bluuebunny/crossref_metadata_2025 huggingface dataset:
‘Bribing the Reds to Give Up’: Rewards Policy in the Malayan Emergency
Authors: Ramakrishna Kumar
Published: July 2002

This article examines the rationale for and evolution of the Malayan government’s rewards for information policy during the Emergency. The policy was formulated as a means of exploiting the rural Chinese peasant/terrorist’s fundamentally materialistic outlook. The policy went through some adjustments over time, and proved its true worth when three factors became dominant by the end of 1957: the Malayan Communist Party’s military and political eclipse, a sufficient degree of terrorist faith in government promises of fair treatment on surrender, and very liberal surrender terms. Although very controversial, the rewards policy was moral to the extent that it helped end the Emergency.
The Ethics of Withdrawing Artificial Food and Fluid from Terminally Ill Patients: an end-of-life dilemma for Japanese nurses and families
Authors: Konishi Emiko , J Davis Anne , Aiba Toshiaki
Published: July 2002

End-of-life issues have become an urgent problem in Japan, where people are among the longest lived in the world and most of them die while connected to high-technology medical equipment. This study examines a sensitive end-of-life ethical issue that concerns patients, families and nurses: the withdrawal of artificial food and fluid from terminally ill patients. A sample of 160 Japanese nurses, who completed a questionnaire that included forced-choice and open-ended questions, supported this act under only two specific conditions: if the patient requested it, and if it relieved the patient’s suffering. They considered that the doctor’s orders, the family’s request, or the patient’s advanced age did not ethically justify this act. A small number of people who had recently lost a relative took part in semistructured interviews focusing on their experiences of their terminally ill relatives being given artificial food and fluid. Ethical, social and cultural factors surrounding this issue are discussed.
The Decision-Making Process when Starting Terminal Care as Assessed by Nursing Staff
Authors: Kuuppelomäki Merja
Published: July 2002

This article deals with making decisions about starting terminal care. The results are part of a larger survey on nurses’ conceptions of terminal care in community health centres in Finland. The importance, frequency and timing of decision making as well as communication and the number of investigations and procedures carried out are examined. The relationship between decision making and the size of a health centre’s catchment population is also discussed. The results make it possible to compare the current situation in Finland with the national law on patients’ rights. The sample consisted of 328 nurses who worked on the wards of 32 community health centres. The data were collected by means of a structured questionnaire and processed with the Statistical Package for Social Sciences software. The nurses agreed that explicit decision making and documentation about starting terminal care were necessary, but it was highlighted that the practice had many shortcomings. Decisions were often made too late and the patients were not always aware of their situation; family members and the nursing staff were mostly better informed. It was noted that many investigations and other procedures were carried out on terminally ill patients, often at the request of family members. Decision making was found to have some relationship to the size of a health centre’s catchment area.
Moral Problems Experienced by Nurses when Caring for Terminally Ill People: a literature review
Authors: Georges Jean-Jacques , Grypdonck Mieke
Published: July 2002

This article is a review of the literature on the subject of how nurses who provide palliative care are affected by ethical issues. Few publications focus directly on the moral experience of palliative care nurses, so the review was expanded to include the moral problems experienced by nurses in the care of the terminally ill patients. The concepts are first defined, and then the moral attitudes of nurses, the threats to their moral integrity, the moral problems that are perceived by nurses, and the emotional consequences of these moral problems are considered in turn. The results show that the moral behaviour of nurses, which is theoretically grounded in commitment to care and to the patient, appears to be shaped by specific processes that lead to engagement or to mental and behavioural disengagement in morally difficult situations. Nurses often appear to fail to recognize the moral dimensions of the problems they experience and also to lack the skills they need to resolve moral problems adequately. Although the findings show that several elements that are beyond the control of nurses, owing to their lack of autonomy and authority, influence their moral experience, intrinsic factors such as feelings of insecurity and powerlessness have a profound effect on nurses’ perceptions and attitudes in the face of moral problems. The moral problems perceived by these nurses are related to end-of-life issues, communication with patients, the suffering of patients, and the appropriateness of the medical treatment.
Burnout and Nurses’ Personal and Professional Values
Authors: Altun İnsaf
Published: July 2002

The research described in this article was a descriptive study for determining the relationship between the degree of burnout experienced by nurses working in Kocaeli (Turkey), and their personal and professional values. A questionnaire was developed by using information gained from the literature on this subject and from the Maslach Burnout Inventory. The questionnaire was delivered to nurses working in two different hospitals (State Hospital of I.zmit and the Gölçük Sea Hospital) in Kocaeli. The sample group was formed from all nurses working in the two hospitals, of whom 160 participated in the study during December 1999 and January 2000.

The results showed that nurses’ personal and professional values play an important role in the degree of burnout they experience. Equality, altruism and aesthetics were ranked first by those experiencing high levels of emotional exhaustion, and freedom was a priority value for those with a low degree of emotional exhaustion. Freedom, altruism and truth were ranked first by those with prominent feelings of personal accomplishment, and equality and aesthetics were priority values for those with less feeling of personal accomplishment. All nurses, therefore, need to identify and clarify their own personal values, beliefs and assumptions about basic truths.
Use of interferon beta in multiple sclerosis: rationale for early treatment and evidence for dose- and frequency-dependent effects on clinical response
Authors: Coyle P K , Hartung H-P
Published: July 2002

The current approach to the use of interferon (IFN) beta in the treatment of multiple sclerosis (MS) is, in general, conservative. However, recent findings about early events in MS and data on dose-response relationships with IFN beta indicate that such an approach may be suboptimal. Four lines of evidence suggest that delays in the initiation of therapy with IFN beta may be detrimental: 1) axonal damage secondary to inflammation starts very early in the course of MS; 2) pathological events occurring early in MS are predictive of the future course of the disease; 3) inflammatory activity in relapsing MS is not confined to episodes of clinical impairment, but often starts before the first such episode and generally continues during remissions; and 4) the immune-mediated activity that underlies MS may become more difficult to control as the disease progresses. An early treatment strategy is also supported by data from two recently published clinical studies. In addition, preclinical and clinical results suggest that the beneficial effects of IFN may be dose- and frequency-dependent. Taken together, these findings indicate that treatment with IFN beta should be started as early as possible in the course of MS, and suggest that, in order to maximize patient benefit, the highest possible dose of IFN beta should be chosen.
The role of MRI as a surrogate outcome measure in multiple sclerosis
Authors: McFarland H F , Barkhof F , Antel J , Miller D H
Published: July 2002

The need for more specific and more sensitive outcome measures for use in testing new therapies in multiple sclerosis (MS) is generally accepted. This need has been accentuated by the realization that the ability to conduct large placebo-controlled trials will be limited in the future. From the first use of magnetic resonance imaging (MRI) to study MS, the ability of this imaging technique to identify areas of the central nervous system damage by the disease process in MS has been impressive. Thus, the possibility that MRI could serve as a surrogate outcome measure in clinical trials in MS has been attractive. The use of MRI as a surrogate outcome measure has been examined by an international group of investigators with expertise in clinical aspects of MS, the use of MRI in MS, and in experimental therapeutics. The group agreed that MRI does not represent a validated surrogate in any clinical form of MS. It was also agreed, however, that MRI does provide a reflection of the underlying pathology in the disease, but no single MRI measurement in isolation was seen as sufficient to monitor disease. The use for multiple imaging techniques, especially new, emerging techniques that may better reflect the underlying pathology, was seen as particularly important in monitoring studies of patients with either secondary or primary progressive MS. The choice of MRI techniques used to monitor new therapies needs to be consistent with the proposed mechanisms of the new therapy and phase of the disease. It was also noted, however, that additional validation is required for nonconventional imaging techniques. Finally, the participants noted that clinical trials using MRI as a primary outcome measure may fail to fully identify the effects of the therapy on clinical measures and that the risk and cost-benefit ratio of the treatment might be unresolved. Thus, before MRI is used as a primary outcome measure, new approaches to trial design must be given careful consideration.
International consensus statement on the use of disease-modifying agents in multiple sclerosis
Authors: Freedman M S , Blumhardt L D , Brochet B , Comi G , Noseworthy J H , Sandberg-Wollheim M , Sørensen P Soelberg ,   Paris Workshop Group
Published: July 2002

Objective: To provide recommendations on the use of disease-modifying agents in the management of multiple sclerosis (MS) and to ensure that treatment will be available to those patients who may benefit. Methods: An initial draft of the consensus statement was prepared by the Steering Committee and amended in the light of written comments from a group of MS specialists. At a subsequent workshop, the wording of the consensus statement was discussed, modified if necessary, and the participants indicated their level of support using an electronic voting system. A new draft of the statement was then sent to a much larger group of international opinion leaders in MS for further comment. Results: A number of statements were agreed, which outline the criteria for consideration of disease-modifying therapy for MS and recommendations for treatment. Each statement was accepted completely, or with only minor reservations by 95% or more of those present at the workshop. Conclusions: Periodic reviews and modifications to the statement will be required, as new approaches to the treatment of MS and other therapeutic agents become available.
Prospective study of multiple sclerosis with early onset
Authors: Ghezzi A , Pozzilli C , Liguori M , Marrosu M G , Milani N , Milanese C , Simone I , Zaffaroni M
Published: July 2002

Fifty-four subjects (36 females and 18 males) affected by clinically definite multiple sclerosis (MS) and with onset of the disease at 15 years of age or before were prospectively studied in five Italian MS centres. Female/male ratio was 4.7 in subjects with age ≥12 years, suggesting a role of hormonal changes in triggering MS onset. The mean follow-up duration was 10.9-5.6 years. The functional systems more frequently involved at onset were the pyramidal and brainstem (both in 28% of cases). The onset was monosymptomatic in 31 subjects (57%). The course was relapsing-remitting in 39 subjects (72%) and relapsing-progressive in 15 (28%). Disability was assessed by the Expanded Disability Status Scale (EDSS): the mean score after 8 years of follow up was 3.5 (-2.5). The score was <4 in 68% of cases, between 4 and 6 in 8% of cases, > 6 in 24% of cases. Disability after 8 years was highly predicted by disability in the first year (p=0.008). There was a tendency to a worse prognosis in relation to the number of relapses in the first 2 years (p=0.08). The outcome was not influenced by the characteristics of symptoms at onset, age and gender.
Does lighting need more photopic luminous efficiency functions?
Authors: Schanda J , Morren L , Rea M , Rositani-Ronchi L , Walraven P
Published: July 2002

In 1924 the Commission Internationale de l’É clairage (CIE) established the photopic luminous efficiency function, V(γ), that subsequently has been used to measure luminance. Some have assumed luminance to be synonymous with brightness. Luminance is based mainly upon flicker photometry, and this methodology does not provide data predictive of the apparent brightness of steadily viewed lights. This paper discusses alternative photopic luminous efficiency functions that could be used for measuring luminance. A proper treatment of brightness is outside the scope of the present paper, although the CIE is actively studying this topic. Moreover, this paper does not discuss the scotopic luminous efficiency function established by the CIE in 1951. Vision research conducted since 1924 using methodologies other than flicker photometry has shown that the V(λ) function slightly underestimates human foveal spectral sensitivity at short wavelengths in the visible spectrum. This has been partly corrected by recommending the VM(λ) luminous efficiency function, but it has been used only by the research community. Further research using both physiological and psychophysical techniques have shown that there are several visual pathways between the eye and the cortex that mediate visual information. For example, the CIE is investigating the adoption of a provisional V10(λ) luminous efficiency function to characterize luminance for off-axis stimuli. Lamp manufacturers and illuminating engineers should be clear that the classical V(λ) function does not predict luminance under all conditions, although it remains a useful measure of the luminance of foveal visual tasks and for describing acuity and reaction time.
Hyperbaric Oxygen Does Not Prevent Neurologic Sequelae after Carbon Monoxide Poisoning
Authors: Gilmer Benjamin , Kilkenny Jane , Tomaszewski Christian , Watts John A.
Published: July 2002

Delayed neurologic sequelae occur in up to 40% of severe carbon monoxide (CO) poisonings. Conflicting clinical data support the efficacy of hyperbaric oxygen (HBO) therapy in the acute treatment of CO poisoning. Objective: To determine whether oxygen therapy reduces neurologic sequelae after CO poisoning in mice. Methods: Male Swiss‐Webster mice were exposed to CO at 1,000 ppm for 40 minutes and then 50,000 ppm until loss of consciousness (LOC) (4‐9 additional minutes). Total time of both phases of CO exposure was 40‐49 minutes. Treatment included HBO with 3 atmospheres (ATA) 100% oxygen, normobaric oxygen (NBO) with 1 ATA 100% oxygen, or ambient air 15 minutes after LOC. All animals underwent passive avoidance training and memory was assessed by measuring step‐down latency (SDL) and step‐up latency (SUL) seven days following CO exposure. Results: Carbon monoxide poisoning induced significant memory deficits (SDLCO= 156 sec; SULCO= 75%) compared with nonpoisoned (NP) animals (SDLNP= 272 sec; SULNP= 100%). Both HBO and NBO did not prevent these neurologic sequelae. Furthermore, no significant neurobehavioral differences were found between HBO and NBO. Histologic examination of the CA1 layer of the hippocampus for pyknotic cells showed significant damage from CO in the air‐treated animals (9.6%) but not in the nonpoisoned animals (3.8%). No significant neuroprotection was seen histologically with NBO and HBO compared with ambient air. Conclusions: These results suggest that HBO is not effective in preventing neurologic sequelae in mice and that there is no benefit of HBO over NBO following severe CO neurotoxicity.
Mild Hypothermia Induced before Cardiac Arrest Reduces Brain Edema Formation in Rats
Authors: Xiao Feng , Zhang Shu , Arnold Thomas C. , Alexander J. Steven , Huang Jian , Carden Donna L. , Conrad Steven A.
Published: July 2002

Objectives: The mechanisms by which hypothermia improves cardiac arrest (CA)‐induced brain damage are unclear. The authors hypothesized that mild hypothermia induced before CA attenuates brain edema formation by preventing neutrophil‐mediated dysfunction of the endothelial cell junction proteins. Methods: Eighteen rats were randomized to normal control surgery (group 1, n = 6), normothermic (37.5°C) CA (group 2, n = 6), or hypothermic (34°C) CA (group 3, n = 6). Hypothermia was induced with external cooling before CA in group 3. Cardiac arrest was induced by 8 minutes of asphyxiation. Brain edema was determined by wet‐to‐dry weight ratio and cerebral spinal fluid pressure (CSFP). Brain neutrophil content was determined by myeloperoxidase (MPO) activity, and occludin degradation was assessed by western blotting. Results: Normothermic CA significantly increased brain wet‐to‐dry weight ratio from 4.52 ± 0.04 in group 1 to 4.80 ± 0.04 in group 2 (p = 0.0003) and CSFP from 3.6 ± 0.9 in group 1 to 8.9 ± 0.9 mm Hg in group 2 (p = 0.004). Mild hypothermia before CA in group 3 significantly reduced brain wet‐to‐dry weight ratio (4.68 ± 0.03, p = 0.008 vs. group 2) and CSFP (3.8 ± 0.5 mm Hg, p = 0.004 vs. group 2). Cardiac arrest increased brain MPO from 0.07 ± 0.025 in group 1 to 0.16 ± 0.02 units/gram brain weight in group 2 (p = 0.006) that was not decreased by hypothermia before CA (0.12 ± 0.02 in group 3 (p = 0.07 vs. group 2). There was no occludin proteolysis in any group. Conclusions: Mild hypothermia before CA decreases CA‐induced brain edema. The hypothermia‐elicited reduction in brain edema does not appear to be neutrophil‐dependent and the early brain edema formation may not involve the proteolysis of occludin.
The Relationship among Depressive and Alcoholic Symptoms and Aggressive Behavior in Adult Male Emergency Department Patients
Authors: Bacaner Nina , Kinney Terry A. , Biros Michelle , Bochert Shelli , Casuto Nadov
Published: July 2002

Objective: To determine the extent to which depressive and alcoholic symptoms are related to aggressiveness in male emergency department (ED) patients. Methods: A cross‐sectional survey design was conducted in a Midwest urban ED. A convenience sample of 302 noncritical male patients completed the survey. Self‐reported aggressiveness, anger problems, Zung depressive symptoms, CAGE alcoholic dependence, and demographics were collected. A conceptual causal model was tested with structural equation (SEQ) modeling. Regression analyses examined the extent to which the Zung scale, CAGE inventory, and demographics explained aggressiveness. Results: The SEQ modeling found that both depressive and alcoholic symptoms linked significantly to aggressiveness. Depressive symptoms linked three times more strongly than alcoholic symptoms to aggressiveness. Model fit statistics suggested that depressive and alcoholic symptoms are plausible causal factors for male aggressiveness. Regression analyses revealed that four items from the Zung scale (irritable, can't sleep, “better off dead,” indecisive) and two items from the CAGE inventory (annoyed when criticized about drinking, need to cut down) explained aggressiveness. Conclusions: In this urban ED population, depressive symptoms linked to aggressiveness three times more strongly than alcoholic symptoms. An abbreviated screening tool that could be used in EDs incorporating Zung and CAGE items may identify males who would benefit from further evaluation for depression, alcoholism, and aggressive behavior.
An Innovative Strategy for Conducting Clinical Research: The Academic Associate Program
Authors: Hollander Judd E. , Singer Adam J.
Published: July 2002

Performance of high‐quality clinical research usually requires procurement of substantial funding to support and sustain the research infrastructure. The authors have developed a program to support a research infrastructure that minimizes financial start‐up costs and maximizes productivity of clinical‐educator faculty with limited protected time. The program integrates clinical research with undergraduate education. The authors report the experience with the academic associate program at two academic institutions. They describe the program, provide measures of program success, and discuss potential methods for other institutions to initiate similar programs. Similar programs can be developed in a variety of outpatient and inpatient settings allowing the performance of high‐quality clinical research in a time‐efficient and cost‐effective manner.
Board Review Series: Emergency Medicine
Authors: McCullough Lynne
Published: July 2002

By Latha Stead. Baltimore, MD: Lippincott Williams & Wilkins, 2000, 673 pp, including index, $28.95 (softcover).
Validation of the Pulmonary Score: An Asthma Severity Score for Children
Authors: Smith Sharon R. , Baty Jack D. , Hodge Dee
Published: July 2002

Objectives: In the absence of a validated “user‐friendly” method of scoring asthma severity, the authors derived the pulmonary score (PS). The purpose of this study was to begin validation trials of the PS by comparing it with the peak expiratory flow rate (PEFR). Methods: The study enrolled a convenience sample of children, aged 5‐17 years, who came to the emergency department (ED) for treatment of an acute asthma exacerbation. The PEFR (best of three attempts) and the PS were measured before and after the first albuterol treatment by a physician and a nurse from a pool of 45 trained observers. The PS includes respiratory rate, wheezing, and retractions, each rated on a 0‐3 scale. Decreasing PS and increasing PEFR indicate clinical improvement. Pre‐ and post‐treatment PEFRs and PSs were compared using paired t‐tests to establish construct validity. Correlation of pre‐ and post‐treatment PSs with PEFRs was measured to establish criterion validity. Results: Forty‐six subjects completed the study. Mean percent predicted PEFR improved after treatment by 20.7% (p = 0.0001), and mean PS by 1.5 for nursing‐obtained scores (p < 0.0001) and 1.9 for physician‐obtained scores (p < 0.0001). Pre‐ and post‐treatment PSs were significantly correlated with PEFRs. Correlations for the nursing‐obtained scores were pre‐treatment r = ‐0.57 (p = 0.0003) and post‐treatment r = ‐0.67 (p = 0.0001), and for the physician‐obtained scores were pre‐treatment r = ‐0.44 (p = 0.003) and post‐treatment r = ‐0.56 (p = 0.0001). The pre‐treatment interrater reliability was 0.62 and the post‐treatment was 0.53. Conclusions: These data support the construct and criterion validities of the PS as a measure of asthma severity among children in the ED. The PS is a practical substitute to estimate airway obstruction in children who are too young or too sick to obtain PEFRs.
Social Bias and Injustice in the Current Health Care System
Authors: Manoach Seth M. , Goldfrank Lewis R.
Published: July 2002

This paper reflects upon historical and modern events and challenges emergency physicians to affirm a genuine commitment to social justice. Such an affirmation does not allow the physician to rest in the belief that the system is inherently just. Rather, it challenges the practitioner to recognize the widespread and inherent injustices that are present. It is probable that significant strides have been made toward protecting the rights and dignity of our patients. Even so, much remains to be done. Poor and minority patients are still less than optimally treated, and increasing marketplace competitiveness may jeopardize some of the recent gains in caring for the uninsured. Future generations may look upon some of the current discriminatory practices of our professional lifetimes with the condemnation that we hold for past abuses.
Profiles in Patient Safety:Sidedness Error
Authors: Shapiro Marc J. , Croskerry Pat , Fisher Steven
Published: July 2002

Abstract. This case describes a 45‐year‐old woman with significant respiratory distress secondary to a left‐sided pleural effusion that mandated an urgent thoracentesis. An adverse event occurred when the physician performed the procedure on the incorrect side of the patient. Results of the incident investigation followed by a discussion of medical errors models, common errors types, human factors considerations, and conditions that contribute to error are presented. Pertinent case‐specific and general concepts of a system approach to reduce this type of medical error are discussed, and educational recommendations are offered.
The Normal Difference in Bilateral Indirect Blood Pressure Recordings in Hypertensive Individuals
Authors: Pesola Gene R. , Pesola Helen R. , Lin Ming , Nelson Michael J. , Westfal Richard E.
Published: July 2002

Abstract. Objective: If there is a significant dichotomy between bilateral systolic blood pressure determinations in both arms in hypertensive individuals, it is often taken as a sign of underlying pathology. The primary objective was to determine what the normal variation might be for a significant difference between blood pressures in both arms. A clinically significant difference was chosen as a systolic blood pressure value greater than 10 mm Hg between the upper extremities, as is commonly quoted at the bedside and in the literature.

Methods: Bilateral indirect blood pressure determinations were obtained in 100 subjects with hypertension in the sitting position. The blood pressure was obtained by two observers, one the recorder and the other who obtained the blood pressure but was blinded to the actual values taken. The order of blood pressure determination in the first arm was determined prior to the study from a table of random numbers. The coefficient of variation in obtaining the blood pressure in each arm was determined in 5 of the 100 subjects. The age, sex, and handedness of each individual were recorded as demographic variables.

Results: The average left and right systolic blood pressures were 139 ± 22 and 141 ± 22 mm Hg, respectively. The average left and right diastolic blood pressures were 78 ± 12 and 79 ± 13 mm Hg, respectively. There was no significant difference between left minus right systolic or diastolic differences (paired t‐test). There was no significant difference between systolic or diastolic blood pressures between gender or between left‐ and right‐handed individuals (nonpaired t‐test). The average coefficients of variation for taking right and left arm systolic pressures were 2.90% and 1.32%, respectively. Eighteen subjects (18%) had differences in systolic blood pressure between both arms exceeding 10 mm Hg (10% to 26%, 95% confidence interval).

Conclusions: Differences of more than 10 mm Hg in indirect systolic blood pressure recordings between arms are frequent in asymptomatic hypertensive individuals and do not per se indicate any pathologic condition. In the right clinical situation, differences that are noted should be repeated and should be added to the total clinical picture when used to determine whether a pathologic condition is present. Assuming no significant aortic or subclavian disease in the population tested, the specificity of the bilateral blood pressure test was 82%.
A Values Proposition for Cancer Care
Authors: Rosa William E. , Epstein Andrew S. , Nelson Judith E.
Published: December 2024

This Viewpoint discusses what a value proposition could look like in oncology and how it should reflect a clinician’s commitment to partner with patients to improve outcomes through individualized communication and shared decision-making centered on the patient’s values.
Synthesis of Copper Matrix Hybrid Composites with Boron‐, Nitrogen‐, and Silicon‐Doped Reduced Graphene Oxide by Hot Press Technique: Investigation of Tribological, Mechanical, and Electrical Conductivity Properties
Authors: Macit Cevher Kursat , Horlu Merve , Aksakal Bünyamin , Er Yusuf
Published: December 2024

Copper and its alloys are widely used in the preparation of metal matrix composites due to their thermal and electrical conductivity. This study aims to improve the mechanical, tribological and electrical conductivity properties of copper (Cu) matrix powders by adding certain amounts (10 wt%) of reduced graphene oxide (rGO) nanopowder, boron (B), nitrogen (N) and silicon (Si) reinforced rGO nanopowder. Hybrid composites were produced by powder metallurgy production methods. The samples were characterized by X‐ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X‐ray spectroscopy (EDX) and Fourier‐transform infrared spectroscopy (FT‐IR) analysis for reinforcement, homogeneity and phase identification. The mechanical and tribological properties of the hybrid composites were investigated by hardness, wear tests and temperature dependent electrical conductivity tests to determine the effect of the reinforcement materials on the Cu matrix structure. The maximum hardness value was obtained from the (Cu–rGO–Si–B–N) hybrid composite with an increase of 193% compared to the pure Cu sample. When the coefficient of friction values of RGO and reinforced rGO hybrid composites were examined, a 219.12% lower coefficient of friction value was observed in the (Cu–rGO–Si–B–N) sample compared to the pure Cu sample. The highest value was observed in the temperature dependent electrical resistance analysis in the rGO reinforced sample.
Giant Polyketide Synthases Biosynthesize a Marine Polyether Biotoxin
Authors: Teufel Robin , Müller Michael
Published: December 2024

Prymnesin toxins were probably the direct cause of the environmental catastrophe in the Oder river in 2022. They belong to the so‐called ladder polyethers, which are among the most toxic non‐proteinogenic substances and have caused a whole series of food poisoning in humans and numerous other incidents of fish deaths. Despite massive efforts, the enzymatic machinery has remained enigmatic. In a recent study, researchers at the Scripps Institution of Oceanography and the University of California, San Diego, have uncovered the initial mechanisms by which algae produce these toxins. Crucial to the breakthrough was the methodological advance in sequencing and assembly that allowed the identification and analysis of the largest polyketide synthase (PKS) known to date, named PKZILLA‐1 and PKZILLA‐2, which enabled, among other things, the confirmation and elucidation of stereocenters. Thus, further investigations into the biosynthesis and other aspects of these highly toxic substances are made possible, which could perhaps make these ′biblical plagues′ predictable.
IrPdCuFeNiCoMo Based Core‐Shell Icosahedron Nanocrystals and Nanocages for Efficient and Robust Acidic Oxygen Evolution
Authors: Long Mairui , Lai Siyuan , Miao Kanghua , Jiang Wendan , Fan Wei , Kang Xiongwu
Published: December 2024

Facets engineering of high entropy alloy (HEA) nanocrystals might be achieved via shape‐controlled synthesis, which is promising but remains challenging in designing Ir‐based catalysts towards efficient and robust oxygen evolution reaction (OER) in acidic medium. Herein, icosahedra nanocrystals featured with PdCu core and IrPdCuFeNiCoMo shell were prepared by wet‐chemical reduction in one‐pot, ascribing to the initial formation PdCu core and subsequent deposition and diffusion of IrPdCuFeNiCoMo HEA shell. Sequential selective chemical etching of PdCu core results in IrPdCuFeNiCoMo HEA nanocages, delivering an overpotential of 235 mV at 10 mA cm−2, 51.0 mV dec−1, and 1624 A gIr−1 at 1.50 V vs reversible hydrogen electrode in a conventional three electrode cell. In a proton exchange membrane water electrolyzer, it delivers a low cell voltage of 1.65 and 1.77 V at a current density of 1.0 and 2.0 A cm−2, respectively, and maintains stable over 900 h at 500 mA cm−2. Theoretical calculations attribute the enhanced intrinsic activity to the broad distribution of the binding energy for OER intermediates on IrPdCuFeNiCoMo HEA, which breaks the linear scaling relationship and accelerates the OER process.
Self‐Assembly and Biological Properties of Highly Fluorinated Oligonucleotide Amphiphiles
Authors: Laurent Quentin , Bona Beatrice L. , Asohan Jathavan , Rosati Marta , Faiad Sinan , Bombelli Francesca Baldelli , Metrangolo Pierangelo , Sleiman Hanadi F.
Published: December 2024

Nucleic acids, used as therapeutics to silence disease‐related genes, offer significant advantages over small molecule drugs: they provide high specificity, the ability to target “undruggable” molecules, and adaptability to a wide range of disease phenotypes. However, their instability in biological media, as well their rapid clearance from the organism limit their applicability, necessitating the use of nanocarriers to overcome these challenges. Among these strategies, spherical nucleic acids (SNA)—composed of a densely packed corona of oligonucleotides around a nanoparticle—have emerged as a powerful tool, in particular when self‐assembled from DNA amphiphiles. This non‐covalent strategy however has caveats, especially when it comes to stability in complex biological media, where these SNAs disassemble in contact to serum proteins. Here, we developed highly fluorinated DNA amphiphiles that readily self‐assemble into SNAs and have tunable stability profiles in biological media. They are made of branched fluorinated moieties with potentially improved biodegradability as compared to their linear counterparts. Depending on the number of fluorophilic interactions, the self‐assembled SNAs can have excellent serum stabilities—up to days—and readily deliver nucleic acid therapeutics for gene silencing applications. These systems show great potential as promising candidates for nucleic acid‐based therapies.
Intramolecular Charge Transfer in Antiaromatic Donor/Acceptor‐Fused s‐Indacenes
Authors: Demachkie Isabella S. , Miller Michael P. , Warren Gabrielle I. , Barker Joshua E. , Strand Eric T. , Zakharov Lev N. , Haley Michael M.
Published: December 2024

Herein we report the synthesis and characterization of four donor/acceptor‐fused s‐indacenes via the late‐stage oxidation of a family of unsymmetrical benzofuran/benzothiophene‐s‐indacene regioisomers. A thorough study of their properties through experimental and computational analysis has revealed the effect of asymmetry on the molecular properties associated with antiaromaticity, as well as a strong correlation between antiaromaticity and intramolecular charge transfer (ICT). The strength of the charge transfer depends on the fusion orientation of the donor and acceptor motifs relative to the s‐indacene core. The two most antiaromatic oxidized isomers exhibit strong evidence of ICT with 30 and 40 nm solvatochromic shifts.
Nitrogen‐Rich Conjugated Macrocycles: Synthesis, Conductivity, and Application in Electrochemical CO2 Capture
Authors: Le Phuong H. , Liu Andong , Zasada Leo B. , Geary Jackson , Kamin Ashlyn A. , Rollins Devin S. , Nguyen Hao A. , Hill Audrey M. , Liu Yayuan , Xiao Dianne J.
Published: December 2024

Here we report a series of nitrogen‐rich conjugated macrocycles that mimic the structure and function of semiconducting 2D metal–organic and covalent organic frameworks while providing greater solution processability and surface tunability. Using a new tetraaminotriphenylene building block that is compatible with both coordination chemistry and dynamic covalent chemistry reactions, we have synthesized two distinct macrocyclic cores containing Ni−N and phenazine‐based linkages, respectively. The fully conjugated macrocycle cores support strong interlayer stacking and accessible nanochannels. For the metal–organic macrocycles, good out‐of‐plane charge transport is preserved, with pressed pellet conductivities of 10−3 S/cm for the nickel variants. Finally, using electrochemically mediated CO2 capture as an example, we illustrate how colloidal phenazine‐based organic macrocycles improve electrical contact and active site electrochemical accessibility relative to bulk covalent organic framework powders. Together, these results highlight how simple macrocycles can enable new synthetic directions as well as new applications by combining the properties of crystalline porous frameworks, the processability of nanomaterials, and the precision of molecular synthesis.
Exploration of the Mechanism of Guaijaverin in Inhibiting Pancreatic Lipase Based on Multispectral Method, Molecular Docking, and Oral Lipid Tolerance Test in Rats
Authors: Gao Xinyu , Jia Kaijie , Li Hong , Liu Shujun , Wang Yang , Tian Jinlong , Zhao Xin , Zhao Pan
Published: December 2024

This study aims to investigate the action mechanism of guaijaverin on pancreatic lipase from multiple perspectives and provide a theoretical basis for the search for new pancreatic lipase inhibitors. The inhibition of pancreatic lipase by guaijaverin was investigated through enzyme inhibition activity experiments, and the IC50 was calculated to determine the type of inhibition of guaijaverin. The mechanism of action was studied by measuring fluorescence, ultraviolet spectra, and circular dichroism. Molecular docking technology was used to explore the binding situation. In addition, in vivo oral lipid tolerance tests in rats were carried out to investigate the inhibitory effect of guaijaverin on pancreatic lipase. Guaijaverin inhibited pancreatic lipase up to 90.63%, confirming its excellent inhibitory ability. The inhibition type was noncompetitive inhibition in reversible inhibition. The multispectral experiments indicated that its quenching type was static quenching and guaijaverin changed the microenvironment and spatial conformation of pancreatic lipase. The molecular docking results showed that the minimum binding energy between the two compounds was −6.96 kcal/mol. In vivo experiments demonstrated that guaijaverin inhibits pancreatic lipase by reducing TG uptake in the body. Guaijaverin has excellent inhibitory effects on pancreatic lipase and has the potential to function as a pancreatic lipase inhibitor.
One‐pot synthesis of spirooxindoles bearing α‐methylene‐γ‐butyrolactone moiety from Morita–Baylis–Hillman carbonates of isatins and paraformaldehyde
Authors: Lee Junseong , Kim Jae Nyoung
Published: December 2024

One‐pot synthesis of spirooxindoles bearing α‐metylene‐γ‐butyrolactone moiety has been carried out by the reaction of Morita–Baylis–Hillman (MBH) carbonates of isatins and paraformaldehyde in the presence of 1,8‐diazabicyclo[5.4.0]undec‐7‐ene (DBU) in refluxing 1,2‐dichloroethane in moderate yields. The reaction proceeded via (i) the formation of resonance‐stabilized N‐ylide from DBU and the MBH carbonate of isatin, (ii) a selective γ‐attack of N‐ylide to formaldehyde, (iii) lactonization to liberate methoxide ion, (iv) addition of methoxide ion to the iminium part of DBU, (v) intramolecular hydride transfer via a six‐membered transition state, and finally (vi) elimination of DBU.
Brain Reactivity and Vulnerability to Social Feedback Following Acute Stress in Early Adolescence
Authors: Celen Zeynep , Murray Ryan J. , Smith Mariana Magnus , Jouabli Sondes , Ivanova Vladimira , Pham Eleonore , Schilliger Zoe , Vuilleumier Patrik , Merglen Arnaud , Klauser Paul , Piguet Camille
Published: December 2024

Introduction

Early adolescence is a time of high psychosocial stress exposure and high stress reactivity, associated with the development of mental disorders. Understanding how the brain reacts to acute and social stressors during this period might help us detect and protect those at risk.

Methods

We used functional magnetic resonance imaging to investigate acute social stress reactivity in non‐clinical adolescents between ages 13 and 15 years (N = 61) with a range of depression scores (Beck Depression Inventory scores 0–32). Participants underwent a modified Montreal Imaging Stress Task (MIST) with psychosocial stress condition consisting of two parts: acute stress (challenging maths) followed by social feedback (positive or negative), separated by brief recovery periods. The test condition was compared to a non‐stressful control. We examined brain responses to social feedback relative to the acute stressor and feedback valence.

Results

Psychosocial stress produced differential activation in the paracingulate gyrus, insula, and deactivation in the ventral striatum. Receiving social feedback, compared to acute stress, activated cortical midline regions such as the medial prefrontal cortex and posterior cingulate cortex. Positive feedback increased activity in frontal pole and middle frontal gyrus whereas negative feedback did not show any differential response in the whole group. However, participants with depressive symptoms reacted with higher activation in the posterior cingulate cortex to negative feedback.

Conclusion

We show that social feedback after an acute stressor activates regions involved in self‐referential processing, with positive feedback eliciting generally higher activation and negative feedback impacting only individuals with vulnerable mood traits during early adolescence.
Design, Synthesis, and Biological Evaluation of Naphthalimide‐Polyamine Conjugate as a Potential Anti‐Colorectal Cancer Agent
Authors: Dai Fujun , Cao Yue , Zhu Chenguang , Li Yibing , Ma Xiaoxuan , Wang Senzhen , Liu Haizhen , Xie Xiaoya , Gao Lei , Wang Yanming , Wang Chaojie
Published: December 2024

Colorectal cancer is the second most common cause of cancer‐related death worldwide, with a rising incidence, highlighting an urgent need for novel therapeutics. In this study, we developed several polyamine conjugates. Compound 6 (C6) was selected as the lead compound and was evaluated for anticancer activity in vitro and in vivo. In vitro experiments showed that C6 inhibited cell proliferation, colony formation, migration, and invasion of colorectal cancer cells while inducing apoptosis, pyroptosis, and autophagosome formation. Genetic or pharmacological inhibition of autophagy weakened C6‐induced apoptosis and gasdermin E (GSDME)‐dependent pyroptosis. Inactivation of caspase 3 activity by AC‐DEVD‐CHO decreased the levels of N‐terminal GSDME induced by C6. Furthermore, animal models exhibited suppressed tumor growth and dissemination after treatment with C6. Taken together, our findings highlight C6 as a potential drug against colorectal cancer.
Synthesis and Fungicidal Activities of Coumarin Derivatives as Succinate Dehydrogenase Inhibitors
Authors: Pu Jiangping , Ren Xingyu , Tuerhong Adalat , Lei Dongyu , Sun Pengzhi , Yan Sichang , Jin Lu , Pan Le
Published: December 2024

Succinate dehydrogenase inhibitors (SDHIs) have been developed to the fastest growing family of fungicides. To develop novel succinate dehydrogenase (SDH) inhibitors, 27 novel non‐amides coumarin derivatives were designed, synthesized, and characterized. The bioassay revealed that most of the target compounds exhibited significant antifungal activity against Botrytis cinerea in vitro. Notably, compounds 1a and 2c with EC50 values of 0.92 and 0.52 µg/mL, respectively, which were better than that of positive control chlorothalonil (EC50 = 3.14 µg/mL). Moreover, in vivo antifungal assay results showed that compound 2c could observably inhibit the growth of B. cinerea on Kuerla pears with remarkable protective at a dosage of 200 µg/mL. The scanning electron microscopy (SEM) and transmission electron microscopy (TEM) investigation indicated that compound 2c significantly damaged the cell structures of B. cinerea mycelium. Three‐dimensional quantitative structure—activity relationship (3D‐QSAR) models were analyzed for structure—activity relationships of all target compounds. Furthermore, molecular docking revealed that compound 2c was able to bind closely to the receptor protein of SDH. Enzyme activity analysis also further verified its inhibitory effect. These results demonstrated that compound 2c may be potential candidate for novel SDH inhibitors, and these results afforded further valuable reference for SDHIs discovery.
Effect of Postoperative Atrial Fibrillation After Cardiac Surgery: A Meta‐Analysis
Authors: Qu Fangzhou , Yang Wei , He Ni , Qu Shangcheng , Zhou Xiao , Ma Huayan , Jiang Xin
Published: December 2024

Background

A meta‐analysis study was conducted to determine how to predict the effect of postoperative atrial fibrillation after cardiac surgery.

Hypothesis

Long‐term mortality and cardiovascular morbidity are linked to postoperative atrial fibrillation.

Method

Until August 2024, a comprehensive literature study was completed, and 3486 connected studies were revised. The 38 selected studies included 241 299 cardiac surgery participants at the beginning of the study. The odds ratio (OR) and 95% confidence intervals (CIs) were used to look at the effect of atrial fibrillation after heart surgery using two‐sided methods and either a fixed or random model.

Results

Individuals with cardiac surgery with postoperative atrial fibrillation had significantly higher mortality at 1 year (OR, 1.39; 95% CI, 1.12–1.72, p < 0.001), mortality at 5 years (OR, 1.61; 95% CI, 1.33–1.94, p < 0.001), mortality at 10 years (OR, 1.61; 95% CI, 1.39–1.87, p < 0.001), and overall stroke (OR, 1.61; 95% CI, 1.34–1.94, p < 0.001) compared to without postoperative atrial fibrillation.

Conclusions

Individuals with cardiac surgery with postoperative atrial fibrillation had significantly higher mortality at 1 year, mortality at 5 years, mortality at 10 years, and overall stroke compared to those without postoperative atrial fibrillation. To validate this discovery, more research and caution must be implemented when interacting with its values.
Oligomerization of 33‐mer Gliadin Peptides: Supramolecular Assemblies in Celiac Disease
Authors: Dodero Verónica I. , Herrera María G.
Published: December 2024

The 33‐mer gliadin peptide and its deamidated derivative, known as 33‐mer DGP, are proteolytically resistant peptides central to the pathomechanism of celiac disease (CeD), the autoimmune presentation of gluten‐related disorders (GRD). Both peptides can form spontaneous oligomers in the nanomolar concentration, leading to the formation of nanostructures. In other protein‐related diseases, oligomers and aggregates are central in their pathomechanism; therefore, it was hypothesized that the oligomerization of proteolytical‐resistant 33‐mer gliadin peptides could be an underrecognized disease trigger. This review focuses on the current understanding of 33‐mer peptides and their oligomers in vitro and cellular experiments. We intend to give the necessary details that incentivize the chemistry community to get involved in the effort to understand the self‐assembly of gliadin peptides and the role of their supramolecular structures in CeD and the other GRD. More research is needed to design effective and safe chemical and/or nutritional interventions beyond the gluten‐free diet.