bluuebunny/crossref_metadata_2025 huggingface dataset:
Parachute mitral valve associated with reticular chordae tendineae in an adult: case report
Authors: Duan Qun-Jun , Duan Cui-Ting , Dong Ai-Qiang , Cheng Hai-Feng
Published: April 2021

Background

Parachute mitral valve with reticular chordae tendineae is an extremely rare anomaly.

Case presentation

We present a case of parachute mitral valve associated with distinctive reticular chordae tendineae in an adult. It was diagnosed from the echocardiogram. The patient was referred for surgery. Valve analysis showed thickened mitral valve leaflets and commissures. The chordae tendinae were lengthy and thick. All the chordae tendinae merged into a solitary papillary muscle. A distinctive reticular fibrous tissue was found on mitral valve apparatus as the chordae tendinae intermixed each other. The only functional communication between the left atrium and the left ventricle was through the reticular spaces. This anomaly was considered to be unrepairable and was replaced with a mechanical valve.

Conclusions

An extremely rare and unique case of parachute mitral valve associated with reticular chordae tendineae was reported. Mitral valve replacement is a reasonable choice in patients with parachute mitral valve with reticular chordae tendineae.
Currarino syndrome: a comprehensive genetic review of a rare congenital disorder
Authors: Dworschak Gabriel C. , Reutter Heiko M. , Ludwig Michael
Published: April 2021

Background

The triad of a presacral mass, sacral agenesis and an anorectal anomaly constitutes the rare Currarino syndrome (CS), which is caused by dorsal–ventral patterning defects during embryonic development. The major causative CS gene is MNX1, encoding a homeobox protein.

Main body

In the majority of patients, CS occurs as an autosomal dominant trait; however, a female predominance observed, implies that CS may underlie an additional mode(s) of inheritance. Often, the diagnosis of CS is established solely by clinical findings, impacting a detailed analysis of the disease. Our combined data, evaluating more than 60 studies reporting patients with CS-associated mutations, revealed a slightly higher incidence rate in females with a female-to-male ratio of 1.39:1. Overall, MNX1 mutation analysis was successful in only 57.4% of all CS patients investigated, with no mutation detected in 7.7% of the familial and 68% of the sporadic patients. Our studies failed to detect the presence of an expressed MNX1 isoform that might explain at least some of these mutation-negative cases.

Conclusion

Aside from MNX1, other genes or regulatory regions may contribute to CS and we discuss several cytogenetic studies and whole-exome sequencing data that have implicated further loci/genes in its etiology.
Psychometric properties of the Thai Mood and Feelings Questionnaire (MFQ) for adolescent depression
Authors: Fuseekul Nanthaka , Orchard Faith , Reynolds Shirley
Published: April 2021

Background

The Mood and Feelings Questionnaire (MFQ) is a widely used screening tool for child and adolescence depression but has not been validated with young people in Thailand. This study aimed to assess the reliability and validity and to determine the optimal clinical cut-off of the Thai MFQ.

Methods

The Thai MFQ was evaluated in two parts. In part 1, The MFQ was translated and back translated into the Thai language and piloted on a small number of Thai adolescents. Then 1275 young people aged 12–18 years from three secondary schools in Thailand completed the MFQ and related measures of depression. In part 2, 138 students were invited to take part in a structured diagnostic interview (the Thai translation of the Kiddie Schedule for Affective Disorders and Schizophrenia for School-Age Children -Present and Lifetime Version (the K-SADS-PL). Of those, 103 students were interviewed and completed the Thai MFQ a second time to assess test–retest reliability. Receiver Operating Characteristics (ROC) analyses were conducted to evaluate diagnosis accuracy and examine the optimal cut-off score of the Thai MFQ.

Results

The Thai MFQ had excellent internal consistency (α = 0.92) and good to moderate test–retest reliability in 2-week and 4-week intervals. The Thai MFQ also had good convergent validity with related measures of depression. The ROC analyses demonstrated that the Thai MFQ also had excellent accuracy distinguishing between depressed and non-depressed adolescents [AUC = 0.95, 95% CI [0.92, 0.99]. A total score of 28 on the Thai MFQ was the optimal cut-off score (sensitivity was 0.97 and specificity was 0.83).

Discussion

The Thai MFQ demonstrated excellent psychometric properties and accurately distinguished between depressed and non-depressed adolescents. It is appropriate to use as a screening measure to identify adolescents with depression in community settings in Thailand.
Rates and risk factors for amputation in people with diabetes in Japan: a historical cohort study using a nationwide claims database
Authors: Kaneko Masanori , Fujihara Kazuya , Harada Mayuko Yamada , Osawa Taeko , Yamamoto Masahiko , Kitazawa Masaru , Matsubayashi Yasuhiro , Yamada Takaho , Seida Hiroyasu , Kodama Satoru , Sone Hirohito
Published: April 2021

Background

The prevalence of diabetes is rising, and diabetes develops at a younger age in East Asia. Although lower limb amputation negatively affects quality of life and increases the risk of cardiovascular events, little is known about the rates and predictors of amputation among persons with diabetes from young adults to those in the “young‐old” category (50–72 y).

Methods

We analyzed data from a nationwide claims database in Japan accumulated from 2008 to 2016 involving 17,288 people with diabetes aged 18–72 y (mean age 50.2 y, HbA1c 7.2%). Amputation occurrence was determined according to information from the claims database. Cox regression model identified variables related to lower limb amputation.

Results

The mean follow‐up time was 5.3 years, during which time 16 amputations occurred (0.17/1000 person‐years). Multivariate Cox regression analysis showed that age (hazard ratio [HR] 1.09 [95% confidence intervals] 1.02–1.16, p = 0.01) and HbA1c (HR 1.46 [1.17–1.81], p < 0.01) were independently associated with amputations. Compared with those aged < 60 years with HbA1c < 8.0%, the HR for amputation was 27.81 (6.54–118.23) in those aged ≥60 years and HbA1c ≥8.0%.

Conclusions

Age and HbA1c were associated with amputations among diabetic individuals, and the rates of amputation were significantly greater in those ≥60 years old and with HbA1c ≥8.0%.
Evaluation of the online-based self-help programme “Selfapy” in patients with unipolar depression: study protocol for a randomized, blinded parallel group dismantling study
Authors: Krämer Rico , Köhler Stephan
Published: April 2021

Background

Patients with mild to moderate depressive symptoms can have limited access to regular treatment; to ensure appropriate care, low-threshold treatment is needed. Effective online interventions could increase the supply of low-threshold treatment. Further research is needed to evaluate the effectiveness of online interventions. This study aims to evaluate the online-based self-help programme “Selfapy” on a sample of depressive subjects and compares the impact of the programme’s unaccompanied version with its therapeutic accompanied version.

Methods

A sample of 400 subjects that have a mild to severe depressive episode (Becks Depression Inventory - II and Hamilton Depression Scale) will be used. Subjects are randomly assigned to immediate access to an unaccompanied course (no support from psychologist via weekly phone calls), immediate access to an accompanied course (support from a psychologist via weekly phone calls) or a waiting list control group (access to the intervention after 24 weeks). The intervention will last for a period of 12 weeks. Depressive symptoms as a primary parameter, as well as various secondary parameters, such as life satisfaction, therapeutic relationships, social activation, self-esteem, attitudes towards Internet interventions and drop-out rates, are recorded at four different points in time: at baseline (T1), 6 weeks after the start of the intervention (T2), 12 weeks after the start of the intervention (T3) and 3 months after completion of the treatment follow-up (T4).

Conclusion

This randomized and controlled, blinded study will make use of a “dismantled” approach to adequately compare the accompanied and unaccompanied versions of the intervention. Positive and meaningful results are expected that could influence the acceptance and implementation of online interventions.

Trial registration

German Clinical Trials Register DRKS00017191. Registered on 14 June 2019
Comparison of various organic acids for xylo-oligosaccharide productions in terms of pKa values and combined severity
Authors: Cao Rou , Liu Xinlu , Guo Jianming , Xu Yong
Published: April 2021

Background

Methods to produce XOS have been intensively investigated, including enzymatic hydrolysis, steam explosion, and acid hydrolysis. Acid hydrolysis is currently the most widely used method to produce XOS due to its advantages of fewer processing steps, stronger raw material adaptability, higher yield, and better reproducibility. Especially, organic acids such as acetic acid, formic acid and xylonic acid work better as compared with mineral acids. However, the catalytic mechanism of different organic acids has been little studied. In this paper, four different organic acids, including formic acid, glycolic acid, lactic acid, and acetic acid were selected to compare their hydrolytic effects.

Results

Using pKa values as the benchmark, the yield of xylo-oligosaccharide (XOS) increased with the increasing value of pKa. The yield of XOS was 37% when hydrolyzed by 5% acetic acid (pKa = 4.75) at 170 ℃ for 20 min. Combined severity (CS), a parameter associated with temperature and reaction time was proposed, was proposed to evaluate the hydrolysis effect. The results of CS were consistent with that of pKa values on both the yield of XOS and the inhibitor.

Conclusion

The results based on pKa values and combined severity, a parameter associated with temperature and reaction time, concluded that acetic acid is a preferred catalyst. Combining the techno-economic analysis and environmental benefits, acetic acid hydrolysis process has lower factory production costs, and it is also an important metabolite and a carbon source for wastewater anaerobic biological treatment. In conclusion, production of xylo-oligosaccharides by acetic acid is an inexpensive, environment-friendly, and sustainable processing technique.
Bioprospecting of wild type ethanologenic yeast for ethanol fuel production from wastewater-grown microalgae
Authors: Romero-Frasca Enrique , Velasquez-Orta Sharon B. , Escobar-Sánchez Viviana , Tinoco-Valencia Raunel , Orta Ledesma María Teresa
Published: April 2021

Background

Wild-type yeasts have been successfully used to obtain food products, yet their full potential as fermenting microorganisms for large-scale ethanol fuel production has to be determined. In this study, wild-type ethanologenic yeasts isolated from a secondary effluent were assessed for their capability to ferment saccharified microalgae sugars.

Results

Yeast species in wastewater were identified sequencing the Internal Transcribed Spacers 1 and 2 regions of the ribosomal cluster. Concurrently, microalgae biomass sugars were saccharified via acid hydrolysis, producing 5.0 ± 0.3 g L−1 of fermentable sugars. Glucose consumption and ethanol production of yeasts in hydrolyzed-microalgae liquor were tested at different initial sugar concentrations and fermentation time. The predominant ethanologenic yeast species was identified as Candida sp., and glucose consumption for this strain and S. cerevisiae achieved 75% and 87% of the initial concentration at optimal conditions, respectively. Relatively similar ethanol yields were determined for both species, achieving 0.45 ± 0.05 (S. cerevisiae) and 0.46 ± 0.05 g ethanol per g glucose (Candida sp.).

Conclusion

Overall, the results provide a first insight of the fermentation capacities of specific wild-type Candida species, and their potential role in ethanol industries seeking to improve their cost-efficiency.
Identification of the major fermentation inhibitors of recombinant 2G yeasts in diverse lignocellulose hydrolysates
Authors: Vanmarcke Gert , Demeke Mekonnen M. , Foulquié-Moreno Maria R. , Thevelein Johan M.
Published: April 2021

Background

Presence of inhibitory chemicals in lignocellulose hydrolysates is a major hurdle for production of second-generation bioethanol. Especially cheaper pre-treatment methods that ensure an economical viable production process generate high levels of these inhibitory chemicals. The effect of several of these inhibitors has been extensively studied with non-xylose-fermenting laboratory strains, in synthetic media, and usually as single inhibitors, or with inhibitor concentrations much higher than those found in lignocellulose hydrolysates. However, the relevance of individual inhibitors in inhibitor-rich lignocellulose hydrolysates has remained unclear.

Results

The relative importance for inhibition of ethanol fermentation by two industrial second-generation yeast strains in five lignocellulose hydrolysates, from bagasse, corn cobs and spruce, has now been investigated by spiking higher concentrations of each compound in a concentration range relevant for industrial hydrolysates. The strongest inhibition was observed with industrially relevant concentrations of furfural causing partial inhibition of both D-glucose and D-xylose consumption. Addition of 3 or 6 g/L furfural strongly reduced the ethanol titer obtained with strain MD4 in all hydrolysates evaluated, in a range of 34 to 51% and of 77 to 86%, respectively. This was followed by 5-hydroxymethylfurfural, acetic acid and formic acid, for which in general, industrially relevant concentrations caused partial inhibition of D-xylose fermentation. On the other hand, spiking with levulinic acid, 4-hydroxybenzaldehyde, 4-hydroxybenzoic acid or vanillin caused little inhibition compared to unspiked hydrolysate. The further evolved MD4 strain generally showed superior performance compared to the previously developed strain GSE16-T18.

Conclusion

The results highlight the importance of individual inhibitor evaluation in a medium containing a genuine mix of inhibitors as well as the ethanol that is produced by the fermentation. They also highlight the potential of increasing yeast inhibitor tolerance for improving industrial process economics.
Age at menarche, age at natural menopause, and risk of rheumatoid arthritis — a Mendelian randomization study
Authors: Zhu Jingjing , Niu Zheng , Alfredsson Lars , Klareskog Lars , Padyukov Leonid , Jiang Xia
Published: April 2021

Background

Hormonal reproductive factors have been suggested to play an important role in the etiology of rheumatoid arthritis (RA), an autoimmune inflammatory disorder affecting primarily women. We conducted a two-sample Mendelian randomization (MR) study examining three relevant exposures, age at menarche (AAM), age at natural menopause (ANM), and age at first birth (AFB) with the risk of RA.

Methods

We collected summary statistics from the hitherto largest GWAS conducted in AAM (N = 329,345), ANM (N = 69,360), AFB (N = 251,151), and RA (Ncase = 14,361,Ncontrol = 43,923), all of European ancestry. We constructed strong instruments using hundreds of exposure-associated genetic variants and estimated causal relationship through different MR approaches including an inverse-variance weighted method, an MR-Egger regression and a weighted median method. We conducted a multivariable MR to control for pleiotropic effect acting in particular through obesity and socioeconomic status. We also performed important sensitivity analyses to verify model assumptions.

Results

We did not find any evidence in support for a causal association between genetically predicted reproductive factors and risk of RA (ORper-SD increment in AAM = 1.06 [0.98–1.15]; ORper-SD increment in ANM = 1.05 [0.98–1.11], ORper-SD increment in AFB = 0.85 [0.65–1.10]). Results remained consistent after removing palindromic SNPs (ORper-SD increment in AAM = 1.06 [0.97–1.15], ORper-SD increment in ANM = 1.05 [0.98–1.13], ORper-SD increment in AFB = 0.81 [0.61–1.07]) or excluding SNPs associated with potential confounding traits (ORper-SD increment in AAM = 1.03 [0.94–1.12], ORper-SD increment in ANM = 1.04 [0.95–1.14]). No outlying instrument was identified through the leave-one-out analysis.

Conclusions

Our MR study does not convincingly support a casual effect of reproductive factors, as reflected by age at menarche, age at menopause, and age at first birth, on the development of RA. Despite the largely augmented set of instruments we used, these instruments only explained a modest proportion of phenotypic variance of exposures. Our knowledge regarding this topic is still insufficient and future studies with larger sample size should be designed to replicate or dispute our findings.
One-month outcomes of patients with SARS-CoV-2 infection and their relationships with lung ultrasound signs
Authors: Mafort Thiago Thomaz , Rufino Rogério , da Costa Claudia Henrique , da Cal Mariana Soares , Monnerat Laura Braga , Litrento Patrícia Frascari , Parra Laura Lizeth Zuluaga , Marinho Arthur de Sá Earp de Souza , Lopes Agnaldo José
Published: April 2021

Background

The role of lung ultrasound (LUS) in evaluating the mid- and long-term prognoses of patients with COVID-19 pneumonia is not yet known. The objectives of this study were to evaluate associations between LUS signs at the time of screening and clinical outcomes 1 month after LUS and to assess LUS signs at the time of presentation with known risk factors for COVID-19 pneumonia.

Methods

This was a retrospective study of data prospectively collected 1 month after LUS screening of 447 adult patients diagnosed with COVID-19 pneumonia. Sonographic examination was performed in screening tents with the participants seated. The LUS signs (B-lines > 2, coalescent B-lines, and subpleural consolidations) were captured in six areas of each hemithorax and a LUS aeration score was calculated; in addition, the categories of disease probability based on patterns of LUS findings (high-probability, intermediate-probability, alternate, and low-probability patterns) were evaluated. The LUS signs at patients’ initial evaluation were related to the following outcomes: symptomatology, the need for hospitalization or invasive mechanical ventilation (IMV), and COVID-19-related death.

Results

According to the evaluations performed 1 month after LUS screening, 36 patients were hospitalised, eight of whom required intensive care unit (ICU) admission and three of whom died. The presence of coalescent B-lines was associated with the need for hospitalization (p = 0.008). The presence of subpleural consolidations was associated with dyspnoea (p < 0.0001), cough (p = 0.003), the need for hospitalization (p < 0.0001), the need for ICU admission (p < 0.0001), and death (p = 0.002). A higher aeration score was associated with dyspnoea (p < 0.0001), the need for hospitalization (p < 0.0001), the need for ICU admission (p < 0.0001), and death (p = 0.003). In addition, patients with a high-probability LUS pattern had a higher aeration score (p < 0.0001) and more dyspnoea (p = 0.024) and more often required hospitalization (p < 0.0001) and ICU admission (p = 0.031).

Conclusions

In patients with COVID-19 pneumonia, LUS signs were related to respiratory symptoms 1 month after LUS screening. Strong relationships were identified between LUS signs and the need for hospitalization and death.
Disseminated intravascular coagulation as a complication of bursitis: angiogenesis and repetitive bleeding as potential factors for disseminated intravascular coagulation: a case report
Authors: Hamada Taisuke , Nishihara Tasuku , Mizuno Yosuke , Kidani Teruki , Tokiwa Hiroki , Abe Naoki , Sekiya Keisuke , Kitamura Sakiko , Takasaki Yasushi , Miura Hiromasa , Yorozuya Toshihiro
Published: April 2021

Background

Malignant tumors, such as acute leukemia and solid cancers, frequently cause disseminated intravascular coagulation. However, cases of disseminated intravascular coagulation as a complication of bursitis were not reported previously.

Case presentation

A 72-year-old Japanese woman was scheduled to undergo resection of a rapidly growing subcutaneous tumor-like lesion on her left back. Preoperative blood tests suggested disseminated intravascular coagulation. The resected lesion was cystic tumor containing a hematoma. After the operation, the patient completely recovered from disseminated intravascular coagulation, indicating that disseminated intravascular coagulation in this case was caused by the tumor. Pathological examination of the resected tumor revealed considerable fibrin deposition and angiogenesis on the cyst wall, which was presumably a response to inflammation and indicated presence of repetitive intratumoral bleeding, subsequently leading to a diagnosis of chronic hemorrhagic bursitis.

Conclusions

Clinicians should note that, despite being benign, soft-tissue tumors accompanied by inflammation with angiogenesis and repetitive intratumoral bleeding can cause disseminated intravascular coagulation, albeit rarely.
Effects of a positive thinking program on hope and sleep quality in Iranian patients with thalassemia: a randomized clinical trial
Authors: Makaremnia Somayeh , Dehghan Manshadi Marieh , Khademian Zahra
Published: April 2021

Background

Thalassemia have a negative impact on the patients' psychological health and sleep quality. This study aimed to determine the effects of a positive thinking training program on hope and sleep quality of patients with thalassemia major.

Methods

This randomized clinical trial was conducted on 78 patients with thalassemia major including 36 males (46.2%) and 42 females (53.8%) with a mean age of 25.56 ± 29.6 in Iran. Subjects were randomly assigned into experimental and control groups. Experimental group received 16 h training based on positive thinking materials published by Martin Seligman. Control group received only usual programs. Data were collected at baseline, as well as immediately and one month after the intervention, using Snyder’s Hope Scale and the Pittsburgh Sleep Quality Index. Data analysis was performed using SPSS Software 18.0; statistical tests included the independent T-test, the Chi-square, Mann Whitney, and Friedman test. Significance level was set at 0.05 in this study.

Results

The experimental group had a significantly higher mean hope score compared to the control group immediately (45.38 ± 7.82 vs. 35.32 ± 5.54, P < 0.001) and one month following intervention (44.67 ± 3.47 vs. 35 ± .54, P < 0.001). Moreover, the mean sleep quality scores of the experimental group was significantly greater than that for control group immediately (5.35 ± 2.02 vs. 7 ± 2.4, P = 0.004) and one month after the intervention (4.23 ± 2.2 vs.7.02 ± 3.03, P < 0.001).

Conclusion

Since our training program on positive thinking improved hope and quality of sleep in patients with thalassemia major, we recommend the use of such courses as an important step toward promotion of hope and sleep quality among these patients.

Trial registration The name of the registry: Iranian Registry of Clinical Trials. Trial Registration Number: IRCT2017010431774N1. URL of the trial registry record: https://en.irct.ir/trial/24923. Registration Date: 07/03/2017.
Can we reestablish a self-sustaining population? A case study on reintroduced Crested Ibis with population viability analysis
Authors: Zhang Yashuai , Wang Fang , Cui Zhenxia , Li Min , Li Xia , Ye Xinping , Yu Xiaoping
Published: April 2021

Background

One of the most challenging tasks in wildlife conservation and management is clarifying which and how external and intrinsic factors influence wildlife demography and long-term viability. The wild population of the Crested Ibis (Nipponia nippon) has recovered to approximately 4400, and several reintroduction programs have been carried out in China, Japan and Korea. Population viability analysis on this endangered species has been limited to the wild population, showing that the long-term population growth is restricted by the carrying capacity and inbreeding. However, gaps in knowledge of the viability of the reintroduced population and its drivers in the release environment impede the identification of the most effective population-level priorities for aiding in species recovery.

Methods

The field monitoring data were collected from a reintroduced Crested Ibis population in Ningshan, China from 2007 to 2018. An individual-based VORTEX model (Version 10.3.5.0) was used to predict the future viability of the reintroduced population by incorporating adaptive patterns of ibis movement in relation to catastrophe frequency, mortality and sex ratio.

Results

The reintroduced population in Ningshan County is unlikely to go extinct in the next 50 years. The population size was estimated to be 367, and the population genetic diversity was estimated to be 0.97. Sensitivity analysis showed that population size and extinction probability were dependent on the carrying capacity and sex ratio. The carrying capacity is the main factor accounting for the population size and genetic diversity, while the sex ratio is the primary factor responsible for the population growth trend.

Conclusions

A viable population of the Crested Ibis can be established according to population viability analysis. Based on our results, conservation management should prioritize a balanced sex ratio, high-quality habitat and low mortality.
Ethnic Specific body fat percent prediction equation as surrogate marker of obesity in Ethiopian adults
Authors: Sinaga Makeda , Sinaga Teshome Melese , Yemane Tilhun , Tegene Elsah , Lindtsrom David , Belachew Tefera
Published: April 2021

Background

Application of advanced body composition measurement methods is not practical in developing countries context due to cost and unavailability of facilities. This study generated ethnic specific body fat percent prediction equation for Ethiopian adults using appropriate data.

Methods

A cross-sectional study was carried ifrom February to April 2015 among 704 randomly selected adult employees of Jimma University. Ethnic specific Ethiopian body fat percent (BF%) prediction equation was developed using a multivariable linear regression model with measured BF% as dependent variable and age, sex, and body mass index as predictor variables. Agreement between fat percent measured using air displacement plethysmography and body fat percent estimated using Caucasian prediction equations was determined using Bland Altman plot.

Results

Comparison of ADP measured and predicted BF% showed that Caucasian prediction equation underestimated body fat percent among Ethiopian adults by 6.78% (P < 0.0001). This finding is consistent across all age groups and ethnicities in both sexes. Bland Altman plot did not show agreement between ADP and Caucasian prediction equation (mean difference = 6.7825) and some of the points are outside 95% confidence interval. The caucasian prediction equation significantly underestimates body fat percent in Ethiopian adults, which is consistent across all ethnic groups in the sample. The study developed Ethnic specific BF% prediction equations for Ethiopian adults.

Conclusion

The Caucasian prediction equation significantly underestimates body fat percent among Ethiopian adults regardless of ethnicity. Ethiopian ethnic-specific prediction equation can be used as a very simple, cheap, and cost-effective alternative for estimating body fat percent among Ethiopian adults for health care provision in the prevention of obesity and related morbidities and for research purposes.
Clinical and radiological imaging as prognostic predictors in COVID-19 patients
Authors: Metwally Maha Ibrahim , Basha Mohammad Abd Alkhalik , Zaitoun Mohamed M. A. , Abdalla Housseini Mohamed , Nofal Hanaa Abu Elazayem , Hendawy Hamdy , Manajrah Esaraa , Hijazy Reham farid , Akbazli Loujain , Negida Ahmed , Mosallam Walid
Published: April 2021

Background

Since the announcement of COVID-19 as a pandemic infection, several studies have been performed to discuss the clinical picture, laboratory finding, and imaging features of this disease. The aim of this study is to demarcate the imaging features of novel coronavirus infected pneumonia (NCIP) in different age groups and outline the relation between radiological aspect, including CT severity, and clinical aspect, including age, oxygen saturation, and fatal outcome. We implemented a prospective observational study enrolled 299 laboratory-confirmed COVID-19 patients (169 males and 130 females; age range = 2–91 years; mean age = 38.4 ± 17.2). All patients were submitted to chest CT with multi-planar reconstruction. The imaging features of NCIP in different age groups were described. The relations between CT severity and age, oxygen saturation, and fatal outcome were evaluated.

Results

The most predominant CT features were bilateral (75.4%), posterior (66.3%), pleural-based (93.5%), lower lobe involvement (89.8%), and ground-glass opacity (94.7%). ROC curve analysis revealed that the optimal cutoff age that was highly exposed to moderate and severe stages of NCIP was 38 years old (AUC = 0.77, p < 0.001). NCIP was noted in 42.6% below 40-year-old age group compared to 84% above 40-year-old age group. The CT severity was significantly related to age and fatal outcome (p < 0.001). Anterior, centrilobular, hilar, apical, and middle lobe involvements had a significant relation to below 90% oxygen saturation. A significant negative correlation was found between CT severity and oxygen saturation (r = − 0.49, p < 0.001). Crazy-paving pattern, anterior aspect, hilar, centrilobular involvement, and moderate and severe stages had a statistically significant relation to higher mortality.

Conclusion

The current study confirmed the value of CT as a prognostic predictor in NCIP through demonstration of the strong relation between CT severity and age, oxygen saturation, and the fatal outcome. In the era of COVID-19 pandemic, this study is considered to be an extension to other studies discussing chest CT features of COVID-19 in different age groups with demarcation of the relation of chest CT severity to different pattern and distribution of NCIP, age, oxygen saturation, and mortality rate.
Additively manufactured metastructure design for broadband radar absorption
Authors: Abdullahi M. B. , Ali M. H.
Published: April 2021

Background

Recent advances in material science and electronics led to the rapid development of communication devices and radar detection techniques resulting in an ever-increasing demand for improved stealth performance of air vehicles during scouts. Absorber design employing metastructure concept has recently become a popular approach to improving radar stealth performance. Metastructure permits the realization of desired absorption characteristics by careful design of geometrical structures and material compositions. In this study, a metastructure designed based on graphite SLS composite for radar absorption has been demonstrated. The unit cell of the proposed structure is simulated by COMSOL Multiphysics to determine the frequency-dependent absorption characteristic of the structure. It is fabricated by using a low-cost selective laser sintering technique of additive manufacturing technology.

Results

The prototype, while measured, shows effective absorption bandwidth of 1.04 GHz that is in reasonable agreement with the simulated response of 2.08 GHz. The optimized structure exhibits ≤ − 10 dB reflectivity within a broad frequency range extending from 7.60 GHz to 18.00 GHz under normal incidence in both TE and TM polarizations. Furthermore, the absorption performance under different polarizations and incident angles has been investigated. Results indicate that the absorber displays polarization indifference and exhibits a wide-angle of incidence tolerance of up to 45° in TE polarization and 30° in TM polarizations.

Conclusion

In this paper, the feasibility of using graphite SLS material to design and 3D print a metastructure design for radar absorbing has been established as confirmed by the simulation and the measurement results. The advantages of low cost, ultra-broad operating band, wide-angle of incidence feature, and polarization insensitivity qualifies the proposed absorber for stealth and electromagnetic shielding applications.
COVID-19: insights into virus–receptor interactions
Authors: Sepahvandi Azadeh , Ghaffari Maryam , Bahmanpour Amir Hossein , Moztarzadeh Fathollah , Zarrintaj Payam , Uludağ Hasan , Mozafari Masoud
Published: April 2021

The recent outbreak of Coronavirus Disease 2019 (COVID-19) calls for rapid mobilization of scientists to probe and explore solutions to this deadly disease. A limited understanding of the high transmissibility of SARS-CoV-2 (Severe acute respiratory syndrome coronavirus 2) relative to other coronavirus strains guides a deeper investigation into the virus/receptor interactions. The cutting-edge studies in thermodynamic and kinetic properties of interactions such as protein-protein interplays have been reviewed in many modeling and analysis studies. Highlighting the thermodynamic assessments of biological interactions and emphasizing the boosted transmissibility of SARS-CoV-2 despite its high similarity in structure and sequence with other coronavirus strains is an important and highly valuable investigation that can lead scientists to discover analytical and fundamental approaches in studying virus’s interactions. Accordingly, we have attempted to describe the crucial factors such as conformational changes and hydrophobicity particularities that influence on thermodynamic potentials in the SARS-COV-2 S-protein adsorption process. Discussing the thermodynamic potentials and the kinetics of the SARS-CoV-2 S-protein in its interaction with the ACE2 receptors of the host cell is a fundamental approach that would be extremely valuable in designing candidate pharmaceutical agents or exploring alternative treatments.
Estimation of transversely isotropic formation parameters using flexural and quadrupole dispersion data in the fast formation
Authors: Zeng Fuqiang , Yue Wenzheng , Li Chao , Wang Yuexiang
Published: April 2021

Borehole acoustic logging plays an important role in inverting the five Thomsen parameters of many formations characterized as a transversely isotropic medium with a vertical axis of symmetry (VTI). In general, these parameters are obtained under certain assumptions, and the formation type defined by the relation of Thomsen parameters is not taken into consideration. We have developed a method to determine the Thomsen parameters of all kinds of fast VTI formations from the first-order flexural and first-order quadrupole dispersion data by dividing the Thomsen parameters inversion process into two parts: low-frequency asymptotic slowness inversion of the flexural or quadrupole dispersion and Thomsen anisotropy parameter inversion by a constrained evolutionary optimization algorithm. Compared with traditional approaches, the new method is not only independent of any assumed correlation among the Thomsen anisotropy parameters but it also provides a more accurate result than the inversion of either of them alone for both kinds of fast VTI formations. The inversion results obtained from either the flexural or quadrupole dispersion data alone are incorrect if the formation type is incorrectly identified, such as misidentifying an isotropic formation as a special VTI formation. The new method can not only identify the type of fast VTI formation, but it also obtains the shear slowness in a special VTI formation, which cannot be obtained by existing methods. Accordingly, the application to synthetic examples validates the significance and necessity of the proposed joint method in inversion of the Thomsen parameters.
High-resolution fixed-point seismic inversion
Authors: Pei Song , Yin Xingyao , Zong Zhaoyun , Li Kun
Published: April 2021

Resolution improvement always presents as the crucial task in geologic inversion. Band-limited characteristics of seismic data and noise make seismic inversion complicated. Specifically, geologic inversion suffers from the deficiency of low- and high-frequency components. We have developed the fixed-point seismic inversion method to alleviate these issues. The problem of solving the objective function is transformed into the problem of finding the fixed point of the objective function. Concretely, a recursive formula between seismic signal and reflection coefficient is established, which is characterized by good convergence and verified by model examples. The error between the model value and the inverted value is reduced to approximately zero after a few iterations. The model examples show that in either case, that is, the seismic traces are noise-free or with a little noise, the model value can almost be duplicated. Even if the seismic trace is accompanied by moderate noise, optimal inverted results can still be obtained with our method. The initial model constraint is further introduced into the objective function to increase the low-frequency component of the inverted results by adding prior information into the target function. The singular value decomposition method is applied to the inversion framework, thus making a high improvement of antinoise ability. Finally, the synthetic models and seismic data are investigated following our method. The inverted results obtained from the fixed-point seismic inversion are compared with those obtained from the conventional seismic inversion, and it is found that the former has a higher resolution than the latter.
Multidisciplinary analysis of hydraulic stimulation and production effects within the Niobrara and Codell reservoirs, Wattenberg Field, Colorado — Part 1: Baseline reservoir conditions
Authors: Bray Matthew , Daves Jacquelyn , Brugioni Daniel , Kamruzzaman Asm , Bratton Tom , Harryandi Sheila , Grechishnikova Alena , Tura Ali , Davis Tom , Simmons Jim
Published: April 2021

In the Wattenberg Field, the Reservoir Characterization Project at the Colorado School of Mines and Occidental Petroleum Corporation (Oxy) (formerly the Anadarko Petroleum Corporation) collected time-lapse seismic data for characterization of changes in the reservoir caused by hydraulic fracturing and production in the Niobrara Formation and Codell Sandstone member of the Carlile Formation. We have acquired three multicomponent seismic surveys to understand the dynamic reservoir changes caused by hydraulic fracturing and production of 11 horizontal wells within a 1 mi2section (the Wishbone Section). The time-lapse seismic survey acquisition occurred immediately after the wells were drilled, another survey after stimulation, and a third survey after two years of production. In addition, we integrate core, petrophysical properties, fault and fracture characteristics, as well as P-wave seismic data to illustrate reservoir properties prior to simulation and production. Core analysis indicates extensive amounts of bioturbation in zones of high total organic content (TOC). Petrophysical analysis of logs and core samples indicates that chalk intervals have high amounts of TOC (>2%) and the lowest amount of clay in the reservoir interval. Core petrophysical characterization included X-ray diffraction analysis, mercury intrusion capillary pressure, N2gas adsorption, and field emission scanning electron microscopy. Reservoir fractures follow four regional orientations, and chalk facies contain higher fracture density than marl facies. Integration of these data assist in enhanced well targeting and reservoir simulation.
Multidisciplinary analysis of hydraulic stimulation and production effects within the Niobrara and Codell reservoirs, Wattenberg Field, Colorado — Part 2: Analysis of hydraulic fracturing and production
Authors: Bray Matthew , Utley Jacob , Ning Yanuri , Dang Angela , Daves Jacquelyn , White Isabel , Alfataierge Ahmed , Eker Erdinc , Davis Tom , Tura Ali , Simmons Jim
Published: April 2021

Enhanced hydrocarbon recovery is essential for continued economic development of unconventional reservoirs. We have focused on dynamic characterization of the Niobrara and Codell Formations in Wattenberg Field through the development and analysis of a full integrated reservoir model. We determine the effectiveness of the hydraulic fracturing and production with two seismic monitor surveys, surface microseismic, completion data, and production data. The two monitor surveys were recorded after stimulation and again after two years of production. Identification of reservoir deformation due to hydraulic fracturing and production improves reservoir models by mapping nonstimulated and nonproducing zones. Monitoring these time-variant changes improves the prediction capability of reservoir models, which in turn leads to improved well and stage placement. We quantify dynamic reservoir changes with time-lapse P-wave seismic data using prestack inversion and velocity-independent layer stripping for velocity and attenuation changes within the Niobrara and Codell reservoirs. A 3D geomechanical model and production data are history matched, and a simulation is run for two years of production. Results are integrated with time-lapse seismic data to illustrate the effects of hydraulic fracturing and production. Our analyses illustrate that chalk facies have significantly higher hydraulic fracture efficiency and production performance than marl facies. In addition, structural and hydraulic complexity associated with faults generate spatial variability in a well’s total production.
Revisit seismic attenuation attributes: Influences of the spectral balancing operation on seismic attenuation analysis
Authors: Li Fangyu , Liu Rongchang , Lou Yihuai , Liu Naihao
Published: April 2021

Seismic attenuation analysis is important for seismic processing and quantitative interpretation. Nevertheless, classic quality factor estimation methods make certain assumptions that may be invalid for a given geologic target and seismic volume. For this reason, seismic attenuation attribute analysis, which reduces some of the theoretical assumptions, can serve as a practical alternative in apparent attenuation characterization. Unfortunately, most of the published literature defines seismic attenuation attributes based on a specific source wavelet assumption, such as the Ricker wavelet, rather than wavelets that exhibit the relatively flat spectrum produced by modern data processing workflows. One of the most common processing steps is to spectrally balance the data either explicitly in the frequency domain or implicitly through wavelet shaping deconvolution. If the poststack seismic data have gone through spectral balancing/whitening to improve their seismic resolution, the wavelet would exhibit a flat spectrum instead of a Ricker or Gaussian shape. We have addressed the influence of spectral balancing on seismic attenuation analysis. Our mathematical analysis shows that attenuation attributes are still effective for poststack seismic data after certain types of spectral balancing. More importantly, this analysis explains why seismic attenuation attributes work for real seismic applications with common seismic processing procedures. Synthetic and field data examples validate our conclusions.
Impact of a Genomic Test on Treatment Decision in a Predominantly African American Population With Favorable-Risk Prostate Cancer: A Randomized Trial
Authors: Murphy Adam B. , Abern Michael R. , Liu Li , Wang Heidy , Hollowell Courtney M. P. , Sharifi Roohollah , Vidal Patricia , Kajdacsy-Balla Andre , Sekosan Marin , Ferrer Karen , Wu Shoujin , Gallegos Marlene , King-Lee Patrice , Sharp Lisa K. , Ferrans Carol E. , Gann Peter H.
Published: April 2021

PURPOSE

The Genomic Prostate Score (GPS), performed on biopsy tissue, predicts adverse outcome in prostate cancer (PCa) and has shown promise for improving patient selection for active surveillance (AS). However, its impact on treatment choice in high-risk populations of African Americans is largely unknown and, in general, the effect of the GPS on this difficult decision has not been evaluated in randomized trials.

METHODS

Two hundred men with National Comprehensive Cancer Network very low to low-intermediate PCa from three Chicago hospitals (70% Black, 16% college graduates) were randomly assigned at diagnosis to standard counseling with or without a 12-gene GPS assay. The primary end point was treatment choice at a second postdiagnosis visit. The proportion of patients choosing AS was compared, and multivariable modeling was used to estimate the effects of various factors on AS acceptance.

RESULTS

AS acceptance was high overall, although marginally lower in the intervention group (77% v 88%; P = .067), and lower still when men with inadequate specimens were excluded ( P = .029). Men with lower health literacy who received a GPS were seven-fold less likely to choose AS compared with controls, whereas no difference was seen in men with higher health literacy ( Pinteraction = .022). Among men with low-intermediate risk, 69% had GPS values consistent with unfavorable intermediate or high-risk cancer. AS choice was also independently associated with a family history of PCa and having health insurance.

CONCLUSION

In contrast to other studies, the net effect of the GPS was to move patients away from AS, primarily among men with low health literacy. These findings have implications for our understanding of how prognostic molecular assays that generate probabilities of poor outcome can affect treatment decisions in diverse clinical populations.
Impact of Previously Unrecognized HLA Mismatches Using Ultrahigh Resolution Typing in Unrelated Donor Hematopoietic Cell Transplantation
Authors: Mayor Neema P. , Wang Tao , Lee Stephanie J. , Kuxhausen Michelle , Vierra-Green Cynthia , Barker Dominic J. , Auletta Jeffrey , Bhatt Vijaya R. , Gadalla Shahinaz M. , Gragert Loren , Inamoto Yoshihiro , Morris Gerald P. , Paczesny Sophie , Reshef Ran , Ringdén Olle , Shaw Bronwen E. , Shaw Peter , Spellman Stephen R. , Marsh Steven G. E.
Published: April 2021

PURPOSE

Ultrahigh resolution (UHR) HLA matching is reported to result in better outcomes following unrelated donor hematopoietic cell transplantation, improving survival and reducing post-transplant complications. However, most studies included relatively small numbers of patients. Here we report the findings from a large, multicenter validation study.

METHODS

UHR HLA typing was available on 5,140 conventionally 10 out of 10 HLA-matched patients with malignant disease transplanted between 2008 and 2017.

RESULTS

After UHR HLA typing, 82% of pairs remained 10 out of 10 UHR-matched; 12.3% of patients were 12 out of 12 UHR HLA-matched. Compared with 12 out of 12 UHR-matched patients, probabilities of grade 2-4 acute graft-versus-host disease (aGVHD) were significantly increased with UHR mismatches (overall P = .0019) and in those patients who were HLA-DPB1 T-cell epitope permissively mismatched or nonpermissively mismatched (overall P = .0011). In the T-cell–depleted subset, the degree of UHR HLA mismatch was only associated with increased transplant-related mortality (TRM) (overall P = .0068). In the T-cell–replete subset, UHR HLA matching was associated with a lower probability of aGVHD (overall P = .0020); 12 out of 12 UHR matching was associated with reduced TRM risk when compared with HLA-DPB1 T-cell epitope permissively mismatched patients, whereas nonpermissive mismatching resulted in a greater risk (overall P = .0003).

CONCLUSION

This study did not confirm that UHR 12 out of 12 HLA matching increases the probability of overall survival but does demonstrate that aGVHD risk, and in certain settings TRM, is lowest in UHR HLA-matched pairs and thus warrants consideration when multiple 10 out of 10 HLA-matched donors of equivalent age are available.