bluuebunny/crossref_metadata_2025 huggingface dataset:
Mythopoetic image of silver in the philosophical lyrics of Zoya Dudina
Authors: Lyubimov Nikolay Ivanovich
Published: July 2021

Within the framework of studying the poetics of modern Mari philosophical poetry, this article analyzes the mythopoetic image of silver in the lyrics of Zoya Dudina. Based on the compilation of poems “Kuanyshym, Kuem Ondal...” (joyful to hug a birch tree… (2012), the author determines the semantics and article functions of this image, which represents the philosophical view and perception of the world of the poetess that in a certain way characterizes the lyrical heroine. From such perspective, the lyrics of Zoya Dudina is examines for the first time. The research methodology employs structural-semantic analysis of the literary works, which allowed describing the structural-semantic aspects the image of silver, revealing the authorial concept of the world and man, as well as the character of the lyrical heroine. It is proven that the Mari poetess Zoya Dudina consistently refers to the image of silver in her lyrics. For the poetess, silver is not a precious metal, which attracts people as jewelry, it is a mythopoetic image, the semantics of which is interrelated with the traditional (pagan) culture of the Mari people. Most of the time, this image is depicted within the structure of the natural picture, and reflects the view and perception of the lyrical heroine; it impersonates natural purity, nobility, faithful love, strong friendship, good intentions, unity the of man, nature, and the traditions. It is also underlined that in the mythological context for the lyrical heroine, silver can even resemble the mood.
Instability in NAD+ metabolism leads to impaired cardiac mitochondrial function and communication
Authors: Lauritzen Knut H , Olsen Maria Belland , Ahmed Mohammed Shakil , Yang Kuan , Rinholm Johanne Egge , Bergersen Linda H , Esbensen Qin Ying , Sverkeli Lars Jansen , Ziegler Mathias , Attramadal Håvard , Halvorsen Bente , Aukrust Pål , Yndestad Arne
Published: August 2021

Poly(ADP-ribose) polymerase (PARP) enzymes initiate (mt)DNA repair mechanisms and use nicotinamide adenine dinucleotide (NAD+) as energy source. Prolonged PARP activity can drain cellular NAD+ reserves, leading to de-regulation of important molecular processes. Here, we provide evidence of a pathophysiological mechanism that connects mtDNA damage to cardiac dysfunction via reduced NAD+ levels and loss of mitochondrial function and communication. Using a transgenic model, we demonstrate that high levels of mice cardiomyocyte mtDNA damage cause a reduction in NAD+ levels due to extreme DNA repair activity, causing impaired activation of NAD+-dependent SIRT3. In addition, we show that myocardial mtDNA damage in combination with high dosages of nicotinamideriboside (NR) causes an inhibition of sirtuin activity due to accumulation of nicotinamide (NAM), in addition to irregular cardiac mitochondrial morphology. Consequently, high doses of NR should be used with caution, especially when cardiomyopathic symptoms are caused by mitochondrial dysfunction and instability of mtDNA.
Physiological and motion signatures in static and time-varying functional connectivity and their subject identifiability
Authors: Xifra-Porxas Alba , Kassinopoulos Michalis , Mitsis Georgios D
Published: August 2021

Human brain connectivity yields significant potential as a noninvasive biomarker. Several studies have used fMRI-based connectivity fingerprinting to characterize individual patterns of brain activity. However, it is not clear whether these patterns mainly reflect neural activity or the effect of physiological and motion processes. To answer this question, we capitalize on a large data sample from the Human Connectome Project and rigorously investigate the contribution of the aforementioned processes on functional connectivity (FC) and time-varying FC, as well as their contribution to subject identifiability. We find that head motion, as well as heart rate and breathing fluctuations, induce artifactual connectivity within distinct resting-state networks and that they correlate with recurrent patterns in time-varying FC. Even though the spatiotemporal signatures of these processes yield above-chance levels in subject identifiability, removing their effects at the preprocessing stage improves identifiability, suggesting a neural component underpinning the inter-individual differences in connectivity.
The role of ventromedial prefrontal cortex in reward valuation and future thinking during intertemporal choice
Authors: Ciaramelli Elisa , De Luca Flavia , Kwan Donna , Mok Jenkin , Bianconi Francesca , Knyagnytska Violetta , Craver Carl , Green Leonard , Myerson Joel , Rosenbaum R Shayna
Published: August 2021

Intertemporal choices require trade-offs between short-term and long-term outcomes. Ventromedial prefrontal cortex (vmPFC) damage causes steep discounting of future rewards (delay discounting [DD]) and impoverished episodic future thinking (EFT). The role of vmPFC in reward valuation, EFT, and their interaction during intertemporal choice is still unclear. Here, 12 patients with lesions to vmPFC and 41 healthy controls chose between smaller-immediate and larger-delayed hypothetical monetary rewards while we manipulated reward magnitude and the availability of EFT cues. In the EFT condition, participants imagined personal events to occur at the delays associated with the larger-delayed rewards. We found that DD was steeper in vmPFC patients compared to controls, and not modulated by reward magnitude. However, EFT cues downregulated DD in vmPFC patients as well as controls. These findings indicate that vmPFC integrity is critical for the valuation of (future) rewards, but not to instill EFT in intertemporal choice.
Cortical magnification in human visual cortex parallels task performance around the visual field
Authors: Benson Noah C , Kupers Eline R , Barbot Antoine , Carrasco Marisa , Winawer Jonathan
Published: August 2021

Human vision has striking radial asymmetries, with performance on many tasks varying sharply with stimulus polar angle. Performance is generally better on the horizontal than vertical meridian, and on the lower than upper vertical meridian, and these asymmetries decrease gradually with deviation from the vertical meridian. Here, we report cortical magnification at a fine angular resolution around the visual field. This precision enables comparisons between cortical magnification and behavior, between cortical magnification and retinal cell densities, and between cortical magnification in twin pairs. We show that cortical magnification in the human primary visual cortex, measured in 163 subjects, varies substantially around the visual field, with a pattern similar to behavior. These radial asymmetries in the cortex are larger than those found in the retina, and they are correlated between monozygotic twin pairs. These findings indicate a tight link between cortical topography and behavior, and suggest that visual field asymmetries are partly heritable.
Within-host evolutionary dynamics of seasonal and pandemic human influenza A viruses in young children
Authors: Han Alvin X , Felix Garza Zandra C , Welkers Matthijs RA , Vigeveno René M , Tran Nhu Duong , Le Thi Quynh Mai , Pham Quang Thai , Dang Dinh Thoang , Tran Thi Ngoc Anh , Ha Manh Tuan , Nguyen Thanh Hung , Le Quoc Thinh , Le Thanh Hai , Hoang Thi Bich Ngoc , Chokephaibulkit Kulkanya , Puthavathana Pilaipan , Nguyen Van Vinh Chau , Nghiem My Ngoc , Nguyen Van Kinh , Dao Tuyet Trinh , Tran Tinh Hien , Wertheim Heiman FL , Horby Peter W , Fox Annette , van Doorn H Rogier , Eggink Dirk , de Jong Menno D , Russell Colin A
Published: August 2021

The evolution of influenza viruses is fundamentally shaped by within-host processes. However, the within-host evolutionary dynamics of influenza viruses remain incompletely understood, in part because most studies have focused on infections in healthy adults based on single timepoint data. Here, we analyzed the within-host evolution of 82 longitudinally sampled individuals, mostly young children, infected with A/H1N1pdm09 or A/H3N2 viruses between 2007 and 2009. For A/H1N1pdm09 infections during the 2009 pandemic, nonsynonymous minority variants were more prevalent than synonymous ones. For A/H3N2 viruses in young children, early infection was dominated by purifying selection. As these infections progressed, nonsynonymous variants typically increased in frequency even when within-host virus titers decreased. Unlike the short-lived infections of adults where de novo within-host variants are rare, longer infections in young children allow for the maintenance of virus diversity via mutation-selection balance creating potentially important opportunities for within-host virus evolution.
Role of direct and indirect social and spatial ties in the diffusion of HIV and HCV among people who inject drugs: a cross-sectional community-based network analysis in New Delhi, India
Authors: Clipman Steven J , Mehta Shruti H , Srikrishnan Aylur K , Zook Katie JC , Duggal Priya , Mohapatra Shobha , Shanmugam Saravanan , Nandagopal Paneerselvam , Kumar Muniratnam S , Ogburn Elizabeth , Lucas Gregory M , Latkin Carl A , Solomon Sunil S
Published: August 2021

Background:

People who inject drugs (PWID) account for some of the most explosive human immunodeficiency virus (HIV) and hepatitis C virus (HCV) epidemics globally. While individual drivers of infection are well understood, less is known about network factors, with minimal data beyond direct ties.

Methods:

2512 PWID in New Delhi, India were recruited in 2017–19 using a sociometric network design. Sampling was initiated with 10 indexes who recruited named injection partners (people who they injected with in the prior month). Each recruit then recruited their named injection partners following the same process with cross-network linkages established by biometric data. Participants responded to a survey, including information on injection venues, and provided a blood sample. Factors associated with HIV/HCV infection were identified using logistic regression.

Results:

The median age was 26; 99% were male. Baseline HIV prevalence was 37.0% and 46.8% were actively infected with HCV (HCV RNA positive). The odds of prevalent HIV and active HCV infection decreased with each additional degree of separation from an infected alter (HIV AOR: 0.87; HCV AOR: 0.90) and increased among those who injected at a specific venue (HIV AOR: 1.50; HCV AOR: 1.69) independent of individual-level factors (p<0.001). In addition, sociometric factors, for example, network distance to an infected alter, were statistically significant predictors even when considering immediate egocentric ties.

Conclusions:

These data demonstrate an extremely high burden of HIV and HCV infection and a highly interconnected injection and spatial network structure. Incorporating network and spatial data into the design/implementation of interventions may help interrupt transmission while improving efficiency.

Funding:

National Institute on Drug Abuse and the Johns Hopkins University Center for AIDS Research.
A precisely adjustable, variation-suppressed eukaryotic transcriptional controller to enable genetic discovery
Authors: Azizoglu Asli , Brent Roger , Rudolf Fabian
Published: August 2021

Conditional expression of genes and observation of phenotype remain central to biological discovery. Current methods enable either on/off or imprecisely controlled graded gene expression. We developed a 'well-tempered' controller, WTC846, for precisely adjustable, graded, growth condition independent expression of genes in Saccharomyces cerevisiae. Controlled genes are expressed from a strong semisynthetic promoter repressed by the prokaryotic TetR, which also represses its own synthesis; with basal expression abolished by a second, 'zeroing' repressor. The autorepression loop lowers cell-to-cell variation while enabling precise adjustment of protein expression by a chemical inducer. WTC846 allelic strains in which the controller replaced the native promoters recapitulated known null phenotypes (CDC42, TPI1), exhibited novel overexpression phenotypes (IPL1), showed protein dosage-dependent growth rates and morphological phenotypes (CDC28, TOR2, PMA1 and the hitherto uncharacterized PBR1), and enabled cell cycle synchronization (CDC20). WTC846 defines an 'expression clamp' allowing protein dosage to be adjusted by the experimenter across the range of cellular protein abundances, with limited variation around the setpoint.
Endomembrane targeting of human OAS1 p46 augments antiviral activity
Authors: Soveg Frank W , Schwerk Johannes , Gokhale Nandan S , Cerosaletti Karen , Smith Julian R , Pairo-Castineira Erola , Kell Alison M , Forero Adriana , Zaver Shivam A , Esser-Nobis Katharina , Roby Justin A , Hsiang Tien-Ying , Ozarkar Snehal , Clingan Jonathan M , McAnarney Eileen T , Stone Amy EL , Malhotra Uma , Speake Cate , Perez Joseph , Balu Chiraag , Allenspach Eric J , Hyde Jennifer L , Menachery Vineet D , Sarkar Saumendra N , Woodward Joshua J , Stetson Daniel B , Baillie John Kenneth , Buckner Jane H , Gale Michael , Savan Ram
Published: August 2021

Many host RNA sensors are positioned in the cytosol to detect viral RNA during infection. However, most positive-strand RNA viruses replicate within a modified organelle co-opted from intracellular membranes of the endomembrane system, which shields viral products from cellular innate immune sensors. Targeting innate RNA sensors to the endomembrane system may enhance their ability to sense RNA generated by viruses that use these compartments for replication. Here, we reveal that an isoform of oligoadenylate synthetase 1, OAS1 p46, is prenylated and targeted to the endomembrane system. Membrane localization of OAS1 p46 confers enhanced access to viral replication sites and results in increased antiviral activity against a subset of RNA viruses including flaviviruses, picornaviruses, and SARS-CoV-2. Finally, our human genetic analysis shows that the OAS1 splice-site SNP responsible for production of the OAS1 p46 isoform correlates with protection from severe COVID-19. This study highlights the importance of endomembrane targeting for the antiviral specificity of OAS1 and suggests that early control of SARS-CoV-2 replication through OAS1 p46 is an important determinant of COVID-19 severity.
Role of Neutrophil Lymphocyte Ratio as a Prognostic Biomarker in COVID-19 Infection in Indian Patients: A Single Centre Observational Study from South India
Authors: Gurusamy Dharma Saranya , Alagesan S , Kandasamy Sunitha , Ugesan Vasuki Selvamur , Saradha M , Kalyanaraman Shantaraman
Published: July 2021

Introduction: Early identification of severe disease in Coronavirus Disease-2019 (COVID-19) infection is important to reduce mortality and for the efficient allocation of medical resources. Several studies have established that severe cases of COVID-19 infections tend to have a higher Neutrophil Lymphocyte Ratio (NLR) and is an independent predictor of mortality. Aim: This study aimed to determine whether NLR can serve as a predictor of the prognosis of COVID-19 infections in Indian patients. Materials and Methods: This study was an ambispective observational single centre study conducted in Tirunelveli Medical College from March 2020 to July 2020. Clinical and laboratory data of 1100 laboratory-confirmed COVID-19 infected patients were reviewed in this study. The patients were categorised as, asymptomatic, mild, moderate, and severe cases based on their clinical presentation. The demographic, clinical characteristics and laboratory data on the day of admission were analysed and compared by tertiles of the NLR. The receiver operating curve was applied to determine the threshold of NLR and the prognostic value was assessed via the Kaplan-Meier curve and regression models. Results: A total of 1100 cases were included in the study and were subdivided based on the clinical presentation into mild (n=226), moderate (n=27), severe (n=67), and asymptomatic (n=780) cases. The overall mortality rate was 4.9%. The ROC curve indicated that NLR is a better predictor of severe disease than other haematological parameters, with 89.3% Area Under the Curve (AUC) at the cut-off value of 2.81 with 80.6% sensitivity and 87.1% specificity. Multivariate analysis established that patients with NLR >2.8 had higher odds (OR=19.809, 95% CI-10.159-38.622) of severe infection and mortality (HR=1.110, 95% CI-1.088-1.113). Kaplan-Meier curve showed a significant difference (p-value<0.001) in the duration of hospital stay between patients with NLR <2.8 (Mean=10.4 days) and NLR >2.8 (13.1 days). Conclusion: Early identification of COVID-19 patients with severe disease is important to reduce mortality. Elevated NLR is associated with severe disease in Severe Acute Resiratory Syndrome Coronavirus-2 (SARS-CoV-2) infection. NLR >2.8 in Indian population, may aid in identification of severe illness necessitating early access to intensive care unit and requirement of respiratory support.
Proximate Composition and Sensory Properties of Dakere (A Nigerian Steamed Agglomerated Dumpling) as Affected by Differential Sieving and Fortiftcation with Legume Flour
Authors: Gadzama Umar Sabo , Agbara Gervase Ikechukwu , Igwegbe Odera Amin
Published: August 2021

Dakere is a traditional steamed agglomerated dumpling produced from either millet (M) or sorghum (S) flour or both (MS). In the current study, millet and sorghum flours were separately fractionated into fine (f) (<250um), medium (m) (250-350um) and coarse (350-500um) fractions. Similar fractions from millet and sorghum were blended to obtain MfSf,MmSm and McSc. Each fraction was fortified separately with 30% toasted bambara groundnut or sesame seed flour or both (20% bambara groundnut and 10% sesame seed flour), blends were coded: MfSf, MmSm, McSc, MfSfB, MmSmB, McScB, MfSfSe, MmSmSe, McScSe, MfSfBSe, MmSmBSe and McScBSe. Experimental design corresponding to a 3x2x2 factorial design was used to generate runs and dakere were produced applying the traditional method of agglomeration of stiff dough followed by steaming, and thereafter dried. Traditional dakere was the experimental control. The blends and the dried modified dakere were evaluated for proximate composition and sensory properties. The moisture, crude protein, crude fat, crude fibre, total ash and carbohydrate contents of the  blended fractions and the fortified blended fractions varied significantly (p<0-05): 9.40-10.55%,11.42-15.80%,1.20-2.22%, 0.62-0.96%, 3.62-7.38% and 63.56-72.30% respectively and for the various modified dakere: 9.20-10.255, 11.70-16.82%, 1.23-2.77%, 0.55-0.88%, 4.64-8.30% and 60.22-70.86% respectively. Blended fractions and fortified blended fractions had greater nutrient density than the control, however more in the blends containing both bambara groundnut and sesame seed flours. As for sensory attributes of the modified dakere, the blended fractions especially MfSf had the best appearance, fortified dakere the best aroma and taste scores especially dakere with sesame seed meal despite the dull appearance. Dakere produced with blended coarse fractions or fortified coarse fractions were crispier and were desired more than others. The overall acceptability scores were generally high, the highest score observed in the sesame seed meal treated dakere. The study had succeeded in enhancing the nutrient density and sensory properties of dakere, an agglomerated stiff dough through the blending of similar flour fractions from millet and sorghum and fortification of the same with grain legume flours.
Assessment of Sexual Functions among Male with Substance Use Disorders
Authors: Tolba Ahmed Osama , Selem Mohammad Abd El Hakim , Ragab Maged Mostafa , Mubarak Ahmed Abd El Rahman , Badawy Adel Abd El Kerem
Published: August 2021

Background: Recent epidemiological and clinical studies confirmed the presence of a strong association between substance use disorders and sexual dysfunctions. Studies have demonstrated that prevalence of sexual dysfunctions among addict was about 30 %the most common problem among male substance abuse patients were Erectile Dysfunction (ED) and delayed ejaculation

Methods: This cohort comparative study was conducted on of 376 males aged between 18 – 50 years who were substance abusers including tramadol, cannabis and poly substance related and addictive disorders. All participants were subjected to psychiatric interview which was done using SCID-5-CV structured clinical interview for DSM-5 disorders. Psychometric, biochemical, medical and drug history evaluations were also performed.

Results: Our results show comparison between four groups (opiates-cannabis-poly substance abuse and control group according to severity of drug abuse, psychiatric evaluation and according to sexual functions. There were statistically significant differences between groups in sociodemographic data mainly in occupational and educational history. There also were statistically significant differences between groups in terms of drug use, psychiatric assessment, assessment of sexual activity, hormonal assessment of the studied population and quality of life assessment.

Conclusions: Long term drug use has a statistically significant negative effect on all domains of male sexual functions. Also average daily dose and severity of addiction are significantly correlated to sexual dysfunctions in patients with tramadol abuse. This is done through an alteration in sex hormone and alters feedback regulations of the pituitary on the hypothalamus.
Ethno Medicinal Plants used for Aphrodisiac Activity in North-East, India
Authors: Choudhury Md Rejwan Ahmed , Basak Mrinmoy
Published: July 2021

North Eastern Region of India is the home for a wide variety of plants with high medicinal value. The wide availability of the plant with high medicinal value has provided the ease of their use for generations among the various ethnic communities of the region to treat various kinds of health issues. This paper presents an extensive review of the various plants that were pointed out in various ethno botanical surveys that are being used by the people of North Eastern India with aphrodisiac activity. The common name along with the biological names and the part used and other details have been reported in the paper with an intention of making it easier for researchers to develop newer herbal aphrodisiac formulations.
A Review Article on the Relation between Anxiety and Depression
Authors: Meshram Ayushi , Jha Rakesh Kumar , Muley Parikshit
Published: July 2021

Anxiety depression is the commonest phenomena in preponderant population. Many individuals might have experience it and still not know, very often in a state of constant denial and negligence with the fact knowingly. The causes can vary from psychological, physiological and traumatic past experiences. This article incorporate studies of anxietydepression and their relationship and causes. Anxiety depression are the most common psychological disorder. Their relationship is very baffling, their symptoms overlaps with each other. There are many causes for it physiological, psychological, behavioural, insomnia, or due to past trauma. Physical exercise reduces the symptoms of mild anxiety and depression.
Development and Validation of a Daily Monitoring Stroke Scale: A Three-Month Follow up Study
Authors: Aradhey Parag , Kumar Sunil , Acharya Sourya
Published: August 2021

Introduction: Stroke is the one of the common health problems world-wide causing significant morbidity and mortality. Various scales are framed and validated for use in stroke trials and clinical use. Most widely used scale for stroke assessment is NIHSS scale but this scale is infrequently used in routine clinical practice. This is because of various limitations like poor representation of posterior circulation deficit and predominant motor and language representation and poor representation of fine motor & cognition deficits in this scale.

Objective: Therefore, the purpose of the present study is to formulate a daily monitoring scale which can objectively assess and prognosticate stroke patients. Present study aims to incorporate daily examined parameters in one instrument to develop a routinely useful tool for neurologist and physician which can be simple, fast, reliable, and reproducible.

Method: We will include GCS score, brainstem reflexes, gaze, speech, distal and proximal motor power, inattention, ataxia, sensory deficits and gait examination parameters in proposed scale. After initial pilot study (15 patients), we will include developmental cohort (400 patients) and validation cohort (60 patients) to formulate and validate this study. Outcome measures will be 30 -day mortality and morbidity assessed at day 30 and 90 with modified Rankin score and Barthel index. Total patients included will be 460 patients with follow up for 3 months

Results: It is expected to develop simple, reliable, and reproducible scale for monitoring of acute stroke patients.
Single‐dose immunisation with a multimerised SARS‐CoV‐2 receptor binding domain (RBD) induces an enhanced and protective response in mice
Authors: Salzer Ralf , Clark Jordan J. , Vaysburd Marina , Chang Veronica T. , Albecka Anna , Kiss Leo , Sharma Parul , Gonzalez Llamazares Andres , Kipar Anja , Hiscox Julian A. , Owen Andrew , Aricescu A. Radu , Stewart James P. , James Leo C. , Löwe Jan
Published: July 2021

The COVID‐19 pandemic, caused by the SARS‐CoV‐2 coronavirus, has triggered a worldwide health emergency. Here, we show that ferritin‐like Dps from hyperthermophilic Sulfolobus islandicus, covalently coupled with SARS‐CoV‐2 antigens via the SpyCatcher system, forms stable multivalent dodecameric vaccine nanoparticles that remain intact even after lyophilisation. Immunisation experiments in mice demonstrated that the SARS‐CoV‐2 receptor binding domain (RBD) coupled to Dps (RBD‐S‐Dps) elicited a higher antibody titre and an enhanced neutralising antibody response compared to monomeric RBD. A single immunisation with RBD‐S‐Dps completely protected hACE2‐expressing mice from serious illness and led to viral clearance from the lungs upon SARS‐CoV‐2 infection. Our data highlight that multimerised SARS‐CoV‐2 subunit vaccines are a highly efficacious modality, particularly when combined with an ultra‐stable scaffold.
Photosystem II
Authors: Shevela Dmitry , Kern Jan F , Govindjee Govindjee , Whitmarsh John , Messinger Johannes
Published: July 2021

Photosystem II (PSII) of plants, algae and cyanobacteria is a specialised protein complex that uses light energy to transfer electrons from water to plastoquinone, producing molecular oxygen and reduced plastoquinone. The PSII complex includes a peripheral antenna containing chlorophyll and other pigments to absorb light, a reaction centre that utilises the excitation energy transferred to it for charge separation, cofactors that stabilise the charge pair via electron transfer reactions, a Mn
4
CaO
5
cluster that oxidises water, and a binding pocket where plastoquinone is reduced. The electrons and protons that PSII extracts from water are employed in the overall photosynthetic process for the reduction of CO
2
, which provides the chemical energy for most life on Earth. PSII is the only known biological source of O
2
produced from water and is responsible for the molecular oxygen in the atmosphere.

Key Concepts

Photosystem II (PSII) is a membrane‐embedded pigment–protein complex, containing more than 20 subunits and approximately 100 cofactors.

The PSII antenna and the PSII reaction centre are distinct protein complexes.

Light is absorbed by chlorophyll, carotenoid and phycobilin pigments in the antenna and the excitation energy is rapidly transferred to the reaction centre.

At the reaction centre, light‐induced charge separation takes place resulting in the formation of a chlorophyll cation and a pheophytin anion that are approximately 10 Å apart; this charge separation is rapidly stabilised by the transfer of the charges to more distant cofactors with smaller differences in redox potentials.

The oxidation of water occurs at the Mn
4
CaO
5
cluster, which is embedded in the two protein subunits D1 and CP43 on the luminal side of PSII.

To oxidise two molecules of water, four oxidising equivalents must be accumulated in the Mn
4
CaO
5
cluster by four consecutive light‐induced charge separations.

Water oxidation by PSII occurs at the Mn
4
CaO
5
cluster, likely via oxo‐oxyl radical coupling in the so‐called S
4
state.

Hydrogen‐bonding networks surrounding the Mn
4
CaO
5
cluster are crucial for its catalytic activity, as well as its structural flexibility.

Bicarbonate ions play regulatory roles for electron transfer through PSII.

The electrons and protons extracted from water by PSII drive the reduction of NADP
+
via Photosystem I, and the production of ATP, respectively.
The Direct Electrospinning and Manipulation of Magic‐Sized Cluster Quantum Dots
Authors: Han Haixiang , Hirsch Krista , Hanrath Tobias , Robinson Richard D. , Shepherd Larissa M.
Published: July 2021

To date, the production of electrospun fibers containing quantum dots (QDs) have required either a carrier material or significant postprocessing. Herein, for the first time, electrospinning only QDs and their ligands using cadmium sulfide (CdS) magic‐sized clusters (MSCs) is demonstrated. The key innovation is the exploitation of MSCs synthesized in a stabilizing organic–inorganic mesophase to create fibers consisting of only QDs and their ligands. The atomic structure of the CdS MSCs remains intact throughout the formation of the uniform, continuous, and highly organized ribbon‐shaped fibers. For higher applied voltage, thinner fibers with more densely packed structures are achieved as compared with a lower voltage. By electrospinning and manipulating fibers, the hierarchical organization of CdS QDs over six orders of magnitude is highlighted. The one‐step, direct fabrication of CdS MSC fibers by traditional electrospinning provides a promising, simple, and economical approach for other types of QDs where continuous high surface area membranes are required. Finally, by embedding fibers into an elastomer matrix, the composite is stretchable (strain, γ ≈ 1.6, without breaking), bendable, and able to be braided and woven.
A Compartmental Silica Nanoreactor for Multienzyme‐Regulated Superactive Catalytic Therapy
Authors: Wu Chu , Qin Limei , Niu Dechao , Wang Xia , Zhang Qi , Shang Yinghui , Hu Min , Han Xiaoke , Shen Saiji , Qin Xing , Xi Songyan , Li Yongsheng , Wang Qigang
Published: July 2021

Many tumor therapies take advantage of upsetting the redox balance in tumor cells, but to do so requires excessive biochemical or physical attacks. The high‐throughput simulation using multi‐pathway techniques described herein can yield an increased efficacy in bio‐oxidation. In this study, compartmental hierarchical nanoreactors are developed as an efficient multi‐pathway singlet oxygen (1O2) generation system for superactive biocatalytic tumor therapy. The penetrated super cavity and connected dual‐mesopore channels of the compartmental multienzyme nanoreactors are designed using the proposed heterogeneous template assembly for multi‐enzyme complex (superoxide dismutase (SOD)‐lactoperoxidase (LPO)) and photosensitizer molecule (indocyanine green (ICG)) encapsulation. Benefiting by the enhanced direct substrate diffusion between the interacting SOD–LPO complex and decrease in external diffusion, the parallel catalysis combined by the superactive cascade biocatalysis and enzyme‐promoted photosensitization effect is verified by this compartmental silica nanoreactor system. The parallel pathways not only make full use of the products of SOD (H2O2 and O2), but also exhibit outstanding capability for 1O2 production, at ≈2.15 and 1.70 times augmented 1O2, respectively. Both in vitro and in vivo studies demonstrate the synergetic 1O2‐mediated inhibition of tumor proliferation, lending this strategy great potential for the treatment of hypoxic tumors.
Understanding Thermal and A‐Thermal Trapping Processes in Lead Halide Perovskites Towards Effective Radiation Detection Schemes
Authors: Rodà Carmelita , Fasoli Mauro , Zaffalon Matteo L. , Cova Francesca , Pinchetti Valerio , Shamsi Javad , Abdelhady Ahmed L. , Imran Muhammad , Meinardi Francesco , Manna Liberato , Vedda Anna , Brovelli Sergio
Published: July 2021

Lead halide perovskites (LHP) are rapidly emerging as efficient, low‐cost, solution‐processable scintillators for radiation detection. Carrier trapping is arguably the most critical limitation to the scintillation performance. Nonetheless, no clear picture of the trapping and detrapping mechanisms to/from shallow and deep trap states involved in the scintillation process has been reported to date, as well as on the role of the material dimensionality. Here, this issue is addressed by performing, for the first time, a comprehensive study using radioluminescence and photoluminescence measurements side‐by‐side to thermally‐stimulated luminescence (TSL) and afterglow experiments on CsPbBr3 with increasing dimensionality, namely nanocubes, nanowires, nanosheets, and bulk crystals. All systems are found to be affected by shallow defects resulting in delayed intragap emission following detrapping via a‐thermal tunneling. TSL further reveals the existence of additional temperature‐activated detrapping pathways from deeper trap states, whose effect grows with the material dimensionality, becoming the dominant process in bulk crystals. These results highlight that, compared to massive solids where the suppression of both deep and shallow defects is critical, low dimensional nanostructures are more promising active materials for LHP scintillators, provided that their integration in functional devices meets efficient surface engineering.
Tissue Programmed Hydrogels Functionalized with GDNF Improve Human Neural Grafts in Parkinson's Disease
Authors: Hunt Cameron P. J. , Penna Vanessa , Gantner Carlos W. , Moriarty Niamh , Wang Yi , Franks Stephanie , Ermine Charlotte M. , de Luzy Isabelle R. , Pavan Chiara , Long Benjamin M. , Williams Richard J. , Thompson Lachlan H. , Nisbet David R. , Parish Clare L.
Published: July 2021

The survival and synaptic integration of transplanted dopaminergic (DA) progenitors are essential for ameliorating motor symptoms in Parkinson's disease (PD). Human pluripotent stem cell (hPSC)‐derived DA progenitors are, however, exposed to numerous stressors prior to, and during, implantation that result in poor survival. Additionally, hPSC‐derived grafts show inferior plasticity compared to fetal tissue grafts. These observations suggest that a more conducive host environment may improve graft outcomes. Here, tissue‐specific support to DA progenitor grafts is provided with a fully characterized self‐assembling peptide hydrogel. This biomimetic hydrogel matrix is programmed to support DA progenitors by i) including a laminin epitope within the matrix; and ii) shear encapsulating glial cell line‐derived neurotrophic factor (GDNF) to ensure its sustained delivery. The biocompatible hydrogel biased a 51% increase in A9 neuron specification—a subpopulation of DA neurons critical for motor function. The sustained delivery of GDNF induced a 2.7‐fold increase in DA neurons and enhanced graft plasticity, resulting in significant improvements in motor deficits at 6 months. These findings highlight the therapeutic benefit of stepwise customization of tissue‐specific hydrogels to improve the physical and trophic support of human PSC‐derived neural transplants, resulting in improved standardization, predictability and functional efficacy of grafts for PD.
Biocompatible Micron‐Scale Silk Fibers Fabricated by Microfluidic Wet Spinning
Authors: Lüken Arne , Geiger Matthias , Steinbeck Lea , Joel Anna‐Christin , Lampert Angelika , Linkhorst John , Wessling Matthias
Published: July 2021

For successful material deployment in tissue engineering, the material itself, its mechanical properties, and the microscopic geometry of the product are of particular interest. While silk is a widely applied protein‐based tissue engineering material with strong mechanical properties, the size and shape of artificially spun silk fibers are limited by existing processes. This study adjusts a microfluidic spinneret to manufacture micron‐sized wet‐spun fibers with three different materials enabling diverse geometries for tissue engineering applications. The spinneret is direct laser written (DLW) inside a microfluidic polydimethylsiloxane (PDMS) chip using two‐photon lithography, applying a novel surface treatment that enables a tight print‐channel sealing. Alginate, polyacrylonitrile, and silk fibers with diameters down to 1 µm are spun, while the spinneret geometry controls the shape of the silk fiber, and the spinning process tailors the mechanical property. Cell‐cultivation experiments affirm bio‐compatibility and showcase an interplay between the cell‐sized fibers and cells. The presented spinning process pushes the boundaries of fiber fabrication toward smaller diameters and more complex shapes with increased surface‐to‐volume ratio and will substantially contribute to future tailored tissue engineering materials for healthcare applications.
Simultaneous Manipulation of Bulk Excitons and Surface Defects for Ultrastable and Highly Selective CO2 Photoreduction
Authors: Shi Yanbiao , Zhan Guangming , Li Hao , Wang Xiaobing , Liu Xiufan , Shi Lujia , Wei Kai , Ling Cancan , Li Zhilin , Wang Hao , Mao Chengliang , Liu Xiao , Zhang Lizhi
Published: July 2021

The objective of photocatalytic CO2 reduction (PCR) is to achieve high selectivity for a single energy‐bearing product with high efficiency and stability. The bulk configuration usually determines charge carrier kinetics, whereas surface atomic arrangement defines the PCR thermodynamic pathway. Concurrent engineering of bulk and surface structures is therefore crucial for achieving the goal of PCR. Herein, an ultrastable and highly selective PCR using homogeneously doped BiOCl nanosheets synthesized via an inventive molten strategy is presented. With B2O3 as both the molten salt and doping precursor, this new doping approach ensures boron (B) doping from the surface into the bulk with dual functionalities. Bulk B doping mitigates strong excitonic effects confined in 2D BiOCl by significantly reducing exciton binding energies, whereas surface‐doped B atoms reconstruct the BiOCl surface by extracting lattice hydroxyl groups, resulting in intimate B‐oxygen vacancy (B‐OV) associates. These exclusive B‐OV associates enable spontaneous CO2 activation, suppress competitive hydrogen evolution and promote the proton‐coupled electron transfer step by stabilizing *COOH for selective CO generation. As a result, the homogeneous B‐doped BiOCl nanosheets exhibit 98% selectivity for CO2‐to‐CO reduction under visible light, with an impressive rate of 83.64 µmol g−1 h−1 and ultrastability for long‐term testing of 120 h.
In Situ Chemical Lithiation Transforms Diamond‐Like Carbon into an Ultrastrong Ion Conductor for Dendrite‐Free Lithium‐Metal Anodes
Authors: Li Zhongzhong , Peng Manqi , Zhou Xiaolong , Shin Kyungsoo , Tunmee Sarayut , Zhang Xiaoming , Xie Chengde , Saitoh Hidetoshi , Zheng Yongping , Zhou Zhiming , Tang Yongbing
Published: July 2021

Lithium (Li)‐metal anodes are of great promise for next‐generation batteries due to their high theoretical capacity and low redox potential. However, Li‐dendrite growth during cycling imposes a tremendous safety concern on the practical application of Li‐metal anodes. Herein, an effective approach to suppress Li‐dendrite growth by coating a polypropylene (PP) separator with a thin layer of ultrastrong diamond‐like carbon (DLC) is reported. Theoretical calculations indicate that the DLC coating layer undergoes in situ chemical lithiation once assembled with the lithium‐metal anode, transforming the DLC/PP separator into an excellent 3D Li‐ion conductor. This in situ lithiated DLC/PP separator can not only mechanically suppress Li‐dendrite growth by its intrinsically high modulus (≈100 GPa), but also uniformly redistributes Li ions to render dendrite‐free lithium deposition. The twofold effects of the DLC/PP separator result in stable cycling of lithium plating/stripping (over 4500 h) at a high current density of 3 mA cm−2. Remarkably, this approach enables more than 1000 stable cycles at 5 C with a capacity retention of ≈71% in a Li || LiFePO4 coin cell and more than 200 stable cycles at 0.2 C in a Li || LiNi0.5Co0.3Mn0.2O2 pouch cell with cathode mass loading of ≈9 mg cm−2.
Highly Efficient Uniaxial In‐Plane Stretching of a 2D Material via Ion Insertion
Authors: Muscher Philipp K. , Rehn Daniel A. , Sood Aditya , Lim Kipil , Luo Duan , Shen Xiaozhe , Zajac Marc , Lu Feiyu , Mehta Apurva , Li Yiyang , Wang Xijie , Reed Evan J. , Chueh William C. , Lindenberg Aaron M.
Published: July 2021

On‐chip dynamic strain engineering requires efficient micro‐actuators that can generate large in‐plane strains. Inorganic electrochemical actuators are unique in that they are driven by low voltages (≈1 V) and produce considerable strains (≈1%). However, actuation speed and efficiency are limited by mass transport of ions. Minimizing the number of ions required to actuate is thus key to enabling useful “straintronic” devices. Here, it is shown that the electrochemical intercalation of exceptionally few lithium ions into WTe2 causes large anisotropic in‐plane strain: 5% in one in‐plane direction and 0.1% in the other. This efficient stretching of the 2D WTe2 layers contrasts to intercalation‐induced strains in related materials which are predominantly in the out‐of‐plane direction. The unusual actuation of LixWTe2 is linked to the formation of a newly discovered crystallographic phase, referred to as Td', with an exotic atomic arrangement. On‐chip low‐voltage (<0.2 V) control is demonstrated over the transition to the novel phase and its composition. Within the Td'‐Li0.5−δWTe2 phase, a uniaxial in‐plane strain of 1.4% is achieved with a change of δ of only 0.075. This makes the in‐plane chemical expansion coefficient of Td'‐Li0.5−δWTe2 far greater than of any other single‐phase material, enabling fast and efficient planar electrochemical actuation.
Bio‐Organic Chiral Nematic Materials with Adaptive Light Emission and On‐Demand Handedness
Authors: Kang Saewon , Li Yingying , Bukharina Daria , Kim Minkyu , Lee Hansol , Buxton Madeline L. , Han Moon Jong , Nepal Dhriti , Bunning Timothy J. , Tsukruk Vladimir V.
Published: July 2021

Real‐time active control of the handedness of circularly polarized light emission requires sophisticated manufacturing and structural reconfigurations of inorganic optical components that can rarely be achieved in traditional passive optical structures. Here, robust and flexible emissive optically‐doped biophotonic materials that facilitate the dynamic optical activity are reported. These optically active bio‐enabled materials with a chiral nematic‐like organization of cellulose nanocrystals with intercalated organic dye generated strong circularly polarized photoluminescence with a high asymmetric factor. Reversible phase‐shifting of the photochromic molecules intercalated into chiral nematic organization enables alternating circularly polarized light emission with on‐demand handedness. Real‐time alternating handedness can be triggered by either remote light illumination or changes in the acidic environment. This unique dynamic chiro‐optical behavior presents an efficient way to design emissive bio‐derived materials for dynamic programmable active photonic materials for optical communication, optical coding, visual protection, and visual adaptation.
Unraveling the Voltage‐Dependent Oxidation Mechanisms of Poly(Ethylene Oxide)‐Based Solid Electrolytes for Solid‐State Batteries
Authors: Seidl Lukas , Grissa Rabeb , Zhang Leiting , Trabesinger Sigita , Battaglia Corsin
Published: July 2021

Using galvanostatic techniques, an oxidative stability up to 4.6 V versus Li/Li+ and beyond has been reported for the prototypical polymer electrolyte consisting of 1 m lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) in poly(ethylene oxide) (PEO). However, no long‐term cycling of a battery with this high cut‐off voltage has been demonstrated. Electrochemical and spectroscopic/spectrometric methods are employed to critically reinvestigate the electrochemical oxidation mechanisms of PEO electrolytes. It is found that the onset of PEO oxidation occurs at much lower voltage of around 3.2 V versus Li/Li+, at which the terminal OH group is deprotonated. At 3.6 V, the chain of the PEO is oxidized. Both processes result in the formation of the strong acid HTFSI, which in turn chemically attacks the PEO to form methanol and 2‐methoxyethanol. A stable cycling of a solid‐state lithium‐metal battery with a high‐energy LiNi0.8Mn0.1Co0.1O2 (NMC811) posititve electrode to an upper cut‐off voltage of 3.6 V versus Li/Li+ is demonstrated, however, resulting in enhanced capacity fading when increasing the upper cut‐off voltage to 3.8 V versus Li/Li+ or higher. Thus, operating PEO electrolytes beyond 3.6 V versus Li/Li+ requires protective layers at the positive electrode‐electrolyte interface to prevent PEO oxidation.
Maize response to combined heat and water stresses under varying growth conditions
Authors: Chukwudi Uchechukwu Paschal , Kutu Funso Raphael , Mavengahama Sydney
Published: July 2021

Identificationof agronomic practices that can ameliorate the negative effect of combined heat and water stress on maize plants is vital in food security strategy. The objective of this study was to evaluate the effect of heat and water stress on the growth of maize (Zea mays L.) under variable growth conditions. A repeated greenhouse factorial experiment laid out in a completely randomized design with four replications was performed. The factors were maize variety, water stress, soil amendment, and soil type. The results showed a depressive effect of water stress on the maize leaf area, chlorophyll content, stem diameter, dry biomass yield, and harvest index. These attributes decreased as the severity of the water stress increased with harvest index dipping by 30.3 and 92.9% in moderate water stress (MS) and terminal water‐stress (TS) plants, respectively. Sandy clay loam soil gave higher maize growth and yield attributes than loamy sand soil. The varied growth conditions imposed by the different water stresses, soil types, and soil amendments elicited different responses from the three maize varieties. Mean stability analyses/ranking identified ZM1523 and WE5323 as the top‐performing varieties under poultry manure amendment for both non‐stress and MS conditions, whereas under TS their performance improved in combined poultry manure/mineral fertilizer and mineral fertilizer treatments. Similarly, WE3128 gave its best performance under mineral fertilizer amendment for non‐stress, MS, and TS conditions. Therefore, under combined heat and water stress conditions, the interaction of maize variety, soil type, and soil amendment should be considered to guarantee a high maize yield.