bluuebunny/crossref_metadata_2025 huggingface dataset:
Robotic single‐site surgery in benign gynecologic diseases: Experiences and learning curve based on 626 robotic cases at a single institute
Authors: Yoo Hae K. , Cho Ahyoung , Cho Eun H. , Kim Soo J. , Shim Ji E. , Lee Sa R. , Jeong Kyungah , Moon Hye‐Sung
Published: July 2020

Aim

The purpose of this study was to report on 626 cases of successful robotic single‐site (RSS) surgeries to address various types of gynecologic disease and to evaluate the outcomes and learning curve inherent to RSS surgery in the gynecology field.

Methods

A total of 626 cases of RSS surgeries were performed by 3 gynecologic surgeons at Ewha Womans University Medical Center, Robot Surgery Center from November 2014 to January 2018 were collected retrospectively. All of the patients' charts were reviewed, and the clinical characteristics and surgical variables were analyzed.

Results

Among the total of 626 cases, there were 220 cases of RSS myomectomy (RSSM), 182 cases of RSS hysterectomy (RSSH), 195 of RSS adnexectomy, 24 of RSS sacrocolpopexy (RSS SCP) and 5 were classified as other RSS surgeries. The patient's mean age was 38.98 ± 10.07 years. There was 3.99 ± 2.15 min of mean docking time and 117.78 ± 51.18 min of mean operating time. The surgical variables were analyzed annually. The total operating time was seen to decrease significantly according to each period. The docking time declined significantly and gradually after 1 year. We also analyzed each of the surgical types by time. The operating time of RSSH, RSSM, RSS adnexectomy and RSS SCP fell over time. The tendency found was for operating time to decline sharply following the first 10 cases. When we analyzed the data at annual intervals, the operating time was most significantly less and stable following the first year. There were a few intraoperative or perioperative complications in 16 cases (2.6%).

Conclusion

Robotic single‐site surgery is a feasible and safe procedure for treating various kinds of gynecologic diseases. The learning curve was approximately 10 cases of RSS surgery in gynecologic disease, having a greater amount of experience at performing RSS surgery was revealed to be key to achieving better surgical outcomes.
Senolytic drugs: from discovery to translation
Authors: Kirkland J. L. , Tchkonia T.
Published: July 2020

Senolytics are a class of drugs that selectively clear senescent cells (SC). The first senolytic drugs Dasatinib, Quercetin, Fisetin and Navitoclax were discovered using a hypothesis‐driven approach. SC accumulate with ageing and at causal sites of multiple chronic disorders, including diseases accounting for the bulk of morbidity, mortality and health expenditures. The most deleterious SC are resistant to apoptosis and have up‐regulation of anti‐apoptotic pathways which defend SC against their own inflammatory senescence‐associated secretory phenotype (SASP), allowing them to survive, despite killing neighbouring cells. Senolytics transiently disable these SCAPs, causing apoptosis of those SC with a tissue‐destructive SASP. Because SC take weeks to reaccumulate, senolytics can be administered intermittently – a ‘hit‐and‐run’ approach. In preclinical models, senolytics delay, prevent or alleviate frailty, cancers and cardiovascular, neuropsychiatric, liver, kidney, musculoskeletal, lung, eye, haematological, metabolic and skin disorders as well as complications of organ transplantation, radiation and cancer treatment. As anticipated for agents targeting the fundamental ageing mechanisms that are ‘root cause’ contributors to multiple disorders, potential uses of senolytics are protean, potentially alleviating over 40 conditions in preclinical studies, opening a new route for treating age‐related dysfunction and diseases. Early pilot trials of senolytics suggest they decrease senescent cells, reduce inflammation and alleviate frailty in humans. Clinical trials for diabetes, idiopathic pulmonary fibrosis, Alzheimer’s disease, COVID‐19, osteoarthritis, osteoporosis, eye diseases and bone marrow transplant and childhood cancer survivors are underway or beginning. Until such studies are done, it is too early for senolytics to be used outside of clinical trials.
Effects of two Postprocessing Methods onto Surface Dimension of in‐Office Fabricated Stereolithographic Implant Surgical Guides
Authors: Ammoun Rami , Dalal Nishchal , Abdulmajeed Aous A. , Deeb George R. , Bencharit Sompop
Published: July 2020

Purpose

To evaluate the effects of two postprocessing methods in terms of the overall, intaglio, and cameo surface dimensions of in‐office stereolithographic fabricated implant surgical guides.

Materials and methods

Twenty identical implant surgical guides were fabricated using a stereolithographic printer. Ten guides were postprocessed using an automated method. The other ten guides were postprocessed using a series of hand washing in combination with ultrasonics. Each guide was then scanned using cone‐beam computed tomography to produce a set of digital imaging and communications in medicine (DICOM) files which were converted into standard tessellation language (STL) files. The STL file was then superimposed onto the original STL design file using the best fit alignment. The average positive and negative surface discrepancy differences in terms of means and variances were analyzed using t‐test (α = 0.05).

Results

For the alternative group, the average positive and negative overall, intaglio, and cameo surface discrepancies were 77.38 ± 10.68 µm and –67.74 ± 6.55 µm; 78.83 ± 8.65 µm and –68.16 ± 5.26 µm; and 70.5 ± 8.48 µm –64.84 ± 5.55 µm, respectively. For the automated group, the average positive and negative overall, intaglio, and cameo surface discrepancies were 51.88 ± 4.38 µm and –170.7 ± 11.49 µm; 64.3 ± 4.44 µm and –89.45 ± 6.25 µm; and 83.59 ± 4.81 µm and –144.26 ± 13.19 µm, respectively. There was a statistical difference between the means of the two methods for the overall, intaglio, and cameo positive and negative discrepancies (p < 0.001).

Conclusions

For a single implant tooth‐supported implant guide, using hand washing with ultrasonics appeared to be consistently better than the automated method. The manual method presented with more positive discrepancies, while the automated method presented with more negative discrepancies.
Working toward a purpose: Examining the cross‐sectional and longitudinal effects of work characteristics on sense of purpose
Authors: Weston Sara J. , Hill Patrick L. , Cardador M. Teresa
Published: July 2020

Objective

Employment appears to influence employees' sense of purpose, insofar as work roles can provide life direction and allow individuals to fulfill meaningful aims or have regular goal‐related activity engagement. However, research is needed on which specific characteristics of the work predict employees' sense of purpose. The current study sought to quantitate the degree to which specific work characteristics, including skill variety, autonomy, coworker support, and supervisor support, were associated with initial levels and changes in purpose. Additionally, we examine positive and negative work‐home spillover as moderators of these relationships.

Methods

We examined hypothesized relationships in a subsample (N = 4,963) of a nationally representative panel study which included between two and three assessments of work characteristics, spillover, and sense of purpose, each roughly 10 years apart.

Results

Using multilevel models to assess within‐person associations and lagged effects, we found that greater skill variety and coworker support but not autonomy or supervisor support, were associated with higher levels of purpose. Moreover, increases in purpose were associated with higher initial levels of skill variety. These relationships were not moderated by spillover.

Conclusion

Individuals with skill variety and coworker support at work appear to experience the strongest levels of sense of purpose.
Perceived Parental Knowledge and Adolescent Substance Use Outcomes
Authors: Fay Heather , LoParo Devon , Shentu Yujia , Vasquez Desirae , Welsh Justine W.
Published: July 2020

BACKGROUND

Whether parental permission of alcohol and other drug use in a home environment is protective against substance‐related negative outcomes remains controversial. We investigated substance use at home, with or without parental knowledge, and its association with substance‐related consequences.

METHODS

The sample consisted of 21,207 U.S. students in the 6th to 12th grades surveyed between 2009 and 2017. Substance use patterns and rates of negative outcomes were analyzed by comparing groups of participants who had not used at home, or had used at home with and/or without parental knowledge.

RESULTS

Adolescents who used substances at home without parental knowledge used alcohol and substances in greater amounts, and tended to have more negative outcomes than those who did not. Students who had not used at home or had used only with parental knowledge tended to have lower levels of use and negative outcomes.

CONCLUSIONS

Using at home without parental knowledge was a consistent risk factor for substance‐related negative outcomes. These results highlight the importance of screening adolescents for the use of alcohol or drugs in the home without parental knowledge, as well as attempting to prevent substance use in the household.
Public Shaming and Attacks on Social Media: The Case of White Evangelical Christians
Authors: Cai Deborah A. , Tolan Colleen
Published: July 2020

In this article, we compare public shaming with attacks on social media by looking at how these tactics have been used regarding White Evangelical Christians in the United States within the current political climate. We first examine public shaming historically and then in its current form on social media. Then, we differentiate shaming from attacks and argue that this distinction is vital for understanding the goals and motives of online use of these tactics. By making this comparison, we can identify the motives and goals of using these types of posts. We conclude with considerations and recommendations about conflict on social media.
Body mass index and all‐cause mortality in patients with percutaneous coronary intervention: A dose–response meta‐analysis of obesity paradox
Authors: Mei Xiaofei , Hu Shengda , Mi Lijie , Zhou Yafeng , Chen Tan
Published: July 2020

The association between body mass index (BMI) and mortality of patients with percutaneous coronary intervention (PCI) is still controversial. We hope to explore whether the ‘obesity paradox’ really exists through this dose–response meta‐analysis. PubMed, Embase and Cochrane databases were systematically searched for eligible studies up to April 2020. The random‐effects restricted cubic spline models were used to evaluate the potential non‐linear relationship between BMI and all‐cause mortality of patients undergoing PCI. Fifteen studies were identified and included total 138 592 participants. The pooled hazard ratio of all‐cause mortality was 0.60 (95% confidence interval: 0.45–0.82) when compared the highest category (mean = 33.32 kg m−2) of BMI with the lowest category (mean = 18.89 kg m−2). A non‐linear U‐shaped dose–response curve between BMI and the risk of all‐cause mortality was found, with higher mortality rate at BMI lower than 27 kg m−2 and higher than 32 kg m−2. The ‘obesity paradox’ does exist after PCI. The association between BMI and the risk of all‐cause mortality for patients undergoing PCI is U shaped, with a nadir of risk at a BMI of 27 to 32 kg m−2 and the highest risk at patients with underweight. The relationship between other prognostic indicators and BMI is worthy of further research.
Detection of serum/salivary exosomal Alix in patients with oral squamous cell carcinoma
Authors: Nakamichi Eiji , Sakakura Hiroki , Mii Shinji , Yamamoto Noriyuki , Hibi Hideharu , Asai Masato , Takahashi Masahide
Published: July 2020

Objective

Owing to variations in the exterior appearances of noncancerous diseases in the oral cavity, clinicians may have difficulty diagnosing oral squamous cell carcinoma (OSCC). Tissue biopsy is confirmatory, but invasive. Therefore, reliable tumor markers for OSCC are required. Here, exosomal Alix (exoAlix) levels were measured in serum/salivary samples from patients with OSCC and healthy controls (HCs).

Methods

Fifty‐seven patients admitted to Nagoya University Hospital from 2017 through 2019 were enrolled, and serum samples (OSCC, n = 29; HC, n = 21) and/or saliva samples (OSCC, n = 23; HC, n = 20) were collected. Exosomal fractions were isolated using ultracentrifugation. ExoAlix levels were measured using enzyme‐linked immunosorbent assay.

Results

Serum/salivary exoAlix levels were significantly higher in patients with OSCC than in HCs. Receiver operating characteristic analyses revealed that sensitivity, specificity, positive predictive value, and area under the curve were 0.345, 1.000, 1.000, and 0.685, respectively, for serum exoAlix and 0.348, 1.000, 1.000, and 0.712, respectively, for salivary exoAlix at optimal cut‐off values (serum, 0.205; saliva, 0.193). All tested OSCC tissue sections (n = 21) were immuno‐reactive for Alix.

Conclusion

Serum and salivary exoAlix were identified as potential diagnostic OSCC biomarkers. Serum exoAlix was suitable for prediction of therapeutic responses.
SNPs at TP63 gene was specifically associated with right‐side cleft lip in Han Chinese population
Authors: Yin Bin , Shi Jia‐Yu , Lin Yan‐Song , Shi Bing , Jia Zhong‐Lin
Published: July 2020

Objectives

Non‐syndromic cleft lip with or without palate is one of the most common birth malformations. TP63 and GREM1 were recently reported to be associated with NSCL/P. However, there were few studies focused on their associations in non‐syndromic cleft lip only (NSCLO).

Design

Initial screening and replication in large cohorts were used to locate the susceptible SNPs of TP63 and GREM1. Firstly, variations were screened among 192 NSCLO cases by the Sanger sequencing. Then, we selected five associated SNPs in initial screening phase and replicated among 1,006 NSCLO cases and 1,823 normal controls.

Results

Initial chi‐square test showed that rs7653848, rs7624324, rs6790167, and rs1345186 in TP63 and rs2280738 in GREM1 achieved statistical significance (p < .05); the subsequent replication analysis showed that rs1345186 was specifically significant in right‐side cleft lip (RCL; p = .017, OR = 1.33, and 95% CI: 1.05–1.69).

Conclusion

This study firstly used the subphenotype of cleft lip samples to verify the association between TP63 and GREM1, which indicated that TP63 is a promising susceptible gene for RCL in Chinese population. And further confirmed the different etiology in the right‐sided cleft lip, left‐sided cleft lip, and bilateral cleft lip of NSCLO. This will give new reference for the future research and genetic counseling.
Epidermolysis bullosa with congenital absence of skin: Review of the literature
Authors: Martinez‐Moreno Adrian , Ocampo‐Candiani Jorge , Alba‐Rojas Erika
Published: July 2020

Background/Objectives

Bart syndrome was initially described as association of congenital absence of skin (CAS), nail abnormalities, and epidermolysis bullosa (EB). Further reports of patients with CAS and EB have been made with wide clinical heterogeneity among them. Current guidelines recommend the elimination of eponyms and use of the descriptive term EB with CAS.

Methods

We performed a PubMed and Medline database search of patients with Bart syndrome or EB with CAS. We included case reports or case series that contained clinical and demographic information.

Results

After review, 55 articles were included, reporting 96 patients. CAS involved the lower extremities in all patients, with additional upper limb, trunk, or head involvement in 17%. In all patients, the time to healing ranged from 2 weeks to 6 months; most received only conservative treatment. The subtype and frequency of associated EB most frequently reported were recessive dystrophic EB (41.4%) and dominant dystrophic EB (22.8%). Extracutaneous features were present in 29 patients; with pyloric atresia and ear malformations being the most common. The prognosis varied based on the subtype of EB and the presence of additional comorbidities; 50% of the patients with junctional EB with pyloric atresia and CAS died during the first months of life, while mortality among those with recessive dystrophic EB was 6.8%.

Conclusion

Epidermolysis bullosa with CAS is a clinically heterogeneous disorder, most often associated with recessive dystrophic EB, but other EB subtypes may occur. Further investigations are necessary to better establish a pathological mechanism for CAS, and its association with EB.
Attentional capture by a color singleton is stronger at spatially relevant than irrelevant locations: Evidence from an ERP study
Authors: Su Yuling , Huang Wanyi , Yang Nan , Yan Ke , Ding Yulong , Qu Zhe
Published: July 2020

Top‐down spatial attention can modulate contingent attentional capture, but the underlying mechanism is still not clear. Using variants of spatial cueing paradigms, our previous event‐related potential study showed that peripheral color singleton cues with task‐relevant features captured attention (indexed by cue‐elicited N2pc) even when the targets appeared at central locations, but the magnitude of attentional capture was smaller than when the targets appeared at same peripheral locations. One reasonable explanation is that the modulation effect is due to spatial relevance of cues. However, several other confounding factors might also explain the modulation effect, such as task difficulty, spread of attentional window, and inside/outside relation between cue and attentional window. In the present study, we rearranged the relative locations between cues and targets to control these factors and to further examine whether inequivalence of attentional capture across attended and unattended locations was a common phenomenon. In two experiments, color singleton cues elicited apparent N2pc components when participants were searching for targets possessing the same color, which replicated typical findings of contingent attentional capture. More importantly, the modulation effect of top‐down spatial attention on the cue‐elicited N2pc still existed even when the factors of task difficulty (Experiment 1), spread of attentional window (Experiment 1), or inside/outside relation between cue and attentional window (Experiment 2) were controlled. These results consistently demonstrate that attentional capture by a color singleton is stronger at spatially relevant locations than at spatially irrelevant locations, suggesting an important role of spatial relevance on contingent attentional capture.
Effects of slow freezing and vitrification on embryo development in domestic cat
Authors: Mokrousova Valentina I. , Okotrub Konstantin A. , Brusentsev Eugeny Y. , Kizilova Elena A. , Surovtsev Nikolai V. , Amstislavsky Sergei Y.
Published: July 2020

Cryopreservation of gametes and embryos is used to maintain genetic diversity of domestic and wild felids. However, felid oocytes and preimplantation embryos contain large amount of intracellular lipids, which affect their cryosensitivity. The objective was to compare the effects of slow freezing and vitrification and to study lipid phase transition (LPT) during cooling in cat embryos. In vitro‐derived embryos were cultured 48 hr up to 4–8 cell stage, thereafter were either slow frozen or vitrified. Propylene glycol (PG) alone was used as a cryoprotective agent (CPA) for slow freezing, and a mixture of PG and dimethyl sulfoxide (DMSO) were used as CPAs for vitrification. After thawing/warming, embryos were in vitro cultured additionally for 72 hr. The total time of in vitro culture was 120 hr for all the groups including non‐frozen controls. Effects of both cryopreservation procedures on the subsequent embryo development and nuclear fragmentation rate in embryonic cells were compared. There was no significant differences among the percentages of embryos achieved morula and early blastocyst stage in frozen‐thawed group (36.4% and 20.0%), in vitrified‐warmed group (34.3% and 28.6%) and in controls (55.6% and 25.9%). Cell numbers as well as nuclear fragmentation rate did not differ in these three groups. Average lipid phase transition (LPT) temperature (T*) was found to be relatively low (–2.2 ± 1.3°C) for the domestic cat embryos. It is supposed that the low LPT of LDs may provide a good background for successful application of slow freezing to domestic cat embryos. Generally, our study indicates that slow freezing and vitrification are both applicable for domestic cat embryo cryopreservation.
Single Layer Centrifugation with 20% or 30% Porcicoll separates the majority of spermatozoa from a sample without adversely affecting sperm quality
Authors: Deori Sourabh , Johannisson Anders , Morrell Jane
Published: July 2020

Centrifugation of boar semen through one layer of 40% colloid (Porcicoll) was previously shown to separate spermatozoa from bacteria without having a detrimental effect on sperm quality. However, some spermatozoa were lost. The purpose of the present study was to determine whether 20% or 30% Porcicoll could be used to recover most of the spermatozoa without impacting on sperm quality. Insemination doses (n = 10) from a commercial boar station were sent to the laboratory at the Swedish University of Agricultural Sciences and processed by Single Layer Centrifugation with 20% and 30% Porcicoll approximately 7 hr after semen collection. The resulting sperm samples and controls were evaluated for sperm quality immediately and again after storage at 16–18°C for 4 and 7 days. Sperm recovery was 94 ± 18% and 87 ± 15% for 20% and 30% Porcicoll, respectively (p > .05). Sperm mitochondrial membrane potential and chromatin integrity were unaffected (p > .05). The proportion of live spermatozoa producing superoxide (9 ± 8%, 7 ± 6% and 3 ± 1%; p < .05), and the proportion of spermatozoa with high stainability DNA (0.68 ± 19%, 0.61 ± 0.22% and 0.96 ± 0.23%; p < .05‐ <0.01), were marginally increased whereas membrane integrity, although high, was lower in the centrifuged samples than in the controls (82 ± 8%, 83 ± 5% versus 92 ± 4%; p < .05). In conclusion, centrifugation through 20% or 30% Porcicoll enables most spermatozoa to be recovered, without having a major effect on sperm quality. These results are encouraging for further studies involving microbiological investigation of the processed samples, and scaling‐up to process larger volumes of boar ejaculates.
How do external conditions affect the design of local governments' sustainability strategies?
Authors: Ji Hyunjung , Darnall Nicole
Published: July 2020

Local governments nationwide have been adopting a variety of sustainability practices in the absence of strong federal guidance. The collection of these practices, which differ in design, forms the local government's sustainability strategy. Some local governments may develop a more focused sustainability strategy to achieve more predictable environmental benefits around a narrower array of environmental issues. By contrast, other local governments are developing a more comprehensive sustainability strategy that is more broadly focused to address complex, interconnected environmental issues. However, the external conditions that give rise to these different strategies is not well understood. Drawing on data for more than 950 U.S. municipal governments, this study provides important evidence that local governments' comprehensive sustainability strategies are influenced more by their community contituents and external environmental settings, with greater pressures in particular from constituents in new economy industries and environmental NGOs. These strategies are also more strongly related to higher disaster risk in the external environmental setting than more focused sustainability strategies. These findings broaden our understanding about why local governments' sustainability strategies differ in their design, which may provide a starting point for understanding how different sustainability strategies relate to actual environmental performance outcomes.
Long‐run productivity trends: A global update with a global index
Authors: Krüger Jens J.
Published: July 2020

This paper documents the results from a macroeconomic total factor productivity analysis with a special focus on disentangling efficiency change and technological change under variable returns to scale. A sample of 93 countries is investigated by nonparametric methods. For the measurement three variants of the Malmquist index (basic, biennial, and global) are used. Specific country groups and selected individual countries are examined. The results show that productivity development is mainly driven by the interplay of technological change and efficiency change with a reversal from a backward shifting frontier function until the mid‐1990s to an advancing frontier thereafter.
Decomposing implicit associations about life and death improves our understanding of suicidal behavior
Authors: O’Shea Brian A. , Glenn Jeffrey J. , Millner Alexander J. , Teachman Bethany A. , Nock Matthew K.
Published: July 2020

The Death/Suicide Implicit Association Test (IAT) is effective at detecting and prospectively predicting suicidal thoughts and behaviors. However, traditional IAT scoring procedures used in all prior studies (i.e., D‐scores) provide an aggregate score that is inherently relative, obfuscating the separate associations (i.e., “Me = Death/Suicide,” “Me = Life”) that might be most relevant for understanding suicide‐related implicit cognition. Here, we decompose the D‐scores and validate a new analytic technique called the Decomposed D‐scores (“DD‐scores”) that creates separate scores for each category (“Me,” “Not Me”) in the IAT. Across large online volunteer samples (N > 12,000), results consistently showed that a weakened association between “Me = Life” is more strongly predictive of having a history of suicidal attempts than is a stronger association between “Me = Death/Suicide.” These findings replicated across three different versions of the IAT and were observed when calculated using both reaction times and error rates. However, among those who previously attempted suicide, a strengthened association between “Me = Death” is more strongly predictive of the recency of a suicide attempt. These results suggest that decomposing traditional IAT D‐scores can offer new insights into the mental associations that may underlie clinical phenomena and may help to improve the prediction, and ultimately the prevention, of these clinical outcomes.
High‐value care for senior medical students
Authors: Lacy Mary , Noronha Leonard
Published: July 2020

Background

Physicians have an opportunity to address rising health care costs by optimising resource use. Recent research suggests that regional spending patterns influence student engagement with high‐ and low‐value behaviours, revealing that these behaviours may be adopted early in training. The major curriculum for the internal medicine clinical experience does not address high‐value care (HVC). At our institution, senior medical students in the subinternship of internal medicine have an increased responsibility in the development and implementation of patient management plans.

Objective

Our study aimed to determine whether a curriculum on HVC delivered to senior medical students would have a lasting impact on the students.

Methods

We implemented a curriculum in HVC for medical students and surveyed them before and after the curriculum as well as prior to graduation about their perceptions and engagement with HVC practices.

Results

We found a statistically significant increase in positive attitudes and reported perception of practice in senior medical students who received the curriculum; this was sustained prior to graduation.

Conclusions

Our study supports the notion that a curriculum in HVC can increase reported HVC practices. Further research should be carried out to assess the impact of efforts to teach medical students about limiting unnecessary care within our medical system.
A Proposed Scheme for Fault Discovery and Extraction Using ANFIS: Application to Train Braking System
Authors: Sparthan Tse , Nzie Wolfgang , Sohfotsing Bertin , Garro Olivier , Beda Tibi
Published: July 2020

This paper showcases the use of model oriented techniques for real time fault discovery and extraction on train track unit. An analytical system model is constructed and simulated in Mathlab to showcase the fair and unfair status of the system. The discovery and extraction phases are centered on a hybrid adaptive neuro-fuzzy inference feature extraction and segregated module. Output module interprites zero (0) as a good status of the traintrack unit and one (1) as an unpleasant status. Final results showcase the robustness and ability to discover and extract multitude of unpleasant scenarios that hinder the smooth operations of train track units due to its high selectivity and sensitivity quality.
Simultaneous Fault Detection and Multivariable Adaptive Hybrid Control for Unbalanced Vibrations of Cracked Flexible Rotor Systems
Authors: Vashisht Rajiv Kumar , Peng Qingjin
Published: July 2020

For the reduction of unbalanced vibrations in a multi-input and multi-output flexible rotor system with electromagnetic actuators (EAs), conventional adaptive feedforward controllers (AFFCs) are very sensitive for changes in rotor spin frequencies. Although frequency updating is used in these controllers, a small variation in the rotor spin frequency can completely reduce their effectiveness. An adaptive notch filter is used in this research for the frequency estimation. By using this external frequency estimation, the performance of the conventional AFFCs can be enhanced. During changes in the rotor spin frequency, fundamental harmonics of the flexible rotor are also excited. Their amplitude is much higher compared to steady-state unbalanced vibrations, which can accelerate the wear and tear of components of EAs. By using feedback controllers, the amplitude of these fundamental harmonics can be reduced significantly. In real rotors with flexible bearing supports, any looseness of bolts and presence of transverse cracks can change system parameters significantly. Multiple harmonics are generated corresponding to even single spinning speed of the rotor. Robust stability as well as performance can be achieved in the presence of uncertainty and rotor crack nonlinearities using feedback controllers designed by mu-synthesis. By using the multiharmonic hybrid control, the higher harmonics can be compensated efficiently in case of a crack in rotor systems. The fast Fourier transform of the control signal can indicate the presence of a transverse crack in an online manner. In this way, active vibration control as well as rotor crack fault detection can be done simultaneously.
Application of Short and Long (Enhanced Vlasov's) Solutions for Cylindrical Shell on Example of Concentrated Radial Force
Authors: Oryniak Andrii , Orynyak Igor
Published: July 2020

Analytical approaches for cylindrical shell are mostly based on expansion of all variables in Fourier series in circumferential direction. This leads to eighth-order differential equation with respect to axial coordinate. Here it is approximately treated as a sum of two fourth-order biquadratic equations. First one assumes that all variables change more quickly in circumferential direction than in axial one (long solution), while the second (short) one is based on opposite assumption. The accuracy and applicability of this approach were demonstrated (Orynyak, I., and Oryniak, A., 2018, “Efficient Solution for Cylindrical Shell Based on Short and Long (Enhanced Vlasov's) Solutions on Example of Concentrated Radial Force,” ASME Paper No. PVP2018-85032) on example of action of one or two concentrated radial forces and compared with finite element method results. This paper is an improvement of our previous work (Orynyak, I., and Oryniak, A., 2018, “Efficient Solution for Cylindrical Shell Based on Short and Long (Enhanced Vlasov's) Solutions on Example of Concentrated Radial Force,” ASME Paper No. PVP2018-85032). Two amendments are made. The first is insignificant one and use slightly modified expressions for bending strains, while the second one relates to the short solution. Here we do not consider any more that circumferential displacement is negligible as compared with radial one. Eventually this improves the accuracy of results, as compared with previous work. For example, for cylinder with radius, R, to wall thickness, h, ratio equal to 20, the maximal inaccuracy for radial displacement in point of force application decreases from 5% to 3%. For thinner cylinder with R/h = 100, this inaccuracy decreases from 2.5% to 1.25%. These inaccuracies are related to larger terms in Fourier expansion, the significance of which decrease when length or area of outer loading becomes greater. The last conclusion is demonstrated for the case of distributed concentrated force acting along short segment on axial line.
A Method to Solve the Heat Transfer Problem in a Circular Duct With an Internal Longitudinal Fin
Authors: Vachagina E. K. , Kadyirov A. I. , Sibgatova K. I. , Yunusova V. S. , Gurmanchuk E. P.
Published: July 2020

The heat transfer problem in a circular duct with an internal longitudinal fin is investigated under constant wall temperature. Different fin heights are considered. The problem is solved in two stages. In the first stage, the distribution of axial velocity corresponding to the fully developed laminar viscous flow is obtained using comsolmultiphysics. In the second stage, the variable-separation method is implemented to reduce the solution of the energy transfer equation under constant wall temperature to an eigenvalue problem. Finally, the temperature distribution is obtained in the analytical form as a series expansion. The influence of fin height on the Nusselt number and the friction factor is discussed.
Heuristic Optimization of Ribbed Cooling Channels With Variable Length and Roughness
Authors: Ejaz Faizan , Hwang Leslie K. , Kwon Beomjin
Published: July 2020

This paper presents a heuristic optimization method for cooling channels with internal repeated-rib roughness. The method rapidly explores a design space to simultaneously optimize two geometric parameters, channel length, and rib roughness ratio. For a rapid and accurate optimization, the method combines a heuristic optimization technique, simulated annealing (SA), and numerically derived closed-form models of heat transfer and pressure drop. It is shown that approximately 1 million designs are evaluated within 6 s, resulting in optimal designs having minimal thermal resistance for given pressure thresholds. Closed-form correlations for developing and fully developed flow are derived by evaluating discrete design points using a finite volume model (FVM). The derived correlations predict the channel properties with acceptable ranges of mean absolute error (<5% for Nusselt number and < 15% for pressure drop) against the FVM. Optimal channel designs exhibit up to about 12 times greater performance factor compared to smooth channels, supporting the efficacy of optimization. The introduced method demonstrates the potential of rapid numerical optimization method in designing heat transfer devices with complex geometries.
Plasma-immersion ion implantation surface oxidation on a cobalt-chromium alloy for biomedical applications
Authors: Catanio Bortolan Carolina , Paternoster Carlo , Turgeon Stéphane , Paoletti Chiara , Cabibbo Marcello , Lecis Nora , Mantovani Diego
Published: July 2020

Co-Cr alloys such as L605 are widely applied for the manufacture of medical devices, including tiny cardiovascular stents. The presence of potentially toxic and allergenic release of Ni, Co, and Cr ions from these devices remains an unsolved concern. Surface modification by oxygen plasma immersion implantation (PIII) could be an excellent technique to create a dense and thin passive oxide layer on a relatively complex shape of a tiny device, such as a stent, thus reducing the potential release of metallic ions. The effect of oxygen PIII was investigated on L605 alloy specimens, from 5 to 50 mTorr gas pressures, and under pulsed bias voltages from −0.1 to −10 kV. The surface chemistry was investigated by x-ray photoelectron spectroscopy, while its morphology and surface energy were evaluated, respectively, by atomic force microscopy and scanning electron microscopy and by a sessile drop static contact angle. Electrochemical characterization was performed by potentiodynamic tests in the saline solution. Mechanical properties of the modified surface layer, specifically film adhesion and hardness (H), were assessed by scratch and nanoindentation tests. Results shown that the oxidized layers were composed of a mixture of Co and Cr oxides and hydroxides and were rich in Co. The corrosion rate was considerably reduced after O PIII, even for treatments using low bias voltage (−0.1 kV) and with consequent low oxygen implantation depth. Moreover, O PIII also improved surface hardness. The oxidized layers were found to have good adhesion and to be scratch resistant.
Surface and bulk characterization of reservoir and cap-rocks: Past, present, and future
Authors: Murugesu Manju Pharkavi , Prasad Manika , Pylypenko Svitlana
Published: July 2020

Geologic formations provide potentially some of the largest volume capacities for CO2 storage or sequestration. Potential storage sites can be deep saline aquifers, depleted oil reservoirs, and coal seams, surrounded by sealing layers to prevent CO2 from leaking. It is therefore critical to understand mechanisms contributing to CO2 trapping and CO2 leaks. Both phenomena are governed by reactions at the interfaces of the reservoir and cap-rocks and are controlled by the complex chemistry and pore structures of rocks. Mechanisms at the macroscale are affected by the processes occurring at the nanoscale. This review highlights the necessity of multitechnique, multiscale characterization of rocks and points to the importance of surface analysis and surface science studies. Two shale rocks (seals) from Niobrara and Agardhfjellet formations with complex surface chemistry are used as examples throughout the paper. Typically, evaluation of rocks with x-ray diffraction, thermogravimetric analysis, Rock-Eval pyrolysis, gas adsorption, and electron microscopy combined with energy dispersive x-ray spectroscopy is conducted to provide valuable information about the bulk mineralogy, elemental composition, pore volume, and adsorbed species on the sample surface. These studies are necessary prior to designing surface sensitive experiments with x-ray photoelectron spectroscopy (XPS), guiding both sample preparation and sample analysis. XPS has been widely used to study the surface composition of rocks during the investigations of their fine-scale wettability, and the main findings are highlighted here. This paper also reviews the existing literature on ambient-pressure XPS, which provides new opportunities to study in situ chemical alteration due to interactions with CO2 and offers recommendations for adapting this technique to study rock-fluid interactions, allowing for the identification of fundamental interactions during CO2 sequestration and guide selection of formation sites for improved storage.
A typology of laterals in twelve English dialects
Authors: Kirkham Sam , Turton Danielle , Leemann Adrian
Published: July 2020

Allophonic patterns of variation in English laterals have been well studied in phonetics and phonology for decades, but establishing broad generalizations across varieties has proven challenging. In this study, a typology of onset/coda lateral distinctions in English is advanced using crowdsourced recordings from 95 speakers across twelve dialects of Anglo (UK) English. Results confirm the existence of dialects with and without onset/coda distinctions, and conditional inference trees are used to identify three main patterns in the data: (1) clear onsets and dark codas; (2) intermediate/dark onsets and dark codas, but with a positional distinction intact; and (3) dark onsets and dark codas, with minimal or no distinctions between positions.
Anti-Chikungunya Virus Monoclonal Antibody That Inhibits Viral Fusion and Release
Authors: Tumkosit Uranan , Siripanyaphinyo Uamporn , Takeda Naokazu , Tsuji Motonori , Maeda Yusuke , Ruchusatsawat Kriangsak , Shioda Tatsuo , Mizushima Hiroto , Chetanachan Prukswan , Wongjaroen Pattara , Matsuura Yoshiharu , Tatsumi Masashi , Tanaka Atsushi
Published: July 2020

Recent outbreaks of chikungunya fever have increased its clinical importance. Neither a specific antiviral drug nor a commercial vaccine for CHIKV infection are available. Here, we show a detailed model of the docking between the envelope glycoprotein of CHIKV and our unique anti-CHIKV-neutralizing monoclonal antibody (CHE19), which inhibits CHIKV membrane fusion and virion release from CHIKV-infected cells. Homology modeling of the neutralizing antibody CHE19 and protein-protein docking analysis of the CHIKV envelope glycoprotein and CHE19 suggested that CHE19 inhibits the viral membrane fusion by stabilizing the E2-E1 heterodimer and inhibits virion release by facilitating the formation of virus aggregation due to the connecting virions, and these predictions were confirmed by experiments. Sequence information of CHE19 and the CHIKV envelope glycoprotein and their docking model will contribute to future development of an effective prophylactic and therapeutic agent.
Codon Usage Optimization in the Prokaryotic Tree of Life: How Synonymous Codons Are Differentially Selected in Sequence Domains with Different Expression Levels and Degrees of Conservation
Authors: López José Luis , Lozano Mauricio Javier , Fabre María Laura , Lagares Antonio
Published: July 2020

The prokaryotic genomes—the current heritage of the most ancient life forms on earth—are comprised of diverse gene sets, all characterized by varied origins, ancestries, and spatial-temporal expression patterns. Such genetic diversity has for a long time raised the question of how cells shape their coding strategies to optimize protein demands (i.e., product abundance) and accuracy (i.e., translation fidelity) through the use of the same genetic code in genomes with GC contents that range from less than 20 to more than 80%. Here, we present evidence on how codon usage is adjusted in the prokaryotic tree of life and on how specific biases have operated to improve translation. Through the use of proteome data, we characterized conserved and variable sequence domains in genes of either high or low expression level and quantitated the relative weight of efficiency and accuracy—as well as their interaction—in shaping codon usage in prokaryotes.
Measurement Error and Resolution in Quantitative Stable Isotope Probing: Implications for Experimental Design
Authors: Sieradzki Ella T. , Koch Benjamin J. , Greenlon Alex , Sachdeva Rohan , Malmstrom Rex R. , Mau Rebecca L. , Blazewicz Steven J. , Firestone Mary K. , Hofmockel Kirsten S. , Schwartz Egbert , Hungate Bruce A. , Pett-Ridge Jennifer
Published: July 2020

One of the biggest challenges in microbial ecology is correlating the identity of microorganisms with the roles they fulfill in natural environmental systems. Studies of microbes in pure culture reveal much about their genomic content and potential functions but may not reflect an organism’s activity within its natural community. Culture-independent studies supply a community-wide view of composition and function in the context of community interactions but often fail to link the two. Quantitative stable isotope probing (qSIP) is a method that can link the identity and functional activity of specific microbes within a naturally occurring community. Here, we explore how the resolution of density gradient fractionation affects the error and precision of qSIP results, how they may be improved via additional experimental replication, and discuss cost-benefit balanced scenarios for SIP experimental design.
System Performance Corresponding to Bacterial Community Succession after a Disturbance in an Autotrophic Nitrogen Removal Bioreactor
Authors: Lu Hsiao-Pei , Shao Yung-Hsien , Wu Jer-Horng , Hsieh Chih-hao
Published: July 2020

Dynamics of microbial communities are believed to be associated with system functional processes in bioreactors. However, few studies have provided quantitative evidence. The difficulty of evaluating direct microbe-system relationships arises from the fact that system performance is affected by convolved effects of microbiota and bioreactor operational parameters (i.e., deterministic external physicochemical forcing). Here, using fine-resolution time series data (daily sampling for 2 months) under controlled operational settings, we performed an in-depth analysis of system performance as a function of the microbial community in the context of bioreactor physicochemical conditions. We obtained statistically evaluated results supporting the idea that monitoring microbial community dynamics could improve the ability to predict system functioning, beyond what could be explained by operational physicochemical variables. Moreover, our results suggested that considering the succession of multiple bacterial taxa would account for more system variation than focusing on any particular taxon, highlighting the need to integrate microbial community ecology for understanding system functioning.
Influence of smoking status on acute biomarker responses to successive days of arduous military training
Authors: Siddall A G , Stokes K A , Thompson D , Izard R , Greeves J , Bilzon J L J
Published: July 2020

Introduction

Habitual smoking is highly prevalent in military populations despite its association with poorer training outcomes. Smoking imposes challenges on the immune and endocrine systems which could alter how smokers acutely respond to, and recover from, intensive exercise particularly over multiple days of training.

Methods

Over a two-day period, 35 male British Army recruits (age 22±3 years; mass 76.9±8.0 kg; height 1.78±0.06 m; 15 smokers) completed a 16.1 km loaded march (19.1 kg additional mass) on the first morning and a best-effort 3.2 km‘log race’(carrying a 60 kg log between six and eight people) on the subsequent morning. Blood samples were obtained on waking and immediately postexercise on both days and analysed for C reactive protein (CRP), interleukin 6 (IL-6), testosterone to cortisol ratio and insulin-like growth factor 1 (IGF-1).

Results

Independent of smoking group, the exercise bouts on both days evoked significant increases in IL-6 (p<0.001) and decreases in testosterone to cortisol ratio (p<0.05). CRP concentrations on day 2 were significantly higher than both time points on day 1 (p<0.001), and a 9% decline in IGF-1 occurred over the two-day period, but was not significant (p=0.063). No significant differences were observed between smokers and non-smokers (p>0.05).

Conclusions

Military-specific tasks elicited inflammatory and endocrine responses, with systemic CRP and IGF-1 indicating that the physiological stress generated during the first training day was still evident on the second day. Despite the well-established impacts of smoking on resting levels of the markers examined, responses to two days of arduous military-specific training did not differ by smoking status.