bluuebunny/crossref_metadata_2025 huggingface dataset:
Medial efferent effects on auditory-nerve responses to tail-frequency tones II: Alteration of phase
Authors: Stankovic Konstantina M. , Guinan John J.
Published: July 2002

It is often assumed that at frequencies in the tuning-curve tail there is a passive, constant coupling of basilar-membrane motion to inner hair cell (IHC) stereocilia. This paper shows changes in the phase of auditory-nerve-fiber (ANF) responses to tail-frequency tones and calls into question whether basilar-membrane-to-IHC coupling is constant. In cat ANFs with characteristic frequencies ⩾10 kHz, efferent effects on the phase of ANF responses to tail-frequency tones were measured. Efferent stimulation caused substantial changes in ANF phase (ΔΦ) (range −80° to +60°, average −15°, a phase lag) with the largest changes at sound levels near threshold and 3–4 octaves below characteristic frequency (CF). At these tail frequencies, efferent stimulation had much less effect on the phase of the cochlear microphonic (CM) than on ANF phase. Thus, since CM is synchronous with basilar-membrane motion for low-frequency stimuli in the cochlear base, the efferent-induced change in ANF phase is unlikely to be due entirely to a change in basilar-membrane phase. At tail frequencies, ANF phase changed with sound level (often by 90°–180°) and the ΔΦ from a fiber was positively correlated with the slope of its phase-versus-sound-level function at the same frequency, as if ΔΦ were caused by a 2–4 dB increase in sound level. This correlation suggests that the processes that produce the change in ANF phase with sound level at tail frequencies are also involved in producing ΔΦ. It is hypothesized that both efferent stimulation and increases in sound level produce similar phase changes because they both produce a similar mix of cochlear vibrational modes.
Studies on Melt Spinning. I. Effect of Molecular Structure and Molecular Weight Distribution on Elongational Viscosity
Authors: Dae Han Chang , Lamonte Ronald R.
Published: July 2002

A melt spinning experiment has been carried out to correlate spinning variables with the molecular weight, molecular weight distribution, and long chain branching of the polymer being spun. Materials chosen for study were three high density polyethylenes having widely different molecular weight distributions, a low density polyethylene having much long chain branching, a polystyrene, and a polypropylene. Molecular characteristics and rheological properties of the materials in simple shearing flow had been independently determined. For the study, a bench scale, melt spinning apparatus was built, and measurements were taken of thread tensions at the take-up device. The axial profiles of thread diameter were measured by a photographic technique. The molten fibers traveled through a heated chamber maintained at the same temperature as the melt. These measurements were then used to determine the elongational viscosity in the absence of any temperature effect.
Dynamic mechanical properties of linear and cross-linked polyurethane
Authors: Prochazka Frederic , Durand Dominique , Nicolai Taco
Published: July 2002

Linear polyurethane melts were prepared by a polycondensation reaction of poly(oxypropylene) (POP) diol with a diisocyanate. Covalently cross-linked gels were obtained using three-armed star POP triol. The glass transition temperature and the viscoelastic properties were investigated as a function of the molar mass of the POP precursors. The variation of Tg is dominated by the density of urethane links. The loss peak of the shear modulus at high frequencies or low temperatures broadens with increasing density of urethane links. The gel modulus of end-linked POP triol decreases linearly with increasing molar mass of the precursors. The loss shear modulus of end-linked POP triol has a power law frequency dependence at low frequencies. The exponent of the power law dependence decreases with increasing molar mass of the precursors. Gels formed with POP triol with molar mass larger than 6 kg/mol show the effect of entanglements at intermediate frequencies.
The US Medicaid Program
Authors: Donohue Julie M. , Cole Evan S. , James Cara V. , Jarlenski Marian , Michener Jamila D. , Roberts Eric T.
Published: September 2022

Importance

Medicaid is the largest health insurance program by enrollment in the US and has an important role in financing care for eligible low-income adults, children, pregnant persons, older adults, people with disabilities, and people from racial and ethnic minority groups. Medicaid has evolved with policy reform and expansion under the Affordable Care Act and is at a crossroads in balancing its role in addressing health disparities and health inequities against fiscal and political pressures to limit spending.

Objective

To describe Medicaid eligibility, enrollment, and spending and to examine areas of Medicaid policy, including managed care, payment, and delivery system reforms; Medicaid expansion; racial and ethnic health disparities; and the potential to achieve health equity.

Evidence Review

Analyses of publicly available data reported from 2010 to 2022 on Medicaid enrollment and program expenditures were performed to describe the structure and financing of Medicaid and characteristics of Medicaid enrollees. A search of PubMed for peer-reviewed literature and online reports from nonprofit and government organizations was conducted between August 1, 2021, and February 1, 2022, to review evidence on Medicaid managed care, delivery system reforms, expansion, and health disparities. Peer-reviewed articles and reports published between January 2003 and February 2022 were included.

Findings

Medicaid covered approximately 80.6 million people (mean per month) in 2022 (24.2% of the US population) and accounted for an estimated $671.2 billion in health spending in 2020, representing 16.3% of US health spending. Medicaid accounted for an estimated 27.2% of total state spending and 7.6% of total federal expenditures in 2021. States enrolled 69.5% of Medicaid beneficiaries in managed care plans in 2019 and adopted 139 delivery system reforms from 2003 to 2019. The 38 states (and Washington, DC) that expanded Medicaid under the Affordable Care Act experienced gains in coverage, increased federal revenues, and improvements in health care access and some health outcomes. Approximately 56.4% of Medicaid beneficiaries were from racial and ethnic minority groups in 2019, and disparities in access, quality, and outcomes are common among these groups within Medicaid. Expanding Medicaid, addressing disparities within Medicaid, and having an explicit focus on equity in managed care and delivery system reforms may represent opportunities for Medicaid to advance health equity.

Conclusions and Relevance

Medicaid insures a substantial portion of the US population, accounts for a significant amount of total health spending and state expenditures, and has evolved with delivery system reforms, increased managed care enrollment, and state expansions. Additional Medicaid policy reforms are needed to reduce health disparities by race and ethnicity and to help achieve equity in access, quality, and outcomes.
Optimal Pharmacologic Treatment of Heart Failure With Preserved and Mildly Reduced Ejection Fraction
Authors: Xiang Boyang , Zhang Ruiqi , Wu Xiaoguang , Zhou Xiang
Published: September 2022

Importance

In recent years, significant progress has been made in the pharmacologic treatment of heart failure (HF) with reduced ejection fraction (HFrEF), but there is still insufficient evidence for drug therapy for HF with preserved ejection fraction (HFpEF) and mildly reduced ejection fraction (HFmrEF).

Objective

To compare the outcomes associated with different drug combinations for the treatment of HFpEF and HFmrEF.

Data Sources

A search of the PubMed, Embase, and Cochrane Central Register of Controlled Trials (CENTRAL) databases was conducted for studies published from inception to October 9, 2021.

Study Selection

Randomized clinical trials on the use of angiotensin-converting enzyme (ACE) inhibitors, angiotensin receptor blockers (ARBs), angiotensin receptor-neprilysin inhibitors (ARNIs), mineralocorticoid receptor antagonists (MRAs), β-blockers, and sodium-glucose cotransporter 2 (SGLT2) inhibitors for patients with HFpEF or HFmrEF.

Data Extraction and Synthesis

Data extraction and bias assessment were independently performed by 2 reviewers following the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guideline. All data for 3 outcomes were pooled with a fixed-effect model.

Main Outcomes and Measures

The main outcomes were first hospitalization for HF, all-cause mortality, and cardiovascular mortality. Hazard ratios (HRs) and 95% credible intervals (CrIs) were evaluated using a bayesian network meta-analysis model.

Results

In this analysis, 19 randomized clinical trials, including 20 633 patients with HF and an ejection fraction of 40% or more, without a remarkable risk of bias were included. Compared with placebo, no treatments were associated with a significant reduction in the risk of all-cause death or cardiovascular death. SGLT2 inhibitors, ARNIs, and MRAs were associated with a significant decrease in the risk of HF hospitalization compared with placebo (SGLT2 inhibitors: HR, 0.71 [95% CrI, 0.60-0.83]; ARNIs: HR, 0.76 [95% CrI, 0.61-0.95]; MRAs: HR, 0.83 [95% CrI, 0.69-0.99]), and SGLT2 inhibitors were the optimal drug class in terms of reducing the risk for HF admission. Sensitivity analysis results demonstrated a progressive decrease in the risk of HF admission and an advance in mean rank associated with the increasing use of drug classes.

Conclusions and Relevance

The findings of this study suggest that SGLT2 inhibitors were the optimal drug class for HFpEF and HFmrEF, consistent with the most recent guideline recommendation. The incremental use of combinations of SGLT2 inhibitors, ACE inhibitors or ARBs, and β-blockers may be associated with accumulative benefits in HF hospitalization rather than all-cause death among patients with HFpEF and HFmrEF.
Poor neck posture and longer working duration during root canal treatment correlated with increased neck discomfort in dentists with <5-years' experience in endodontics
Authors: Adulyawat Watcharapa , Chokechanachaisakul Uraiwan , Janwantanakul Prawit
Published: September 2022

Objective

This study investigated the effects of neck posture and working duration during each step of root canal treatment (i.e. opening the canal [OC], length determination, mechanical instrumentation, try main cone, and filling the root canal) on neck discomfort (ND) in dentists with <5-years' endodontic experience.

METHODS

Twenty-four dentists performed a one-visit endodontic treatment of an upper molar in a phantom head model. A video was recorded to evaluate the dentists᾽ neck postures using the Modified-Dental Operator Posture Assessment Instrument (M-DOPAI) and treatment duration. The M-DOPAI divides the dentists᾽ neck postures into three categories: acceptable, compromised, or harmful posture. The participants rated their ND using Borg᾽s CR-10 scale every 10 min. and at the end of each treatment step. The relationships between neck posture/treatment duration and Borg᾽s CR-10 scores were examined using partial correlation.

RESULTS

The number of compromised and harmful neck postures during the endodontic procedure (r = 0.43, P = .04) and treatment duration (r = 0.58 P = .005) significantly correlated with ND at the end of treatment. The number of compromised and harmful neck postures during the OC step (r = 0.75, P < .001) and the duration of the OC step (r = .70, P < .001) significantly correlated with ND at the end of the step.

CONCLUSION

Poor neck postures and long working duration during endodontic treatment correlated with ND among inexperienced dentists. Neck pain interventions should focus on neck postures and work duration during root canal treatment, particularly in the OC step.
Protein metalation in a nutshell
Authors: Osman Deenah , Robinson Nigel J.
Published: September 2022

Metalation, the acquisition of metals by proteins, must avoid mis‐metalation with tighter binding metals. This is illustrated by four selected proteins that require different metals: all show similar ranked orders of affinity for bioavailable metals, as described in a universal affinity series (the Irving–Williams series). Crucially, cellular protein metalation occurs in competition with other metal binding sites. The strength of this competition defines the intracellular availability of each metal: its magnitude has been estimated by calibrating a cells' set of DNA‐binding, metal‐sensing, transcriptional regulators. This has established that metal availabilities (as free energies for forming metal complexes) are maintained to the inverse of the universal series. The tightest binding metals are least available. With these availabilities, correct metalation is achieved.
AAPM Task Group 298: Recommendations on certificate program/alternative pathway candidate education and training
Authors: Prisciandaro Joann I. , Burmeister Jay W. , DeLuca Paul M. , Gerbi Bruce J. , Giger Maryellen L. , Robar James L. , Seibert J. Anthony
Published: September 2022

Entry into the field of clinical medical physics is most commonly accomplished through the completion of a Commission on Accreditation of Medical Physics Educational Programs (CAMPEP)‐accredited graduate and residency program. To allow a mechanism to bring valuable expertise from other disciplines into clinical practice in medical physics, an “alternative pathway” approach was also established. To ensure those trainees who have completed a doctoral degree in physics or a related discipline have the appropriate background and didactic training in medical physics, certificate programs and a CAMPEP‐accreditation process for these programs were initiated. However, medical physics–specific didactic, research, and clinical exposure of those entering medical physics residencies from these certificate programs is often comparatively modest when evaluated against individuals holding Master's and/or Doctoral degrees in CAMPEP‐accredited graduate programs. In 2016, the AAPM approved the formation of Task Group (TG) 298, “Alternative Pathway Candidate Education and Training.” The TG was charged with reviewing previous published recommendations for alternative pathway candidates and developing recommendations on the appropriate education and training of these candidates. This manuscript is a summary of the AAPM TG 298 report.
Light‐Induced Ammonia Generation over Defective Carbon Nitride Modified with Pyrite
Authors: Zander Judith , Timm Jana , Weiss Morten , Marschall Roland
Published: September 2022

Photocatalytic nitrogen fixation under ambient conditions is currently widely explored in an attempt to develop a sustainable alternative for the Haber–Bosch process. In this work, defect‐rich carbon nitride, one of the most investigated photocatalysts reported in literature for ammonia generation, is combined with earth‐abundant and bioinspired FeS2 to improve the activity for ammonia production. By this combination, an activity enhancement of ≈400% compared to unmodified carbon nitride is achieved. The optimal FeS2 loading is established to be 1 wt%, with ammonia yields of up to 800 µg L−1 after irradiation for 7 h. By detailed material characterization of the electronic and material properties of the composites before and after the photocatalytic reaction, it is revealed that NH3 generation occurs not photocatalytically from N2, but via a light‐induced reduction of N–CN groups adjacent to nitrogen vacancies in the structure of defect‐rich carbon nitride. FeS2 acts similar to a cocatalyst, enhancing the ammonia yield by π‐back‐donation from Fe‐centers to the imine nitrogen of the defect‐rich carbon nitride, thereby activating the structure and boosting the ammonia generation from cyano groups.
Diagnosing gangrenous cholecystitis on computed tomography using deep learning: A preliminary study
Authors: Okuda Yoichi , Saida Tsukasa , Morinaga Keigo , Ohara Arisa , Hara Akihiro , Hashimoto Shinji , Takahashi Shinji , Goya Tomoyuki , Ohkohchi Nobuhiro
Published: September 2022

Aim

To compare deep learning and experienced physicians in diagnosing gangrenous cholecystitis using computed tomography images and explore the feasibility of diagnostic assistance for acute cholecystitis requiring emergency surgery.

Methods

This retrospective study included 25 patients with pathologically confirmed gangrenous cholecystitis and 129 patients with noncomplicated acute cholecystitis who underwent computed tomography between 2016 and 2021 at two institutions. All available computed tomography images at the time of the initial diagnosis were used for the analysis. A deep learning model based on a convolutional neural network was trained using 1,517 images of 112 patients (18 patients with gangrenous cholecystitis and 94 patients with acute cholecystitis) and tested with 68 images of 42 patients (seven patients with gangrenous cholecystitis and 35 patients with acute cholecystitis). Three blinded, experienced physicians independently interpreted the test images. The sensitivity, specificity, accuracy, and area under the receiver operating characteristic curve were compared between the convolutional neural network and the reviewers.

Results

The convolutional neural network (sensitivity, 0.70; 95% confidence interval [CI], 0.44–0.87, specificity, 0.93; 95% CI, 0.88–0.96, accuracy, 0.89; 95% CI, 0.81–0.95, area under the receiver operating characteristic curve, 0.84; 95% CI, 0.68–1.00) had achieved a better diagnostic performance than the reviewers (ex. sensitivity, 0.55; 95% CI, 0.30–0.77, specificity, 0.67; 95% CI, 0.62–0.71, accuracy, 0.65; 95% CI, 0.57–0.72, area under the receiver operating characteristic curve, 0.63; 95% CI, 0.44–0.82; P = 0.048 for area under the receiver operating characteristic curve versus convolutional neural network).

Conclusions

Deep learning had a better diagnostic performance than experienced reviewers in diagnosing gangrenous cholecystitis and has potential applicability for assisting in identifying indications for emergency surgery in the future.
Nonlinear Topological Photonic Insulator in Synthetic Space
Authors: Wu Erjie , Li Guangzhen , Yu Danying , Wang Luojia , Yuan Luqi , Chen Xianfeng
Published: September 2022

As an emerging field, nonlinear topological photonics attracts great attention nowadays, where pioneering works show interesting phenomena including topological edge solitons and nonlinearity‐induced coupling of light into topological edge states. In this work, the nonlinear effects in a photonic topological insulator in the synthetic space including the frequency axis of light, in a ring resonant array under dynamic modulations are studied, where the four‐wave mixing nonlinear process is included. Such nonlinear process not only induces local interactions, but also creates long‐range interactions in the frequency dimension. These results show destruction on topologically protected edge states when the nonlinear effects are increasing. Moreover, it also breaks the symmetry in the synthetic space as well as the band structure, which reflects different propagation behaviors for the different input sources with positive and negative frequency shifts and exhibits short‐time robustness in weak nonlinear cases. This work hence explores the role of nonlinear effects in affecting the edge modes in the synthetic space, which may be useful in quantum many‐body simulations and find possible applications in information processing.
A quantitative synthesis of approaches, biases, successes, and failures in marine forest restoration, with considerations for future work
Authors: Earp Hannah S. , Smale Dan A. , Pérez‐Matus Alejandro , Gouraguine Adam , Shaw Paul W. , Moore Pippa J.
Published: September 2022

Marine forests is a term commonly used for coastal marine habitats formed by dense stands of brown macroalgae, typically consisting of kelp and fucoids. These habitats are highly productive, offer habitat to numerous marine organisms, and support a range of invaluable ecosystem services. Despite their importance, marine forests are declining in many regions around the world as a result of interacting global, regional, and local‐scale stressors. Consequently, interest in restoration as a tool to mitigate these declines and reinstate marine forests is growing.

Recent reviews have provided insights into marine forest restoration; however, for the most part, a synthesis of restoration success is lacking. A meta‐analysis and quantitative review of published marine forest restoration efforts was conducted to examine: (i) how restoration affects the abundance and morphology of marine forest species; and (ii) trends in marine forest restoration success.

The meta‐analysis of 25 studies revealed that restoration positively influences the abundance and morphology of marine forest species. The quantitative review of 63 studies demonstrated that taxa and restoration technique were important factors influencing restoration success, and revealed a bias towards the monitoring and reporting of abundance and morphological response variables. The review also highlighted a lack of monitoring and/or reporting of environmental variables at restoration sites, and limited comparative research across environmental contexts and restored species.

It is shown that successful marine forest restoration is possible at experimental scales, but that better monitoring and reporting of restoration efforts, alongside increased project durations, could improve our understanding of restoration success at the ecosystem level. Considerations for future marine forest restoration efforts are also provided. It is hoped that the review will advance marine forest restoration efforts, allowing the preservation of these valuable ecosystems and their associated services.
Aggregation‐Induced Emission and Single‐Molecule Magnet Behavior of TPE‐Based Ln(III) Complexes
Authors: Wu Jinjiang , Zhao Chen , Zhu Zhenhua , Li Xiao‐Lei , Ashebr Tesfay G. , Tang Jinkui
Published: September 2022

Multifunctional lanthanide complexes have been studied extensively owing to their promising applications in information storage, luminescence sensors and magneto‐optical devices, etc. Here, we report the facile synthesis of two discrete highly thermally stable lanthanide compounds, Ln(hfac)3(TPE‐tz) (Ln=Eu, Dy), by the reaction of the AIE‐active organic ligand with Ln(III) β‐diketonate precursor. Due to different energy gaps between the triplet state of the ligand and the accepted level of Ln(III) ions, Eu(hfac)3(TPE‐tz) exhibited remarkably enhanced luminescence intensity upon aggregation, i. e., a typical AIE behavior, while Dy(hfac)3(TPE‐tz) displayed weak characteristic emission bands of Dy(III) ions. In addition, Dy(hfac)3(TPE‐tz) showed field‐induced SMM behavior. This work shows that careful choice of auxiliary ligands paves the way for the construction of multifunctional lanthanide smart materials.
Animal evidence considered in determination of cannabis smoke and Δ9‐tetrahydrocannabinol as causing reproductive toxicity (developmental endpoint): Part III. Proposed neurodevelopmental mechanisms of action
Authors: Niknam Yassaman , Iyer Poorni , Campbell Marlissa A. , Moran Francisco , Sandy Martha S. , Zeise Lauren
Published: September 2022

This review summarizes the most common potential pathways of neurodevelopmental toxicity due to perinatal exposure to Δ9‐tetrahydrocannabinol (Δ9‐THC) that lead to behavioral and other adverse outcomes (AOs). This is Part III in a set of reviews highlighting the animal‐derived data considered by California's Developmental and Reproductive Toxicant Identification Committee (DARTIC) in 2019. The Hazard Identification Document (HID) provided to the DARTIC included a summary of human, whole animal, and mechanistic data on the neurodevelopmental toxicity of cannabis smoke and Δ9‐THC. The literature search for mechanistic data has been updated through 2020. We focus on mechanistic pathways relating to behavioral and other neurodevelopmental outcomes of perinatal exposure to Δ9‐THC. The endocannabinoid system (EC system) plays a crucial role in many processes involved in neurodevelopment and exposure to Δ9‐THC can alter these processes. Whole animal studies report changes in cognitive ability, behavior, and motor function after prenatal exposure to Δ9‐THC. Findings from mechanistic studies add to this evidence and further provide information regarding the pathways leading to these outcomes. Neuromechanistic studies can bridge the gaps between molecular initiating events and apical neurodevelopmental endpoints caused by a chemical. They offer insight into potential alterations in the same pathways by other chemicals that can also result in AOs. Studies of cannabinoid receptor agonist‐induced molecular alterations and provide deep biological plausibility at the mechanistic level for the cognitive, behavioral, and motor impairments observed in animal studies after perinatal exposure to Δ9‐THC.
Comparative binding affinity analysis of dual CDK2/FLT3 inhibitors
Authors: Ghosh Suparna , Cho Seung Joo
Published: September 2022

Selective inhibition of cyclin‐dependent kinase 2 (CDK2) using small molecules is gaining popularity for the treatment of certain types of acute myeloid leukemia (AML). In this study, we used different molecular modeling techniques to investigate the structure–activity relationship (SAR) and binding modalities of dual CDK2/FLT3 inhibitors. The key chemical characteristics of the 3H‐pyrazolo[4,3‐f]quinoline derivatives were highlighted as descriptive colored contours using comparative molecular similarity analysis (CoMSIA). Modifying chemical groups in existing compounds along these contours could improve CDK2 selectivity over FMS‐like tyrosine kinase 3 (FLT3). We determined the ligand affinities for CDK2 by estimating the binding free energy using molecular mechanics generalized Born surface area (MM‐GBSA) and umbrella sampling (US) simulations. Reasonable correlations were found between the computed and experimental binding energies, suggesting that MM‐GBSA and US can be used to reliably predict the binding affinities of new compounds in the more potent CDK2 drug development process.
Recent Advances in PROTAC Technology Toward New Therapeutic Modalities
Authors: Yokoo Hidetomo , Naganuma Miyako , Oba Makoto , Demizu Yosuke
Published: September 2022

Proteolysis targeting chimeras (PROTACs) have emerged as a powerful technology for the degradation of disease‐related proteins by the hijacking of the endogenous ubiquitin‐proteasome system. A multitude of bifunctional PROTACs have been developed using small‐molecule ligands; one ligand binds to the target protein of interest and one ligand binds to an E3 ligase. The characteristics of those PROTACs vary, including their reversible or irreversible covalent binding to the target protein, their binding to orthosteric and allosteric sites, their agonist or antagonist activity, and their use of multiple ligands. In addition, oligopeptides and nucleotides have recently been used as alternative targeting ligands. The properties of PROTACs, such as selectivity, delivery and sensitivity to drug resistance, can be improved through the use of a variety of targeting ligand modalities. This minireview introduces the mechanisms and behavior of small‐molecule based PROTACs as well as targeted proteolysis techniques using peptides and nucleic acids as targeting ligands.
Retroperitoneal necrotizing soft tissue infections: A case report and literature review
Authors: Kejela Segni , Bekele Solomon
Published: September 2022

Necrotizing soft tissue infections of the retroperitoneal is a rare disease identity. Here we present a 50‐year‐old male patient who underwent surgical exploration for retroperitoneal necrotizing soft tissue infection. Postoperatively, he was put on broad‐spectrum antibiotics. He passed on after the first exploration and debridement.
Intraperitoneal hemorrhage due to segmental arterial mediolysis associated with cerebral vasospasm after subarachnoid hemorrhage
Authors: Matsuura Chie , Fuchinoue Yutaka , Terazono Sayaka , Kondo Kosuke , Harada Naoyuki , Sugo Nobuo
Published: September 2022

A man in his 50s with no significant past medical history developed subarachnoid hemorrhage due to ruptured left middle cerebral artery aneurysm. On the ninth hospital day, he had a ruptured visceral aneurysm with segmental arterial mediolysis, and we successfully treated with transarterial embolization using metallic coils.
Cationic Molybdenum Imido Alkylidene N‐Heterocyclic Carbene Complexes Confined in Mesoporous Silica: Tuning Transition States Towards Z‐Selective Ring‐Opening Cross‐Metathesis
Authors: Goldstein Elizabeth L. , Ziegler Felix , Beurer Ann‐Katrin , Traa Yvonne , Bruckner Johanna R. , Buchmeiser Michael R.
Published: September 2022

We recently reported a method for selective macro(mono)cyclization of dienes utilizing catalysts confined inside the pores of mesoporous silica, which we believe occurs due to suppression of oligomerization due to pore size. We hypothesized, however, that the system of cationic molybdenum imido alkylidene N‐heterocyclic carbene (NHC) catalysts immobilized selectively inside the mesopores of silica materials could address much more subtle selectivity differences, such as E/Z selectivity in ring‐opening/cross‐metathesis (ROCM). Upon investigation, we observed that surface‐bound cationic molybdenum imido alkylidene NHC catalysts indeed display an increased Z‐selectivity, especially during the early stages of the reaction. This effect was present when the catalyst was confined inside a pore, as well as when the catalyst was bound to non‐porous silica, which led us to conclude it is an effect caused by the catalyst being bound directly to the surface of a silica material where the proximity of the catalyst to the surface governs the transition state. Kinetic investigations revealed that significant post‐metathesis olefin isomerization occurs, the amount of which seems to be governed by the rate of diffusion of the product away from the active catalyst, with smaller pore sizes resulting in higher Z‐selectivity at higher conversion, attributable to faster diffusion of the product out of the pore than diffusion back into the pore.
Understanding the effects of empowering leadership on positive and negative performance behaviors: A manufacturing sector study
Authors: Turcotte‐Légaré Nicolas , Gaudet Marie‐Claude , Doucet Olivier
Published: September 2022

For several years, the North American manufacturing sector has been facing several labour issues that undermine productivity. To address these issues and remain competitive, manufacturing firms must implement measures to promote overall worker performance. This study presents an integrative to understand the differentiated impact of empowering leadership (EL) on four dimensions of performance (task, citizenship, innovation, deviance) through two mediators (psychological empowerment (PE) and affective organizational commitment). Structural equation modeling was used to analyze data from 250 employee–supervisor dyads in the manufacturing industry. On the one hand, our results reveal that EL exerts a positive influence on citizenship and innovative behavior through increased PE. On the other hand, it is negatively associated to deviance behaviors through heightened levels of affective organizational commitment. This study allows us to better understand how EL enhances multiple performance dimensions necessary to organizations' competitiveness in manufacturing and other sectors.
Facile Synthesis of S‐Fused Multi‐Membered Polycyclic Heterocycles: A Construction Strategy towards Thermally Stable Thiepine Derivatives
Authors: Ming Binbin , Yan Chuan , Xie Shoudong , Liu Si , Ren Yingjian , Zong Hao , Chen Weinan , Zhou Gang
Published: September 2022

Comprehensive Summary

S‐fused heterocycles have become popular building blocks to construct functional polycyclic compounds. In contrast to the abundant synthetic methodologies for thiophene‐fused aromatics, the synthesis of S‐heterocycles containing six‐membered thiopyran and seven‐membered thiepine rings is much less reported owing to their unfavorable synthetic protocols and the thermal instabilities. Herein, a series of thiepine‐containing polycyclic S‐heterocycles have been successfully synthesized via different synthetic routes which involve initial construction of sulfur bridges and final ring‐closure reactions. Therefore, the dilithium intermediates are excluded, which facilitates the fusion on the thiepine ring with different S‐heterocycles, including thiophene and thiopyran derivatives. Typically, a S‐fused multi‐membered polycyclic compound simultaneously involving thiophen, thiopyran, and thiepine rings has been successfully prepared. Interestingly, nucleus‐independent chemical shift calculations reveal that the incorporated thiopyran and thiepine rings demonstrate aromatic and nonaromatic characteristics, respectively. Moreover, the thermal stabilities of the thiepine derivatives have been tremendously improved after the fusion on the three vinyl groups in the thiepine unit, which is attributed to the enhancements of the activation energies for the S‐extrusion reactions, as revealed by density functional theory calculations. Therefore, our findings not only provide a facile synthetic methodology for S‐fused multi‐membered polycyclic heterocycles, but also furnish a novel construction strategy towards thermally stable thiepine derivatives.
Predictive value of HMGB1 for atrial fibrillation recurrence after cryoballoon ablation in paroxysmal atrial fibrillation patients
Authors: Li Xinxin , Zhao Cuiting , Li Meng , Yu Hongxiao , Liu Xiping , Zhu Qing , Song Xiaokun , Wang Yonghuai , Yu Bo , Ma Chunyan
Published: September 2022

Background

Cryoballoon ablation (CBA) is recommended for patients with symptomatic drug refractory paroxysmal atrial fibrillation (pAF). However, substantial atrial fibrillation (AF) recurrence is common during follow‐up. Searching for a potential biomarker representing both myocardial injury and inflammation to identify patients at high risk of AF recurrence after CBA is very meaningful for postoperative management of AF patients.

Hypothesis

To evaluate the clinical efficacy of high‐mobility group box 1 (HMGB1) protein released from the left atrium to predict AF recurrence in pAF patients after CBA at 1‐year follow‐up.

Methods

We included 72 pAF patients who underwent CBA. To determine the expression levels of HMGB1, left atrial blood samples were collected from the patients before CBA and after the procedure through the transseptal sheath. Patients were followed up for AF recurrence for 1 year.

Results

A total of 19 patients of the 72 experienced AF recurrence. The level of postoperative HMGB1 (HMGB1post) was higher in the AF recurrence group than in the AF non recurrence group (p = .03). However, no differences were noted in the levels of other biomarkers such as preoperative high‐sensitivity C‐reactive protein (hs‐CRP), postoperativehs‐CRP, and preoperative HMGB1 between the two groups. Multiple logistic regression analysis revealed that a higher level of serum HMGB1post was associated with AF recurrence (odds ratio: 5.29 [1.17–23.92], p = .04). Receiver operating characteristic analysis revealed that HMGB1post had a moderate predictive power for AF recurrence (area under the curve: 0.68; sensitivity: 72%; and specificity: 68%). The 1‐year AF‐free survival was significantly lower in patients with a high HMGB1post level than in those with a low HMGB1post level (hazard ratio: 3.81 [1.49–9.75], p = .005).

Conclusion

In pAF patients who under went CBA, the level of HMGB1 after CBA was associated with AF recurrence and demonstrated a moderate predictive power. Thus, we offer a potential biomarker to identify pAF patients at high risk of AF recurrence.
The Role of Nanocrystal Facets in Sustainable Organic Synthesis
Authors: Das Soumyadip , Chanda Kaushik
Published: September 2022

The effective synthesis of noble‐metal nanocrystals with controllable shapes opens up several possibilities for manipulating their physicochemical characteristics as well as improving their figures of merit in a number of applications. The availability of this new class of nanomaterials has helped heterogeneous catalysis and surface research in particular, as the atomic structure shown on the surface of a nanocrystal is ultimately governed by its geometric form. The immediate benefits might include a considerable increase in catalytic activity or selectivity, as well as a significant decrease in material costs, all while offering a well‐defined model system for mechanistic investigation. This review paper presents a complete overview of recent developments in the synthesis of noble‐metal nanocrystals with well‐tuned morphologies, as well as their outstanding performance in a wide range of catalytic activities in organic synthesis. Nanocrystals having different shapes such as cubic, cuboctahedra, octahedra, rhombic dodecahedra, etc. exhibited a major role in facet‐dependent catalytic activity in the organic synthesis. Synthesis of organic molecules such as heterocyclic molecule synthesis, coupling reaction (C−C coupling), hydrogenation reaction, oxidation, and peptide synthesis are highly affected by nanocrystals with a particular surface facet. We expect that this review article will provide the motivation and a pathway for the development of next‐generation catalysts, which are critical in a variety of applications for organic synthesis.
Perfect Polar Alignment of Parallel Beloamphiphile Monolayers: Synthesis, Characterization, and Crystal Architectures of Unsymmetrical Phenoxy‐Substituted Acetophenone Azines
Authors: Bhoday Harmeet , Lewis Michael , Kelley Steven P. , Glaser Rainer
Published: September 2022

It remains a great challenge to achieve polar order in organic molecular crystals because anti‐parallel alignment of side‐by‐side molecules is intrinsically preferred. We have addressed this problem with a rational design that focuses on the polar stacking of parallel beloamphiphile monolayers (PBAMs) with strong lateral quadrupole‐quadrupole attractions. We employ arene‐arene interactions as lateral synthons. The first successes were achieved with unsymmetrical donor (X), acceptor (Y) substituted acetophenone azines which form polar PBAMs with double T‐contacts between the azines. Near‐perfect alignment was achieved with the methoxy series of (MeO, Y)‐azines with Y=Cl, Br, I. Here, we report on the synthesis, the characterization (GC/MS, 1H NMR, 13C NMR, FTIR), the crystallization, and the single‐crystal X‐ray analyses of the phenoxy series of (PhO, Y)‐acetophenone azines with Y=F, Cl, Br, I. Properties of (RO, Y) azines were computed at the APFD/6‐311G* level and are discussed with reference to p‐nitroaniline (PNA). This (PhO, Y) series embodies an improved PBAM design based on triple T‐contacts which is shown to facilitate faster crystallization and to produce larger crystals. Perfect polar‐alignment has been achieved for the phenoxy series of (PhO, Y)‐azines with Y=Cl, Br, I and the (PhO, F)‐azine also features near‐perfect dipole alignment.
Clonality, polyploidy and spatial population structure in Baltic Sea Fucus vesiculosus
Authors: Preston Roxana , Blomster Jaanika , Schagerström Ellen , Seppä Perttu
Published: September 2022

Genetic characteristics of populations can have substantial impacts on the adaptive potential of a species. Species are heterogeneous, often defined by variability at a range of scales including at the genetic, individual and population level. Using microsatellite genotyping, we characterize patterns underlying the genetic heterogeneity in marine macroalga Fucus vesiculosus, with a particular focus on two forms: attached and free‐living. Here we demonstrate that sympatric populations representing the two forms display marked differences in characteristics of reproduction and genetic diversity. Asexual reproduction was ubiquitous in the free‐living form despite being almost entirely absent in the attached form, while signals of polyploidy were common in both forms despite the distinct reproductive modes. Gene flow within and between the forms differed, with barriers to gene flow occurring between forms at various spatial scales due to the reproductive modes employed by individuals of each form. The divergent genetic characteristics of F. vesiculosus demonstrate that intraspecific differences can influence the properties of populations with consequential effects on the whole ecosystem. The differing genetic patterns and habitat requirements of the two forms define separate but closely associated ecological entities that will likely display divergent responses to future changes in environmental conditions.
Linalool attenuated ischemic injury in PC12 cells through inhibition of caspase‐3 and caspase‐9 during apoptosis
Authors: Hosseini Azar , Pourheidar Elham , Rajabian Arezoo , Asadpour Elham , Hosseinzadeh Hossein , Sadeghnia Hamid Reza
Published: September 2022

Numerous studies have indicated the pharmacological properties of linalool, a volatile terpene alcohol found in many flowers and spice plants, including anti‐nociceptive, anti‐inflammatory, and neuroprotective activities. The aim of this study was to explore the mechanisms of neuroprotection provided by (±) linalool and its enantiomer, (R)‐(−) linalool against oxygen, and glucose deprivation/reoxygenation (OGD/R) in PC12 cells. PC12 cells were treated with (±) linalool and (R)‐(−) linalool before exposure to OGD/R condition. Cell viability, reactive oxygen species (ROS) production, malondialdehyde (MDA) level, DNA damage, and the levels of proteins related to apoptosis were evaluated using MTT, comet assay, and western blot analysis, respectively. IC50 values for the PC12 cells incubated with (±) linalool and (R)‐(−) linalool were 2700 and 2600 μM after 14 h, as well as 5440 and 3040 μM after 18 h, respectively. Survival of the ischemic cells pre‐incubated with (±) linalool and (R)‐(−) linalool (100 μM of both) increased compared to the cells subjected to the OGD/R alone (p < .001). ROS and MDA formation were also decreased following incubation with (±) linalool and (R)‐(−) linalool compared to the OGD/R group (p < .01). In the same way, pre‐treatment with (±) linalool and (R)‐(−) linalool significantly reduced OGD/R‐induced DNA injury compared to that seen in OGD/R group (p < .001). (±) Linalool and (R)‐(−) linalool also restored Bax/Bcl‐2 ratio and cleaved caspase‐3 and caspase‐9 (p < .001, p < .01) following ischemic injury. The neuroprotective effect of linalool against ischemic insult might be mediated by alleviation of oxidative stress and apoptosis.
Clay mineral diagenesis in alternating mudstone‐sandstone beds from Late Palaeozoic strata of the Anadarko Basin, United States
Authors: Zanoni Giovanni , Šegvić Branimir , Sweet Dustin E.
Published: September 2022

Closely interbedded mudstone and sandstone are rarely the focus of clay mineral diagenetic studies; as such, it is not understood if these various rock types follow the same or different diagenetic pathway(s) during burial. Over a depth span of ~2,300 to 4,200 m, 95 core samples of alternating Pennsylvanian mudstone/sandstone from the hydrocarbon‐rich Anadarko Basin in Oklahoma have been characterized petrographically, mineralogically, and chemically. The investigated fine‐grained sediment is argillaceous to siliceous mudstone, dominated by Illite/mica and mixed‐layer illite–smectite. The sandstone is variably classified as quartz and mudclast‐rich litharenite to sub‐litharenite, which is commonly carbonate‐cemented. This contribution provides evidence for a very similar diagenetic evolution of the clay mineral assemblages across all rock types despite the discrepancies in porosity and permeability of the host rock. We posit that the incorporation of micrometre‐scale mudclasts through bioturbation of the sandstone may explain the relatively uniform compositional characteristics of illite–smectite, chlorite, and kaolinite. Inferences are drawn from a detailed clay mineral quantification of these interbedded lithologies aid to our understanding of the clay mineral distribution and speciation in Pennsylvanian strata of the Anadarko Basin, which further helps to constrain the reservoirs' physical, chemical, and structural properties.
The mediating role of hope in relation with fear of COVID‐19 and mental health: A study on tertiary level students of Rajshahi District
Authors: Sarker Pramath C. , Sugawara Daichi , Nishad Md. Fazle Rabbi
Published: September 2022

Background and Aims

The novel coronavirus disease (COVID‐19) is influential in all parts of people's lives, specifically psychological states due to the fear related to the pandemic. Thus, this study aimed to investigate the mediating role of hope in the connection between the fear of COVID‐19 and mental health among tertiary college students of Rajshahi district during the COVID‐19 disease.

Method

A cross‐sectional survey was conducted among tertiary college students a sample of 498 participants (53.4% females and 46.6% males) ranged between ages 19 and 31 (M = 22.03 ± 1.92) and participants filled out the fear of COVID‐19 Scale, Trait Hope Scale, and General Health Questionnaire.

Result

In the case of correlation analysis, fear of COVID‐19 is reversely correlated with mental health, while lower but positive correlations were found with hope. Findings from the process macro v3.5 by Hayes analysis for the study model indicated that hope mediated in the relationship between the fear of COVID‐19 and mental health controlling for gender, and socioeconomic status, and the hypothesized model explained approximately 27% of the variance in mental health.

Conclusion

Overall, the findings suggest that a high level of mental health is impacted by a low level of fear of COVID‐19. Additionally, a low level of fear of COVID‐19 contributes to increasing levels of hope, which enhances mental health.
Point of care prehospital ultrasound in Basic Emergency Services in Portugal
Authors: Lobo Manuel José Cruz Duarte , Tavares Sérgio Carlos Castanheira Nunes Miravent , Pereira de Almeida Rui Pedro
Published: September 2022

Background and Aims

The Point of Care Ultrasound and Point‐of‐Care Ultrasound in Resource‐Limited Settings are differentiated diagnostic methods using ultrasound, essential in urgent patients screening, allowing better guidance in the diagnostic process and therapeutic approach. This study intends to observe the impact of these techniques in two Basic Emergency Services (SUB) in Portugal.

Methods

A longitudinal study was carried out in two remote locations in Portugal (SUB N and SUB S). Data were collected by trained radiographers in each location, and a total of 972 exams were considered. Imaging findings were documented by exam type, the exam normality and the resolution after exam. χ2 and Cramer's V tests were performed to check significant correlations between the variables.

Results

Regarding the type of echographic findings, 289 (29.7%) were considered normal, 628 (64.6%) were classified as abnormal and 55 (5.7%) were considered inconclusive. As for the type of resolution, 58% had local resolution, 24% were referred to a hospital emergency service and 18% referred to ambulatory care. Regarding the Location versus Resolution after exam versus Findings variables, it was verified a stronger statistically significant association for the exams considered “Abnormal” (Cramer's V = 0.414; p < 0.001). In the variables Location versus Findings versus Resolution after exam, it was verified a stronger statistical significance for “Referral to Ambulatory” (Cramer V = 0.443; p < 0.001) although Referral for Hospital (Cramer V = 0.252; p = 0.003) or Local Resolution (Cramer V = 0.252; p < 0.001) also had a moderate association strength.

Conclusion

Ultrasonography is a useful diagnostic tool for patients screening, having an influence on patient management in remote settings. Given the limited literature in Portugal about this matter, further research and literature will be needed to support and complement the results of this study.