bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of light fluctuations on photosynthesis and metabolic flux in Synechocystis sp. PCC 6803
Authors: Imada Tatsumi , Yamamoto Chiaki , Toyoshima Masakazu , Toya Yoshihiro , Shimizu Hiroshi
Published: January 2023

In nature, photosynthetic organisms are exposed to fluctuating light, and their physiological systems must adapt to this fluctuation. To maintain homeostasis, these organisms have a light fluctuation photoprotective mechanism, which functions in both photosystems and metabolism. Although the photoprotective mechanisms functioning in the photosystem have been studied, it is unclear how metabolism responds to light fluctuations within a few seconds. In the present study, we investigated the metabolic response of Synechocystis sp. PCC 6803 to light fluctuations using 13C‐metabolic flux analysis. The light intensity and duty ratio were adjusted such that the total number of photons or the light intensity during the low‐light phase was equal. Light fluctuations affected cell growth and photosynthetic activity under the experimental conditions. However, metabolic flux distributions and cofactor production rates were not affected by the light fluctuations. Furthermore, the estimated ATP and NADPH production rates in the photosystems suggest that NADPH‐consuming electron dissipation occurs under fluctuating light conditions. Although we focused on the water–water cycle as the electron dissipation path, no growth effect was observed in an flv3‐disrupted strain under fluctuating light, suggesting that another path contributes to electron dissipation under these conditions.
Controlled Membrane Transport in Polymeric Biomimetic Nanoreactors
Authors: Cao Shoupeng , Ivanov Tsvetomir , de Souza Melchiors Marina , Landfester Katharina , Caire da Silva Lucas
Published: January 2023

Polymersome‐based biomimetic nanoreactors (PBNs) have generated great interest in nanomedicine and cell mimicry due to their robustness, tuneable chemistry, and broad applicability in biologically relevant fields. In this concept review, we mainly discuss the state of the art in functional polymersomes as biomimetic nanoreactors with membrane‐controlled transport. PBNs that use environmental changes or external stimuli to adjust membrane permeability while maintaining structural integrity are highlighted. By encapsulating catalytic species, PBNs are able to convert inactive substrates into functional products in a controlled manner. In addition, special attention is paid to the use of PBNs as tailored artificial organelles with biomedical applications in vitro and in vivo, facilitating the fabrication of next‐generation artificial organelles as therapeutic nanocompartments.
Young children's career aspirations: Gender differences, STEM ambitions, and expected skill use
Authors: Conlon Rachel A. , Barroso Connie , Ganley Colleen M.
Published: January 2023

This study examines young children's career aspirations, gender differences in those aspirations, and children's perceptions of the amount of math and science used in careers. We asked 1634 students in first to third grades what job they wanted in the future and how much they thought they would use math or science in it. Career aspirations were sorted into 27 career categories, of which 12 showed significant gender differences. Notably, boys were more likely to indicate military, manual labor, and math/computer science careers, and girls were more likely to indicate stay at home parent, education, and animal care careers. Students aspiring to science, technology, engineering, and mathematics (STEM) careers thought they would use science, but not math, more than non‐STEM‐aspiring students did. School counseling interventions focused on specific STEM subfields, and education highlighting links between school subjects and careers requirements may benefit students and reduce gender inequality in STEM fields.
Alkoxyphosphorane/Borane Cooperative Alkylations: A Frustrated Lewis Pair Version of the Mitsunobu Reaction
Authors: Chen Ting , Mei Yanbo , Liu Liu Leo , Zhao Yufen , Wu Yile , Stephan Douglas W.
Published: January 2023

The combination of the alkoxyphosphoranes, Ph2P(OR)(O2C6Cl4) and the borane B(C6F5)3 generates the zwitterions 3 which act as FLP to effect the alkylation of several nucleophiles affording C−C, C−N, C−H and C−Cl coupling products. A DFT study shows the reaction proceeds via an FLP activation pathway generating an alkoxyphosphonium intermediate which effects the alkylation of the nucleophiles, akin to the Mitsunobu reaction.
Second‐Generation CD73 Inhibitors Based on a 4,6‐Biaryl‐2‐thiopyridine Scaffold
Authors: Ghoteimi Rayane , Braka Abdennour , Rodriguez Céline , Cros‐Perrial Emeline , Duvauchelle Valentin , Uttaro Jean‐Pierre , Mathé Christophe , Ménétrier‐Caux Christine , Jordheim Lars Petter , Chaloin Laurent , Peyrottes Suzanne
Published: January 2023

Various series of 4,6‐biaryl‐2‐thiopyridine derivatives were synthesized and evaluated as potential ecto‐5′‐nucleotidase (CD73) inhibitors. Two synthetic routes were explored and the coupling of 4,6‐disubstituted 3‐cyano‐2‐chloro‐pyridines with selected thiols allowed us to explore the structural diversity. Somehow divergent results were obtained in biological assays on CD73 inhibition using either the purified recombinant protein or cell‐based assays, highlighting the difficulty to target protein‐protein interface on proteins existing as soluble and membrane‐bound forms. Among the 18 new derivatives obtained, three derivatives incorporating morpholino substituents on the 4,6‐biaryl‐2‐thiopyridine core were shown to be able to reverse the adenosine‐mediated immune suppression on human T cells. The higher blockade efficiency was observed for 2‐((3‐cyano‐4,6‐bis(4‐morpholinophenyl)pyridin‐2‐yl)thio)‐N‐(isoxazol‐3‐yl)acetamide (with total reversion at 100 μM) and methyl 2‐((3‐cyano‐4,6‐bis(4‐morpholinophenyl)pyridin‐2‐yl)thio)acetate (with partial reversion at 10 μM). Thus, this series of compounds illustrates a new chemotype of CD73 allosteric inhibitors.
Adverse late health outcomes among children treated with 3D radiotherapy techniques: Study design of the Dutch pediatric 3D‐RT study
Authors: Beijer Josien G. M. , Kok Judith L. , Janssens Geert O. , Streefkerk Nina , de Vries Andrica C. H. , Slagter Cleo , Maduro John H. , Kroon Petra S. , Grootenhuis Martha A. , van Dulmen‐den Broeder Eline , Loonen Jacqueline J. , Wendling Markus , Tissing Wim J. E. , van der Pal Helena J. , Louwerens Marloes , Bel Arjan , den Hartogh Jaap , van der Heiden‐van der Loo Margriet , Kremer Leontien C. M. , Teepen Jop C. , Ronckers Cécile M.
Published: January 2023

Background

Adverse late health outcomes after multimodal treatment for pediatric cancer are diverse and of prime interest. Currently available evidence and survivorship care guidelines are largely based on studies addressing side‐effects of two dimensional planned radiotherapy.

Aims

The Dutch pediatric 3D‐planned radiotherapy (3D‐RT) study aims to gain insight in the long‐term health outcomes among children who had radiotherapy in the 3D era. Here, we describe the study design, data‐collection methods, and baseline cohort characteristics.

Methods and Results

The 3D‐RT study represents an expansion of the Dutch Childhood Cancer Survivor study (DCCSS) LATER cohort, including pediatric cancer patients diagnosed during 2000–2012, who survived at least 5 years after initial diagnosis and 2 years post external beam radiotherapy. Individual cancer treatment parameters were obtained from medical files. A national infrastructure for uniform collection and archival of digital radiotherapy files (Computed Tomography [CT]‐scans, delineations, plan, and dose files) was established. Health outcome information, including subsequent tumors, originated from medical records at the LATER outpatient clinics, and national registry‐linkage. With a median follow‐up of 10.9 (interquartile range [IQR]: 7.9–14.3) years after childhood cancer diagnosis, 711 eligible survivors were identified. The most common cancer types were Hodgkin lymphoma, medulloblastoma, and nephroblastoma. Most survivors received radiotherapy directed to the head/cranium only, the craniospinal axis, or the abdominopelvic region.

Conclusion

The 3D‐RT study will provide knowledge on the risk of adverse late health outcomes and radiation‐associated dose‐effect relationships. This information is valuable to guide follow‐up care of childhood cancer survivors and to refine future treatment protocols.
Enhancement of video demosaicing techniques using optimization algorithm
Authors: Alphonse Babitha , Alfred Sylam Boyed Wesley
Published: January 2023

Demosaicing and denoising are the most significant steps in the imaging process for both images and videos. The correlation noise corrupts the image quality, such that an accurate interpretation of the image is avoided. Thus, demosaicing is utilized to restructure the full‐color image from imperfect color samples. In this article, cat shuffled shepherd optimization‐based local polynomial approximation and intersection of confidence intervals (Cat SSO‐based LPA‐ICI) approach is developed for video demosaicing. The LPA‐ICI model is employed for frame demosaicing in which the second‐order polynomial interpolation filter coefficients are produced using the devised optimization algorithm, named cat SSO technique. Similarly, generative adversarial network classifier is also applied for frame demosaicing. In addition, initialization and flow estimation is performed for the demosaicing process. Besides, spatio temporal demosaicing model is utilized in order to get a noise‐free sequence. However, the developed cat SSO technique is newly devised by the incorporation of the shuffled shepherd optimization algorithm and cat swarm optimization technique. The created video demosaicing model outperformed with peak signal‐to‐noise ratio, root mean square error, and second derivative‐like measure of enhancement values of 56.85 dB, 0.46, and 60.62, respectively.
Perfect Core‐Shell Octahedral B@B38+, Be@B38, and Zn@B38 with an Octa‐Coordinate Center as Superatoms Following the Octet Rule
Authors: Yan Qiao‐Qiao , Zhao XiaoYun , Zhang Ting , Li Si‐Dian
Published: January 2023

Planar, tubular, cage‐like, and bilayer boron clusters Bn+/0/− (n=3∼48) have been observed in joint experimental and theoretical investigations in the past two decades. Based on extensive global searches augmented with first‐principles theory calculations, we predict herein the smallest perfect core‐shell octahedral borospherene Oh B@B38+ (1) and its endohedral metallo‐borospherene analogs Oh Be@B38 (2), and Oh Zn@B38 (3) which, with an octa‐coordinate B, Be or Zn atom located exactly at the center, turn out to be the well‐defined global minima of the systems highly stable both thermodynamically and dynamically. B@B38+ (1) represents the first boron‐containing molecule reported to date which contains an octa‐coordinate B center covalently coordinated by eight face‐capping boron atoms at the corners of a perfect cube in the first coordination sphere. Detailed natural bonding orbital (NBO) and adaptive natural density partitioning (AdNDP) bonding analyses indicate that these high‐symmetry core‐shell complexes X@B38+/0/− (X=B, Be, Zn) as super‐noble gas atoms follow the octet rule in coordination bonding patterns (1S21P6), with one delocalized 9c‐2e S‐type coordination bond and three delocalized 39c‐2e P‐type coordination bonds formed between the octa‐coordinate X center and its octahedral Oh B38 ligand to effectively stabilize the systems. Their IR, Raman, and UV‐Vis spectra are computationally simulated to facilitate their spectroscopic characterizations.
A Further Study on Calcium Phosphate Gardens Grown from the Interface of κ‐Carrageenan‐based Hydrogels and Counterion Solutions
Authors: Fogde Anna , Rosqvist Emil , Le Trung‐Anh , Smått Jan‐Henrik , Sandberg Thomas , Huynh Tan‐Phat
Published: January 2023

Originating from the concept of classical chemical gardens, a new field coined ‘chemobrionics’ has recently emerged. In the present work, two chemobrionic systems grown from a hydrogel/liquid interface at different time scales (for 1, 7, 14 or 28 days) were investigated, i. e., a calcium‐based hydrogel with a phosphate counterion solution (Ca‐gel) and a phosphate‐based hydrogel with a calcium counterion solution (P‐gel). The initial pH changes of the systems were investigated, and the obtained tubular structures were studied using optical microscopy, SEM, AFM, PXRD and TGA. One of the important findings is that the tubes obtained in the Ca‐gel system were straight and long, which could be explained by the larger pH difference observed between the hydrogel and the counterion solution in this system (ΔpH∼2.1) compared to the P‐gel system (ΔpH∼0). The Ca‐gel structures remained overall more amorphous even though increased crystallinity was observed in both systems with increased time spent in counterion solution. Both systems contained hydroxyapatite phases, with additional calcite phases observed for the P‐gel structures and traces of κ‐carrageenan for the Ca‐gel structures. Our study provides a promising method for controlling tubular macrostructures through adjusting the reaction conditions such as maturation time and pH.
A Comprehensive Formulation of Aqueous Electrolytes for Low‐Temperature Supercapacitors
Authors: Ah‐Lung Guillaume , Flamme Benjamin , Maréchal Manuel , Ghamouss Fouad , Jacquemin Johan
Published: January 2023

Safer‐by‐design and sustainable energy storage devices are envisioned to be among the required 2.0 solutions to satisfy the fast growing energy demands. Responding to this evolution cannot be freed from a global and synergetic approach to design the requisite electrolytes taking into account the toxicity, the eco‐compatibility and the cost of their constituents. To target low‐temperature applications, a non‐toxic and cost‐efficient eutectic system comprising LiNO3 in water with 1,3‐propylene glycol as co‐solvent was selected to design a ternary electrolyte with a wide liquid range. By using this electrolyte in an electrochemical double‐layer capacitor (EDLC), the operating voltage of the device reaches an optimum of 2.0 V at −40 °C over more than 100 h of floating. Moreover, after being set up at 20 °C, the temperature resilience of the capacitance is near total, demonstrating thus a promising feature related to the suitable thermal and electrochemical behaviours of the tested EDLC devices.
Evaluation of the detection of the homologous transfusion of a red blood cell concentrate in vivo for antidoping
Authors: Marchand Alexandre , Roulland Ingrid , Semence Florian , Jaffredo Franck , Dehainault Catherine , Le Guiner Soizic , Le Pajolec Marie‐Gaëlle , Donati Francesco , Mekacher Lamine Redouane , Lamek Kahina , Ericsson Magnus
Published: January 2023

Two doping cases of homologous blood transfusion (HBT) during Tokyo 2020 Summer Olympics have shown that more controls are needed. The method of detection using flow cytometry to evaluate the expression of minor blood group antigens from red blood cells (RBCs) and identify different RBC populations is efficient but still complex to perform with multiple antigens detection. Recently, the interest of using forensic DNA analysis was also highlighted as a potential new method to detect HBT, with possibility to start from dried blood spots (DBS) instead of fresh blood. After a first phase of development, a protocol was validated for HBT detection using DNA analysis after extraction from DBS. Presence of a second DNA was clear down to 2% of donor blood in vitro. A flow cytometry protocol was also developed with preparation and analysis in 96‐well plates and detection of two different antigens per well using two secondary antibodies with distinct fluorophores. The objective of the project was to evaluate the window of detection of an HBT performed in vivo with 150 mL of RBC concentrate. Blood samples obtained over 7 weeks post‐transfusion were analyzed. DNA profiling from DBS was not sensitive enough to detect the presence of a second DNA even 1 day after transfusion. On the contrary, the flow cytometry protocol was very efficient and allowed identification of several double populations of RBC (expressing/non‐expressing several antigens) until day 50 post‐transfusion. This protocol can be fully validated for a future application to doping control samples.
Still Elusive – Pd(II)‐Mediated Base Pairing by an Acetophenone Oxime Palladacycle within 15N‐Labelled Double‐Helical Oligonucleotides
Authors: Toiviala Maaret , Kleemola Vesa , Maity Sajal , Lönnberg Tuomas
Published: January 2023

Both α and β anomers of an acetophenone C‐nucleoside were synthesized and incorporated in the middle of short oligodeoxynucleotides. The ketone oligonucleotides were converted to 15N‐labelled oxime oligonucleotides by treatment with 15N‐hydroxylamine and, finally, cyclopalladated by treatment with lithium tetrachloropalladate. Comparison of the UV melting profiles of duplexes bearing the β anomer of either the palladacyclic or the metal‐free oxime C‐nucleoside suggested formation of a stable Pd(II)‐mediated base pair, especially with adenine or thymine as the base pairing partner. Melting profiles of the corresponding duplexes bearing the α anomer were much more convoluted, precluding meaningful comparison. 15N NMR spectra were obtained for the β anomeric oxime oligonucleotide as well as its palladacyclic derivative but the signals unfortunately diminished below detection limit when the latter was hybridized with a complementary strand placing a 15N3‐labelled thymine opposite to the palladacyclic residue.
Nitrogen‐Doped TiO2 Nanotubes‐Catalyzed Synthesis of Small D‐π‐A‐Type Knoevenagel Adducts and β‐Enaminones
Authors: Sultana Shaik , Kumar Godugu , Sarma Loka Subramanyam , Venkatramu Vemula , Gangi Reddy Nallagondu Chinna
Published: January 2023

For the first time, interstitial nitrogen‐doped TiO2 nanotubes (INDTNTs) have been utilized as heterogeneous green catalysts for the synthesis of D‐π‐A‐type Knoevenagel adducts (3) and β‐enaminones (6). Notable advantages of the present method include its wide substrate scope, low catalyst loading, avoiding the use of hazardous bases and solvents, products do not require chromatographic purification, high yields, catalyst reusability, etc. The optimized catalyst, INDTNTs‐4 has been characterized by XRD, HRTEM, and XPS techniques. The photophysical and electrochemical properties of D‐π‐A‐type 3 and 6 have been evaluated. The study revealed that the colour tunability (cold white light to orange light) and the HOMO/LUMO levels depend mainly on the presence of various electron donating and withdrawing groups on the aromatic/heteroaromatic rings of 3 and 6. The results indicate that the D‐π‐A‐type 3 and 6 could be promising materials for the fabrication of optoelectronic devices.
Shaking table test of a 10‐story self‐centering tube building
Authors: Song Zhaoyang , Zhou Ying , Lu Yiqiu
Published: January 2023

The severe damage of conventionally designed buildings and consequent socioeconomic impacts after major seismic events have spurred the development of self‐centering systems with high seismic resilience. Post‐tensioned (PT) walls with rocking interfaces allowed to open and close and unbonded PT bars that provide most of the re‐centering ability have been developed extensively as a promising self‐centering technology. Aiming at providing essential insights into the seismic performance of self‐centering tube systems, a 1/6‐scale ten‐story self‐centering tube building was designed, constructed, and tested on a shaking table subjected to a series of unidirectional and bidirectional ground motions with increasing intensities. The test building consisted of a self‐centering tube that included four PT walls and provided the primary lateral force resistance in both directions, a perimeter rocking frame that was designed mainly to carry gravity loads, and particular connections with slots to accommodate the potential displacement incompatibility among the PT walls and surrounding components. The experimental results indicated the excellent seismic performance of the test building that had reliable structural integrity and experienced only confined damage even when subjected to extremely high intensities. The building also exhibited satisfactory re‐centering ability with minimal residual deformations at the conclusion of testing. It was demonstrated that the self‐centering tube system is a desirable low‐damage alternative to traditional tube systems in earthquake‐prone regions. The benchmark data from this test provided unique suggestions and support for further research on the design methods, numerical modeling, and experimental testing of self‐centering tube systems.
Distribution‐based PV module degradation model
Authors: Lai Guangzhi , Wang Dong , Wang Ziyue , Fan Fu , Wang Qihang , Wang Ruyi
Published: January 2023

The degradation of photovoltaic modules has an impact on various parameters of photovoltaic modules. Ignoring the degradation of photovoltaic modules or inaccurate estimation of the degradation will lead to wrong power dispatching strategies and lead to economic losses. For PV module life estimation or reliability estimation, it is necessary to first establish an accurate statistical degradation model of PV module. The main goal of this paper is to analyze a selection of explicit PV module degradation model based on distribution. Since the degradation is related to time, the study assumed that those parameters in Gamma or Gaussian distributions are related to time. Five models are calculated based on maximum likelihood estimation and particle swarm optimization. Through verification and comparison on the measured PV module degradation data, the performance of these models in four cases: long‐term data fitting, long‐term data prediction, single‐module short‐term data fitting, and multimodule short‐term data fitting are evaluated. The results show that the model proposed in this paper has a great improvement over the original model, and the constant‐σ Gaussian distribution degradation model achieves the best performance.
Influence of blade trailing edge profile on unsteady pressure pulsations in a multistage centrifugal pump
Authors: Cui Bao‐Ling , Sun Fu‐You , Zhang Yu‐Liang , Liu Jin‐Xin , Xiao Jun‐Jian
Published: January 2023

Changing the shape of the blade trailing edge profile of a centrifugal pump is one of the effective means to improve the internal unsteady flow and pressure pulsation of a centrifugal pump. In this paper, the effect of four shapes of the blade trailing edge profile on the internal nonconstant pressure pulsation and internal flow of a multistage centrifugal pump is investigated by numerical simulation. The four types of blade trailing edges include prototype impeller (original trailing edge), pressure surface cut (ellipse on pressure side [EPS]), suction surface cut (ellipse on suction side [ESS]), and two‐side cut (ellipse on both sides). The results show that reasonable cutting of the trailing edge of the blade can reduce the pressure pulsation of the centrifugal pump. By comparing the pressure pulsation at fBPF, we found that the blade trailing edge profile can change the pressure pulsation. When the speed decreases, the periodicity of pressure pulsation becomes worse and the amplitude of pressure pulsation at fBPF decreases. The static pressure distribution at the trailing edge of the blade shows that EPS and ESS can effectively reduce the area of the high‐pressure gradient region at the trailing edge of the blade, and the dynamic–static interference effect is weakened, which leads to a lower pressure pulsation amplitude. The distribution of turbulent energy in different blade trailing edge centrifugal pumps corresponds to the distribution of static pressure in different blade trailing edge centrifugal pumps, further demonstrating the reliability of the static pressure distribution. The results of this study will further provide theoretical support for the optimization of the blade trailing edge profile.
Improved Gentry–Halevi's fully homomorphic encryption‐based lightweight privacy preserving scheme for securing medical Internet of Things
Authors: Praveen Ramalingam , Pabitha Parameswaran
Published: January 2023

Internet of Medical Things (IoMT) solutions have proliferated rapidly in the COVID‐19 pandemic era. The smart medical sensors capture real‐time data from remote patients and communicate it to medical servers in a secure and privacy‐preserving manner. It is a herculean challenge to guarantee security and privacy in Medical IoT applications. Hence, an improved Gentry–Halevi's fully homomorphic encryption‐based (IGHFHE) lightweight privacy preserving user authentication scheme is proposed in this work. The scheme is proposed with an integer matrix computation strategy for securing data computation with privacy protection. It adopts the translation process of Gentry–Halevi's fully homomorphic encryption process for performing homomorphic addition and multiplication, then encrypt an integer matrix modulo that represents a positive integer. Extensive informal investigation and simulation of the proposed IGHFHE scheme shows that it is more resistant to well‐known attacks for preventing authentication breaches. Also, the proposed IGHFHE scheme reduced computational and storage overhead by 4.98% and 5.78% respectively on average in comparison to other prevailing schemes.
An emerging natural antioxidant therapy for COVID‐19 infection patients: Current and future directions
Authors: Shrivastava Amit Kumar , Sahu Prafulla Kumar , Cecchi Teresa , Shrestha Laxmi , Shah Sanjay Kumar , Gupta Anamika , Palikhey Anjan , Joshi Bishal , Gupta Pramodkumar P. , Upadhyaya Jitendra , Paudel Mahendra , Koirala Niranjan
Published: January 2023

Severe acute respiratory syndrome coronavirus‐2 (SARS‐CoV‐2) affects millions of people worldwide. The article aims to review the therapeutic perspective on natural antioxidants, their mechanism of action, pharmacokinetics in management and cure of COVID‐19/ SARS‐CoV‐2 infection. We conducted a literature search including World Health Organization and National Institute of Health guidelines and clinical trials registered with ClinicalTrials.gov limited to antioxidants in COVID‐19 management. Elderly, immunocompromised patients, and others with underlying health conditions or multiple comorbidities have a high mortality rate. Disrupted redox homeostasis and oxidative stress seem to be biological pathways that may increase personal vulnerability to infection. Antioxidants like vitamins C, D, E, epigallocatechin‐3 gallate, and morin have been reported to protect against COVID‐19 disease. Reactive oxygen species are immunological regulatory elements of viral replication. Natural antioxidants exhibit potential action in preventing inflammation and organ dysfunction during viral infection. They also increase glutathione level, oxygenation rate, and immunological responses in the treatment of sepsis and acute respiratory distress syndrome. No wonder the selection of prevention, treatment, and cure of COVID‐19 and SARS‐CoV‐2 mainly depends upon the antiviral and immunoregulatory activity which they possess. Yet, their efficacy against COVID‐19 is of great concern and demands extensive study.
Associations between spontaneous electroencephalogram oscillations and oxygen saturation across normobaric and hypobaric hypoxia
Authors: Hutcheon Evan A. , Vakorin Vasily A. , Nunes Adonay , Ribary Urs , Ferguson Sherri , Claydon Victoria E. , Doesburg Sam M.
Published: January 2023

High‐altitude indoctrination (HAI) trains individuals to recognize symptoms of hypoxia by simulating high‐altitude conditions using normobaric (NH) or hypobaric (HH) hypoxia. Previous studies suggest that despite equivalent inspired oxygen levels, physiological differences could exist between these conditions. In particular, differences in neurophysiological responses to these conditions are not clear. Our study aimed to investigate correlations between oxygen saturation (SpO2) and neural responses in NH and HH. We recorded 5‐min of resting‐state eyes‐open electroencephalogram (EEG) and SpO2 during control, NH, and HH conditions from 13 participants. We applied a multivariate framework to characterize correlations between SpO2 and EEG measures (spectral power and multiscale entropy [MSE]), within each participant and at the group level. Participants were desaturating during the first 150 s of NH versus steadily desaturated in HH. We considered the entire time interval, first and second half intervals, separately. All the conditions were characterized by statistically significant participant‐specific patterns of EEG–SpO2 correlations. However, at the group level, the desaturation period expressed a robust pattern of these correlations across frequencies and brain locations. Specifically, the first 150 s of NH during desaturation differed significantly from the other conditions with negative absolute alpha power–SpO2 correlations and positive MSE–SpO2 correlations. Once steadily desaturated, NH and HH had no significant differences in EEG–SpO2 correlations. Our findings indicate that the desaturating phase of hypoxia is a critical period in HAI courses, which would require developing strategies for mitigating the hypoxic stimulus in a real‐world situation.
Changes in white matter microstructure following serial ketamine infusions in treatment resistant depression
Authors: Taraku Brandon , Woods Roger P. , Boucher Michael , Espinoza Randall , Jog Mayank , Al‐Sharif Noor , Narr Katherine L. , Zavaliangos‐Petropulu Artemis
Published: January 2023

Ketamine produces fast‐acting antidepressant effects in treatment resistant depression (TRD). Though prior studies report ketamine‐related changes in brain activity in TRD, understanding of ketamine's effect on white matter (WM) microstructure remains limited. We thus sought to examine WM neuroplasticity and associated clinical improvements following serial ketamine infusion (SKI) in TRD. TRD patients (N = 57, 49.12% female, mean age: 39.9) received four intravenous ketamine infusions (0.5 mg/kg) 2–3 days apart. Diffusion‐weighted scans and clinical assessments (Hamilton Depression Rating Scale [HDRS‐17]; Snaith Hamilton Pleasure Scale [SHAPS]) were collected at baseline and 24‐h after SKI. WM measures including the neurite density index (NDI) and orientation dispersion index (ODI) from the neurite orientation dispersion and density imaging (NODDI) model, and fractional anisotropy (FA) from the diffusion tensor model were compared voxelwise pre‐ to post‐SKI after using Tract‐Based Spatial Statistics workflows to align WM tracts across subjects/time. Correlations between change in WM metrics and clinical measures were subsequently assessed. Following SKI, patients showed significant improvements in HDRS‐17 (p‐value = 1.8 E‐17) and SHAPS (p‐value = 1.97 E‐10). NDI significantly decreased in occipitotemporal WM pathways (p < .05, FWER/TFCE corrected). ΔSHAPS significantly correlated with ΔNDI in the left internal capsule and left superior longitudinal fasciculus (r = −0.614, p‐value = 6.24E‐09). No significant changes in ODI or FA were observed. SKI leads to significant changes in the microstructural features of neurites within occipitotemporal tracts, and changes in neurite density within tracts connecting the basal ganglia, thalamus, and cortex relate to improvements in anhedonia. NODDI may be more sensitive for detecting ketamine‐induced WM changes than DTI.
Perspectives of human–water co‐evolution of blue–green water resources in subtropical areas
Authors: Pan Zihao , Yang Shengtian , Lou Hezhen , Li Chaojun , Zhang Jun , Zhang Yujia , Luo Ya , Li Xi
Published: January 2023

Blue–green water resources and their transformation play a vital role in crop production and ecosystem services regulation, and their distribution and utilization are affected by human activity, such as policy‐driven green water resources development projects. However, it is unclear how policy‐driven green water resources development projects, such as the Grain for Green Project (GGP) in China, affect eco‐environmental quality and socio‐economic development, that is, human–water co‐evolution. Therefore, considering the GGP in a subtropical ungauged basin in southern China as an example, based on remote sensing hydrological station (RSHS) technology and multisource remote sensing data, this study analyzed the impact of the GGP on human–water co‐evolution from the perspective of blue–green water resources. The results show that: (1) From 2001 to 2020 the GGP transformed more blue water resources into green water resources, resulting in an increase in green water resources of 282.29% compared to that of blue water resources. (2) Due to the initial success of the GGP in 2005, there was a distinct positive correlation between the green water coefficient (GWC) and basin development index (BDI) from 2005 to 2020 (R2 = 0.70, p < 0.05), indicating that the GGP did not cause conflict between the sustainability of socio‐economic development and the health of the ecological environment. (3) In the GGP scenario, in which the cultivated land area maintained 50% of the current decreasing rate, the overall efficiency index maintain a continuously increasing trend at an average rate of 0.001 year−1 from 2021 to 2050, which not only improved the eco‐environmental quality but also met cultivated land demand. This research reveals the role of GGP in promoting the transformation from blue to green water resources, and proves the feasibility of the simultaneous promotion of GGP and socio‐economic development, providing significant insights for the promotion of policy‐driven green water resources development projects and long‐term blue–green water resources planning and management in other countries or regions.
PM2.5 induces autophagy‐dependent ferroptosis by endoplasmic reticulum stress in SH‐SY5Y cells
Authors: Guo Can Can , Xu Zhao Meng , Lyu Yi , Li Xiao Hui , Li Zhao Fei , He Hui , Tian Feng Jie , Zheng Jin Ping
Published: January 2023

Fine particulate matter (PM2.5) has been a global environmental problem threatening public health in recent years. PM2.5 exposure was associated with an increased risk of neurodegenerative diseases related to neuronal apoptosis. Ferroptosis is a nonapoptotic form of programmed the cell death, characterized by excess iron‐dependent lipid peroxidation products. Whether PM2.5 could induce ferroptosis in cells and thus be involved in its neurotoxicity is unknown. In this study, we found that PM2.5 induced endoplasmic reticulum stress, apoptosis, autophagy, and ferroptosis in neuroblastoma human neuroblastoma cells (SH‐SY5Y). Interestingly, ferroptosis was the predominant form of mortality in the presence of high doses of PM2.5 exposure. In addition, the endoplasmic reticulum stress inhibitor 4‐phenylbutyric acid (4‐PBA) inhibited PM2.5‐induced cellular autophagy, apoptosis, and ferroptosis. Autophagy inhibitors chloroquine (CQ) alleviated PM2.5‐induced ferroptosis but did not reverse apoptosis. We also found that inhibition of both endoplasmic reticulum stress and autophagy reversed the PM2.5‐induced increase in the expression level of cytophagy nuclear receptor coactivator 4 (NCOA4). Our results suggested that PM2.5‐induced ferroptosis in SH‐SY5Y cells was autophagy‐dependent ferroptosis due to endoplasmic reticulum stress, which might be associated with the elevation of iron content caused by NCOA4‐mediated ferritin autophagy.
Heterogeneity in winged helix‐turn‐helix and substrate DNA interactions: Insights from theory and experiments
Authors: Boral Aparna , Mitra Devrani
Published: January 2023

Specific interactions between transcription factors (TFs) and substrate DNA constitute the fundamental basis of gene expression. Unlike in TFs like basic helix‐loop‐helix or basic leucine zippers, prediction of substrate DNA is extremely challenging for helix‐turn‐helix (HTH). Experimental techniques like chromatin immunoprecipitation combined with massively parallel DNA sequencing remains a viable option. We characterize the molecular basis of heterogeneity in HTH‐DNA interaction using in silico tools and thence validate them experimentally. Given the profound functional diversity in HTH, we focus primarily on winged‐HTH (wHTH). We consider 180 wHTH TFs, whose experimental three‐dimensional structures are available in DNA bound/unbound conformations. Starting with PDB‐wide scanning and curation of data, we construct a phylogenetic tree, which distributes 180 wHTH sequences under multiple sub‐groups. Structure‐sequence alignment followed by detailed intra/intergroup analysis, covariation studies and extensive network theory analysis help us to gain deep insight into heterogeneous wHTH‐substrate DNA interactions. A central aim of this study is to find a consensus to predict the substrate DNA sequence for wHTH, amidst heterogeneity. The strength of our exhaustive theoretical investigations including molecular docking are successfully tested through experimental characterization of wHTH TF from Sulfurimonas denitrificans.
Causal linkage of tobacco smoking with ageing: Mendelian randomization analysis towards telomere attrition and sarcopenia
Authors: Park Sehoon , Kim Seong Geun , Lee Soojin , Kim Yaerim , Cho Semin , Kim Kwangsoo , Kim Yong Chul , Han Seung Seok , Lee Hajeong , Lee Jung Pyo , Joo Kwon Wook , Lim Chun Soo , Kim Yon Su , Kim Dong Ki
Published: January 2023

Background

Ageing traits and frailty are important health issues in modern medicine. Evidence supporting the causal effects of tobacco smoking on various ageing traits is required.

Methods

This study performed Mendelian randomization (MR) analysis instrumenting 377 genetic variants associated with being an ever‐smoker at a genome‐wide significance level to test the causal estimates from tobacco smoking. The outcome data were obtained from 337 138 white British ancestry participants from the UK Biobank. Leucocyte telomere length, appendicular lean mass index, subjective walking pace, handgrip strength, and wristband accelerometry‐determined physical activity degree were collected as ageing‐related outcomes. Summary‐level MR analysis was performed using the inverse variance‐weighted method and pleiotropy‐robust MR methods, including weighted median and MR‐Egger. Observational association between the outcome traits and phenotypically being an ever‐smoker was also investigated.

Results

Summary‐level MR analysis indicated that a higher genetic predisposition for tobacco smoking was significantly associated with shorter leucocyte telomere length (twofold increase in prevalence of smoking towards standardized Z‐score, −0.041 [−0.054, −0.028]), lower appendicular lean mass index (−0.007 [−0.010, −0.005]), slower walking pace (ordinal category, −0.047 [−0.054, −0.033]) and lower time spent on moderate‐to‐vigorous physical activity (hours per week, −0.39 [−0.56, −0.23]). The causal estimates were non‐significant towards handgrip strength phenotype (kg, 0.074 [−0.055, 0.204]). Pleiotropy‐robust MR results generally supported the main causal estimates. The observational findings also showed significant association between being an ever‐smoker and the ageing traits.

Conclusions

Genetically predicted and observational tobacco smoking status are significantly associated with poor ageing phenotypes. Healthcare providers may continue to reduce tobacco use, which may be helpful in reducing the burden of ageing and frailty.
Saccharin‐catalyzed multicomponent cascade reactions for the synthesis of 1,2,3,4,6‐pentasubstituted piperidines
Authors: Xia Zihao , Wu Lisha , Yan Shiqiang , Zhao Hanqing
Published: January 2023

A convenient and efficient method is developed for the synthesis of 1,2,3,4,6‐pentasubstituted piperidines via a three‐component, one‐pot domino reaction of β‐ketoesters, aromatic aldehydes, and aromatic amines in the presence of a catalytic amount of saccharin in methanol at 40°C. The desired piperidines could be easily collected through simple filtration with excellent diastereoselectivities.
Locomotor adaptations in the Early Miocene species Diamantomys luederitzi (Rodentia, Mammalia) from Uganda (Napak)
Authors: Bento Da Costa Laura , Bardin Jérémie , Senut Brigitte
Published: January 2023

The study of morphological adaptations to different ecological parameters among fossil vertebrates has been an important challenge in recent decades. In this paper, we focus on the link between morphological traits and locomotor behavior such as terrestriality, fossoriality and arboreality (including gliding). One of the most diverse groups in which various locomotor habits are represented is rodents, occupying a wide range of ecological niches. This work highlights morphological variations in skulls and humerus in extant rodents with varying locomotion, to predict this parameter in the extinct species Diamantomys luederitzi (Early Miocene, Napak, Uganda). Linear discriminant analysis and phylogenetic flexible discriminant analysis are used to analyze datasets obtained via traditional morphometry (measurements) and geometric morphometrics (landmarks). The results show good discrimination between locomotor groups for both structures in extant species: the skull has a wider and longer rostrum in terrestrial and fossorial taxa compared to arboreal rodents, is also higher and posteriorly wider in fossorial taxa; the distal humerus shows elongation of the trochlea and capitulum and a higher trochlea in fossorial and terrestrial species, allowing an increase of stability instead of mobility, which is more important in arboreal taxa for movement in trees. In D. luederitzi, all skull analyses except one predicted it as a terrestrial species, the other prediction as a glider was possibly linked to the diet. For the distal humerus, this species has been predicted as a terrestrial, fossorial and arboreal taxon in differing analyses, reflected by morphological traits represented in these different locomotor categories. These varying predictions could highlight the intraspecific variation in this fossil species as well as its locomotor repertoire, raising a discussion about the use of different methods in such analyses. In addition to these predictions, several issues are discussed, such as the presence of locomotor signal in the skull and its validity in locomotor studies, as well as the relevance of the use of fragmentary material in such analyses. The results obtained in this work highlight the importance of the locomotor signal in these structures, as well as the possibility of taking into account poorly preserved material, in particular the distal humerus.
B‐cell cytokine responses to Porphyromonas gingivalis in patients with periodontitis and healthy controls
Authors: Danielsen Anne Katrine , Damgaard Christian , Massarenti Laura , Østrup Peter , Riis Hansen Peter , Holmstrup Palle , Nielsen Claus H.
Published: January 2023

Background

Cytokine‐producing B cells play a well‐established role in modifying immune responses in chronic inflammatory diseases. We characterized B‐cell cytokine responses against periodontitis‐associated bacteria in patients with periodontitis.

Methods

Blood and saliva samples were collected from patients with periodontitis grade B (N = 31) or grade C (N = 25), and 25 healthy controls (HCs). Mononuclear cells were stimulated with Porphyromonas gingivalis, Fusobacterium nucleatum, Staphylococcus epidermidis, or Cutibacterium acnes, and B‐cell production of tumor necrosis factor (TNF)‐α, interleukin (IL)‐6, interferon (IFN)‐γ, IL‐10 and transforming growth factor (TGF)‐β by B cells was assessed by flow cytometry.

Results

HCs had higher baseline frequencies of B cells producing IFN‐γ or TNF‐α than grade B patients, but only B cells from grade B patients showed significant differentiation into IFN‐γ‐, TNF‐α‐, TGF‐β‐, or IL‐10‐producing cells after challenge with P. gingivalis and into IFN‐γ‐, TGF‐β‐, or IL‐10‐producing cells after challenge F. nucleatum. Notably, the baseline frequency of IL‐10‐producing B cells from grade C patients correlated inversely with clinical attachment loss (AL). The major proportion of the IFN‐γ‐ and TGF‐β‐producing B cells were CD27+ memory cells, while the IL‐10‒producing B cells were mainly CD27−CD5−.

Conclusions

B cells from grade B patients, particularly those harboring P. gingivalis, showed proinflammatory B‐cell responses to P. gingivalis. Moreover, the baseline frequency of IL‐10‐producing B cells in the grade C group correlated inversely with AL, suggesting a diminished immunoregulatory capacity of IL‐10‒producing B cells in these patients.
Chlorogenic acid improves intestinal morphology by enhancing intestinal stem‐cell activity
Authors: Qin Yumei , Wang Suqiang , Huang Weiwei , Li Kejin , Wu Min , Liu Weilin , Han Jianzhong
Published: January 2023

BACKGROUND

Chlorogenic acid (CGA), as one of the most abundant naturally occurring phenolic acids, has been documented to be beneficial for intestinal health. However, the underlying mechanism is still not fully understood. The adult intestinal stem cell is the critical driver of epithelial homeostasis and regeneration.

RESULTS

This study hypothesized that CGA exerted intestinal health effects by modulating intestinal stem‐cell functions. Lgr5‐EGFP mice were treated for 14 days, and intestinal organoids derived from these mice were treated for 3 days, using CGA solution. In comparison with the control group, CGA treatment increased intestinal villous height and crypt depth in mice and augmented the area expansion and the number of budding intestinal organoids. Quantitative polymerase chain reaction (qPCR) analysis revealed that CGA treatment significantly increased the expression of genes coding intestinal stem‐cell markers in intestinal tissue and organoids, and upregulated the expression of genes coding secretory cell lineages and enterocytes, although not statistically significantly. Fluorescence‐activated cell‐sorting analysis further confirmed that CGA augmented the number of stem cells. 5‐Ethynyl‐2'‐deoxyuridine (EdU) incorporation and Ki67 immunostaining results also demonstrated that CGA treatment enhanced intestinal stem‐cell proliferation.

CONCLUSION

Altogether, our findings indicate that CGA could activate intestinal stem‐cell and epithelial regeneration, which could contribute to the improvement of intestinal morphology or organoid growth of mice. This highlights a promising mechanism for CGA as an excellent candidate for the formulation of dietary supplements and functional foods for intestinal protection. © 2023 Society of Chemical Industry.