bluuebunny/crossref_metadata_2025 huggingface dataset:
Fabrication of In Situ Grown Hydroxyapatite Nanoparticles Modified Porous Polyetheretherketone Matrix Composites to Promote Osteointegration and Enhance Bone Repair
Authors: Wang Ningning , Qi Desheng , Liu Lu , Zhu Yanlin , Liu Hong , Zhu Song
Published: February 2022

The repairment of critical-sized bone defects is a serious problem that stimulates the development of new biomaterials. In this study, nanohydroxyapatite (nHA)-doped porous polyetheretherketone (pPEEK) were successfully fabricated by the thermally induced phase separation method and hydrothermal treatment. Structural analysis was performed by X-ray diffraction. The water contact angles and scanning electron microscopy were measured to assess physical properties of surfaces. The mechanical strength of the composites is also determined. Microcomputed tomography is used to characterize the nHA content of the composites. The in vitro bioactivity of the composites with or without nHA was investigated by using murine pre-osteoblasts MC3T3-E1, and the results of cytotoxicity and cell proliferation assays revealed that the cytocompatibility of all specimens was good. Adherence assays were employed to examine the adhesion and morphology of cells on different materials. However, nHA-doped composites induced cell attachment and cell spreading more significantly. Osteogenic differentiation was investigated using alkaline phosphatase activity and alizarin red staining, and these in vitro results demonstrated that composites containing nHA particles enhanced osteoblast differentiation. Its effectiveness for promoting osteogenesis was also confirmed in an in vivo animal experiment using a tibial defective rat model. After 8 weeks of implantation, compared to the pure PEEK and pPEEK without nHA groups, the nHA-pPEEK group showed better osteogenic activity. The results indicate that the nHA-pPEEK composites are possibly a well-designed bone substitute for critical-sized bone defects by promoting bone regeneration and osteointegration successfully.
Enhanced Antimicrobial, Cytotoxicity, Larvicidal, and Repellence Activities of Brown Algae, Cystoseira crinita-Mediated Green Synthesis of Magnesium Oxide Nanoparticles
Authors: Fouda Amr , Eid Ahmed M. , Abdel-Rahman Mohamed Ali , EL-Belely Ehab F. , Awad Mohamed A. , Hassan Saad El-Din , AL-Faifi Zarraq E. , Hamza Mohammed F.
Published: February 2022

Herein, the metabolites secreted by brown algae,Cystoseira crinita, were used as biocatalyst for green synthesis of magnesium oxide nanoparticles (MgO-NPs). The fabricated MgO-NPs were characterized using UV-vis spectroscopy, Fourier transforms infrared spectroscopy (FT-IR), Transmission Electron Microscopy (TEM), Scanning Electron Microscopy linked with energy-dispersive X-ray (SEM-EDX), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). Data showed successful formation of crystallographic and spherical MgO-NPs with sizes of 3–18 nm at a maximum surface plasmon resonance of 320 nm. Moreover, EDX analysis confirms the presence of Mg and O in the sample with weight percentages of 54.1% and 20.6%, respectively. Phyco-fabricated MgO-NPs showed promising activities against Gram-positive bacteria, Gram-negative bacteria, andCandida albicanswith MIC values ranging between 12.5 and 50 μg mL−1. The IC50value of MgO-NPs against cancer cell lines (Caco-2) was 113.4 μg mL−1, whereas it was 141.2 μg mL−1for normal cell lines (Vero cell). Interestingly, the green synthesized MgO-NPs exhibited significant larvicidal and pupicidal activity againstMusca domestica.At 10 μg mL−1MgO-NPs, the highest mortality percentages were 99.0%, 95.0%, 92.2%, and 81.0% for I, II, III instars’ larvae, and pupa ofM. domestica, respectively, with LC50values (3.08, 3.49, and 4.46 μg mL−1), and LC90values (7.46, 8.89, and 10.43 μg mL−1), respectively. Also, MgO-NPs showed repellence activity for adults ofM. domesticaat 10 μg mL−1with 63.0%, 77.9%, 84.9%, and 96.8% after 12, 24, 48, and 72 h, respectively.
Metabolic Changes During Growth and Reproductive Phases in the Liver of Female Goldfish (Carassius auratus)
Authors: Ladisa Claudia , Ma Yifei , Habibi Hamid R
Published: February 2022

Hormones of the brain-pituitary-peripheral axis regulate metabolism, gonadal maturation, and growth in vertebrates. In fish, reproduction requires a significant energy investment to metabolically support the production of hundreds of eggs and billions of sperms in females and males, respectively. This study used an LC-MS-based metabolomics approach to investigate seasonally-related changes in metabolic profile and energy allocation patterns in female goldfish liver. We measured basal metabolic profile in female goldfish at three phases of the reproductive cycle, including 1) Maximum growth period in postovulatory regressed phase, 2) mid recrudescence in fish with developing follicles, and 3) late recrudescence when the ovary contains mature ovulatory follicles. We also investigated changes in the liver metabolism following acute treatments with GnRH and GnIH, known to be involved in controlling reproduction and growth in goldfish. Chemometrics combined with pathway-driven bioinformatics revealed significant changes in the basal and GnRH/GnIH-induced hepatic metabolic profile, indicating that metabolic energy allocation is regulated to support gonadal development and growth at different reproductive cycles. Overall, the findings support the hypothesis that hormonal control of reproduction involves accompanying metabolic changes to energetically support gonadotropic and somatotropic activities in goldfish and other oviparous vertebrates.
Engineered Cell Membrane-Derived Nanocarriers: The Enhanced Delivery System for Therapeutic Applications
Authors: Yu Biao , Xue Xu , Yin Zhifeng , Cao Liehu , Li Mengmeng , Huang Jianping
Published: February 2022

There has been a rapid development of biomimetic platforms using cell membranes as nanocarriers to camouflage nanoparticles for enhancing bio-interfacial capabilities. Various sources of cell membranes have been explored for natural functions such as circulation and targeting effect. Biomedical applications of cell membranes-based delivery systems are expanding from cancer to multiple diseases. However, the natural properties of cell membranes are still far from achieving desired functions and effects as a nanocarrier platform for various diseases. To obtain multi-functionality and multitasking in complex biological systems, various functionalized modifications of cell membranes are being developed based on physical, chemical, and biological methods. Notably, many research opportunities have been initiated at the interface of multi-technologies and cell membranes, opening a promising frontier in therapeutic applications. Herein, the current exploration of natural cell membrane functionality, the design principles for engineered cell membrane-based delivery systems, and the disease applications are reviewed, with a special focus on the emerging strategies in engineering approaches.
Method Improving for Isolation and Characterization of Allergy-Inducing Polymer Impurities in Cefotaxime Sodium Medicines Available From Pharmaceutical Industry
Authors: Fu Yanan , Li Jin , Feng Fang , Yin Lihui
Published: February 2022

Objective: To prepare and validate the chemical structure of the cefotaxime dimer and cefotaxime trimer impurities available from pharmaceutical industry.

Methods: A polymer stock solution of cefotaxime sodium was obtained using a concentrated solution degradation method. The cefotaxime dimer and trimer impurities were separated and purified by preparative reversed-high-performance liquid chromatograph (RP-HPLC), and the pure cefotaxime dimer and trimer were obtained by a freeze-drying method. The two impurities were characterized by infrared (IR) spectroscopy, ultraviolet (UV) spectroscopy, mass spectroscopy, and nuclear magnetic resonance (NMR, including one-dimensional and two-dimensional NMR). The groups corresponding to the characteristic absorption peaks in the UV and IR spectra were analyzed, and the 1H and 13C NMR signals were assigned.

Results: The cefotaxime dimer was isolated and purified from the actual sample of industrial medicines, and chemical structure of the dimer is the same as in the dimers investigated earlier. The polymerization sites and stereoscopic configuration of trimer impurity was validated for the first time.

Conclusion: This study is of great significance for the study of the structures and quality control of polymer impurities in cephalosporin drugs. Promoting the polymerization sites study and providing a technical basis for allergic study of polymer impurities.
Pseudomonas aeruginosa Is More Tolerant Under Biofilm Than Under Planktonic Growth Conditions: A Multi-Isolate Survey
Authors: Thöming Janne G. , Häussler Susanne
Published: February 2022

Biofilm-associated bacteria exhibit profound changes in bacterial physiology. They thrive in the environment but also in the human host in protected sessile communities. Antimicrobial therapy usually fails, despite the absence of genotypic resistance, and it is commonly accepted that biofilm-grown bacteria are up to 1,000-fold more resistant than planktonic cells. We are only at the beginning to understand the reasons for biofilm recalcitrance, and systematic approaches to describe biofilm-induced tolerance phenotypes are lacking. In this study, we investigated a large and highly diverse collection of 352 clinical Pseudomonas aeruginosa isolates for their antimicrobial susceptibility profiles under biofilm growth conditions towards the antibiotics ciprofloxacin, tobramycin, and colistin. We discovered characteristic patterns of drug-specific killing activity and detected conditional tolerance levels far lower (in the range of the minimal inhibitory concentration (MIC)), but also far higher (up to 16,000-fold increase compared to planktonic cells) than generally believed. This extremely broad distribution of biofilm-induced tolerance phenotypes across the clinical isolates was greatly influenced by the choice of the antibiotic. We furthermore describe cross-tolerance against ciprofloxacin and tobramycin, but not colistin, and observed an additive activity between biofilm-induced tolerance and genetically determined resistance. This became less evident when the biofilm-grown cells were exposed to very high antibiotic concentrations. Although much more remains to be learned on the molecular mechanisms underlying biofilm-induced tolerance, our data on intra-species variations in tolerance profiles provide valuable new insights. Furthermore, our observation that colistin appears to act independently of the tolerance mechanisms of individual clinical strains could make colistin a valuable therapeutic option in chronic biofilm-associated infections characterized by the presence of particularly tolerant strains.
Real-World Experience With a Large Bore Vascular Closure Device During TAVI Procedure: Features and Predictors of Access-Site Vascular Complications
Authors: Masiero Giulia , D'Angelo Livio , Fovino Luca Nai , Fabris Tommaso , Cardaioli Francesco , Rodinò Giulio , Benedetti Alice , Boiago Mauro , Continisio Saverio , Montonati Carolina , Sciarretta Tommaso , Zuccarelli Vittorio , Scotti Andrea , Lorenzoni Giulia , Pavei Andrea , Napodano Massimo , Fraccaro Chiara , Iliceto Sabino , Marchese Alfredo , Esposito Giovanni , Tarantini Giuseppe
Published: February 2022

Backgrounds

Among vascular closure devices (VCDs), the novel collagen plug-based MANTA VCD is the first designed for large bore percutaneous access. We aimed to assess the features and predictors of access-site vascular complications in an unselected trans-femoral transcatheter aortic valve replacement (TF-TAVR) population.

Methods

Patients undergoing large bore arteriotomy closure with 18F MANTA VCD following TF-TAVR at a large tertiary care center from September 2019 to January 2021 were prospectively analyzed. Primary Outcome was the MANTA VCD access-site-related complications according to Valve Academic Research Consortium-3 (VARC) definitions. Its incidence and predictors were evaluated.

Results

Eighty-eight patients (median age 82 years, 48% male, 3.3 median Society of Thoracic Surgeons score) undergoing TF-TAVR were included, mostly (63%) treated with a self-expandable device and with outer diameter sizes varied from 18F to 24-F. MANTA VCD technical success rate was 98%, while 10 patients (11%) experienced MANTA VCD access-site vascular complications which included 8% of minor complications and only to 2% of major events resulting in VARC type ≥2 bleeding. Vessel occlusion/stenosis (60%), perforation (20%), and pseudoaneurysm/dissection/hematoma (20%) occurred, but all were managed without surgical treatment. Independent predictors of failure were age (p = 0.04), minimum common femoral artery diameter (CFA) (p < 0.01), sheath-to-femoral-artery ratio (SFAR) (p < 0.01), and a lower puncture height (p = 0.03). A CFA diameter <7.1 mm with a SFAR threshold of 1.01 were associated with VCD failure.

Conclusions

In a more comers TF-TAVR population, MANTA VCD was associated with reassuring rates of technical success and major access-site vascular complications. Avoiding lower vessel size and less puncture site distance to CFA bifurcation might further improve outcomes.
Maturation Fetus Ascending Aorta Elastic Properties: Circumferential Strain and Longitudinal Strain by Velocity Vector Imaging
Authors: Zhong Xin , Luo Yuanchen , Zhou Dan , Liu Minghui , Zhou Jiawei , Xu Ran , Zeng Shi
Published: February 2022

Objective

This study aimed to assess the circumferential and longitudinal strain of the fetal ascending aortic (AA) wall and establish a gestational age-associated longitudinal reference for aortic wall strain during the second half of pregnancy.

Methods

Singleton fetuses with gestational age (GA) at 20 + 0 to 24 + 6 weeks were prospectively collected from a low-risk population. Global circumferential strain (GCS) and mean longitudinal strain (MLS) of the ascending aorta were measured serially at 4-week intervals using the velocity vector imaging (VVI) technique. Fractional polynomials were conducted to obtain the best-fitting curves between GA and AA strains. GA-specific reference percentiles of GCS and MLS were established by multilevel modeling.

Results

A total of 223 fetuses with a total of 1,127 serial observations were enrolled. GCS presented a second-degree fractional polynomial smoothing regression along GA (R2 = 0.635, P < 0.05). Fetal aortic GCS remained unchanged at ~27.29% (20.36–35.6%) before 31 weeks and increased significantly from 31.36% (26.38–37.12%) at 31 weeks to 43.29% (30.5–56.78%) at term. MLS presented a third-degree fractional polynomial smoothing regression along GA (R2 = 0.465, P < 0.05). MLS remained steady at ~10.03% (3.28–17.62%) between 20 and 31 weeks and then increased significantly from 12.68% (7.42–20.1%) at 32 weeks to 17.5% (9.67–25.34%) at term. The GCS was significantly higher than the MLS in the ascending aorta wall (p < 0.001).

Conclusion

The fetal ascending aorta wall demonstrates obviously greater circumferential strain than longitudinal strain. Both strains remained steady before the late trimester and then gradually increased until delivery, suggesting progressive maturation of aortic elasticity mechanics.
Predicting ICU Mortality in Rheumatic Heart Disease: Comparison of XGBoost and Logistic Regression
Authors: Xu Yixian , Han Didi , Huang Tao , Zhang Xiaoshen , Lu Hua , Shen Si , Lyu Jun , Wang Hao
Published: February 2022

Background

Rheumatic heart disease (RHD) accounts for a large proportion of Intensive Care Unit (ICU) deaths. Early prediction of RHD can help with timely and appropriate treatment to improve survival outcomes, and the XGBoost machine learning technology can be used to identify predictive factors; however, its use has been limited in the past. We compared the performance of logistic regression and XGBoost in predicting hospital mortality among patients with RHD from the Medical Information Mart for Intensive Care IV (MIMIC-IV) database.

Methods

The patients with RHD in the MIMIC-IV database were divided into two groups retrospectively according to the availability of data and its clinical significance based on whether they survived or died. Backward stepwise regression was used to analyze the independent factors influencing patients with RHD, and to compare the differences between the two groups. The XGBoost algorithm and logistic regression were used to establish two prediction models, and the areas under the receiver operating characteristic curves (AUCs) and decision-curve analysis (DCA) were used to test and compare the models. Finally, DCA and the clinical impact curve (CIC) were used to validate the model.

Results

Data on 1,634 patients with RHD were analyzed, comprising 207 who died during hospitalization and 1,427 survived. According to estimated results for the two models using AUCs [0.838 (95% confidence interval = 0.786–0.891) and 0.815 (95% confidence interval = 0.765–0.865)] and DCA, the logistic regression model performed better. DCA and CIC verified that the logistic regression model had convincing predictive value.

Conclusions

We used logistic regression analysis to establish a more meaningful prediction model for the final outcome of patients with RHD. This model might be clinically useful for patients with RHD and help clinicians to provide detailed treatments and precise management.
Applying the Digital Health Social Justice Guide
Authors: Figueroa Caroline A. , Murayama Hikari , Amorim Priscila Carcamo , White Alison , Quiterio Ashley , Luo Tiffany , Aguilera Adrian , Smith Angela D. R. , Lyles Courtney R. , Robinson Victoria , von Vacano Claudia
Published: February 2022

Introduction

Digital health, the use of apps, text-messaging, and online interventions, can revolutionize healthcare and make care more equitable. Currently, digital health interventions are often not designed for those who could benefit most and may have unintended consequences. In this paper, we explain how privacy vulnerabilities and power imbalances, including racism and sexism, continue to influence health app design and research. We provide guidelines for researchers to design, report and evaluate digital health studies to maximize social justice in health.

Methods

From September 2020 to April 2021, we held five discussion and brainstorming sessions with researchers, students, and community partners to develop the guide and the key questions. We additionally conducted an informal literature review, invited experts to review our guide, and identified examples from our own digital health study and other studies.

Results

We identified five overarching topics with key questions and subquestions to guide researchers in designing or evaluating a digital health research study. The overarching topics are: 1. Equitable distribution; 2. Equitable design; 3. Privacy and data return; 4. Stereotype and bias; 5. Structural racism.

Conclusion

We provide a guide with five key topics and questions for social justice digital health research. Encouraging researchers and practitioners to ask these questions will help to spark a transformation in digital health toward more equitable and ethical research. Future work needs to determine if the quality of studies can improve when researchers use this guide.
Capacity and Readiness Assessment of Healthcare Facilities for Digital Health Interventions Against Tuberculosis and HIV in Addis Ababa, Ethiopia
Authors: Getachew Emnet , Woldeamanuel Yimtubezinash , Manyazewal Tsegahun
Published: February 2022

Background

There is a high level of concern that low-income countries lack the capacity and readiness to effectively adopt, implement, and scale up digital health interventions (DHIs). We aimed to assess the infrastructure and human resource capacity and readiness of healthcare facilities to adopt and implement any new DHI for tuberculosis (TB) and HIV care and treatment in Addis Ababa, Ethiopia.

Method

We carried out a cross-sectional, mixed-methods study in 14 public healthcare facilities that provide TB and HIV care and treatment services. Providers' perceived readiness to adopt and implement digital health was assessed using a self-administered questionnaire designed based on an adapted eHealth readiness assessment model that covers six domains: core readiness, organizational cultural readiness, value proposition readiness, technological readiness, regulatory policy readiness, and operational resource readiness. The infrastructure and human resource capacity were assessed on-site using a tool adapted from the Technology Infrastructure Checklist. Internal consistency was assessed using Cronbach's alpha, and the significant relationship between the composite variables was assessed using Pearson's correlation coefficients (r).

Result

We assessed 14 facilities on-site and surveyed 60 TB and HIV healthcare providers. According to Cronbach's alpha test, all the six technology acceptance domains had a value of >0.8, suggesting a strong interrelatedness between the measuring items. The correlation between technological readiness and operational resource readiness was significant (r = 0.8). The providers perceived their work environment as good enough in electronic data protection, while more efforts are needed in planning, training, adapting, and implementing digital health. Of the 14 facilities, 64.3% lack the plan to establish a functional local area network, and 43% lack skilled staff on payroll to provide maintenance of computers and other digital technologies.

Conclusion

Like many developing countries, there was a modest infrastructure and human resource capacity and readiness of public healthcare facilities in Addis Ababa, Ethiopia, to nurture and strengthen DHIs across the TB and HIV cascades of care. Technological and operational resource readiness, including funding and a Well-trained workforce, are essential for successful implementation and use of digital health against the two infectious diseases of global importance in such settings.
Stretching, Shaking, Inflating: Volcanic-Tectonic Interactions at a Rifting Silicic Caldera
Authors: Muirhead James D. , Illsley-Kemp Finnigan , Barker Simon J. , Villamor Pilar , Wilson Colin J. N. , Otway Peter , Mestel Eleanor R. H. , Leonard Graham S. , Ellis Susan , Savage Martha K. , Bannister Stephen , Rowland Julie V. , Townsend Dougal , Hamling Ian J. , Hreinsdóttir Sigrún , Smith Bubs , McGregor Ross , Snowden Madisen , Shalla Yaasameen
Published: February 2022

Silicic caldera volcanoes are frequently situated in regions of tectonic extension, such as continental rifts, and are subject to periods of unrest and/or eruption that can be triggered by the interplay between magmatic and tectonic processes. Modern (instrumental) observations of deformation patterns associated with magmatic and tectonic unrest in the lead up to eruptive events at silicic calderas are sparse. Therefore, our understanding of the magmatic-tectonic processes associated with volcanic unrest at silicic calderas is largely dependent on historical and geological observations. Here we utilize existing instrumental, historical and geological data to provide an overview of the magmatic-tectonic deformation patterns operating over annual to 104 year timescales at Taupō volcano, now largely submerged beneath Lake Taupō, in the rifted-arc of the Taupō Volcanic Zone. Short-term deformation patterns observed from seismicity, lake level recordings and historical records are characterized by decadal-scale uplift and subsidence with accompanying seismic swarms, ground shaking and surface ruptures, many of which may reflect magma injections into and around the magma reservoir. The decadal-scale frequency at which intense seismic events occur shows that ground shaking, rather than volcanic eruptions, is the primary short-term local hazard in the Taupō District. Deformation trends near and in the caldera on 101–104 yr timescales are atypical of the longer-term behavior of a continental rift, with magma influx within the crust suppressing axial subsidence of the rift basin within ∼10 km of the caldera margin. Examination of exposed faults and fissures reveals that silicic volcanic eruptions from Taupō volcano are characterized by intense syn-eruptive deformation that can occasionally extend up to 50 km outside the caldera structure, including ground shaking, fissuring and triggered fault movements. We conclude that eruption and unrest scenarios at Taupō volcano depend on the three-way coupling between the mafic-silicic-tectonic systems, with eruption and/or unrest events leading to six possible outcomes initially triggered by mafic injection either into or outside the magma mush system, or by changes to the tectonic stress state.
Analysis of the Clinical Characteristics and Pituitary Function of Patients in Central China With Rathke’s Cleft Cysts
Authors: Zhang Lixia , Li Xueyuan , Li Chong , Wang Zhifang , Zheng Lili , Qin Guijun , Wang Shoujun , Xu Lijun
Published: February 2022

Objective

A Rathke’s cleft cyst (RCC) is a common, benign, cystic disease that often leads to hypophyseal dysfunction or head symptoms. The relationship between RCCs and pituitary gland function is not clear. We therefore carried out a study to examine this relationship in greater detail.

Methods

The study was a retrospective, cohort design in patients diagnosed with a RCC between January 2019 to July 2021 at the First Affiliated Hospital of Zhengzhou University, China.

Results

A total of 221 patients were enrolled and then divided into study cohorts according to the diameter of the RCC, clinical manifestations, and surgical treatment received. The majority of patients were symptomatic (143/221), including 83 cases of dizziness and headache, 9 of vision loss and visual field defect, and 2 of diabetes insipidus. 52 cases had abnormal pituitary function, with 8 cases interestingly showing high adrenocorticotropic-hormone (ACTH) and cortisone levels, while 8 juvenile cases had developed central precocious puberty. Patients with larger RCCs were more likely to present with headaches and dizziness, with subjects who suffered from these symptoms having high ACTH and cortisone levels.

Conclusion

Although the size of a RCC is not an important factor influencing hypopituitary function, we consider that endocrine evaluation should be carried out in all patients with a RCC.
Case Report: A Novel Point Mutation of SOX3 in a Subject With Growth Hormone Deficiency, Hypogonadotrophic Hypogonadism, and Borderline Intellectual Disability
Authors: Li Jing , Zhong Yuxia , Guo Tao , Yu Yerong , Li Jianwei
Published: February 2022

SOX3 is critical for the development of the pituitary, brain, and face, and SOX3 mutations may lead to hypopituitarism, intellectual disability, and craniofacial abnormalities. Common SOX3 mutations are duplications and deletions of the whole or part of SOX3, yet only a few cases with point mutations were reported by far. We present a case with growth retardation, small penis, and learning difficulty. Further assessment confirmed growth hormone deficiency, hypogonadotropic hypogonadism (HH), and borderline intellectual disability. He also responded well to gonadotropin-releasing hormone stimulation test, which suggests defects in the hypothalamus, contrary to previous studies that reported defects in the pituitary. A pathogenic frame-shift mutation of SOX3 was found. A heterogeneous missense mutation in SEMA3A was identified in this patient as well, which may also contribute to the development of HH. As far as we know, this is the first report that a frame-shift mutation of SOX3 constitutes rare genetic causes of HH and growth hormone deficiency. Whether mutations in these two genes act synergistically in the pathogenesis of the patient’s phenotype remains to be further investigated. We believe that our case extends the phenotypic spectrum and genetic variability of SOX3 mutation.
The Capitalization Effect of Natural Amenities on Housing Price in Urban China: New Evidence From Changsha
Authors: Tuofu Huang , Qingyun He , Xiao Ouyang
Published: February 2022

This study takes Changsha, an emerging mega-city in China, as a sample to analyze the influence of natural amenity (NA) on housing prices during different periods. We divided the NA into four categories according to their characteristics: Green Space (GS), Wetland Park (WP), XiangRiver Scenic Belt (XR), and green ratio within a community. The housing transaction data is used to calculate the accessibility of a settlement to nearest NA via the distance. The capitalization effect of NA is investigated through a geographic weighted regression (GWR), combined with the hedonic theory. Results show that ①the impact and scope of NA on housing prices gradually expanded during years. ②As the key nature landscape of Changsha, the impact coefficient of XR has risen from 2.34% in 2012 to 5.32% in 2020. WP has a remarkable increase for affecting housing prices, rising from 1.24 to 3.65%. Effect of GS keeps in line during years, at 2.34–3.72%. And green ratio’s impact increase from 3.61 to 4.55%. ③The higher capitalization effect of NA undergoes a spatial expansion from the central area to urban fringe over time, which also implies the capitalization of NA is becoming more pronounced. ④Residential communities impacted by NA have a propensity to separate over time. This study provides a different perspective in defining the importance of natural amenities in urban habitat of modern China.
Gated Communities: Inter- and Intraspecific Diversity of Endosymbionts Across Four Sympatric Aphid Species
Authors: Henry Youn , Brechbühler Esther , Vorburger Christoph
Published: February 2022

Aphids have evolved tight relationships with heritable endosymbionts, i.e., bacteria hosted within their tissues. Besides the primary endosymbiont Buchnera aphidicola, aphids host many facultative secondary endosymbionts with functions they may or may not benefit from. The different phenologies, lifestyles, and natural enemies of aphid species are predicted to favor the selection for distinct endosymbiont assemblages, as well as the emergence of intra-specific genetic diversity in the symbiotic bacteria. In this study, we (1) investigated the diversity of endosymbionts associated with four species from the genus Aphis in the field, and (2) we characterized the genetic diversity of Hamiltonella defensa, an endosymbiont that protects aphids against parasitoid wasps. We observed strong differences in the composition of endosymbiont communities among the four aphid species. H. defensa was clearly the dominant symbiont, although its abundance in each species varied from 25 to 96%. Using a multilocus sequence-typing approach, we found limited strain diversity in H. defensa. Each aphid species harbored two major strains, and none appeared shared between species. Symbiont phylogenies can thus help to understand the (seemingly limited) mobility of endosymbionts in aphid communities and the selection forces driving strain diversification.
Metagenomic Geolocation Using Read Signatures
Authors: Chappell Timothy , Geva Shlomo , Hogan James M. , Lovell David , Trotman Andrew , Perrin Dimitri
Published: February 2022

We present a novel approach to the Metagenomic Geolocation Challenge based on random projection of the sample reads from each location. This approach explores the direct use of k-mer composition to characterise samples so that we can avoid the computationally demanding step of aligning reads to available microbial reference sequences. Each variable-length read is converted into a fixed-length, k-mer-based read signature. Read signatures are then clustered into location signatures which provide a more compact characterisation of the reads at each location. Classification is then treated as a problem in ranked retrieval of locations, where signature similarity is used as a measure of similarity in microbial composition. We evaluate our approach using the CAMDA 2020 Challenge dataset and obtain promising results based on nearest neighbour classification. The main findings of this study are that k-mer representations carry sufficient information to reveal the origin of many of the CAMDA 2020 Challenge metagenomic samples, and that this reference-free approach can be achieved with much less computation than methods that need reads to be assigned to operational taxonomic units—advantages which become clear through comparison to previously published work on the CAMDA 2019 Challenge data.
Speciation of Genes and Genomes: Conservation of DNA Polymorphism by Barriers to Recombination Raised by Mismatch Repair System
Authors: Radman Miroslav
Published: February 2022

Some basic aspects of human and animal biology and evolution involve the establishment of biological uniqueness of species and individuals within their huge variety. The discrimination among closely related species occurs in their offspring at the level of chromosomal DNA sequence homology, which is required for fertility as the hallmark of species. Biological identification of individuals, i.e., of their biological “self”, occurs at the level of protein sequences presented by the MHC/HLA complex as part of the immune system that discriminates non-self from self. Here, a mechanistic molecular model is presented that can explain how DNA sequence divergence and the activity of key mismatch repair proteins, MutS and MutL, lead to 1) genetic separation of closely related species (sympatric speciation) (Fitch and Ayala, Proceedings of the National Academy of Sciences, 1994, 91, 6717–6720), 2) the stability of genomes riddled by diverged repeated sequences, and 3) conservation of highly polymorphic DNA sequence blocks that constitute the immunological self. All three phenomena involve suppression of recombination between diverged homologies, resulting in prevention of gene sharing between closely related genomes (evolution of new species) as well as sequence sharing between closely related genes within a genome (e.g., evolution of immunoglobulin, MHC, and other gene families bearing conserved polymorphisms).
Magnitude, Trends, and Determinants of Institutional Delivery Among Reproductive Age Women in Kersa Health and Demographic Surveillance System Site, Eastern Ethiopia: A Multilevel Analysis
Authors: Raru Temam Beshir , Ayana Galana Mamo , Yuya Mohammed , Merga Bedasa Taye , Kure Mohammed Abdurke , Negash Belay , Birhanu Abdi , Alemu Addisu , Dessie Yadeta , Dheresa Merga
Published: February 2022

Background

Institutional delivery service utilization is a critical and proven intervention for reducing maternal and neonatal mortality. Institutional delivery service utilization can improve maternal health and wellbeing by ensuring safe delivery and reducing problems occurring during childbirth. In Ethiopia, almost all previous researches were cross-sectional studies and most of them were based on small sample sizes and there are no sufficient reports for the trends. Therefore, this study aimed to assess the magnitude, trends, and determinants of institutional delivery using surveillance data from the Kersa Health and Demographic Surveillance System (HDSS), in Eastern Ethiopia from 2015 to 2020.

Methods

The study was conducted among reproductive-aged women selected from the Kersa HDSS site, Eastern Ethiopia for the duration of 2015 to 2020. Data were extracted from the Kersa HDSS database system. After coding and recoding, the data was exported to R software for further analysis. A chi-squared test was used for trends to examine the significance of the change. A multilevel logistic regression model was fitted to identify determinants of institutional delivery. An adjusted odds ratio with a 95% confidence interval (CI) was used to measure the strength of the associations. Statistical significance was declared at a p-value < 0.05.

Results

A total of 20,033 reproductive age women were employed for analysis. The overall magnitude of institutional delivery was 45.03% with 95% CI (44.33–45.72). The institutional delivery has shown a decreasing trend over the 6 years' and there is statistical significance for the declining. Semi-urban resident [AOR = 2.33, 95% CI: 1.37–4.48], urban resident [AOR = 7.18, 95% CI: 5.24, 8.71], read and write [AOR = 1.54, 95% CI: 1.18, 2.01], literate [AOR = 1.46, 95% CI: 1.34–1.59], and antenatal care [AOR = 1.73, 95% CI: 1.58–1.88] were significantly associated with institutional delivery.

Conclusion

The magnitude of institutional delivery was relatively low and has shown a decreasing trend. Community-based interventions should be strengthened to reverse the decreasing trend of institutional delivery. Targeted information dissemination and communication should be provided to those mothers who have no formal education and attention should be given to rural residents.
Antigen Reactivity and Clinical Significance of Autoantibodies Directed Against the Pyruvate Dehydrogenase Antigen Complex in Patients With Connective Tissue Disease
Authors: Ceribelli Angela , Isailovic Natasa , Gorlino Carolina , Assandri Roberto , Vecellio Matteo , De Santis Maria , Satoh Minoru , Selmi Carlo
Published: February 2022

Introduction

Antimitochondrial antibodies (AMAs) are the hallmark of primary biliary cholangitis (PBC) but can be identified also in patients with connective tissue disease, namely, systemic sclerosis (SSc). Protein immunoprecipitation (IP) and IP-Western blot (WB) can be used to confirm AMA positivity directed at the pyruvate dehydrogenase complex (PDC) subunits E1α, E1β, E2/E3, and E3BP in patients showing a cytoplasmic reticular pattern at indirect immunofluorescence when performed in a screening setting before the onset of overt cholestasis in rheumatic patients.

Patients and Methods

We studied sera from 285 patients affected by connective tissue disease [SSc, n = 144; dermato/polymyositis (DM/PM), n = 56; and undifferentiated connective tissue disease (UCTD), n = 85] by indirect immunofluorescence (IIF), protein-IP, and IP-WB to identify specific PDC subunits recognized by AMA.

Results

Twenty percent (57/285) of sera from patients with connective tissue disease had a cytoplasmic reticular pattern at IIF, and in 77% (44/57, including 20 SSc, 12 PM/DM, and 12 UCTD) of these, we detected different titers of autoantibodies against the PDC subunits, specifically against PDC-E2. Among these sera, 4 (9%) tested positive for anti-E1α, 15 (34%) for anti-E1β, and 16 (36%) for anti-E3BP. Four of the 20 AMA-positive SSc cases (20%) had been already diagnosed with PBC, and all were positive for autoantibodies against the subunits PDC-E2, E3, and E3BP.

Conclusions

Using IIF and IP, we confirm that autoantibodies against the PDC components are detected in rheumatic patients with PBC or without liver dysfunction. In view of the strong predictive value of AMA for PBC, a strict follow-up of these latter patients is warranted for an early diagnosis of the disease.
Genetic Diversity and Structure of Tropical Porites lutea Populations Highlight Their High Adaptive Potential to Environmental Changes in the South China Sea
Authors: Luo Yanqiu , Huang Wen , Yu Kefu , Li Ming , Chen Biao , Huang Xueyong , Qin Zhenjun
Published: February 2022

Global climate change and anthropogenic disturbance have significantly degraded biodiversity in coral reef ecosystems. The genetic potential and adaptability of corals are key factors used to predict the fate of global coral reefs under climate change. In this study, we used eight microsatellite loci to study the patterns of reproduction, genetic diversity, and genetic structure of 302 Porites lutea samples across 13° latitudes in the South China Sea (8.8644°N–22.6117°N). The results indicated that P. lutea reproduces largely via sexual reproduction on scales of 5 m and greater and has abundant gene diversity. Additionally, the tropical populations harbored high genetic diversity (based on alleles, effective number of alleles, gene diversity, and heterozygosity). In contrast, genetic diversity was lower in subtropical coral populations. Genetic variation values and pairwise FST revealed that tropical and subtropical populations had significantly different genetic structures. Finally, the Mantel tests showed that the genetic differentiation and genetic variation of P. lutea were strongly correlated with sea surface temperature and slightly correlated with geographical distance. These results indicated that tropical P. lutea populations have high genetic potential and adaptability because of their sexual reproduction and genetic diversity, giving them a greater capacity to cope with climate change. Subtropical coral populations showed lower genetic diversity and, thus, relatively poor genetic resilience in response to low average sea surface temperature and human activities. Our study provides a theoretical basis for the protection and restoration of coral reefs.
Uncertainties in the Projected Patterns of Wave-Driven Longshore Sediment Transport Along a Non-straight Coastline
Authors: Zarifsanayei Amin Reza , Antolínez José A. A. , Etemad-Shahidi Amir , Cartwright Nick , Strauss Darrell , Lemos Gil
Published: February 2022

This study quantifies the uncertainties in the projected changes in potential longshore sediment transport (LST) rates along a non-straight coastline. Four main sources of uncertainty, including the choice of emission scenarios, Global Circulation Model-driven offshore wave datasets (GCM-Ws), LST models, and their non-linear interactions were addressed through two ensemble modelling frameworks. The first ensemble consisted of the offshore wave forcing conditions without any bias correction (i.e., wave parameters extracted from eight datasets of GCM-Ws for baseline period 1979–2005, and future period 2081–2100 under two emission scenarios), a hybrid wave transformation method, and eight LST models (i.e., four bulk formulae, four process-based models). The differentiating factor of the second ensemble was the application of bias correction to the GCM-Ws, using a hindcast dataset as the reference. All ensemble members were weighted according to their performance to reproduce the reference LST patterns for the baseline period. Additionally, the total uncertainty of the LST projections was decomposed into the main sources and their interactions using the ANOVA method. Finally, the robustness of the LST projections was checked. Comparison of the projected changes in LST rates obtained from two ensembles indicated that the bias correction could relatively reduce the ranges of the uncertainty in the LST projections. On the annual scale, the contribution of emission scenarios, GCM-Ws, LST models and non-linear interactions to the total uncertainty was about 10–20, 35–50, 5–15, and 30–35%, respectively. Overall, the weighted means of the ensembles reported a decrease in net annual mean LST rates (less than 10% under RCP 4.5, a 10–20% under RCP 8.5). However, no robust projected changes in LST rates on annual and seasonal scales were found, questioning any ultimate decision being made using the means of the projected changes.
Sulfur-Rich Ageing Mechanism of Silicone Encapsulant Used in LED Packaging: An Experimental and Molecular Dynamic Simulation Study
Authors: Chen Wei , Chen Ye , Cao Yixing , Cui Zhen , Fan Xuejun , Zhang Guoqi , Fan Jiajie
Published: February 2022

In a light-emitting diode (LED) package, silicone encapsulant serves as a chip protector and enables the light to transmit, since it exhibits the advantages of high light transmittance, high refractive index, and high thermal stability. However, its reliability is still challenged under harsh operation conditions. In this study, the optical and mechanical properties of silicone encapsulant, including appearance, light transmittance, Young’s modulus, and tensile strength, were experimentally monitored during the sulfur-rich ageing process. Meanwhile, the Fourier transform infrared (FTIR) spectroscopy and molecular dynamics (MD) simulation were used to reveal its degradation mechanism. The results show that 1) in the sulfur (S8)-rich ageing process, the severe vulcanization reaction occurred in silicone encapsulant assisted only by high temperature and high moisture, with the existence of H2S as the reaction product of S8 and H2O vapor. 2) Vulcanization characterized by the formation of the sulfhydryl (-SH) group lowered both optical and mechanical properties of silicone encapsulant. 3) The hydrolysis reaction featured by the formation of the hydroxyl (-OH) group decreased the mechanical performances of silicone encapsulant but brought slight harm to its optical performances.
Influence of Zn Injection on Corrosion of 304SS Under PWR Primary Side Conditions
Authors: Wei Haibo , Lin Jingwei , Liu Zhikun , Wu Lina , Chi Lisheng
Published: February 2022

The structural materials in nuclear power plants experience corrosion under high temperature water chemistry environments, which could result in serious safety issues. Zinc injection to the primary side chemistry has been demonstrated to reduce corrosion rate of the structural materials and radiation dose rate by modifying the oxide film formed on the structural materials. The purpose of this work is to investigate the effect of Zn addition at different concentrations on 304SS under PWR primary side conditions by SEM, GIXRD, Raman spectrum, XPS, electrochemical method and thermodynamic calculation. When Zn concentration is increased, the number and size of Fe-based spinel oxide particles in the outer layer decreases while Cr-based spinel oxide in the inner layer remains unchanged. The corrosion current density of 304SS and defect density of the oxide film decrease with increasing Zn concentration. These results conclude that corrosion resistance of 304SS is enhanced in the presence of Zn. In addition, the thermodynamic analyses on the spinel oxides of surface were performed and the results are in good agreement with the experimental observations presented in this work.
Training Deep Neural Networks to Reconstruct Nanoporous Structures From FIB Tomography Images Using Synthetic Training Data
Authors: Sardhara Trushal , Aydin Roland C. , Li Yong , Piché Nicolas , Gauvin Raynald , Cyron Christian J. , Ritter Martin
Published: February 2022

Focused ion beam (FIB) tomography is a destructive technique used to collect three-dimensional (3D) structural information at a resolution of a few nanometers. For FIB tomography, a material sample is degraded by layer-wise milling. After each layer, the current surface is imaged by a scanning electron microscope (SEM), providing a consecutive series of cross-sections of the three-dimensional material sample. Especially for nanoporous materials, the reconstruction of the 3D microstructure of the material, from the information collected during FIB tomography, is impaired by the so-called shine-through effect. This effect prevents a unique mapping between voxel intensity values and material phase (e.g., solid or void). It often substantially reduces the accuracy of conventional methods for image segmentation. Here we demonstrate how machine learning can be used to tackle this problem. A bottleneck in doing so is the availability of sufficient training data. To overcome this problem, we present a novel approach to generate synthetic training data in the form of FIB-SEM images generated by Monte Carlo simulations. Based on this approach, we compare the performance of different machine learning architectures for segmenting FIB tomography data of nanoporous materials. We demonstrate that two-dimensional (2D) convolutional neural network (CNN) architectures processing a group of adjacent slices as input data as well as 3D CNN perform best and can enhance the segmentation performance significantly.