bluuebunny/crossref_metadata_2025 huggingface dataset:
Geochemical Characteristics, Zircon U-Pb Ages and Lu-Hf Isotopes of Pan-African Pegmatites from the Larsemann Hills, Prydz Bay, East Antarctica and Their Tectonic Implications
Authors: Zong Shi , Cui Yingchun , Ren Liudong , Zhang Hao , Chen Shaocong , Wang Weixuan , Li Shenggui
Published: December 2023

Prydz Bay is an important part of the Pan-African high-grade tectonic mobile belt. The focus of this investigation, by applying zircon LA-ICP-MS U-Pb geochronology, zircon Lu-Hf isotope systematics, and whole-rock geochemistry, is on Pan-African pegmatites in the Larsemann Hills of Prydz Bay, East Antarctica, their association with country rocks, and the formation conditions. Based on the obtained results, it is concluded that the pegmatites exhibit elevated levels of silica and alkali and possess peraluminous features. These pegmatites originated during the late Neoproterozoic–Early Cambrian (Pan-African) event, specifically in the D2–D4 stages. The D2 stage occurred between 546 and 562 Ma, followed by D3-stage pegmatites around 534 Ma. The pegmatites from the D2–D3 stages are considered to originate from Paleoproterozoic crustal materials, while there are at least two phases of pegmatites in the D4 stage (~517 Ma and ~521 Ma). The D4-1 pegmatite (~521 Ma) suggested both Paleo–Mesoproterozoic crustal origin, perhaps connected to extension. The D4-2 pegmatite (~517 Ma) originated from the crust layers. In the Larsemann Hills, Pan-African pegmatites formed in a recurring regime of tension. Therefore, the obtained data elucidate that a Pan-African stretching process might have occurred in Prydz Bay.
Study on the Relationship between the Structure and Pyrolysis Characteristics of Lignin Isolated from Eucalyptus, Pine, and Rice Straw through the Use of Deep Eutectic Solvent
Authors: Li Tengfei , Jin Xin , Shen Xinyao , Liu Hangdan , Tong Ruiping , Qiu Xuzhen , Xu Junfei
Published: December 2023

Understanding the pyrolysis product distributions of deep eutectic solvent (DES)-isolated lignins (DESLs) from different types of biomass is of great significance for lignin valorization. The structure and pyrolysis properties of DESLs obtained from eucalyptus (E-DESL), pine (P-DESL), and rice straw (R-DESL) were studied through the use of various methods such as elemental analysis, GPC, HS-GC, and NMR techniques, and the pyrolysis characteristics and product distributions of the DESLs were also further investigated through the use of TGA, Py-GC/MS, and tubular furnace pyrolysis. DESLs with high purity (88.5–92.7%) can be efficiently separated from biomass while cellulose is retained. E-DESL has a relatively low molecular weight, and P-DESL has a relatively higher hydrogen–carbon effective ratio and a lower number of condensation structures. The Py-GC/MS results show that, during DESL pyrolysis, the monomeric aromatic hydrocarbons, p-hydroxyphenyl-type phenols, and catechol-type phenols are gradually released when the guaiacyl-type phenols and syringyl-type phenols decrease with the rising temperature. 4-methylguaiacol and 4-methylcatechol, derived from the guaiacyl-type structural units, are positively correlated with temperature, which causes a significant increase in products with a side-chain carbon number of 1 from P-DESL pyrolysis. 4-vinylphenol, as a representative product of the R-DESL, derived from p-hydroxyphenyl-type structural units, also gradually increased. In addition, the P-DESL produces more bio-oil during pyrolysis, while gases have the highest distribution in E-DESL pyrolysis. It is of great significance to study the characteristic product distribution of lignin isolated through the use of DES for lignin directional conversion into specific high-value aromatic compounds.
Isolation of Polyphenols from Aqueous Extract of the Halophyte Salicornia ramosissima
Authors: Fredsgaard Malthe , Tchoumtchoua Job , Kohnen Stephan , Chaturvedi Tanmay , Thomsen Mette Hedegaard
Published: December 2023

Polyphenols from residual non-food grade Salicornia ramosissima have health-promoting effects in feed, food, or nutraceutical applications. Therefore, the isolation of polyphenols is of interest from a series of environmentally friendly isolation methods with recyclable solvents. The isolation of polyphenols from non-food grade S. ramosissima was investigated using sequential membrane filtration with and without acid pretreatment, liquid–liquid extraction, resin adsorption, and centrifugal partition chromatography (CPC); analyzed by the Folin–Ciocalteu assay for total polyphenols; and finally analyzed using UPLC-TQMS in negative ion-spray mode for detection of 14 polyphenols. Sequential membrane filtration and acid hydrolysis indicated the polyphenols forming complexes with other compounds, retaining the polyphenols in the retentate fraction of large molecular weight cut-off membrane sizes. Conventional liquid–liquid extraction using sequential ethyl acetate and n-butanol showed most polyphenols were extracted, apart from chlorogenic acids, indicating a low isolation efficiency of higher polarity polyphenols. Analysis of the extract after resin adsorption by Amberlite XAD-4 resin showed high efficiency for separation, with 100% of polyphenols adsorbed to the resin after 13 bed volumes and 96.7% eluted from the resin using ethanol. CPC fractionations were performed to fractionate the concentrated extract after resin adsorption. CPC fractionations of the 14 polyphenols were performed using an organic or aqueous phase as a mobile phase. Depending on the mobile phase, different compounds were isolated in a high concentration. Using these easily scalable methods, it was possible to comprehensively study the polyphenols of interest from S. ramosissima and their isolation mechanics. This study will potentially lead the way for the large-scale isolation of polyphenols from S. ramosissima and other complex halophytes. The compounds of the highest concentration after CPC fractionation were isoquercitrin and hyperoside (155.27 mg/g), chlorogenic acid (85.54 mg/g), cryptochlorogenic acid (101.50 mg/g), and protocatechuic acid (398.67 mg/g), and further isolation using CPC could potentially yield novel polyphenol nutraceuticals.
5-Oxo-ETE/OXER1: A Link between Tumor Cells and Macrophages Leading to Regulation of Migration
Authors: Kalyvianaki Konstantina , Salampasi Evangelia Maria , Katsoulieris Elias N. , Boukla Eleni , Vogiatzoglou Amalia P. , Notas George , Castanas Elias , Kampa Marilena
Published: December 2023

Chronic inflammation is an important factor in the development of cancer. Macrophages found in tumors, known as tumor associated macrophages (TAMs), are key players in this process, promoting tumor growth through humoral and cellular mechanisms. 5-oxo-6,8,11,14-eicosatetraenoic acid (5-oxo-ETE), an arachidonic acid metabolite, has been described to possess a potent chemoattractant activity for human white blood cells (WBCs). The biological actions of 5-oxo-ETE are mediated through the GPCR 5-oxo-6E,8Z,11Z,14Z-eicosatetraenoic acid receptor (OXER1). In addition, we have previously reported OXER1 as one of the membrane androgen receptors with testosterone antagonizing 5-oxo-ETE’s actions. OXER1 is highly expressed in inflammatory cells and many normal and cancer tissues and cells, including prostate and breast cancer, promoting cancer cell survival. In the present study we investigate the expression and role of OXER1 in WBCs, THP-1 monocytes, and THP-1 derived macrophages, as well as its possible role in the interaction between macrophages and cancer cells (DU-145 and T47D). We report that OXER1 is differentially expressed between WBCs and macrophages and that receptor expression is modified by LPS treatment. Our results show that testosterone and 5-oxo-ETE can act in an antagonistic way affecting Ca2+ movements, migration, and cytokines’ expression in immune-related cells, in a differentiation-dependent manner. Finally, we report that 5-oxo-ETE, through OXER1, can attract macrophages to the tumor site while tumor cells’ OXER1 activation in DU-145 prostate and T47D breast cancer cells, by macrophages, induces actin cytoskeletal changes and increases their migration.
MVNMDA: A Multi-View Network Combing Semantic and Global Features for Predicting miRNA–Disease Association
Authors: Yang Chen , Wang Zhen , Zhang Shanwen , Li Xiaoqian , Wang Xuqi , Liu Jiashan , Li Ruixiang , Zeng Sihao
Published: December 2023

A growing body of experimental evidence suggests that microRNAs (miRNAs) are closely associated with specific human diseases and play critical roles in their development and progression. Therefore, identifying miRNA related to specific diseases is of great significance for disease screening and treatment. In the early stages, the identification of associations between miRNAs and diseases demanded laborious and time-consuming biological experiments that often carried a substantial risk of failure. With the exponential growth in the number of potential miRNA-disease association combinations, traditional biological experimental methods face difficulties in processing massive amounts of data. Hence, developing more efficient computational methods to predict possible miRNA-disease associations and prioritize them is particularly necessary. In recent years, numerous deep learning-based computational methods have been developed and have demonstrated excellent performance. However, most of these methods rely on external databases or tools to compute various auxiliary information. Unfortunately, these external databases or tools often cover only a limited portion of miRNAs and diseases, resulting in many miRNAs and diseases being unable to match with these computational methods. Therefore, there are certain limitations associated with the practical application of these methods. To overcome the above limitations, this study proposes a multi-view computational model called MVNMDA, which predicts potential miRNA-disease associations by integrating features of miRNA and diseases from local views, global views, and semantic views. Specifically, MVNMDA utilizes known association information to construct node initial features. Then, multiple networks are constructed based on known association to extract low-dimensional feature embedding of all nodes. Finally, a cascaded attention classifier is proposed to fuse features from coarse to fine, suppressing noise within the features and making precise predictions. To validate the effectiveness of the proposed method, extensive experiments were conducted on the HMDD v2.0 and HMDD v3.2 datasets. The experimental results demonstrate that MVNMDA achieves better performance compared to other computational methods. Additionally, the case study results further demonstrate the reliable predictive performance of MVNMDA.
PPy-Coated Mo3S4/CoMo2S4 Nanotube-like Heterostructure for High-Performance Lithium Storage
Authors: Tang Fei , Jiang Wei , Xie Jingjing , Zhao Deyang , Meng Yanfeng , Yang Zhenglong , Lv Zhiqiang , Xu Yanbin , Sun Wenjuan , Jiang Ziqiao
Published: December 2023

Heterostructured materials show great potential to enhance the specific capacity, rate performance and cycling lifespan of lithium-ion batteries owing to their unique interfaces, robust architectures, and synergistic effects. Herein, a polypyrrole (PPy)-coated nanotube-like Mo3S4/CoMo2S4 heterostructure is prepared by the hydrothermal and subsequent in situ polymerization methods. The well-designed nanotube-like structure is beneficial to relieve the serious volume changes and facilitate the infiltration of electrolytes during the charge/discharge process. The Mo3S4/CoMo2S4 heterostructure could effectively enhance the electrical conductivity and Li+ transport kinetics owing to the refined energy band structure and the internal electric field at the heterostructure interface. Moreover, the conductive PPy-coated layer could inhibit the obvious volume expansion like a firm armor and further avoid the pulverization of the active material and aggregation of generated products. Benefiting from the synergistic effects of the well-designed heterostructure and PPy-coated nanotube-like architecture, the prepared Mo3S4/CoMo2S4 heterostructure delivers high reversible capacity (1251.3 mAh g−1 at 300 mA g−1), superior rate performance (340.3 mAh g−1 at 5.0 A g−1) and excellent cycling lifespan (744.1 mAh g−1 after 600 cycles at a current density of 2.0 A g−1). Such a design concept provides a promising strategy towards heterostructure materials to enhance their lithium storage performances and boost their practical applications.
Virtual Reality Assessment of Attention Deficits in Traumatic Brain Injury: Effectiveness and Ecological Validity
Authors: Malegiannaki Amaryllis-Chryssi , Garefalaki Evangelia , Pellas Nikolaos , Kosmidis Mary H.
Published: January 2024

Early detection is crucial for addressing attention deficits commonly associated with Traumatic brain injury (TBI), informing effective rehabilitation planning and intervention. While traditional neuropsychological assessments have been conventionally used to evaluate attention deficits, their limited ecological validity presents notable challenges. This study explores the efficacy and validity of a novel virtual reality test, the Computerized Battery for the Assessment of Attention Disorders (CBAAD), among a cohort of TBI survivors (n = 20), in comparison to a healthy control group (n = 20). Participants, ranging in age from 21 to 62 years, were administered a comprehensive neuropsychological assessment, including the CBAAD and the Attention Related Cognitive Errors Scale. While variations in attentional performance were observed across age cohorts, the study found no statistically significant age-related effects within either group. The CBAAD demonstrated sensitivity to attentional dysfunction in the TBI group, establishing its value as a comprehensive test battery for assessing attention in this specific population. Regression analyses demonstrated the CBAAD’s effectiveness in predicting real-life attentional errors reported by TBI patients. In summary, the CBAAD demonstrates sensitivity to attentional dysfunction in TBI patients and the ability to predict real-world attentional errors, establishing its value as a comprehensive test battery for assessing attention in this specific population. Its implementation holds promise for enhancing the early identification of attentional impairments and facilitating tailored rehabilitation strategies for TBI patients.
Determining the Dependence of Single Nitrogen−Vacancy Center Light Extraction in Diamond Nanostructures on Emitter Positions with Finite−Difference Time−Domain Simulations
Authors: Zhu Tianfei , Zeng Jia , Wen Feng , Wang Hongxing
Published: December 2023

In this study, we obtained a diamond nanocone structure using the thermal annealing method, which was proposed in our previous work. Using finite–difference time–domain (FDTD) simulations, we demonstrate that the extraction efficiencies of nitrogen–vacancy (NV) center emitters in nanostructures are dependent on the geometries of the nanocone/nanopillar, emitter polarizations and axis depths. Our results show that nanocones and nanopillars have advantages in extraction from emitter dipoles with s− and p−polarizations, respectively. In our simulations, the best results of collection efficiency were achieved from the emitter in a nanocone with s−polarization (57.96%) and the emitter in a nanopillar with p−polarization (38.40%). Compared with the nanopillar, the photon extraction efficiency of the emitters in the nanocone is more sensitive to the depth and polarization angle. The coupling differences between emitters and the nanocone/nanopillar are explained by the evolution of photon propagation modes and the internal reflection effects in diamond nanostructures. Our results could have positive impacts on the design and fabrication of NV center−based micro− and nano−optics in the future.
The Association between Caffeine Consumption from Coffee and Tea and Sleep Health in Male and Female Older Adults: A Cross-Sectional Study
Authors: van der Linden Mette , Olthof Margreet R. , Wijnhoven Hanneke A. H.
Published: December 2023

Poor sleep health is common in older adults and is associated with negative health outcomes. However, the relationship between caffeine consumption and sleep health at an older age is poorly understood. This study investigated the association between caffeine consumption and sleep health in community-dwelling older males and females in The Netherlands. Cross-sectional analyses were performed using data from 1256 participants aged 61–101 years from the Longitudinal Ageing Study Amsterdam. Self-reported questions assessed sleep disturbances (including sleep latency, continuity, and early awakening), sleep duration, and perceived sleep quality. Caffeine consumption was determined with questions about frequency, quantity, and type of coffee and tea consumption. Logistic and linear regression models were used, controlling for potential confounders, and interaction by sex and age was tested. Caffeine consumption showed significant interactions with sex (p < 0.005) in association with sleep health outcomes. Older females who abstained from caffeine consumption reported more sleep disturbances (β = 0.64 [95%CI 0.13; 1.15]) and had greater odds of short sleep duration (<7 h/day) (OR = 2.26 [95% CI 1.22; 4.20]) compared to those who consumed caffeine. No associations were observed for long sleep duration (>8 h/day) and perceived sleep quality. No associations were observed in older males. Caffeine abstinence was associated with more sleep disturbances and short sleep duration in older females, but not in males. The observed association in older females may reflect reverse causation, suggesting that females may have different motivations for discontinuing caffeine consumption than males.
Vitamin D and K Supplementation Is Associated with Changes in the Methylation Profile of U266-Multiple Myeloma Cells, Influencing the Proliferative Potential and Resistance to Bortezomib
Authors: Łuczkowska Karolina , Kulig Piotr , Baumert Bartłomiej , Machaliński Bogusław
Published: December 2023

Multiple myeloma (MM) is a plasma cell malignancy that, despite recent advances in therapy, continues to pose a major challenge to hematologists. Currently, different classes of drugs are applied to treat MM, among others, proteasome inhibitors, immunomodulatory drugs, and monoclonal antibodies. Most of them participate in an interplay with the immune system, hijacking its effector functions and redirecting them to anti-MM activity. Therefore, adjuvant therapies boosting the immune system may be potentially beneficial in MM therapy. Vitamin D (VD) and vitamin K (VK) have multiple so called “non-classical” actions. They exhibit various anti-inflammatory and anti-cancer properties. In this paper, we investigated the influence of VD and VK on epigenetic alterations associated with the proliferative potential of MM cells and the development of BTZ resistance. Our results showed that the development of BTZ resistance is associated with a global decrease in DNA methylation. On the contrary, both control MM cells and BTZ-resistant MM cells exposed to VD alone and to the combination of VD and VK exhibit a global increase in methylation. In conclusion, VD and VK in vitro have the potential to induce epigenetic changes that reduce the proliferative potential of plasma cells and may at least partially prevent the development of resistance to BTZ. However, further ex vivo and in vivo studies are needed to confirm the results and introduce new supplementation recommendations as part of adjuvant therapy.
Adherence to Dietary Recommendations in Organized Living Beneficiaries with Severe Mental Disorders and Their Caregivers
Authors: Šoher Lidija , Cvijetić Stokanović Milica , Prša Sara , Miškulin Maja , Kenjerić Daniela
Published: December 2023

People with severe mental disorders often require special care. Other than institutionalized care, some organizations provide housing options and special care in the form of organized living. Few studies provide a detailed description of nutrient intake in this type of care. The aim of this prospective study was to assess nutritional status and adherence to dietary recommendations in both people with mental disorders (beneficiaries) and their caregivers. Across three levels of care, 46 beneficiaries and 19 caregivers participated in the study. The mean intakes of energy (kcal/day) and macro- and micronutrients (g/day) were estimated from a 3-day dietary record and compared with dietary reference values (DRVs) set by the European Food Safety Authority (EFSA). The majority of participants did not meet energy intake recommendations (kcal/day). The contribution of total fat to energy intake (% E) was higher than recommended in both beneficiaries and caregivers with 42.1 ± 4.4% and 38.5 ± 6.5%, respectively. A total of 45.2% of beneficiaries and 61.1% of caregivers had their carbohydrate intake within the recommended range. Fiber intake was well below the recommendations (25 g/day) in all groups. Across all levels of care, lower micronutrient intake for pantothenic acid, biotin, folate, potassium, magnesium, copper, selenium, and iodine was observed. Based on the current results, the development and implementation of nutritional guidelines may be targeted to specific populations and nutrient intakes.
The Effect of Vitamin D Supplementation in Pregnant Women with Overweight and Obesity: A Randomised Controlled Trial
Authors: Ku Chee Wai , Lee Angeline Jia Wen , Oh Benjarat , Lim Celeste Hong Fei , Chang Ting Yu , Yap Fabian , Chan Jerry Kok Yen , Loy See Ling
Published: December 2023

The impact of vitamin D supplementation on 25-hydroxyvitamin D (25OHD) levels, metabolic status, and pregnancy outcomes in pregnant women with overweight and obesity (OW/OB) is uncertain. This study aimed to examine whether administrating 800 IU of vitamin D3 orally would improve maternal serum 25OHD levels, lipid profile, and pregnancy outcomes compared to 400 IU. This was a two-arm, parallel, non-blinded randomised controlled trial involving 274 pregnant women recruited from KK Women’s and Children’s Hospital, with a body mass index of ≥25 kg/m2 within 16 weeks gestation. The participants were randomly assigned to receive 800 IU/day (intervention group) or 400 IU/day (control group) of oral vitamin D3 supplements. The primary outcomes were maternal serum 25OHD and lipid levels at 24–28 weeks gestation. The secondary outcomes included maternal and birth outcomes. Compared with controls (n = 119), the intervention group (n = 112) exhibited higher 25OHD levels at 24–28 weeks gestation (adjusted mean difference 6.52 nmol/L; 95% confidence interval 2.74, 10.31). More women in the intervention group achieved sufficient 25OHD levels (77.7% vs. 55.5%; p < 0.001). No differences were observed in lipid profiles or maternal or birth outcomes between the groups. An additional 400 IU of oral vitamin D3 supplementation increased serum 25OHD levels but did not impact lipid profiles or pregnancy outcomes.
Evidence of West Nile Virus Circulation in Horses and Dogs in Libya
Authors: Ben-Mostafa Kholoud Khalid , Savini Giovanni , Di Gennaro Annapia , Teodori Liana , Leone Alessandra , Monaco Federica , Alaoqib Mohammed Masoud A. , Rayes Abdunnabi A. , Dayhum Abdunaser , Eldaghayes Ibrahim
Published: December 2023

West Nile virus (WNV) is a globally significant mosquito-borne Flavivirus that causes West Nile disease (WND). In Libya, evidence of WNV circulation has been reported in humans but never in animals. The aim of this study was to determine the seroprevalence of WNV infection in horses and dogs in Libya. In total, 574 and 63 serum samples were collected from apparently healthy, unvaccinated horses and dogs, respectively, between 2016 and 2019. A commercially available competitive enzyme-linked immunosorbent assay (c-ELISA) kit was initially used to test the collected samples for the presence of WNV Ig-G antibodies. Positive and doubtful sera were also tested using a more specific virus neutralisation assay to confirm whether the ELISA-positive results were due to WNV or other Flavivirus antibodies. The seroprevalence of WNV IgG antibodies according to ELISA was 13.2% out of 574 of total horses’ samples and 30.2% out of 63 of total dogs’ samples. The virus neutralisation test (VNT) confirmed that 10.8% (62/574) and 27% (17/63) were positive for WNV-neutralising titres ranging from 1:10 to 1:640. Univariable analysis using chi-square tests was conducted to measure the statistical significance of the association between the hypothesized risk factors including city, sex, breed, and age group and were then analyzed using the subsequent multivariable logistic regression model for horse samples. Age group was found to be the only significant risk factor in this study. The results of the present study provide new evidence about WNV circulation in Libya.
Anti-Hcp1 Monoclonal Antibody Is Protective against Burkholderia pseudomallei Infection via Recognizing Amino Acids at Asp95-Leu114
Authors: Wu Pan , Rao Chenglong , Liu Wenzheng , Zhang Ziyuan , Nan Dongqi , Chen Jiangao , Wang Minyang , Wen Yuan , Yan Jingmin , Yue Juanjuan , Mao Xuhu , Li Qian
Published: December 2023

Melioidosis, a severe tropical illness caused by Burkholderia pseudomallei, poses significant treatment challenges due to limited therapeutic options and the absence of effective vaccines. The pathogen’s intrinsic resistance to numerous antibiotics and propensity to induce sepsis during acute infections further complicate management strategies. Thus, exploring alternative methods for prevention and treatment is crucial. Monoclonal antibodies (mAbs) have emerged as a promising strategy for the prevention and treatment of infectious diseases. This study focused on generating three mAbs (13F1, 14G11, and 15D9) targeting hemolysin-coregulated protein 1 (Hcp1), a protein involved in the type VI secretion system cluster 1 (T6SS1) of B. pseudomallei. Notably, pretreatment with 13F1 mAb significantly reduced the intracellular survival of B. pseudomallei and inhibited the formation of macrophage-derived multinucleated giant cells (MNGCs). This protective effect was also observed in vivo. We identified a sequence of amino acids (Asp95-Leu114) within Hcp1 as the likely binding site for 13F1 mAb. In summary, our findings reveal that 13F1 mAb counteracts infection by targeting Hcp1, offering potential new targets and insights for melioidosis prevention.
Examining the Antioxidant and Superoxide Radical Scavenging Activity of Anise, (Pimpinella anisum L. Seeds), Esculetin, and 4-Methyl-Esculetin Using X-ray Diffraction, Hydrodynamic Voltammetry and DFT Methods
Authors: Rossi Miriam , Caruso Francesco , Thieke Natalie , Belli Stuart , Kim Alana , Damiani Elisabetta , Morresi Camilla , Bacchetti Tiziana
Published: December 2023

Pimpinella anisum L., or anise, is a plant that, besides its nutritional value, has been used in traditional medical practices and described in many cultures in the Mediterranean region. A possible reason for anise’s therapeutic value is that it contains coumarins, which are known to have many biomedical and antioxidant properties. HPLC analysis in our laboratory of the anise extract shows the presence of the coumarin esculetin. We used a hydrodynamic voltammetry rotating ring–disk electrode (RRDE) method to measure the superoxide scavenging abilities of anise seeds and esculetin, which has marked scavenging activity. A related coumarin, 4-methyl-esculetin, also showed strong antioxidant activity as measured by RRDE. Moreover, this study includes the X-ray crystal structure of esculetin and 4-methyl-esculetin, which reveal the H-bond and the stacking intermolecular interactions of the two coumarins. Coordinates of esculetin crystal structure were used to perform a DFT study to arrive at the mechanism of superoxide scavenging. Besides performing a H(hydroxyl) abstraction in esculetin position 6 by superoxide, the scavenging also includes the presence of a second superoxide radical in a π–π approach. Both rings of esculetin were explored for this attack, but only the pyrone ring was effective. As a result, one product of esculetin scavenging is H2O2 formation, while the second superoxide remains π–π trapped within the pyrone ring to form an esculetin-η-O2 complex. Comparison with other coumarins shows that subtle structural differences in the coumarin framework can imply marked differences in scavenging. For instance, when the catechol moiety of esculetin (position 6,7) is shifted to position 7,8 in 4-methyl-7,8-dihydroxy coumarin, that coumarin shows a superoxide dismutase action, which, beside H2O2 formation, includes the formation and elimination of a molecule of O2. This is in contrast with the products formed through esculetin superoxide scavenging, where a second added superoxide remains trapped, and forms an esculetin-η-O2 complex.
Designing a Long Optical Path Direct-Injection-Integrated Cavity for Laser Absorption Spectroscopy
Authors: Gao Quyouyang , Zheng Yuquan , Wang Long , Li Chengliang , Zhang Jialun , Wu Hao , Han Yanxue , Wang Shuo
Published: December 2023

Trace gas measurement has a wide range of applications needed in industrial, medical, and environmental protection. With the evolution of time, the demand for real-time, sensitivity, and accuracy of gas detection has been increasingly heightened. Off-axis integrated cavity output spectroscopy (OA-ICOS) is an effective method for the high-sensitivity detection of trace gases. It uses an integrated cavity with two highly reflective mirrors to provide a long optical path, which guarantees its high sensitivity. However, as the reflectivity of the mirrors increases, the intensity of the output light decreases, and the signal-to-noise ratio decreases. This contradiction makes it difficult to achieve a long optical path and a high signal-to-noise ratio together. To combat this issue, this paper proposes a type of integrated cavity using a direct-injection method. This structure, under equivalent mirror conditions, can maintain an effective absorption optical path very close to the original off-axis integrated cavity while increasing the output light intensity hundreds of times. This enhancement increases the sensitivity of OA-ICOS.
Nonlinear Scattering of 248 nm Wavelength Light in High-Pressure SF6 and CH4 Gases for the Temporal Compression of a 20 ns KrF Laser Pulse
Authors: Zvorykin Vladimir D. , Metreveli Gocha E. , Smetanin Igor’ V. , Shutov Alexey V. , Ustinovskii Nikolay N. , Veliev Polad V.
Published: December 2023

The nonlinear compression of narrowband (Δν ≈ 0.2 cm−1) 20 ns KrF laser pulses in SF6 at 10 atm and in CH4 at 50 atm pressure was studied. Both SBS and SRS optically phase-conjugated backward-reflected radiation was registered with an energy reflectivity of 10–14% in SF6 and CH4. In SF6, the SBS pulses gradually shortened from 10 ns to 2–3 ns with a decrease in pumping to the SBS threshold of ~10 mJ, while the SRS pulse had the shortest length of 30–60 ps for the maximal pumping of 120 mJ and broadened near the SRS threshold of ~30 mJ. For the SRS pulse energy, the ~2 mJ peak power 5 × 107 W was tenfold higher than the pump power. The theoretical model predicted a soliton-like SRS pulse compression to a temporal length of the order of the vibrational relaxation time. There was no pulse compression of backward SBS and SRS radiation in CH4, while, in the forward direction, SRS pulses shortened to 3–4 ns at reduced pumping.
Dispersive Fourier Transform Spectrometer Based on Mode-Locked Er-Doped Fiber Laser for Ammonia Sensing
Authors: Aprelov Nikolay A. , Vatnik Ilya D. , Kharenko Denis S. , Redyuk Alexey A.
Published: December 2023

Dispersive Fourier transform (DFT) has emerged as a powerful technique, enabling the transformation of spectral information from an optical pulse into a temporal waveform. This advancement facilitates the implementation of absorption spectroscopy using a single-pixel photodetector and a pulsed laser, particularly effective when operating on wavelengths near the absorption lines of the gas under study. This paper introduces a DFT-spectrometer employing a mode-locked tunable fiber laser with the central wavelength of 1531.6 nm. We demonstrate fast acquisition NH3 absorption spectroscopy with a 0.2 nm spectral resolution, achieved through the utilization of the HITRAN database for estimating ammonia concentrations. Alongside the successful demonstration of NH3 absorption spectroscopy, we explore practical limiting factors influencing the system’s performance. Furthermore, we discuss potential avenues for enhancing sensitivity and spectral resolution, aiming to enable more robust and accurate gas sensing applications.
Genome-Wide Identification and Expression Analysis of the Trehalose-6-phosphate Synthase and Trehalose-6-phosphate Phosphatase Gene Families in Rose (Rosa hybrida cv ‘Carola’) under Different Light Conditions
Authors: Fan Yingdong , Gao Peng , Zhou Tong , Pang Siyu , Zhang Jinzhu , Yang Tao , Zhang Wuhua , Dong Jie , Che Daidi
Published: December 2023

Trehalose, trehalose-6-phosphate synthase (TPS),and trehalose-6-phosphatase (TPP) have been reported to play important roles in plant abiotic stress and growth development. However, their functions in the flowering process of Rosa hybrida have not been characterized. In this study we found that, under a short photoperiod or weak light intensity, the content of trehalose in the shoot apical meristem of Rosa hybrida cv ‘Carola’ significantly decreased, leading to delayed flowering time. A total of nine RhTPSs and seven RhTPPs genes were identified in the genome. Cis-element analysis suggested that RhTPS and RhTPP genes were involved in plant hormones and environmental stress responses. Transcriptome data analysis reveals significant differences in the expression levels of RhTPSs and RhTPPs family genes in different tissues and indicates that RhTPPF and RhTPPJ are potential key genes involved in rose flower bud development under different light environments. The results of quantitative real-time reverse transcription (qRT-PCR) further indicate that under short photoperiod and weak light intensity all RhTPP members were significantly down-regulated. Additionally, RhTPS1a, RhTPS10, and RhTPS11 were up-regulated under a short photoperiod and showed a negative correlation with flowering time and trehalose content decrease. Under weak light intensity, RhTPS11 was up-regulated and negatively regulated flowering, while RhTPS5, RhTPS6, RhTPS7b, RhTPS9, and RhTPS10 were down-regulated and positively regulated flowering. This work lays the foundation for revealing the functions of RhTPS and RhTPP gene families in the regulation of rose trehalose.
Small Sized Yet Powerful: Nuclear Distribution C Proteins in Plants
Authors: Vassileva Valya , Georgieva Mariyana , Todorov Dimitar , Mishev Kiril
Published: December 2023

The family of Nuclear Distribution C (NudC) proteins plays a pivotal and evolutionarily conserved role in all eukaryotes. In animal systems, these proteins influence vital cellular processes like cell division, protein folding, nuclear migration and positioning, intracellular transport, and stress response. This review synthesizes past and current research on NudC family members, focusing on their growing importance in plants and intricate contributions to plant growth, development, and stress tolerance. Leveraging information from available genomic databases, we conducted a thorough characterization of NudC family members, utilizing phylogenetic analysis and assessing gene structure, motif organization, and conserved protein domains. Our spotlight on two Arabidopsis NudC genes, BOB1 and NMig1, underscores their indispensable roles in embryogenesis and postembryonic development, stress responses, and tolerance mechanisms. Emphasizing the chaperone activity of plant NudC family members, crucial for mitigating stress effects and enhancing plant resilience, we highlight their potential as valuable targets for enhancing crop performance. Moreover, the structural and functional conservation of NudC proteins across species suggests their potential applications in medical research, particularly in functions related to cell division, microtubule regulation, and associated pathways. Finally, we outline future research avenues centering on the exploration of under investigated functions of NudC proteins in plants.
Exploitation and Utilization of Generated Oil and Gas by Pyrolysis Simulation Modeling of Shale Source Rocks under the Condition of In Situ Conversion
Authors: Luo Xia , Hou Lianhua , Zhao Zhongying , Lin Senhu , Pang Zhenglian , Zhang Lijun , Han Wenxue , Li Yong
Published: January 2024

Previous studies have mainly focused on the source rocks of the 7th Member of Yanchang Formation (Chang 7 Member) in the Ordos Basin, with very few studies focusing on the extracts from the source rocks. These extracts have important guiding significance for studying the in situ conversion process of shale oil. Taking the shale source rock of the Chang 7 Member as an example, this paper selected the extract of shale source rock (i.e., retained oil), which has been less studied previously, as the sample to carry out the hydrocarbon-generating pyrolysis simulation experiment of a semi-open–semi-closed system. Seven groups of parallel simulation experiments were designed with a pressure of 20 MPa. The generated oil and gas were collected and quantified, and their geochemical characteristics were researched. In addition, the generated oil and gas were investigated from aspects of cumulative yield and net increased yield, and the chromatographic and mass spectral characteristics of the generated oil were also researched. Based on this, an inductive hydrocarbon generation model of retained oil in shale source rocks was established: slow hydrocarbon generation stage (300–320 °C), rapid hydrocarbon generation stage (320–360 °C), and residual oil pyrolysis stage (0.79%Ro–1.47%Ro). This study is of important significance to guide the research on the in situ conversion process of shale source rock.
Stretchable Superhydrophobic Surfaces: From Basic Fabrication Strategies to Applications
Authors: Liu Wendong , Wang Xiaojing , Xiang Siyuan , Lian Yuechang , Tao Shengyang
Published: January 2024

Superhydrophobic surfaces find extensive applications in various fields, including self-cleaning, liquid manipulation, anti-icing, and water harvesting. To achieve superhydrophobicity, the surfaces are designed with hierarchical nano- and/or microscale protrusions. These structures result in a static contact angle above 150° and a sliding/rolling-off angle below 10° when water droplets deposit on the surface. The combination of hierarchical structures and low-surface energy materials contributes to this unique liquid-repellent property. In addition to liquid repellency, the durability of these surfaces is crucial for practical applications, which has prompted the exploration of stretchable superhydrophobic surfaces as a viable solution. The flexibility of these surfaces means that they are effectively safeguarded against mechanical damage and can withstand daily wear and tear. Over the last decade, considerable research has been dedicated to developing stretchable superhydrophobic surfaces to expand their potential applications. This review provides an overview of stretchable superhydrophobic surfaces, specifically emphasizing current processing strategies and their prospective applications. Additionally, we present a forward-looking perspective on future fabrication methods to create robust superhydrophobic surfaces, further enhancing their practicality and versatility.
Bottomhole Pressure Prediction of Carbonate Reservoirs Using XGBoost
Authors: Sun Hao , Luo Qiang , Xia Zhaohui , Li Yunbo , Yu Yang
Published: January 2024

The bottomhole pressure is one of the key parameters for oilfield development and decision-making. However, due to factors such as cost and equipment failure, bottomhole pressure data is often lacking. In this paper, we established a GA-XGBoost model to predict the bottomhole pressure in carbonate reservoirs. Firstly, a total of 413 datasets, including daily oil production, daily water production, daily gas production, daily liquid production, daily gas injection rate, gas–oil ratio, and bottomhole pressure, were collected from 14 wells through numerical simulation. The production data were then subjected to standardized preprocessing and dimensionality reduction using a principal component analysis. The data were then split into training, testing, and validation sets with a ratio of 7:2:1. A prediction model for the bottomhole pressure in carbonate reservoirs based on XGBoost was developed. The model parameters were optimized using a genetic algorithm, and the average adjusted R-squared score from the cross-validation was used as the optimization metric. The model achieved an adjusted R-squared score of 0.99 and a root-mean-square error of 0.0015 on the training set, an adjusted R-squared score of 0.84 and a root-mean-square error of 0.0564 on the testing set, and an adjusted R-squared score of 0.69 and a root-mean-square error of 0.0721 on the validation set. The results demonstrated that in the case of fewer data variables, the GA-XGBoost model had a high accuracy and good generalization performance, and its performance was superior to other models. Through this method, it is possible to quickly predict the bottomhole pressure data of carbonate rocks while saving measurement costs.
NU-Biped-4.5: A Lightweight and Low-Prototyping-Cost Full-Size Bipedal Robot
Authors: Folgheraiter Michele , Yessirkepov Sharafatdin , Umurzakov Timur
Published: December 2023

This paper presents the design of a new lightweight, full-size bipedal robot developed in the Humanoid Robotics Laboratory at Nazarbayev University. The robot, equipped with 12 degrees of freedom (DOFs), stands at 1.1 m tall and weighs only 15 kg (excluding the battery). Through the implementation of a simple mechanical design and the utilization of off-the-shelf components, the overall prototype cost remained under USD 5000. The incorporation of high-performance in-house-developed servomotors enables the robot’s actuation system to generate up to 2400 W of mechanical power, resulting in a power-to-weight ratio of 160 W/kg. The details of the mechanical and electrical design are presented alongside the formalization of the forward kinematic model using the successive screw displacement method and the solution of the inverse kinematics. Tests conducted in both a simulation environment and on the real prototype demonstrate that the robot is capable of accurately following the reference joint trajectories to execute a quasi-static gait, achieving an average power consumption of 496 W.
Manifestation of Internal Waves in the Structure of an Artificial Slick Band
Authors: Ermoshkin Alexey , Shomina Olga , Molkov Aleksandr , Bogatov Nikolay , Salin Mikhail , Kapustin Ivan
Published: December 2023

The results of a field experiment devoted to observing slick-band shape variations occurring due to the action of heterogeneous currents related to the passage of internal waves are presented and analyzed on the basis of numerical simulation. The spatiotemporal structure of a train of five solitons of internal waves has been retrieved. Their evolution in the coastal area is demonstrated based on the analysis of propagation characteristics. It is shown that the first soliton, characterized by the higher values of amplitude and width, collapsed when entering shallow water near the observation platform. The parameters of an artificial slick band affected by the passage of internal waves are determined. It is shown that the direction and width of the slick band are related to the direction and magnitude of the upper-ocean horizontal current, which contains a component related to the internal wave. The results of numerical simulation are qualitatively and quantitatively consistent with experimental data at short distances from the platform. An analysis of the conditions responsible for different regimes of slick-band response to the upper-ocean currents generated by propagating internal waves has been performed.
Multi-Temporal and Time-Lag Responses of Terrestrial Net Ecosystem Productivity to Extreme Climate from 1981 to 2019 in China
Authors: Huang Yiqin , Xu Xia , Zhang Tong , Jiang Honglei , Xia Haoyu , Xu Xiaoqing , Xu Jiayu
Published: December 2023

The escalating frequency and severity of extreme climate greatly impact the carbon dynamics of terrestrial ecosystems worldwide. To understand the multi-temporal response of net ecosystem productivity (NEP) to extreme climate, we investigated 11 temperature and precipitation extreme indices across different vegetation types in China. From 1981 to 2019, the results showed that NEP in China increased at a rate of 0.64 g·m−2·a−2. Extreme climate demonstrated a significant warming trend and a non-significant moistening trend; specifically, maximum daily minimum temperature (TNx) exhibited a significant increase at a rate of 0.34 °C/10 a, while maximum 5-day precipitation (Rx5day) showed an insignificant increase at a rate of 1.78 mm/10 a. NEP was significantly impacted by extreme temperature at the annual, seasonal, and monthly scales, but moderately impacted by extreme precipitation. Specifically, extreme temperature had the most significant effect on grassland, with minimal influence on cropland. In contrast, extreme precipitation had the most significant effect on forest, with minimal impact on cropland. Moreover, the lagged time for extreme precipitation was longer than that for extreme temperature. Extreme precipitation exhibited a corresponding lagged time of at least 2 months (p < 0.01), while extreme temperature exhibited a lagged time of at least 1 month (p < 0.01). The maximum lag time observed was 4 months (p < 0.01). Our findings provide valuable insights into the multi-temporal response of NEP to extreme climate in China and inform sustainable development practices in the region.
An Interstation Undifferenced Real-Time Time Transfer Method with Refined Modeling of Receiver Clock
Authors: Lyu Dong , Liu Genyou , Zhao Wenhao , Liao Wei , Zhang Bo , Lyu Minghui
Published: December 2023

Due to their advantages of high measurement accuracy and wide coverage, global navigation satellite systems (GNSSs) can carry out long-distance time transfers, among which the precise point positioning (PPP) method is widely used. However, the accuracy and stability of PPP real-time time transfer are restricted by the real-time satellite clock offset products. In addition, the receiver clock offset is usually estimated using the white noise model, which ignores the correlation of the clock offsets between adjacent epochs and the stability of the atomic clock itself. In order to obtain higher performance time transfer results, we propose an interstation undifferenced time transfer method with refined modeling of the receiver clock. This method takes the satellite clock offset as the parameter to be estimated, which can avoid the influence of external satellite clock offset products. In addition, the refined modeling of the receiver clock can improve the strength of the model and the accuracy of time transfer. Based on the ultrarapid satellite orbit products provided by the International GNSS Service (IGS), time transfer experiments are carried out using data from IGS observatories and self-collected data. The results show that sub-nanosecond accuracy can be achieved in real-time time transfer using this method. Compared with the traditional PPP model, the accuracies of the four time links are increased by 88.4%, 92.9%, 88.6%, and 74.5%, respectively, and the stability is increased by approximately 66.4% on average. Moreover, after applying the clock offset constraint model, frequency stability is further improved, in which the short-term stability is improved significantly, with a maximum of 86.9% and an average improvement of approximately 66.8%.