bluuebunny/crossref_metadata_2025 huggingface dataset:
Antibiotic Decision-Making in the ICU
Authors: Parra-Rodriguez Luis , Guillamet M. Cristina Vazquez
Published: February 2022

It is well established that Intensive Care Units (ICUs) are a focal point in antimicrobial consumption with a major influence on the ecological consequences of antibiotic use. With the high prevalence and mortality of infections in critically ill patients, and the clinical challenges of treating patients with septic shock, the impact of real life clinical decisions made by intensivists becomes more significant. Both under- and over-treatment with unnecessarily broad spectrum antibiotics can lead to detrimental outcomes. Even though substantial progress has been made in developing rapid diagnostic tests that can help guide antibiotic use, there is still a time window when clinicians must decide the empiric antibiotic treatment with insufficient clinical data. The continuous streams of data available in the ICU environment make antimicrobial optimization an ongoing challenge for clinicians but at the same time can serve as the input for sophisticated models. In this review, we summarize the evidence to help guide antibiotic decision-making in the ICU. We focus on 1) deciding if to start antibiotics, 2) choosing the spectrum of the empiric agents to use, and 3) de-escalating the chosen empiric antibiotics. We provide a perspective on the role of machine learning and artificial intelligence models for clinical decision support systems that can be incorporated seamlessly into clinical practice in order to improve the antibiotic selection process and, more importantly, current and future patients' outcomes.
Infections Due to Acinetobacter baumannii–calcoaceticus Complex: Escalation of Antimicrobial Resistance and Evolving Treatment Options
Authors: Lynch Joseph P. , Clark Nina M. , Zhanel George G.
Published: February 2022

Bacteria within the genus Acinetobacter (principally A. baumannii–calcoaceticus complex [ABC]) are gram-negative coccobacilli that most often cause infections in nosocomial settings. Community-acquired infections are rare, but may occur in patients with comorbidities, advanced age, diabetes mellitus, chronic lung or renal disease, malignancy, or impaired immunity. Most common sites of infections include blood stream, skin/soft-tissue/surgical wounds, ventilator-associated pneumonia, orthopaedic or neurosurgical procedures, and urinary tract. Acinetobacter species are intrinsically resistant to multiple antimicrobials, and have a remarkable ability to acquire new resistance determinants via plasmids, transposons, integrons, and resistance islands. Since the 1990s, antimicrobial resistance (AMR) has escalated dramatically among ABC. Global spread of multidrug-resistant (MDR)-ABC strains reflects dissemination of a few clones between hospitals, geographic regions, and continents; excessive antibiotic use amplifies this spread. Many isolates are resistant to all antimicrobials except colistimethate sodium and tetracyclines (minocycline or tigecycline); some infections are untreatable with existing antimicrobial agents. AMR poses a serious threat to effectively treat or prevent ABC infections. Strategies to curtail environmental colonization with MDR-ABC require aggressive infection-control efforts and cohorting of infected patients. Thoughtful antibiotic strategies are essential to limit the spread of MDR-ABC. Optimal therapy will likely require combination antimicrobial therapy with existing antibiotics as well as development of novel antibiotic classes.
Intra-abdominal Infections
Authors: Napolitano Lena M.
Published: February 2022

Intra-abdominal infections (IAIs) are a common cause of sepsis, and frequently occur in intensive care unit (ICU) patients. IAIs include many diagnoses, including peritonitis, cholangitis, diverticulitis, pancreatitis, abdominal abscess, intestinal perforation, abdominal trauma, and pelvic inflammatory disease. IAIs are the second most common cause of infectious morbidity and mortality in the ICU after pneumonia. IAIs are also the second most common cause of sepsis in critically ill patients, and affect approximately 5% of ICU patients. Mortality with IAI in ICU patients ranges from 5 to 50%, with the wide variability related to the specific IAI present, associated patient comorbidities, severity of illness, and organ dysfunction and failures. It is important to have a comprehensive understanding of IAIs as potential causes of life-threatening infections in ICU patients to provide the best diagnostic and therapeutic care for optimal patient outcomes in the ICU.
Sex-Based Difference in Clinical Presentation and Outcomes—A Single-Center Experience
Authors: Anandan Harini , Maharajan Rashmi , Begam Shahina , Victor Suma M.
Published: February 2022

Background and Aim The aim of this study was to compare the gender-based differences in baseline characteristics, clinical presentation, and outcomes among patients who underwent percutaneous coronary intervention (PCI) in our institute.

Methods This is a single-center, retrospective observational study. A total of 1,595 patients underwent PCI from a period of January 2019 to December 2019, in which 1,293 were males and 302 were females. Demographic characteristics, clinical and procedural details, and their in-hospital outcomes were all collected and analyzed.

Results Females presenting with symptoms were older than males (58 vs. 60.8 years, p < 0.001) and had higher body mass index (26.2 ± 6.7 vs. 27.2 ± 4, p < 0.001). Risk factors like diabetes mellitus (57.8 vs. 69.5%, p < 0.001) and systemic hypertension (50.2 vs. 65%, p < 0.001) were more common in females. Women were more likely to present with unstable angina (16.2 vs. 22.7%, p-0.009) and the rate of thrombolysis is low in women who presented with ST-elevation myocardial infarction (13.5 vs. 6.3%, p < 0.001). There was no significant difference in in-hospital mortality between both groups, but bleeding complications were higher in females (1.3 vs. 4%, p-0.006).

Conclusion Women who underwent PCI tend to be older and had higher rates of diabetes, hypertension, and obesity. Although mortality rates did not differ between groups, bleeding risk is higher in women.
Home Monitoring Programs for Patients Testing Positive for SARS-CoV-2: An Integrative Literature Review
Authors: Lara Brenda , Kottler Janey , Olsen Abigail , Best Andrew , Conkright Jessica , Larimer Karen
Published: February 2022

Background The severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) pandemic threatened to oversaturate hospitals worldwide, necessitating rapid patient discharge to preserve capacity for the most severe cases. This need, as well as the high risk of SARS-CoV-2 transmission, led many hospitals to implement remote patient monitoring (RPM) programs for SARS-CoV-2 positive patients in an effort to provide care that was safe and preserve scarce resources.

Objective The aim of this study is to provide an integrative review of peer-reviewed literature on different RPM programs that were implemented for SARS-CoV-2 positive patients including their strengths and challenges.

Methods A search was conducted for peer reviewed literature using PubMed, CINAHL, OVID, and Google Scholar. Peer-reviewed studies written in English or Spanish and published between 2019 and 2021 on RPM of SARS-CoV-2-positive patients were considered. Information was extracted according to a qualitative content analysis method, informed by the Comparison of Mobile Patient Monitoring Systems Framework.

Results Of 57 retrieved articles, 10 publications were included. The sample sizes ranged from 75 to 48,290 and the monitoring length ranged from 7 to 30 days. Information regarding the comparison framework was summarized. Main strengths of using RPM for SARS-CoV-2 positive patients was participant acceptance, feasibility, safety, and resource conservation. Main limitations were the lack of information on patient data security measures, robust outcomes testing, and identification of the most effective biomarkers to track SARS-CoV-2 decompensation.

Conclusion Different RPM programs for SARS-CoV-2 were implemented, from sending home participants with a pulse oximeter and collecting readings via call to modifying existing mobile applications and sending holistic health questionnaires to participants. This review determined that RPM is beneficial to SARS-CoV-2 positive patients; however, its effectiveness can be improved by further research. Mainly, identifying what patient data are most effective at tracking SARS-CoV-2 decompensation by utilizing advanced technology already in the market.
Cystic Echinococcosis of Liver and Spleen Communicating to the Lung: A Rare Case
Authors: Kalita Jitu Mani , Naveenraj Palanisamy , Jain Vidhi , Kumar Deepak , Tak Vibhor , Garg Pawan Kumar , Nag Vijaya Lakshmi
Published: February 2022

The annual cystic echinococcosis (CE) incidence in endemic countries is between 1 and 200 per 100,000 population. The clinical manifestations of CE are associated with damage or dysfunction of target organs and affect primarily the liver in around 70% of cases and lungs in around 20% of cases. The involvement of the spleen is rarely seen, representing 2 to 6% of all CE cases. We describe a 60-year-old female patient who presented with 15 days' history of intermittent fever and abdominal distension, having significant hepatosplenomegaly. CE was diagnosed involving the liver, spleen, and lungs and was confirmed radiologically and microbiologically. CE is caused by the larval or cystic stage of the zoonotic dog-tapeworm. Humans can be infected by ingestion of contaminated food or water. At present, there are nine species under the genus Echinococcus with E. granulosus sensu stricto having worldwide distribution, while the rest are focally distributed. CE involving multiple organs is rare. CE should be taken into consideration in patients with these symptoms in endemic areas.
Association of Serum Cyclophilin A Levels with Severity of Coronary Artery Disease
Authors: Manaswini Namilakonda , Sreedevi Neelam N. , Thummala Sabitha , Saibaba Kompella S.S. , Mohammed Noorjahan , Satish Oruganti Sai
Published: February 2022

Objective The disequilibrium between oxidant and antioxidant systems causes oxidative stress. Further, it disrupts the cell and releases reactive oxygen species (ROS), which in turn damages the vascular functions. Cyclophilin A (CypA), an immunophilin, is released in a highly regulated manner from vascular smooth muscle cells and multiplies the deleterious effects of ROS, associated with cardiovascular diseases. Thus, the aim of the present study is to correlate serum CypA levels with the severity of coronary artery disease (CAD).

Materials and Methods Study participants composed of 103 adult subjects, among whom 73 subjects were cases who were diagnosed as CAD angiographically. Thirty years of age and gender-matched subjects were taken as controls. The cases were further divided into single, double, and triple vessel disease subgroups. Blood samples were collected for the estimation of serum CypA, malondialdehyde (MDA), high-sensitive C-reactive protein (hsCRP), lipid profile, and plasma-glycated hemoglobin (HbA1C) by relevant biochemical methods.

Statistical Analysis The analysis was done using SPSS version 25. The data were expressed as median/mean and interquartile range/standard error. The groups were compared using the Mann–Whitney U-test and the Kruskal–Wallis test. p-Value less than 0.05 was considered statistically significant. Comparison of area under the curve (AUC) in receiver operating characteristic (ROC) curves was performed. A correlation was done by Spearman rank correlation.

Results The mean levels of serum CypA, hsCRP, and MDA in cases were significantly higher than those of controls (38 vs. 27 ng/mL, 18 vs. 5.1 mg/L, and 26 vs. 14 nmol/mL, p < 0.001). A positive correlation was observed between serum levels of CypA versus hsCRP and CypA versus MDA (r = 0.36 p = 0.00, r = 0.52, p = 0.00). At cut-off values greater than 33 ng/mL and 2.1 mg/L, serum CypA and hsCRP have 71% sensitivity, 93% specificity (AUC = 0.83), 84% sensitivity, and 70% specificity (AUC = 0.78) respectively. The number of occluded vessels was positively correlated with both CypA and hsCRP. Also, Serum CypA showed a significant positive correlation with HbA1C.

Conclusion Serum CypA can be used as a valuable biomarker for CAD.
Infective Endocarditis: New Challenges in a Classic Disease
Authors: Cuervo Guillermo , Hernández-Meneses Marta , Falces Carles , Quintana Eduard , Vidal Bárbara , Marco Francesc , Perissinotti Andrés , Carratalà Jordi , Miro Jose M. ,   The Hospital Clinic and the Hospital of Bellvitge Endocarditis Team Investigators
Published: February 2022

Infective endocarditis is a relatively rare, but deadly infection, with an overall mortality of around 20% in most series. Clinical manifestations have evolved in response to significant epidemiological shifts in industrialized nations, with a move toward a nosocomial or health-care-related pattern, in older patients, with more episodes associated with prostheses and/or intravascular electronic devices and a predominance of staphylococcal and enterococcal etiology.

Diagnosis is often challenging and is based on the conjunction of clinical, microbiological, and imaging information, with notable progress in recent years in the accuracy of echocardiographic data, coupled with the recent emergence of other useful imaging techniques such as cardiac computed tomography (CT) and nuclear medicine tools, particularly 18F-fluorodeoxyglucose positron emission/CT.

The choice of an appropriate treatment for each specific case is complex, both in terms of the selection of the appropriate agent and doses and durations of therapy as well as the possibility of using combined bactericidal antibiotic regimens in the initial phase and finalizing treatment at home in patients with good evolution with outpatient oral or parenteral antimicrobial therapies programs. A relevant proportion of patients will also require valve surgery during the active phase of treatment, the timing of which is extremely difficult to define. For all the above, the management of infective endocarditis requires a close collaboration of multidisciplinary endocarditis teams.
Primary Cutaneous Aspergillosis in an Immunocompetent Patient: A Case Report from a Tertiary Care Hospital in Chennai
Authors: Ravichandran Sathyakamala , Shanmugam Priyadarshini , Thayikkannu Ambujavalli Balakrishnan , Elangovan Pradeep
Published: February 2022

Aspergillosis is a systemic fungal infection that commonly affects immunocompromised individuals and, less frequently, immunocompetent individuals. It is the most common opportunistic fungal disease after candidiasis. This is primarily a pulmonary infection and can also involve other body sites like paranasal sinuses and cutaneous tissues. Aspergillus fumigatus, Aspergillus niger, and Aspergillus flavus are the common species infecting humans. Primary cutaneous aspergillosis (PCA) is usually caused by A. flavus and A. fumigatus. It is commonly seen in immunocompromised patients such as those suffering from diabetes, malignancies, tuberculosis, human immunodeficiency virus, or patients on long-term steroids and antibiotics. In this article, we report a case of PCA, in the immediate postoperative period, following a road traffic accident, in an immunocompetent patient. This posed a diagnostic challenge to the treating physicians. A. flavus was confirmed with 10% potassium hydroxide mount, lactophenol cotton blue, and growth on Sabouraud dextrose agar from tissue culture sample. Antifungal treatment was initiated with oral itraconazole 200 mg after performing antifungal susceptibility testing based on Clinical and Laboratory Standards Institute guidelines. The patient's condition improved and was discharged. Thus, early detection of PCA combined with medical and surgical intervention can successfully eradicate infection and help in preventing disseminated aspergillosis.
Overview of Biologic Agents Used in Skin and Soft Tissue Reconstruction
Authors: Parham Matthew J. , Grush Andrew E. , Smerica Abel , Wen Y. Edward , Depani Monal , Ferry Andrew M. , Jones Lloyd M. , Thornton James F.
Published: February 2022

Wound healing is a highly complex process mediated by cellular interactions at the microscopic level. Increased understanding of wound healing physiology has served as the foundation for translational research to develop biologic wound care technologies that have profoundly affected patient care. As the reader will see throughout this series in Seminars in Plastic Surgery, biologic wound technologies have broad applications and have greatly impacted the reconstructive ladder. Despite their frequent use, many surgeons lack familiarity with the myriad of products available on the market along with each product's relative advantages and shortcomings. This overview will discuss the classification of biologic wound agents used to reconstruct defects of the skin and soft tissue along with the advantages and disadvantages associated with their use.
Cerebral Venous Thrombosis
Authors: Aamodt Anne Hege , Skattør Thor Håkon
Published: February 2022

Cerebral venous thrombosis (CVT) is a rare form of stroke that often affects younger age groups, especially reproductive age group females. CVT is a potentially fatal neurological condition that can be frequently overlooked due to the vague nature of its clinical and radiological presentation. Headache is the most common presenting symptom. However, a wide range of symptoms can be present and the symptom onset can be acute, subacute, or chronic. Neuroimaging is mandatory in cases where CVT is suspected. Both magnetic resonance venography and computed tomography venography can confirm a diagnosis of CVT. Anticoagulation with low-molecular-weight heparin is the mainstay of treatment. Intracranial hemorrhage is not considered a contraindication to the use of anticoagulants in CVT. Endovascular intervention is still controversial but can be a treatment option for patients with neurological deterioration or thrombus progression, despite the use of anticoagulation or with development of new or worsening intracerebral hemorrhage. Patients with CVT have an increased risk of recurrence of CVT and other types of venous thromboembolism. This review provides an overview of the epidemiology, diagnosis, and treatment of CVT in adults. Commentary about increased presentation of CVT in patients with coronavirus disease 2019 (COVID-19), or after immunization against COVID-19, is also provided.
Theoretical analysis and comparison of unitary coupled-cluster and algebraic-diagrammatic construction methods for ionization
Authors: Hodecker Manuel , Dempwolff Adrian L. , Schirmer Jochen , Dreuw Andreas
Published: February 2022

This article describes a novel approach for the calculation of ionization potentials (IPs), or, more generally, electron-detachment energies, based on a unitary coupled-cluster (UCC) parameterization of the ground-state wave function. Explicit working equations for a scheme referred to as IP-UCC3 are given, providing electron-detachment energies and spectroscopic amplitudes of electron-detached states dominated by one-hole excitations correct through third order. In the derivation, an expansion of the UCC transformed Hamiltonian involving Bernoulli numbers as expansion coefficients is employed. Both the secular matrix and the effective transition moments are shown to be essentially equivalent to the strict third-order algebraic-diagrammatic construction scheme for the electron propagator (IP-ADC). Interestingly, due to the Bernoulli expansion, neglecting triple substitutions in the UCC expansion manifold does not affect the third-order consistency of the IP-UCC effective transition moments. Finally, the equivalence between ADC and UCC excited-state schemes is shown to not hold in fourth or higher order due to a different treatment of the correlated excited-state basis.
Physics-constrained Bayesian inference of state functions in classical density-functional theory
Authors: Yatsyshin Peter , Kalliadasis Serafim , Duncan Andrew B.
Published: February 2022

We develop a novel data-driven approach to the inverse problem of classical statistical mechanics: Given the experimental data on the collective motion of a classical many-body system, how does one characterize the free energy landscape of that system? By combining non-parametric Bayesian inference with physically motivated constraints, we develop an efficient learning algorithm that automates the construction of approximate free-energy functionals. In contrast to optimization-based machine learning approaches, which seek to minimize a cost function, the central idea of the proposed Bayesian inference is to propagate a set of prior assumptions through the model, derived from physical principles. The experimental data are used to probabilistically weigh the possible model predictions. This naturally leads to humanly interpretable algorithms with full uncertainty quantification of predictions. In our case, the output of the learning algorithm is a probability distribution over a family of free energy functionals, consistent with the observed particle data. We find that surprisingly small data samples contain sufficient information for inferring highly accurate analytic expressions of the underlying free-energy functionals, making our algorithm highly data efficient. In particular, we consider classical particle systems with excluded volume interactions, which are ubiquitous in nature, while being highly challenging in terms of free energy modeling. We validate our approach on the paradigmatic case of one-dimensional fluid and develop inference algorithms for the canonical and grand-canonical statistical–mechanical ensembles. Extensions to higher dimensional systems are conceptually straightforward, while standard coarse-graining techniques allow one to easily incorporate attractive interactions.
Application of aerating techniques for noise suppression in capillary tubes
Authors: Zhang Yu , Liu Yicai , Liu Shiyan , Yao Yao
Published: February 2022

A method for suppressing noise in capillary tubes was developed with aerating techniques. The refrigerant R600a was added to the outlet of a throttling capillary from the end of a transition tube between the capillary and evaporator. To investigate the flow characteristic of R600a in the transition tube, a two-phase flow quasi-steady simulation was performed using the mixture model. The Schnerr–Sauer cavitation model was used, and the turbulence model was realizable k − ɛ. Numerical results show that the local pressure and negative mass transfer rate can both be reduced at the downstream of the capillary where bubbles collapse, when bypass capillaries are used in the aerating model. An experimental system was built to measure the noise in a transition tube with/without a bypass capillary. Results show that the noise sound pressure level decreased by 2 dB on average when aerating techniques were used. This research describes the complex mechanism of the throttling flashing process and provides an effective method to suppress the noise in capillary tubes, which will be beneficial to improve occasional sharp noise in a household refrigerator.
Effect of substrate temperature on sputter-deposited boron carbide films
Authors: Bayu Aji L. B. , Shin S. J. , Bae J. H. , Engwall A. M. , Hammons J. A. , Lepró X. , Catarineu N. , Mirkarimi P. B. , Kucheyev S. O.
Published: February 2022

Sputter deposition of B4C films with tailored physical properties remains a challenge. Here, we systematically study how substrate temperature influences the properties of B4C films deposited by direct current magnetron sputtering onto planar substrates held at temperatures in the range of 100−510°C. Results show that all films are amorphous stoichiometric B4C, with low O content of ∼1 at. %. Films deposited onto substrates at 100°C exhibit high compressive residual stress and decreased mechanical properties. For elevated substrate temperatures in the range of 180−510°C, film mass density, surface roughness, Young’s modulus, and hardness are weakly dependent on substrate temperature. However, in this temperature range, an increase in substrate temperature leads to larger residual compressive stress accompanied by a corresponding reduction in the concentration of nanoscale inhomogeneities. At least for the landing atom ballistics conditions studied here, a substrate temperature range of ∼185−250°C is optimum for growing films with near-zero intrinsic residual stress. The overall weak substrate temperature dependence of film properties revealed in this work is favorable for the development of a robust deposition process, particularly for the case of deposition onto non-planar substrates where temperature control is often challenging.
Data-driven identification of dynamical models using adaptive parameter sets
Authors: Wilson Dan
Published: February 2022

This paper presents two data-driven model identification techniques for dynamical systems with fixed point attractors. Both strategies implement adaptive parameter update rules to limit truncation errors in the inferred dynamical models. The first strategy can be considered an extension of the dynamic mode decomposition with control (DMDc) algorithm. The second strategy uses a reduced order isostable coordinate basis that captures the behavior of the slowest decaying modes of the Koopman operator. The accuracy and robustness of both model identification algorithms is considered in a simple model with dynamics near a Hopf bifurcation. A more complicated model for nonlinear convective flow past an obstacle is also considered. In these examples, the proposed strategies outperform a collection of other commonly used data-driven model identification algorithms including Koopman model predictive control, Galerkin projection, and DMDc.
Pressure-induced transition from pure electronic to mixed ionic-electronic conduction in strontium hydride
Authors: Wang Qinglin , Zhang Haiwa , Duan Susu , Li Peifang , Ou Tianji , Sang Dandan , Zhang Guozhao , Jiao Hui , Zhang Xin , Shi Ying , Li Yinwei , Liu Cailong
Published: February 2022

The heavier alkaline-earth hydrides AeH2 (Ae = Ca, Sr, and Ba) are considered as promising materials for hydrogen energy storage. Pressure-induced structural changes in AeH2 materials could improve hydrogen transport properties and result in a better understanding of the structure-property relationship. In this work, pressure evolution of carrier transport properties of SrH2 was investigated using impedance spectroscopy measurements at room temperature and first-principles calculations. The pressure-induced structure phase transition from a Pnma phase to a P63/mmc phase was accompanied by a transition from pure electronic conduction to mixed ionic-electronic conduction, which was related to the ionic migration barrier energy. In the P63/mmc phase, the H− ionic and electronic resistances of bulk and grain boundaries were distinguished, respectively. The total resistance of SrH2 decreased by about four orders of magnitude after the phase transition. This work provides critical insight into the structure-conduction relationship and the role of grain boundaries in the transport process of alkaline-earth hydrides under high pressure.
Modeling transverse momentum exchange in partially vegetated flow
Authors: Li Dian , Liu Mengyang , Huai Wenxin
Published: February 2022

In this study, theoretical and experimental methods are applied to investigate streamwise velocity profiles and transverse momentum exchange in the quasi-equilibrium region in partially vegetated channels. A new eddy viscosity model is proposed to model the transverse momentum exchange in consideration of bottom turbulence, stem-scale turbulence, and turbulence induced by coherent structures. Results show that turbulence induced by coherent structures is the dominant contributor to the momentum exchange. The proposed eddy viscosity model can be well applied for different setups by varying only one proportionality constant (ξ), which is inversely proportional to the canopy drag (CDa). The lateral distribution of eddy viscosity is also well predicted and shows a peak just outside the canopy. By assuming the canopy as a rough wall and setting the zero-plane displacement within the canopy to the distance of penetration width, we find that the lateral profiles of the mean streamwise velocity in the outer shear layer follow logarithmic curves. A quantitative relationship between roughness length and canopy drag (CDa) is, thus, determined similar to that in turbulent rough-wall boundary layers.
Performance of laser ablation propulsion with a high-repetition rate and high-power laser
Authors: Igarashi Kazuki , Iwasa Momoka , Sasaki Toru , Takahashi Kazumasa , Kikuchi Takashi
Published: February 2022

We investigated the propulsive performance of laser ablation propulsion using a high-power and highly repetitive pulsed laser. We demonstrated 100 shots of burst laser irradiation with an aluminum target using repetition frequencies of 0.017 Hz and 1 kHz. The impulse and plasma exhaust velocities were measured using a pressure sensor and an orifice probe. The momentum-coupling coefficient and the specific impulse were estimated from the aforementioned measurements for every shot. The results showed that the momentum-coupling coefficient increased with highly repetitive laser irradiation. The specific impulse increased with increasing shot number for the case of high-repetition frequency. Therefore, high-repetition operation improves the propulsive performance, especially the specific impulse.
Characterizing modal exponential growth behaviors of self-excited transverse and longitudinal thermoacoustic instabilities
Authors: Zhao Dan , Guan Yiheng
Published: February 2022

Self-excited thermoacoustic instabilities as frequently observed in rocket motors, gas turbines, ramjets, and aeroengine afterburners are highly detrimental and undesirable for engine manufacturers. Conventionally, modal analysis of such combustion instability is conducted by examining the eigenfrequencies. In this work, thermoacoustic dynamics coupling studies are performed as an alternative approach to predict and characterize modal growth behaviors in the presence of transverse and longitudinal combustion instabilities. Unsteady heat release is assumed to depend on the temperature rate of change that results from the chemical reaction. Coupling the unsteady heat release model with traveling waves enables the modal growth rate of acoustic disturbances to be predicted, thus providing a platform to gain insights onto stability behaviors of the combustor. Both modal growth and total energy analyses of acoustic disturbances are performed by linearizing the unsteady heat release model and recasting it into the classical time-lag N−τ formulation with respect to the velocity potential function ϕ. It is shown from both analyses that the amplitude of any acoustic disturbances tends to increase exponentially with time, until the growth rate is limited by some dissipative process ζ. The chemical reaction rate increase with temperature is shown to be unstable with respect to acoustic wave motions. Furthermore, the maximum modal “growth rate” is determined in the absence of acoustic losses, i.e., ζ = 0. The derived maximum growth rate is experimentally confirmed to be greater than those practically measured ones from both Rijke tubes and swirling combustors. A phase drift is also experimentally observed. Finally, the effects of (1) the interaction index N, (2) the time-delay τ, (3) the ratio γ of the specific heats, and (4) the acoustic losses/damping ζ are examined via cases studies. They are found to vary the critical temperature rate of change of the chemical reaction or the critical frequency ωcri above which the combustion system becomes unstable.
Study on the processing characteristics of sapphire wafer polished with different properties plates
Authors: Lin Chen , Xu Yongchao , Wang Qianting
Published: February 2022

To realize the processing demands of the sapphire wafer surface with scratch-free and nano-scale roughness by mechanical polishing, a novel flexible polishing plate was developed by using soft unsaturated resin. The surface characteristics, material removal rate, and residual stress of the sapphire wafer after the flexible polishing process have been compared with those of the sapphire wafer after the rigid polishing process. Both theoretical and simulation analysis results show that the abrasive particles in the flexible polishing exhibit an apparent yielding effect during the polishing course, which contributes to the achievement of plastic flow removal for the wafer surface. The experimental results show that the surface roughness and subsurface damage of the sapphire wafer polished by the flexible polishing process can be decreased by 18.7% and 57.3%, respectively, compared with those of the sapphire wafer polished by the rigid polishing process.
Scanning nitrogen-vacancy center magnetometry in large in-plane magnetic fields
Authors: Welter P. , Rhensius J. , Morales A. , Wörnle M. S. , Lambert C.-H. , Puebla-Hellmann G. , Gambardella P. , Degen C. L.
Published: February 2022

Scanning magnetometry with nitrogen-vacancy (NV) centers in diamond has emerged as a powerful microscopy for studying weak stray field patterns with nanometer resolution. Due to the internal crystal anisotropy of the spin defect, however, external bias fields—critical for the study of magnetic materials—must be applied along specific spatial directions. In particular, the most common diamond probes made from {100}-cut diamond only support fields at an angle of θ=55° from the surface normal. In this paper, we report fabrication of scanning diamond probes from {110}-cut diamond where the spin anisotropy axis lies in the scan plane (θ=90°). We show that these probes retain their sensitivity in large in-plane fields and demonstrate scanning magnetometry of the domain pattern of Co–NiO films in applied fields up to 40 mT. Our work extends scanning NV magnetometry to the important class of materials that require large in-plane fields.
Risk assessment of using phosphate and calcium fertilisers for continuously flooded rice cultivation in a soil co-contaminated with cadmium and antimony
Authors: Shi ShengJie , Wu QianHua , Zhu YanMing , Fan ZhiLian , Rensing Christopher , Liu Hong , Feng RenWei
Published: February 2022

Antimony (Sb) pollution is causing serious concerns in some regions globally, such as around the XiKuangShan mine in China, which is the largest Sb mine in the world. However, remediation measures are scarce. In this study, we assessed the effects of two fertilisers, sodium dihydrogen phosphate (NaH2PO4 at 200, 500 and 2000 mg kg−1) and calcium chloride (CaCl2 at 20, 80 and 200 mg kg−1), on uptake by rice (Oryza sativa L.) of Sb, cadmium (Cd) and arsenic (As) from contaminated soil under flooded conditions. Despite a very low soil As concentration (10.89 mg kg−1), the results showed that flooded conditions will result in excess accumulation of As in rice grains. NaH2PO4 generally enhanced the release of As and Sb by increasing pH and competitive adsorption in the soil, which resulted in their accumulation in many tissues of the rice plants. NaH2PO4 (200 mg kg−1) significantly reduced soil available Cd concentration by increasing soil pH, which resulted in a decrease in Cd concentration in the roots and husks. CaCl2 at 200 mg kg−1 decreased soil pH, and CaCl2 treatments increased the available Sb concentration, although not as much as NaH2PO4. Both NaH2PO4 and CaCl2 enhanced the formation of root iron plaques, and in many cases increased the concentrations of As, Cd and Sb in the root plaques, suggesting a storage role rather than a barrier of root iron plaques for plant uptake of As, Cd and Sb. CaCl2 at 200 mg kg−1 was the most effective treatment for reducing As, Sb and Cd concentrations in rice grains. We conclude that utilisation of fertilisers containing P on a soil co-contaminated by Sb and Cd poses a risk of Sb and As accumulation under continuous flooded conditions, whereas addition of CaCl2 at 200 mg kg−1 may control As, Sb and Cd accumulation in grains of rice plants under these conditions.
Selenium bioconcentration in Canadian oat (Avena sativa) from soils treated with nanoscale elemental selenium
Authors: Zeinali Sahar , Yoon Kyong Sup , Esselman Elizabeth , Lin Zhi-Qing
Published: February 2022

Development of selenium (Se)-enriched agricultural products can increase human daily dietary Se intake in Se-deficient areas. Canadian oat (Avena sativa L. cv. Saddle) is one of the common cereal grains in the world. Previous studies have shown that Se accumulation in oat can be significantly affected by soil Se, but few have dealt with different chemical forms of Se, including emerging nanoscale elemental Se particles (SeNPs). Because SeNPs have unique chemical and physical properties in comparing with bulk elemental Se, this laboratory study determined the effects of soil SeNP treatments of 0, 1, 5, and 10 mg/kg on Se bioconcentration in oat grain, compared with bulk elemental Se or selenate (Na2SeO4). The results showed that the soil SeNP treatments significantly increased Se concentrations in oat grain with an increase in the treatment level from 1 to 10 mg/kg (P < 0.05). The distribution of Se accumulated in oat tissues followed a descending order of root and grain > husk > stem and leaf. While the grain yield was reduced with the higher soil selenate treatments of 5–10 mg/kg, the soil SeNP treatment of 1–10 mg/kg significantly enhanced the oat grain yield, compared with the control. Concentrations of Se in oat grains in the soil SeNP treatments were approximately 7–20-fold higher than were the concentrations of those in the soil bulk elemental Se treatments, but were about 7–26% of the concentrations in oat grains in the soil selenate treatments. This study demonstrated that nanoscale elemental Se particles could be used for development of soil Se-amended fertilisers for Se-biofortified oat.
Effects of environments and cultivars on grain ionome of spring wheat grown in Kazakhstan and Russia
Authors: Morgounov Alexey , Savin Timur , Flis Paulina , Babkenov Adylkhan , Chudinov Vladimir , Kazak Anastasiya , Koksel Hamit , Likhenko Ivan , Sharma Ram , Shelaeva Tatyana , Shepelev Sergey , Shreyder Ekaterina , Shamanin Vladimir
Published: February 2022

Kazakhstan–Siberian Network on Spring Wheat Improvement unites 18 spring wheat (Triticum aestivum L.) research and breeding programs and presents opportunities to study genotype × environment interactions. Trial data from six locations in Kazakhstan and Russia in 2017–18 were used for grain ionomics analysis to evaluate the relative contributions of environment and genotype to variation in elemental composition and to formulate a methodology to enhance concentrations of important minerals in grain. The effect of year was least important to variation. For several elements (P, S, Cu, Mn and Mo), the effect of site was 2–3 times higher than the effect of genotype. The effects of genotype and site were similar for Ca, Mg, Fe, Cd and Sr concentration. Average broad-sense heritability across six sites in both years was: (for macroelements) Mg 0.59 > Ca 0.50 > K 0.44 > P 0.30 > S 0.20; and (for microelements) Zn 0.44 > Mn 0.41 > Cu 0.40 > Fe 0.38. Biplot analysis grouped the traits into five clusters: (1) concentrations of Co, Cu, Mo and Sr; (2) concentrations of Mg, P and Zn; (3) concentrations of K and Ni; (4) protein content, concentrations of Cd, Fe, Mn and S; and (5) grain yield, concentrations of Ca and Rb. These associations reflect regional soil and environment variation independent of genotype. Protein content had positive and significant genotypic correlations with Mg (0.57), P (0.60), S (0.68), Fe (0.64), Cu (0.50), Mn (0.50) and Zn (0.53). A combination of high grain yield, relatively high protein content, and high concentrations of P, S, Mn, Cu and Zn (singly or combined) was identified in the genotypes Element-22 (check cultivar), Lutescens-3-04-21-11, and Silach. The study contributes to research and cultivar development to improve the nutritional profile of grain for consumers.
Trafficking-defective mutant PROKR2 cycles between endoplasmic reticulum and Golgi to attenuate endoplasmic reticulum stress
Authors: Song Yong Bhum , Park Seung-Yeol , Park Kunyou , Hwang Hayoung , Carroll Rona S. , Hsu Victor W. , Kaiser Ursula B.
Published: February 2022

Significance

The endoplasmic reticulum (ER) possesses a quality control system that prevents misfolded proteins from leaving the ER for routing to the ER-associated degradation pathway. Some misfolded proteins can escape the ER to reach the Golgi, where they are then retrieved from the Golgi back to the ER for degradation, but why this occurs needs to be clarified. Studying a mutant prokineticin receptor 2 identified in patients with hypogonadotropic hypogonadism as a model, we find that the post-ER retrieval system provides another layer of quality control and also lowers the load of misfolded proteins in the ER to reduce ER stress. Our findings reveal the importance of a post-ER quality control mechanism in contributing to cellular homeostasis.
A deletion account of referential null objects in Basque Spanish
Authors: Vázquez-Lozares Almike
Published: February 2022

I propose a deletion analysis for null D(irect) O(bject)s in the Spanish of the Basque Country, based on a D(efiniteness)-feature on DO clitics and on Basque-Spanish v. When the DO clitic has a D-feature, as is the case with lo(s)/la(s), its features form a proper subset of the features of v, and deletion of the clitic ensues in terms of a chain reduction à la Nunes (2004), as proposed in Roberts (2010). Importantly, DOs with human antecedents are not deleted because they undergo leísmo. I argue that le does not have a D-feature and, therefore, its features are not a proper subset of the features of v, thus precluding deletion.
Code-mixing and semantico-pragmatic resources in francophone Maine
Authors: Vogh Kendall
Published: February 2022

This chapter reports some results of an exploratory corpus study (Vogh 2018) investigating whether bilingual speakers might use code-mixing to leverage the contextualized meanings (i.e., meanings-in-use) of specific lexical resources that happen to be ‘in the other code’. A total of 206 code-mixed tokens of yeah, yes, ouais, and oui from nine videotaped oral history interviews of Franco-Americans in Maine are considered. Drawing on sociolinguistic, qualitative semantic, and discourse-analytic approaches, I find that the speakers studied do prefer different meanings-in-use for resources from their different languages, suggesting that “what speakers wish to say” (Backus 2001: 150) is indeed a relevant factor in code-mixing and in how bilingual speakers experience their bilingualism.
Ströntistel es min Bloom
Authors: Böhmer Franziska
Published: February 2022

Jens Mungard’s poem Min Bloom is often thought to be the author’s statement that he – by comparing himself with a sea holly – saw himself as an outsider in the community. Some of Mungard’s letters show that he wished to use the “sea holly” as a pseudonym. As one of these letters contains the poem Min Bloom, it is in this case possible that there is a connection between the author and the lyrical speaker. This poem does, however, slightly differ in its original form from the one which is best known today. One changed word modifies the statement of an individual who is excluded from the community. There are three other poems in which Mungard wrote about the sea holly. A comparison of the four poems shows that the lyrical speaker compares and identifies himself with this plant. The sea holly becomes a link between history and the present, it is deep-rooted and can brave outside influences. The lyrical speaker gains strength and comfort from this identification.
Eine strukturelle Untersuchung der „Erzählungen des alten Besenbinders Jens Drefsen“ von Christian Johansen
Authors: Böhmer Mareike
Published: February 2022

The “Erzählungen des alten Besenbinders Jens Drefsen” by Christian Johansen is a complex framework story. The short stories found in it are contained in two frames at different time levels. There are similarities between this story and the “Friesische Sagen und Erzählungen” by Christian Peter Hansen. He also wrote a story with a double frame, and dealt with sagas. Johansen used a few sagas which Hansen had already sent to Karl Müllenhoff, the collector of sagas. It is striking that the German version is freely translated and therefore seems to be an independent story. This fits Johansen’s intention that the story is an example for words and phrases in the Frisian language. Thus, the translation is first of all for a general understanding.
Die niederdeutschen Wenkerübersetzungen aus dem Saterland
Authors: Bosse Temmo
Published: February 2022

There exist in total nine so-called “Wenker questionnaires” from the Saterland, the last linguistic enclave of the East Frisian language, which originate from Georg Wenker’s large dialect survey in the 19th century. Five of these questionnaires contain Frisian linguistic material. The other four document the Low German spoken in the Saterland. This language was above all important for the Sater Frisians as a means of communication with the surrounding areas. A recent study maintains that the Low German spoken by the Sater Frisians exhibits no interference from Frisian. However, in two of the four Low German questionnaires from the Saterland shown here, Frisian elements are clearly recognisable. In this article, the Wenker questionnaires are presented and placed in their historical context.
Zu Semantik und Grammatik des Verbs füünj/fu ‘bekommen’ im Nordfriesischen
Authors: Fleischer Jürg
Published: February 2022

Hoekstra (2018) shows that the North Frisian verb füünj/fu ‘to get’ is used more broadly than its basic meaning suggests. For example, it is also used as a positional verb ‘to put’. In other uses, füünj/fu is best analyzed as a copula or auxiliary. Currently, little is known about possible dialect differences. This question is interesting since contact to Danish is usually considered responsible for the North Frisian semantic expansion of füünj/fu. This article investigates potential dialect differences based on parallel text analyses, i.e. comparisons of texts extant in more than one North Frisian version. This way, differences in the use of füünj/fu can be established. The results suggest that Fering-Öömrang is prone to using fu as an auxiliary and copula, while certain lexical developments are more widespread on the mainland. The North Frisian dialects seem to differ with regard to varying paths of semantic expansion of füünj/fu.
Ritual walks, chronotopic moves
Authors: Jensma Goffe
Published: February 2022

On the basis of a – partially stylometric – analysis of his poetry, this article shows how the work of one of Friesland’s most famous poets, Obe Postma (1868–1963), can best be understood as a series of Bakthinian chronotopes, accounts of simultaneous movements through time and space. Whereas for the reader this procedure results simply in lyrical descriptions of the Frisian countryside throughout its long history, for Postma himself his poetry was also aimed at evoking and reviving his own blissful childhood memories. This was not unlike the way Marcel Proust’s sensations were triggered by his aunt Mathilde’s famous Madeleine biscuits. However, whereas Proust was coincidentally overcome by this sensation, Postma went proactively looking for it. His poems had a real-life equivalent in the ritual countryside strolls he used to take on Sunday afternoons.