bluuebunny/crossref_metadata_2025 huggingface dataset:
The Metabolome and the Gut Microbiota for the Prediction of Necrotizing Enterocolitis and Spontaneous Intestinal Perforation: A Systematic Review
Authors: Moschino Laura , Verlato Giovanna , Duci Miriam , Cavicchiolo Maria Elena , Guiducci Silvia , Stocchero Matteo , Giordano Giuseppe , Fascetti Leon Francesco , Baraldi Eugenio
Published: September 2022

Necrotizing enterocolitis (NEC) is the most devastating gastrointestinal emergency in preterm neonates. Research on early predictive biomarkers is fundamental. This is a systematic review of studies applying untargeted metabolomics and gut microbiota analysis to evaluate the differences between neonates affected by NEC (Bell’s stage II or III), and/or by spontaneous intestinal perforation (SIP) versus healthy controls. Five studies applying metabolomics (43 cases, 95 preterm controls) and 20 applying gut microbiota analysis (254 cases, 651 preterm controls, 22 term controls) were selected. Metabolomic studies utilized NMR spectroscopy or mass spectrometry. An early urinary alanine/histidine ratio >4 showed good sensitivity and predictive value for NEC in one study. Samples collected in proximity to NEC diagnosis demonstrated variable pathways potentially related to NEC. In studies applying untargeted gut microbiota analysis, the sequencing of the V3–V4 or V3 to V5 regions of the 16S rRNA was the most used technique. At phylum level, NEC specimens were characterized by increased relative abundance of Proteobacteria compared to controls. At genus level, pre-NEC samples were characterized by a lack or decreased abundance of Bifidobacterium. Finally, at the species level Bacteroides dorei, Clostridium perfringens and perfringens-like strains dominated early NEC specimens, whereas Clostridium butyricum, neonatale and Propionibacterium acnei those at disease diagnosis. Six studies found a lower Shannon diversity index in cases than controls. A clear separation of cases from controls emerged based on UniFrac metrics in five out of seven studies. Importantly, no studies compared NEC versus SIP. Untargeted metabolomics and gut microbiota analysis are interrelated strategies to investigate NEC pathophysiology and identify potential biomarkers. Expression of quantitative measurements, data sharing via biorepositories and validation studies are fundamental to guarantee consistent comparison of results.
Effect of the COVID-19 Pandemic on Healthy Components of Diet and Factors Associated with Unfavorable Changes among University Students in France
Authors: Miller Lise , Déchelotte Pierre , Ladner Joel , Tavolacci Marie-Pierre
Published: September 2022

Introduction: The COVID-19 pandemic and the lockdowns have affected many aspects of university students’ daily lives, including their dietary habits. This study aimed to evaluate the change of diet quality of university students before and during the COVID-19 period, and the factors associated with unfavorable changes in diet quality. Methods: An online cross-sectional study was performed in May 2021 among Rouen (France) university students. Socio-demographic characteristics, body mass index, depression, academic stress, risk of eating disorders and food security were collected. The French “Programme National Nutrition Santé-Guidelines Score 2” (PNNS-GS2) was used to access diet quality. Results: A total of 3508 students were included, 74.4% were female, the mean age was 20.7 (SD = 2.3), and 7.0% were in a situation of food insecurity. The PNNS-GS2 score decreased between the pre- and the COVID-19 pandemic period for 33.1% of university students. The associated factors with the decrease in the PNNS-GS2 score were food insecurity, financial insecurity, not living with parents, depression, academic stress, eating disorders, being in the two first years of study and having been infected by COVID-19. Conclusions: Diets with healthy components decreased for one-third of university students since the COVID-19 pandemic, and this was shown to be associated with food insecurity, poor mental health and eating disorder. This study provides important information to help public health authorities and universities give better support to student health feeding programs during pandemics and lockdowns.
Correlations between Fatty Acid Profile and Body Fat Distribution in Postmenopausal Women—A Cross Sectional Study
Authors: Cybulska Anna Maria , Rachubińska Kamila , Skonieczna-Żydecka Karolina , Drozd Arleta , Pawlik Jolanta , Stachowska Ewa , Cymbaluk-Płoska Aneta , Grochans Elżbieta
Published: September 2022

The aim of the study was to assess the fatty acid profile of the whole blood of postmenopausal women, taking into account anthropometric parameters. The study involved 156 healthy women with an average age of 60 (SD = 6.3 years) years who were living in the West Pomerania Province (Poland). An original questionnaire was presented to all patients, conducting anthropometric measurements of them: weight, height, waist and hip circumference, body mass index (BMI), waist–hip ratio (WHR) and body adipose index (BAI), as well as an assessment of the fatty acid profile by employing gas chromatography. It has been observed that in menopausal women, the concentration of C16:1 increases with respect to their BMI (r = 0.205 p = 0.01). Similar correlations were noted with regard to body weight (C16:1 r = 0.177 p = 0.029). It was also shown that the concentration of C18trans11 (r = −0.166 p = 0.039), 18:2n6 (r = −0.165 p = 0.04) and n6/n9 (r = −0.194 p = 0.015) were negatively correlated with respect to their WHR, while the levels C16:1 (r = 0.22 p = 0.006), C18:1n9 (r = 0.22 p = 0.007), C24:1 (r = 0.251 p = 0.002), MUFA (r = 0.227 p = 0.046) and n9 (r = 0.224 p = 0.005) were correlated positively with respect to their BAI. The fatty acid profile of the whole blood of postmenopausal women is modulated to a poor extent by anthropometric variables. Therefore, more prospective research is warranted.
Nova1 or Bim Deficiency in Pancreatic β-Cells Does Not Alter Multiple Low-Dose Streptozotocin-Induced Diabetes and Diet-Induced Obesity in Mice
Authors: Brahma Manoja K. , Xiao Peng , Popa Madalina , Negueruela Javier , Vandenbempt Valerie , Demine Stéphane , Cardozo Alessandra K. , Gurzov Esteban N.
Published: September 2022

The loss of functional pancreatic β-cell mass is an important hallmark of both type 1 and type 2 diabetes. The RNA-binding protein NOVA1 is expressed in human and rodent pancreatic β-cells. Previous in vitro studies indicated that NOVA1 is necessary for glucose-stimulated insulin secretion and its deficiency-enhanced cytokine-induced apoptosis. Moreover, Bim, a proapoptotic protein, is differentially spliced and potentiates apoptosis in NOVA1-deficient β-cells in culture. We generated two novel mouse models by Cre-Lox technology lacking Nova1 (βNova1−/−) or Bim (βBim−/−) in β-cells. To test the impact of Nova1 or Bim deletion on β-cell function, mice were subjected to multiple low-dose streptozotocin (MLD-STZ)-induced diabetes or high-fat diet-induced insulin resistance. β-cell-specific Nova1 or Bim deficiency failed to affect diabetes development in response to MLD-STZ-induced β-cell dysfunction and death evidenced by unaltered blood glucose levels and pancreatic insulin content. In addition, body composition, glucose and insulin tolerance test, and pancreatic insulin content were indistinguishable between control and βNova1−/− or βBim−/− mice on a high fat diet. Thus, Nova1 or Bim deletion in β-cells does not impact on glucose homeostasis or diabetes development in mice. Together, these data argue against an in vivo role for the Nova1-Bim axis in β-cells.
COVID-19 Infection among Nursing Students in Spain: The Risk Perception, Perceived Risk Factors, Coping Style, Preventive Knowledge of the Disease and Sense of Coherence as Psychological Predictor Variables: A Cross Sectional Survey
Authors: Serrano-Gómez Diego , Velasco-González Verónica , Alconero-Camarero Ana Rosa , González-López José Rafael , Antonín-Martín Montserrat , Borras-Santos Alicia , Edo-Gual Montserrat , Gea-Caballero Vicente , Gómez-Urquiza José L. , Meneses-Monroy Alfonso , Montaña-Peironcely Montserrat , Sarabia-Cobo Carmen
Published: September 2022

The exploration of patterns of health beliefs about COVID-19 among nursing students may be beneficial to identify behaviors, attitudes and knowledge about contagion risk. We sought to analyze the variables of risk perception, perceived risk factors, coping style, sense of coherence and knowledge of preventive measures as possible predictors of having suffered from COVID-19. Participants were nursing students from 13 universities in Spain. Sociodemographic and health variables were collected. To test the independent variables, the Perception Risk Coping Knowledge (PRCK-COVID-19) scale was created and validated because there was no specific survey for young people adapted to the pandemic situation of COVID-19. It was validated with adequate psychometric properties. A total of 1562 students (87.5% female, mean age 21.5 ± 5.7 years) responded. The high perception of the risk of contagion, the high level of knowledge and a coping style focused on the situation were notable. Significant differences by gender were found in the coping styles, problem-focused, avoidance and knowledge scales, with women scoring higher in all categories. The multiple regression analysis was significant (F = 3.68; p < 0.001). The predictor variables were the coping styles subscale search for support and the intrinsic and extrinsic perceived risk factors. Our model predicts that nursing students with a social support-based coping style are at a higher risk of becoming infected with COVID-19, based on their own health belief model.
Recent Methods for the Viability Assessment of Bacterial Pathogens: Advances, Challenges, and Future Perspectives
Authors: Trinh Kieu The Loan , Lee Nae Yoon
Published: September 2022

Viability assessment is a critical step in evaluating bacterial pathogens to determine infectious risks to public health. Based on three accepted viable criteria (culturability, metabolic activity, and membrane integrity), current viability assessments are categorized into three main strategies. The first strategy relies on the culturability of bacteria. The major limitation of this strategy is that it cannot detect viable but nonculturable (VBNC) bacteria. As the second strategy, based on the metabolic activity of bacteria, VBNC bacteria can be detected. However, VBNC bacteria sometimes can enter a dormant state that allows them to silence reproduction and metabolism; therefore, they cannot be detected based on culturability and metabolic activity. In order to overcome this drawback, viability assessments based on membrane integrity (third strategy) have been developed. However, these techniques generally require multiple steps, bulky machines, and laboratory technicians to conduct the tests, making them less attractive and popular applications. With significant advances in microfluidic technology, these limitations of current technologies for viability assessment can be improved. This review summarized and discussed the advances, challenges, and future perspectives of current methods for the viability assessment of bacterial pathogens.
SARS-CoV-2 Variants Identification: Overview of Molecular Existing Methods
Authors: Berno Giulia , Fabeni Lavinia , Matusali Giulia , Gruber Cesare Ernesto Maria , Rueca Martina , Giombini Emanuela , Garbuglia Anna Rosa
Published: September 2022

Since the beginning of COVID-19 pandemic the Real Time sharing of genome sequences of circulating virus supported the diagnostics and surveillance of SARS-CoV-2 and its transmission dynamics. SARS-CoV-2 straightaway showed its tendency to mutate and adapt to the host, culminating in the emergence of variants; so it immediately became of crucial importance to be able to detect them quickly but also to be able to monitor in depth the changes on the whole genome to early identify the new possibly emerging variants. In this scenario, this manuscript aims to provide an overview of the existing methods for the identification of SARS-CoV-2 variants (from rapid method based on identification of one or more specific mutations to Whole Genome sequencing approach-WGS), taking into account limitations, advantages and applications of them in the field of diagnosis and surveillance of SARS-CoV-2.
How to Inhibit Nuclear Factor-Kappa B Signaling: Lessons from Poxviruses
Authors: Reus Joshua B. , Rex Emily A. , Gammon Don B.
Published: September 2022

The Nuclear Factor-kappa B (NF-κB) family of transcription factors regulates key host inflammatory and antiviral gene expression programs, and thus, is often activated during viral infection through the action of pattern-recognition receptors and cytokine–receptor interactions. In turn, many viral pathogens encode strategies to manipulate and/or inhibit NF-κB signaling. This is particularly exemplified by vaccinia virus (VV), the prototypic poxvirus, which encodes at least 18 different inhibitors of NF-κB signaling. While many of these poxviral NF-κB inhibitors are not required for VV replication in cell culture, they virtually all modulate VV virulence in animal models, underscoring the important influence of poxvirus–NF-κB pathway interactions on viral pathogenesis. Here, we review the diversity of mechanisms through which VV-encoded antagonists inhibit initial NF-κB pathway activation and NF-κB signaling intermediates, as well as the activation and function of NF-κB transcription factor complexes.
Stability Study, Quantification Method and Pharmacokinetics Investigation of a Coumarin–Monoterpene Conjugate Possessing Antiviral Properties against Respiratory Syncytial Virus
Authors: Nemolochnova Arina G. , Rogachev Artem D. , Salnikova Olga P. , Khomenko Tatyana M. , Volcho Konstantin P. , Yarovaya Olga I. , Fatianova Alina V. , Pokrovsky Andrey G. , Salakhutdinov Nariman F.
Published: September 2022

The stability of a new coumarin derivative, agent K-142, bearing α-pinene residue and possessing antiviral activity against respiratory syncytial virus (RSV) was studied in whole mice blood in vitro, and a method for its quantification in this matrix was developed and validated. The sample preparation method was precipitation of whole blood with a mixture of 0.2 M ZnSO4 with MeOH (2:8 v/v) containing 2-adamantylamine hydrochloride as an internal standard (IS). Analysis was carried out by HPLC-MS/MS using reversed phase chromatography and a triple quadrupole mass spectrometer 6500 QTRAP (SCIEX) in multiple reaction monitoring (MRM) mode. The transitions 351.2 → 217.1 Da and 152.2 → 93.1/107.2 Da were monitored for K-142 and the IS, respectively. The method was validated in terms of selectivity, calibration curve, LLOQ, accuracy and precision, stability, recovery and carry over. The developed method was used for a pharmacokinetics study of the compound after its oral administration to mice at a dose of 20 mg/kg.
The Impact of Low Cardiac Output on Propofol Pharmacokinetics across Age Groups—An Investigation Using Physiologically Based Pharmacokinetic Modelling
Authors: Allegaert Karel , Abbasi Mohammad Yaseen , Michelet Robin , Olafuyi Olusola
Published: September 2022

Background: pathophysiological changes such as low cardiac output (LCO) impact pharmacokinetics, but its extent may be different throughout pediatrics compared to adults. Physiologically based pharmacokinetic (PBPK) modelling enables further exploration. Methods: A validated propofol model was used to simulate the impact of LCO on propofol clearance across age groups using the PBPK platform, Simcyp® (version 19). The hepatic and renal extraction ratio of propofol was then determined in all age groups. Subsequently, manual infusion dose explorations were conducted under LCO conditions, targeting a 3 µg/mL (80–125%) propofol concentration range. Results: Both hepatic and renal extraction ratios increased from neonates, infants, children to adolescents and adults. The relative change in clearance following CO reductions increased with age, with the least impact of LCO in neonates. The predicted concentration remained within the 3 µg/mL (80–125%) range under normal CO and LCO (up to 30%) conditions in all age groups. When CO was reduced by 40–50%, a dose reduction of 15% is warranted in neonates, infants and children, and 25% in adolescents and adults. Conclusions: PBPK-driven, the impact of reduced CO on propofol clearance is predicted to be age-dependent, and proportionally greater in adults. Consequently, age group-specific dose reductions for propofol are required in LCO conditions.
Gene Electrotransfer into Mammalian Cells Using Commercial Cell Culture Inserts with Porous Substrate
Authors: Vindiš Tina , Blažič Anja , Khayyat Diaa , Potočnik Tjaša , Sachdev Shaurya , Rems Lea
Published: September 2022

Gene electrotransfer is one of the main non-viral methods for intracellular delivery of plasmid DNA, wherein pulsed electric fields are used to transiently permeabilize the cell membrane, allowing enhanced transmembrane transport. By localizing the electric field over small portions of the cell membrane using nanostructured substrates, it is possible to increase considerably the gene electrotransfer efficiency while preserving cell viability. In this study, we expand the frontier of localized electroporation by designing an electrotransfer approach based on commercially available cell culture inserts with polyethylene-terephthalate (PET) porous substrate. We first use multiscale numerical modeling to determine the pulse parameters, substrate pore size, and other factors that are expected to result in successful gene electrotransfer. Based on the numerical results, we design a simple device combining an insert with substrate containing pores with 0.4 µm or 1.0 µm diameter, a multiwell plate, and a pair of wire electrodes. We test the device in three mammalian cell lines and obtain transfection efficiencies similar to those achieved with conventional bulk electroporation, but at better cell viability and with low-voltage pulses that do not require the use of expensive electroporators. Our combined theoretical and experimental analysis calls for further systematic studies that will investigate the influence of substrate pore size and porosity on gene electrotransfer efficiency and cell viability.
Optimization of Lipid Nanoparticles by Response Surface Methodology to Improve the Ocular Delivery of Diosmin: Characterization and In-Vitro Anti-Inflammatory Assessment
Authors: Zingale Elide , Rizzo Salvatore , Bonaccorso Angela , Consoli Valeria , Vanella Luca , Musumeci Teresa , Spadaro Angelo , Pignatello Rosario
Published: September 2022

Diosmin is a flavonoid with a great variety of biological activities including antioxidant and anti-inflammatory ones. Its cytoprotective effect in retinal pigment epithelium cells under high glucose conditions makes it a potential support in the treatment of diabetic retinopathy. Despite its benefits, poor solubility in water reduces its potential for therapeutic use, making it the biggest biopharmaceutical challenge. The design of diosmin-loaded nanocarriers for topical ophthalmic application represents a novelty that has not been yet explored. For this purpose, the response surface methodology (RSM) was used to optimize nanostructured lipid carriers (NLCs), compatible for ocular administration, to encapsulate diosmin and improve its physicochemical issues. NLCs were prepared by a simple and scalable technique: a melt emulsification method followed by ultrasonication. The experimental design was composed of four independent variables (solid lipid concentration, liquid lipid concentration, surfactant concentration and type of solid lipid). The effect of the factors was assessed on NLC size and PDI (responses) by analysis of variance (ANOVA). The optimized formulation was selected according to the desirability function (0.993). Diosmin at two different concentrations (80 and 160 µM) was encapsulated into NLCs. Drug-loaded nanocarriers (D-NLCs) were subjected to a physicochemical and technological investigation revealing a mean particle size of 83.58 ± 0.77 nm and 82.21 ± 1.12 nm, respectively for the D-NLC formulation prepared with diosmin at the concentration of 80 µM or 160 µM, and a net negative surface charge (−18.5 ± 0.60 and −18.0 ± 1.18, respectively for the two batches). The formulations were analyzed in terms of pH (6.5), viscosity, and adjusted for osmolarity, making them more compatible with the ocular environment. Subsequently, stability studies were carried out to assess D-NLC behavior under different storage conditions up to 60 days, indicating a good stability of NLC samples at room temperature. In-vitro studies on ARPE-19 cells confirmed the cytocompatibility of NLCs with retinal epithelium. The effect of D-NLCs was also evaluated in-vitro on a model of retinal inflammation, demonstrating the cytoprotective effect of D-NLCs at various concentrations. RSM was found to be a reliable model to optimize NLCs for diosmin encapsulation.
Changes in Perceived Stress of Pharmacy Students Pre- and Mid-COVID-19 Pandemic
Authors: Pham Dylan M. , Yang Jia X. , Lee Kelly C.
Published: September 2022

Objective: The objective of this study was to examine (1) the difference in perceived stress in first-year pharmacy students before and during the COVID-19 pandemic and (2) the difference in perceived stress among pharmacy students working different numbers of hours. Methods: Perceived Stress Scale (PSS), via an electronic survey, was administered throughout 2016–2021 using Qualtrics. End-of-year PSS scores were compared between the pre-pandemic group (2016–2018) and mid-pandemic group (2019–2021) using independent t-test and ANCOVA. All analyses were conducted using IBM SPSS Statistic Version 28.0. Results: A total of 209 first-year pharmacy students participated (response rate of 88%). No significant difference in mean PSS score was detected in the mid-pandemic cohort when compared to pre-pandemic. The mean PSS score was greater in those who worked greater than 10 h weekly compared to those who worked less. Those who did not work had an even greater mean PSS score than those who worked. Conclusions: No significant difference was observed in perceived stress between the pre-pandemic and mid-pandemic cohorts, and an increased perceived stress score was observed in pharmacy students who did not work in comparison to students who worked 1–9 h and 10–29 h.
The Influence of Health Behavior Theory on Implementation Practice and Science: Brief Review and Commentary
Authors: Sales Anne E. , Farr Stacy L. , Spertus John A.
Published: September 2022

As research defines new treatments and policies to improve the health of patients, an increasing challenge has been to translate these insights into routine clinical practice to benefit patients and society. An important exploration is how theories of human behavior change fit into the science of implementation and quality improvement. In this paper, we begin with a brief review of the intellectual roots of implementation science and quality improvement, followed by a discussion of how theories and principles of behavior change can inform both goals and challenges in using behavior change theories. The insights offered through health behavior change theory have led to changes in how we plan for implementation and select, develop, design and tailor implementation interventions and strategies. While the degree to which organizational and external contexts influence the behavior of providers in these organizations varies widely, some degree of context external to the individual is important and needs adequate consideration. In short, health behavior change theory is essential but not sufficient to integrate in most implementation efforts, where priority must be given to both individual factors and contexts in which individuals operate.
Self-Pity as Resilience against Injustice
Authors: Mendonça Dina
Published: September 2022

This paper proposes that being able to feel self-pity is important to be resilient against injustices because it enables self-transformation. The suggestion for this reassessment of self-pity as a crucial self-conscious emotion for a more humanistic world aims to be an example of how philosophical reflection can be insightful for emotion research. The first part of the paper outlines a general introduction of philosophy of emotions and a description of how Hume’s analysis of pride changed its meaning and pertinently linked it to human agency. The second part of the paper is devoted to self-pity and aims to offer a modified interpretation of its experience, ultimately suggesting that it is a way to cultivate resistance and endure injustices in the world. It begins by putting forward the generally accepted take on self-pity and then suggests that dismissing self-pity may increase its duration, and ultimately work as a type of denial of the world’s injustices. After describing how self-pity can be seen as a tour de force where the self is in a relationship of pity with itself, it further elaborates how self-pity may be taken as a type of calibration similar to how sleep works for the functioning organism. This makes it possible to interpret self-pity as a way to resiliently resist injustices while not dismissing them and keeping up the struggle to make the world a better place. Finally, the concluding remarks point out some consequences for the education of emotions and possible future research directions to be explored. Analogously to the undeniable way by which Hume changed the meaning of the emotion of pride, the conclusion hopes that a new way to understand self-pity is available. The overall goal is to amplify the already existing psychological descriptions showing the complementary role of philosophical research for the development of emotion research in general.
Fiber Optic Sensor with a Gold Nanowire Group Array for Broad Range and Low Refractive Index Detection
Authors: Xiao Gongli , Su Jiapeng , Yang Hongyan , Ou Zetao , Li Haiou , Liu Xingpeng , Chen Zanhui , Luo Yunhan , Li Jianqing
Published: September 2022

To achieve high performance and wide range detection, we propose an ultra-wide range high sensitivity plasmonic fiber optic sensor with a gold (Au) nanowire group array, which has both propagating surface plasmon resonance (PSPR) and local surface plasmon resonance (LSPR) sensing characteristics. The PSPR, LSPR, and PSPR+LSPR are presented as Au thin layers, Au spheres (or Au nanowires), and Au nanowire group arrays, respectively, and their respective properties are analyzed from theoretical, simulated, and numerical aspects. When detection is performed, the presence of both evanescent wave and electric field forces in the Au nanowire group array combines to significantly improve the sensor’s detection capability. Detection simulation analysis was performed using COMSOL Multiphysics software. The range of refractive indices that can be detected is 1.08 to 1.37 in the optical band from 1210 nm to 2140 nm. In the detection range, the maximum sensitivity of the detected wavelength is 13,000 nm/RIU. Our proposed sensor has a broad range, high sensitivity, and low refractive index detection, and has good research value and application prospects.
Power Loss Reduction of Angled Metallic Wedge Plasmonic Waveguides via the Interplay between Near-Field Optical Coupling and Modal Coupling
Authors: Liao Yin-Song , Wu Jia-Ren , Thakur Diksha , Hsu Jy-Shan , Dwivedi Ram Prakash , Chang Sheng Hsiung
Published: September 2022

Coupled metallic-wedge nano-plasmonic (CWP) waveguides were predicted as the best building blocks, which can realize ultra-compact and broadband integrated optical circuits (IOCs) due to the localized near-field distributions at the dielectric/metal interfaces. Our simulation results show that the manipulations of the near-field distribution and the near-field modal coupling in CWP waveguides can effectively minimize the power loss by varying the wedge angles, which can avoid the loss from the metallic structure and thereby improving the practical application in IOCs.
High Performance Planar Antimony-Based Superlattice Photodetectors Using Zinc Diffusion Grown by MBE
Authors: Li Jiakai , Saroj R. K. , Slivken Steven , Nguyen V. H. , Brown Gail , Razeghi Manijeh
Published: September 2022

In this letter, we report a mid-wavelength infrared (MWIR) planar photodetector based on InAs/InAs1−xSbx type-II superlattices (T2SLs) that has a cut-off wavelength of 4.3 μm at 77 K. The superlattice for the device was grown by molecular beam epitaxy while the planar device structure was achieved by Zinc diffusion process in a metal–organic chemical vapor deposition reactor. At 77 K, the peak responsivity and the corresponding quantum efficiency had the value of 1.42 A/W and 48% respectively at 3.7 μm under −20 mV for the MWIR planar photodetector. At 77 K, the MWIR planar photodetector exhibits a dark current density of 2.0 × 10−5 A/cm2 and the R0A value of ~3.0 × 102 Ω∙cm2 under −20 mV, which yielded a specific detectivity of 4.0 × 1011 cm·Hz1/2/W at 3.7 μm. At 150 K, the planar device showed a dark current density of 6.4 × 10−5 A/cm2 and a quantum efficiency of 49% at ~3.7 μm under −20 mV, which yielded a specific detectivity of 2.0 × 1011 cm·Hz1/2/W.
Photonic Measurement for Doppler Frequency Shift and Angle of Arrival Based on a Dual-Polarization Dual-Drive Mach–Zehnder Modulator
Authors: Meng Qingqing , Lin Tao , Zhu Zihang , Wang Guodong , Li He , Li Xuan , Yu Longqiang , Zhao Shanghong
Published: September 2022

A novel photonic-assisted system for realizing the simultaneous measurement of Doppler frequency shift (DFS) and angle of arrival (AOA) is proposed. It is a simplified structure that is based on a dual-polarization dual-drive Mach–Zehnder modulator (DPol-DDMZM). The DFS direction can be accurately determined by comparing the phase relationship between the upper and lower low-frequency signal waveforms. An amplitude comparison function (ACF), which constructs a one-to-one mapping between the power ratio and the phase difference of echo microwave signals, can reduce the AOA measurement errors. The simulation results show that the simulated ACFs agree well with the theoretical ACFs, and the measurement errors of AOA are less than ±2.8° in a range of 0° to 78°. Moreover, the DFS can be realized by analyzing the spectrum of the low-frequency electrical signal with a measurement error of less than ±0.05 Hz. The system structure is compact and cost-effective, which provides an alternative solution for modern radar and electronic warfare receivers.
Generation of Photonic Hooks under Point-Source Illumination from Patchy Microcylinders
Authors: Shang Qingqing , Xu Chu , Tang Fen , Li Jiaji , Fan Yao , Yuan Caojin , Wang Zengbo , Zuo Chao , Ye Ran
Published: September 2022

Photonic hook (PH) is a new type of non-evanescent light beam with subwavelength curved structures. It has shown promising applications in super-resolution imaging and has the potential to be used in micromachining, optical trapping, etc. PHs are generally produced by illuminating mesoscale asymmetric particles with optical plane waves. In this work, we used the finite-difference time-domain (FDTD) method to investigate the PH phenomenon under point-source illumination. We found that the PHs can be effectively generated from point-source illuminated patchy particles. By changing the background refractive index, particle diameters and the position and coverage ratio of Ag patches, the characteristics of the PHs can be effectively tuned. Moreover, the structure of the intensity distribution of the light field generated from small and large particles can have an opposite bending direction due to the near-field light-matter interaction.
The Role of Microalgae in the Biogeochemical Cycling of Methylmercury (MeHg) in Aquatic Environments
Authors: Gojkovic Zivan , Skrobonja Aleksandra , Funk Christiane , Garbayo Ines , Vílchez Carlos
Published: September 2022

Methylmercury (MeHg) is the most important and the most abundant organic Hg pollutant in the aquatic ecosystem that can affect human health through biomagnification. It is the most toxic organic Hg form, which occurs naturally and by human-induced contamination in water and is further biomagnified in the aquatic food web. MeHg is the only Hg form that accumulates in living organisms and is able to cross the blood–brain barrier, presenting an enormous health risk. Anthropogenic activity increases eutrophication of coastal waters worldwide, which promotes algae blooms. Microalgae, as primary producers, are especially sensitive to MeHg exposure in water and are an important entrance point for MeHg into the aquatic food web. MeHg assimilated by microalgae is further transferred to fish, wildlife and, eventually, humans as final consumers. MeHg biomagnifies and bioaccumulates in living organisms and has serious negative health effects on humans, especially newborns and children. Knowledge of the microalgae–MeHg interaction at the bottom of the food web provides key insights into the control and prevention of MeHg exposure in humans and wildlife. This review aims to summarize recent findings in the literature on the microalgae–MeHg interaction, which can be used to predict MeHg transfer and toxicity in the aquatic food web.
Microbial Community Succession Associated with Poplar Wood Discoloration
Authors: Zhang Xiaohua , Liu Hao , Han Heming , Zhang Bo , Zhang Cunzhi , He Jian , Li Shunpeng , Cao Hui
Published: September 2022

Microbes are common inhabitants of wood, but little is known about the relationship between microbial community dynamics during wood discoloration. This study uses simulation experiments to examine the changes in the microbial communities in poplar wood at different succession stages. The composition and structure of the microbial communities changed significantly in different successional stages, with an overarching pattern of bacterial diversity decreasing and fungal diversity increasing from the early to the late successional stages. Nevertheless, succession did not affect the composition of the microbial communities at the phylum level: Proteobacteria and Acidobacteria dominated the bacterial communities, while Ascomycota and Basidiomycota dominated the fungal communities. However, at the genus level, bacterial populations of Sphingomonas and Methylobacterium, and fungal populations of Sphaeropsis were significantly more prevalent in later successional stages. Stochastic assembly processes were dominant in the early successional stages for bacteria and fungi. However, variable selection played a more critical role in the assembly processes as succession proceeded, with bacterial communities evolving towards more deterministic processes and fungal communities towards more stochastic processes. Altogether, our results suggest that bacteria and fungi exhibit different ecological strategies in poplar wood. Understanding those strategies, the resulting changes in community structures over time, and the relationship to the different stages of poplar discoloration, is vital to the biological control of that discoloration.
Effect of Stock Plant Growing Medium and Density upon a Cutting Propagation System for Tea Tree, Melaleuca alternifolia
Authors: Lowe Gail E. , Shepherd Mervyn , Rose Terry J. , Raymond Carolyn
Published: September 2022

To offer a viable alternative to seedling deployment of tea tree, clones will require the development of an efficient, robust, and vegetative propagation system for the large number of plants needed for plantations (i.e., typically 33,000 plants/ha). This study investigated the productivity of an intensive management system for tea tree stock plants and rooted cuttings grown in a subtropical environment (Lismore, NSW, Australia). Three stock plant densities (30, 100, and 200 plants/m2) were tested in coir and potting mix media (consisting of peat+perlite+vermiculite), with 11 settings of cuttings undertaken between April 2019 and March 2020. All stock plants in each media type survived 11 harvests and remained productive; however after 13 months, many plants in the coir media, appeared chlorotic and showed symptoms of iron deficiency. Rooting and cutting survival rates using the mini cutting technique were high, ranging from a maximum mean monthly setting value of 87.7% ± 4 at 84 days post-setting in potting mix, to a minimum of 80.4% ± 3.7 in coir. The most productive treatment was at high stock plant density in potting mix which had the potential to produce 13,440 plants/year/m2. Overall coir appeared less productive, but the pattern of difference among treatments was similar. For the highest system productivity, it is recommended to grow stock plants in potting mix at high densities and modulate temperatures to between 18 °C and 28 °C. Late spring and early summer were the best time for harvesting and setting tea tree mini cuttings in the subtropics.
Microhabitat and Pollinator Differentiation Drive Reproductive Isolation between Two Sympatric Salvia Species (Lamiaceae)
Authors: Ling Tial C. , Phokasem Patcharin , Sinpoo Chainarong , Yang Yong-Ping , Disayathanoowat Terd
Published: September 2022

Evaluation of multiple barriers contributing to reproductive isolation between sympatric plant species is key to understanding the mechanism of their coexistence; however, such investigations in biodiversity hotspots are still rare. In this study, we investigated and compared geography, microhabitat, phenology, flora, and pollinators, in addition to pollen–pistil interactions, seed production, and seed germination of the closely related sympatric Salvia digitaloides and S. flava on Yulong Snow Mountain, Southwestern Yunnan, China. The geographic distribution of these species overlapped, but their adaptation to physical and chemical properties of soil microhabitats differed. They shared the same flowering time but differed in flower size, style length, nectar volume, sugar concentration, and flower longevity. Both species shared bumblebees as effective pollinators, but flower constancy for the two species was relatively strong. Pollen tube growth, seed production, and seed germination were lower in interspecific than in intraspecific crosses. Our study suggested that microhabitat and pollinator isolation acted as the most important isolating barriers in maintaining the coexistence of the two Salvia species. Our study also highlighted that post-pollination barriers play an important role in preventing the gene flow between these two Salvia species.
High Temporal Variability in Late Blight Pathogen Diversity, Virulence, and Fungicide Resistance in Potato Breeding Fields: Results from a Long-Term Monitoring Study
Authors: Runno-Paurson Eve , Nassar Helina , Tähtjärv Terje , Eremeev Viacheslav , Hansen Merili , Niinemets Ülo
Published: September 2022

Long-term site-specific studies describing changes in the phenotypic variability of Phytophthora infestans populations allow quantitative predictions of pathogen spread and possible outbreaks of epidemics, and provide key input for regional resistance breeding programs. Late blight samples were collected from potato (Solanum tuberosum) breeding fields in Estonia during a twelve-year study period between 2001 and 2014. In total, 207 isolates were assessed for mating type and 235 isolates for metalaxyl resistance and 251 isolates for virulence factors. The frequency of mating types strongly fluctuated across the years, whereas the later period of 2010–2014 was dominated by the A2 mating. Despite fluctuations, both mating types were recorded in the same fields in most years, indicating sustained sexual reproduction of P. infestans with oospore production. Metalaxyl-resistant and intermediately resistant strains dominated in the first years of study, but with the progression of the study, metalaxyl-sensitive isolates became dominant, reaching up to 88%. Racial diversity, characterized by normalized Shannon diversity index decreased in time, varying from 1.00 in 2003 to 0.43 in 2013. The frequency of several virulence factors changed in a time-dependent manner, with R2 increasing and R6, R8, and R9 decreasing in time. Potato cultivar resistance background did not influence the frequency of P. infestans mating type, response to metalaxyl, and racial diversity. However, the diversity index decreased in time among isolates collected from resistant and susceptible cultivars, and remained at a high level in moderately resistant cultivars. These data demonstrate major time-dependent changes in racial diversity, fungicide resistance, and virulence factors in P. infestans, consistent with alterations in the control strategies and popularity of potato cultivars with different resistance.
Nitrate Leaching Mitigation Options in Two Dairy Pastoral Soils and Climatic Conditions in New Zealand
Authors: Matse Dumsane Themba , Jeyakumar Paramsothy , Bishop Peter , Anderson Christopher W. N.
Published: September 2022

This lysimeter study investigated the effect of late-autumn application of dicyandiamide (DCD), co-poly acrylic-maleic acid (PA-MA), calcium lignosulphonate (LS), a split-application of calcium lignosulphonate (2LS), and a combination of gibberellic acid (GA) and LS (GA + LS) to reduce N leaching losses during May 2020 to December 2020 in lysimeter field sites in Manawatu (Orthic Pumice soil) and Canterbury (Pallic Orthic Brown soil), New Zealand. In a second application, urine-only, GA only and GA + LS treatments were applied during July 2020 in mid-winter on both sites. Results showed that late-autumn application of DCD, 2LS and GA + LS reduced mineral N leaching by 8%, 16%, and 35% in the Manawatu site and by 34%, 11%, and 35% in the Canterbury site, respectively when compared to urine-only. There was no significant increase in cumulative herbage N uptake and yield between urine-treated lysimeters in both sites. Mid-winter application of GA and GA + LS reduced mineral N leaching by 23% and 20%, respectively in the Manawatu site relative to urine-only treated lysimeters, but no significant reduction was observed in the Canterbury site. Our results demonstrated the potential application of these treatments in different soils under different climate and management conditions.
Structured Populations of Critically Endangered Yellow Water Lily (Nuphar shimadai Hayata, Nymphaeaceae)
Authors: Mantiquilla Junaldo A. , Lu Hsueh-Yu , Shih Huei-Chuan , Ju Li-Ping , Shiao Meng-Shin , Chiang Yu-Chung
Published: September 2022

Yellow water lily (Nuphar shimadai Hayata) is a critically endangered species in Taiwan. Here, we examined genetic structures of four extant populations, WP, GPa, GPb and GPn, using 39 simple sequence repeat (SSR) markers. Positive genetic correlation was observed within 50 m, beyond which no correlation was detected due to isolation by distance according to Mantel correlogram. This suggests a significant genetic structuring of the species. Besides, multilocus genotype (MLG) analysis revealed that GPa was a panmictic population and the species’ putative center of origin. Genetic exchange was observed between GPa and GPb populations, which likely resulted from their geographic proximity. Nevertheless, there was a strong asymmetric migration detected from GPa to WP, but a recent genetic barrier prevented dispersal further northward (WP). Geneland estimated the best number of clusters as K = 2, where WP distinctly separated from the rest of the populations. In STRUCTURE output of K = 3, a third cluster was abundant only in WP. We suggest to consider GPn and WP as separate conservation units, being far from GPa. There is indeed a need to investigate these populations; as predicted, Ne = 1.6 to 3.0 is considered low and that may put the species at risk of extinction.
Genetic Containment for Molecular Farming
Authors: Klocko Amy L.
Published: September 2022

Plant molecular farming can provide humans with a wide variety of plant-based products including vaccines, therapeutics, polymers, industrial enzymes, and more. Some of these products, such as Taxol, are produced by endogenous plant genes, while many others require addition of genes by artificial gene transfer. Thus, some molecular farming plants are transgenic (or cisgenic), while others are not. Both the transgenic nature of many molecular farming plants and the fact that the products generated are of high-value and specific in purpose mean it is essential to prevent accidental cross-over of molecular farming plants and products into food or feed. Such mingling could occur either by gene flow during plant growth and harvest or by human errors in material handling. One simple approach to mitigate possible transfer would be to use only non-food non-feed species for molecular farming purposes. However, given the extent of molecular farming products in development, testing, or approval that do utilize food or feed crops, a ban on use of these species would be challenging to implement. Therefore, other approaches will need to be considered for mitigation of cross-flow between molecular farming and non-molecular-farming plants. This review summarized some of the production systems available for molecular farming purposes and options to implement or improve plant containment.
Multi-Walled Carbon Nanotubes Functionalized with Hydroxamic Acid Derivatives for the Removal of Lead from Wastewater: Kinetics, Isotherm, and Thermodynamic Studies
Authors: Al-Faiyz Yasair S. S. , Gouda Mohamed
Published: September 2022

Hydroxamic acids are recognized chelators for various metals; however, using them as functional groups on carbon nanotubes (CNTs) is rare. In this study, novel multi-walled carbon nanotubes (MWCNTs) functionalized with hydroxamic acid derivatives were developed. The MWCNTs were first oxidized, and the resulting product, MWCNT-COOH (A), was treated with oxalyl chloride to yield MWCNT-COCl. The functionalized MWCNTs were susceptible to reacting with the hydroxylamine derivatives of type R–NHOH and produced MWCNTs functionalized with the following hydroxamic acid derivatives (MWCNT-HA): MWCNT-CONOHMe (B), MWCNT-CONOHCOMe(C), and MWCNT-CONOHPh (D). The synthesized derivatives were confirmed by various techniques such as scanning electron microscopy, X-ray photoelectron spectroscopy, and Raman spectroscopy. In order to examine their chelation ability, these materials were examined as possible new adsorbents for harmful Pb(II) particles. The adsorption efficiency of the functionalized MWCNT adsorbents toward Pb(II) was investigated. The effects of the adsorbent dose, temperature, pH, and time on adsorption efficiency were considered, and adsorption boundaries that resulted in enhanced effectiveness were obtained. The developed materials were found to have extraordinary coordination sites, such as amine, hydroxyl, and carboxyl groups, which served as excellent chelating specialists for the Pb(II) particles. Thermodynamic and kinetic investigations revealed the unconstrained nature of the adsorption of Pb(II) by the developed MWCNT adsorbents at room temperature. The adsorption was noted to follow the pseudo-second-order and Langmuir isotherm models.