels for cooking including biomass (firewood, charcoal, sawdust), kerosene and liquefied petroleum gas (LPG) were used both indoors and outdoors. Results: Of the study households, 651 (77%) reported exclusive use of firewood and 141 (17%) reported using more than one source of fuel. Exclusive use of firewood was greater in rural communities (94%) than in peri-urban communities (38%). In peri-urban communites, use of multiple fuels including LPG, wood, sawdust and kerosene, was more common (44.75%). A total of 25.03% of households in both peri-urban and rural communities reported using bottled gas (or liquified petroleum gas (LPG) for cooking. Motivations for choice of fuel included, price, availability (easy access), rapidity, tradition or culture related factorsConclusion: Wood is the main cooking fuel in both peri-urban and rural communities in the Dschang Health District. Work to help households (especially those who are resource poor) to adopt LPG equipment for cooking, and use in a more exclusive way is required.
Development of a Multivariable Prediction Model to Identify Patients Unlikely to Complete a Colonoscopy Following an Abnormal FIT Test in Community Clinics
Authors: Petrik Amanda , Keast Erin , Johnson Eric , Smith David H. , Coronado Gloria D.
Published: November 2020

Background: Colorectal cancer (CRC) is the 2 nd leading cancer killer in the US. The Strategies and Opportunities to STOP Colon Cancer in Priority Populations (STOP CRC) project aimed to increase CRC screening among patients in Federally Qualified Health Centers (FQHCs) through a mailed fecal immunochemical test (FIT) outreach program. However, rates of completion of the follow-up colonoscopy following an abnormal FIT remain low. We developed a multivariable prediction model using data available in the electronic health record to assess the probability of patients obtaining a colonoscopy following an abnormal FIT test.
Methods: To assess the probability of obtaining a colonoscopy, we used Cox regression to develop a risk prediction model among a retrospective cohort of patients with an abnormal FIT result.
Results: Of 1596 patients with an abnormal FIT result, 556 (34.8%) had a recorded colonoscopy within 6 months. The model shows adequate separation of patients across risk levels for non-adherence to follow-up colonoscopy (bootstrap-corrected C-statistic > 0.63). The refined model included 8 variables: age, race, insurance, GINI income inequality, long term anticoagulant use, receipt of a flu vaccine in the past year, frequency of missed clinic appointments, and clinic site. Probability of obtaining a follow-up colonoscopy within 6 months varied across quintiles; patients in the lowest quintile had an estimated 18% chance, whereas patients in the top quintile had a greater than 55% chance of obtaining a follow-up colonoscopy.
Conclusions: Knowing who is unlikely to follow-up on an abnormal FIT test could help identify patients who need an early intervention aimed at completing a follow-up colonoscopy.
Trial registry: This trial was registered at ClinicalTrials.gov (NCT01742065) on December 5, 2012. The protocol is available.
High Resolution Computed Tomography Finding in 552 Patients with Symptomatic COVID-19: First Report from North of Iran
Authors: Majidi Hadi , Bani-Mostafavi Elham-Sadat , Mardanshahi Zahra , Godazandeh Farnaz , Gasemian Roya , Heydari Keyvan , Alizadeh-Navaei Reza
Published: November 2020

Purpose: Due to the emergence of the new Coronavirus-2019 and the lack of sufficient information about infected patients, this study was conducted to investigate the Chest High Resolution Computed Tomography (HRCT) findings of patients infected with the new Coronavirus 2019.Methods: This cross-sectional study was performed on COVID-19 patients referred to Medical Imaging Centers of Sari, Mazandaran, Iran, on March 2020 for Computed Tomography Scan (CT-Scan). Symptomatic patients were referred to the Medical Imaging Center for diagnosis confirmation through CT-scan. In addition to age and sex, HRCT findings were collected from the picture archiving and communication system (PACS) for further evaluations.Results: Out of 552 patients with mean age of 14.8 ± 51.2 years, the male/female ratio was 1.38 to 1. The most common expressive findings in patients were ground-glass opacity (GGO) (87.3%), peripheral distribution (82.4%) and posterior distribution (81.5%). The most conflicting findings in patients were pleural effusion (7.6%), peribronchovascular distribution (7.6%), and lymphadenopathy (5.1%). The peripheral distribution (p = 0.034), round opacities (p = 0.02), single lobe (p = 0.003) and pleural effusion (p = 0.037) were significantly in people under and over 50 years of age.Conclusion: In summary, the present study indicated that in addition to GGO, peripheral distribution findings could be a vital diagnostic choice in COVID-19 patients.
A preoperative mortality risk assessment model for Standford type A acute aortic dissection
Authors: Kuang Juntao , Yang Jue , Wang Qiuji , Yu Changjiang , Li Ying , Fan Ruixin
Published: November 2020

OBJECTIVES Acute aortic dissection type A is a life-threatening disease required emergency surgery during acute phase. Different clinical manifestations, laboratory tests, and imaging features of patients with acute aortic dissection type A are the risk factors of preoperative mortality. This study aims to establish a simple and effective preoperative mortality risk assessment model for patients with acute aortic dissection type A.METHODS A total of 673 Chinese patients with acute aortic dissection type A who were admitted to our hospital were retrospectively included. All patients were unable to receive surgically treatment within 3 days from the onset of disease. The patients included were divided into the survivor and deceased groups, and the endpoint event was preoperative death. Multivariable analysis was used to investigate predictors of preoperative mortality and to develop a prediction model.RESULTS Among the 673 patients, 527 patients survived (78.31%) and 146 patients died (21.69%). The developmental dataset had 505 patients, calibration by Hosmer Lemeshow was significant (χ2 = 3.260, df = 8, P = 0.917) and discrimination by area under ROC curve was 0.8,448 (95% CI, 0.8,007-0.8,888). The validation dataset had 168 patients, calibration was significant (χ2 = 5.500, df = 8, P = 0.703) and the area under the ROC curve was 0.8,086 (95% CI, 0.7,291-0.8,881). The following independent variables increased preoperative mortality: age (OR = 1.008, P = 0.510), abrupt chest pain (OR = 3.534, P < 0.001), lactic in arterial blood gas ≥ 3 mmol/L (OR = 3.636, P < 0.001), inotropic support (OR = 8.615, P < 0.001), electrocardiographic myocardial ischemia (OR = 3.300, P = 0.001), innominate artery involvement (OR = 1.625, P = 0.104), right common carotid artery involvement (OR = 3.487, P = 0.001), superior mesenteric artery involvement (OR = 2.651, P = 0.001), false lumen / true lumen of ascending aorta ≥ 0.75 (OR = 2.221, P = 0.007) . Our data suggest that a simple and effective preoperative death risk assessment model has been established.CONCLUSIONS Using a simple and effective risk assessment model can help clinicians quickly identify high-risk patients and make appropriate medical decisions.
Solar Cycle Related Variation in Solar Diﬀerential Rotation and Meridional Flow in Solar Cycle 24
Authors: Imada Shinsuke , Matoba Kengo , Fujiyama Masashi , Iijima Haruhisa
Published: November 2020

We studied temporal variation of the diﬀerential rotation and poleward meridional circulation during solar cycle 24 using the magnetic element feature tracking technique. We used line-of-sight magnetograms obtained using the Helioseismic and Magnetic Imager aboard the Solar Dynamics Observatory from May 01, 2010 to March 26, 2020 (for almost the entire period of solar cycle 24, Carrington Rotation from 2096 to 2229) and tracked the magnetic element features every 1 hour. We also estimated the diﬀerential rotation and poleward meridional flow velocity profiles. The observed profiles are consistent with those of previous studies on diﬀerent cycles. Typical properties resulting from torsional oscillations can also be observed from solar cycle 24. The amplitude of the variation was approximately ±10 m s−1. Interestingly, we found that the average meridional flow observed in solar cycle 24 is faster than that observed in solar cycle 23. In particular, during the declining phase of the cycle, the meridional flow of the middle latitude is accelerated from 10 to 17 m s−1, which is almost half of the meridional flow itself. The faster meridional flow in solar cycle 24 might be the result of the weakest cycle during the last 100 years.
Health services utilisation and out-of-pocket (OOP) expenditures in public and private facilities in Pakistan: An empirical analysis of the 2013-14 OOP Health Expenditure Survey
Authors: Khalid Faraz , Raza Wajeeha , Hotchkiss David R. , Soelaeman Rieza H.
Published: November 2020

Background As low- and middle-income countries progress towards Universal Health Coverage, there is an increasing focus on measuring out-of-pocket (OOP) expenditure and health services utilisation within countries. While there have been several reforms to improve health services coverage and financial protection in Pakistan, there is limited empirical research comparing OOP expenditure and health services utilisation between public and private facilities and exploring their determinants, a knowledge gap addressed in this study. Methods We used data from 2013-14 OOP Health Expenditure Survey, a population-based household survey carried out for Pakistan’s National Health Accounts. The analysis included 7,969 encounters from 4,293 households. We conducted bivariate analyses to describe patterns of care utilisation, estimated annualized expenditures by type and sector of care, and assessed expenditure composition. We used multivariable logistic regression modeling to identify factors associated with sector of care and generalized linear model (GLM) with log link and gamma distribution to identify determinants of OOP expenditures stratified by type of care (inpatient and outpatient). Results Most encounters (82.5%) were in the private sector and were for outpatient visits (85%). Several public-private differences were observed in annualized expenditures and expenditure components. Logistic regression results indicate males, wealthier individuals, Punjab and Sindh residents, and those in smaller households were more likely to access private outpatient care. In the inpatient model, rural residents were more likely to use a private provider, while Khyber Pakhtunkhwa residents were less likely to use private care. GLM results indicate private sector inpatient expenditures were approximately PKR 6,660 (USD 61.8) higher than public sector expenditures, but no public-private differences were observed for outpatient expenditures. Several demographic factors were significantly associated with outpatient and inpatient expenditures. Of note, expenditures increased with increasing wealth, decreased with increasing household size, and differed by province and region. Conclusions This is the first study comprehensively investigating how healthcare utilisation and OOP expenditures vary by sector, type of care, and socio-economic characteristics in Pakistan. The findings are expected to be particularly useful for the next phase of social health protection programs and supply side reforms, as they highlight sub-populations with higher OOP and private sector utilization.