Spontaneous Molecule Aggregation for Nearly Single-Ion Conducting Sol Electrolyte to Advance Aqueous Zinc Metal Batteries: The Case of Tetraphenylporphyrin.

Zn metal as a promising anode of aqueous batteries faces severe challenges from dendrite growth and side reactions. Here, tetraphenylporphyrin tetrasulfonic acid (TPPS) is explored as an electrolyte additive for advanced Zn anodes. It is interesting to note that TPPS spontaneously assembles into unique aggregates. As they adsorb on the Zn anode, the aggregates enhance the resistance to electrolyte percolation and dendrite growth compared to single molecules. Meanwhile, TPPS facilitates anion association in the solvation sheath of Zn2+, and boosts the transference number of Zn2+ up to 0.95. Therefore, anion-related side reactions and anion-induced electrode overpotentials are reduced accordingly. In this context, the electrolyte containing TPPS exhibits excellent electrochemical performance. Even under a high loading of MnO2 (25 mg cm-2), a limited Zn supply (N/P ratio=1.7), and a lean electrolyte (15 µL mAh-1), the full cells still represent a higher cumulative capacity compared to the reported data. The advantages of this electrolyte are also adapted to other cathode materials. The pouch cells of Zn||NaV3O8 ⋅ 1.5H2O realize a capacity of ~0.35 Ah at 0.4 C under harsh conditions.

Advancements in aqueous zinc-iodine batteries: a review.

Aqueous zinc-iodine batteries stand out as highly promising energy storage systems owing to the abundance of resources and non-combustible nature of water coupled with their high theoretical capacity. Nevertheless, the development of aqueous zinc-iodine batteries has been impeded by persistent challenges associated with iodine cathodes and Zn anodes. Key obstacles include the shuttle effect of polyiodine and the sluggish kinetics of cathodes, dendrite formation, the hydrogen evolution reaction (HER), and the corrosion and passivation of anodes. Numerous strategies aimed at addressing these issues have been developed, including compositing with carbon materials, using additives, and surface modification. This review provides a recent update on various strategies and perspectives for the development of aqueous zinc-iodine batteries, with a particular emphasis on the regulation of I2 cathodes and Zn anodes, electrolyte formulation, and separator modification. Expanding upon current achievements, future initiatives for the development of aqueous zinc-iodine batteries are proposed, with the aim of advancing their commercial viability.

Zn(002)-preferred and pH-buffering triethanolamine as electrolyte additive for dendrite-free Zn anodes.

Zn anodes of aqueous batteries face severe challenges from side reactions and dendrite growth. Here, triethanolamine (TEOA) is developed as an electrolyte additive to address these challenges. It enhances the exposure of Zn(002) and diminishes the change in pH. Therefore, the electrolyte containing TEOA shows improved electrochemical performance.

Secondary Bonding Channel Design Induces Intercalation Pseudocapacitance toward Ultrahigh-Capacity and High-Rate Organic Electrodes.

Organic electrode materials have shown extraordinary promise for green and sustainable electrochemical energy storage devices, but usually suffer from low specific capacity and poor rate capability, which is largely caused by inactive components and diffusion-controlled Li+ intercalation. Herein, high-rate Li+ intercalation pseudocapacitance in organic molecular crystals is achieved through introducing weak secondary bonding channels, far exceeding their theoretical capacity based on redox chemistry at functional groups. The authors' combined experimentally electrochemical characterization with first-principles calculations show that the heterocyclic organic molecule 2,2'-bipyridine-4,4'-dicarboxylic acid (BPDCA) crystal permits a four-electron redox reaction at conventional CO and CN groups and a six-electron intercalation pseudocapacitance along conjugated alkene hydrogen bonding channels (H2 NC5 H⋯OC(OH)) and heterocyclic aromatic stacking channels (C5 H3 N⋯NH3 C5 ). The BPDCA electrode delivers an ultrahigh reversible capacity of 1206 mAh g-1 at 0.5 A g-1 and an exceptional rate capability. A 4.8 V high-energy/power-density BPDCA anode-based hybrid Li-ion capacitor is thus realized. This work opens a new avenue for developing organic intercalation pseudocapacitive materials via secondary bonding structure design.

Development and Evaluation of a Tele-Education Program for Neonatal ICU Nurses in Armenia.

PURPOSE: Neonatal mortality currently accounts for more than 60% of all infant mortality in Armenia. The majority of health professionals in Neonatal Intensive Care Units (NICU) however, have had no specialized training in neonatology. Local and global agencies have emphasized the need for improvement in the education and skills of NICU health professionals. The objective of this study was to design, implement, and evaluate an innovative tele-education program for NICU nurses in Armenia. DESIGN AND METHODS: Seven online tele-education courses were designed on various neonatal nursing topics using Final Cut Pro and translated professionally to Armenian. The videos were uploaded to YouTube. All NICU nurses employed in two hospitals (n = 35) in Yerevan, Armenia, completed a diagnostic pretest, course viewing, a posttest, and a satisfaction survey for each topic. A difference in knowledge was defined as the number of correct test answers obtained before and after the course. Participant satisfaction was measured using a Likert scale. RESULTS: The combined average for completed pre-tests for all courses was 45% and 71% for post-tests, which was statistically significant for each course (p < 0.05). A majority of the nurses either agreed or strongly agreed with all of the satisfaction parameters of the course. CONCLUSIONS: These results support a tele-education model for effectively providing continuing education to NICU nurses in Armenia. A similar platform could be used to establish nationwide certification programs for neonatal nurses. PRACTICE IMPLICATIONS: Tele-education technology can be used effectively by nursing educators working in global health as part of international learning collaboratives.

Handshake-free zone in a neonatal intensive care unit: Initial feasibility study.

BACKGROUND: The handshake represents a social custom with special importance in health care settings. However, handshakes can transmit disease and compliance with hand hygiene protocols averages <50%. We hypothesized that a handshake-free zone (HFZ) could be established within our neonatal intensive care unit (NICU) and would be well-received by patient families and their health care providers (HCPs). METHODS: We established an HFZ and conducted a prospective cohort study in the NICU at 2 UCLA Medical Centers. Data collection tools included questionnaires for NICU families and their HCPs. RESULTS: Handshake greetings occurred more frequently before than during the HFZ, as reported by HCPs (P = .0002) and patient families (P = .05). Before the HFZ, physicians were more likely than nurses to shake hands with patient families (P = .001), and believe the handshake was extremely important (P = .002); during the HFZ physicians' behaviors and attitudes shifted toward those of the nurses. All patient families and 66% of HCPs believed the NICU should consider establishing an HFZ. CONCLUSIONS: The HFZ decreased the frequency of handshakes within the NICU. The influence of the HFZ on HCP behavior and attitudes varied with gender and profession. Patient families and most HCPs supported the implementation of an HFZ.

Direct Analysis of Xanthine Stimulants in Archaeological Vessels by Laser Desorption Resonance Enhanced Multiphoton Ionization.

Resonance enhanced multiphoton ionization spectroscopy (REMPI) generates simultaneous vibronic spectroscopy and fragment free mass spectrometry to identify molecules within a complex matrix. We combined laser desorption with REMPI spectroscopy to study organic residues within pottery sherds from Maya vessels (600-900 CE) and Mississippian vessels (1100-1200 CE), successfully detecting three molecular markers, caffeine, theobromine, and theophylline, associated with the use of cacao. This analytical approach provides a high molecular specificity, based on both wavelength and mass identification. At the same time, the high detection limit allows for direct laser desorption from sherd scrapings, avoiding the need for extracting organic constituents from the sherd matrix.

Probing the mechanism of insulin aggregation with added metalloporphyrins.

The mechanism of inhibition of insulin-based amyloid gel formation by metal derivatives of tetrakis(4-sulfonatophenyl)porphyrin has been investigated. Time-course UV/vis measurements in conjunction with atomic force microscopy (AFM) were used to study the correlation between observed kinetics and amyloid structure for various concentration ranges of added metalloporphyrins. Observed structures include fibrils as well as circular, ring-like structures formed as a result of the interaction of insulin with porphyrin. In addition, binding studies demonstrate that the effectiveness of inhibition of the various metalloporphyrins is directly related to the strength of binding to insulin. It is suggested that both the electron distribution in the porphyrin core and the tendency to form porphyrin dimers affect both the structure of amyloid formed and the kinetic profile of the reaction.

Magnetic resonance spectroscopy reveals an impaired brain metabolic profile in mice resistant to cerebral malaria infected with Plasmodium berghei ANKA.

Malaria is a major cause of morbidity and mortality with an annual death toll exceeding one million. Severe malaria is a complex multisystem disorder, including one or more of the following complications: cerebral malaria, anemia, acidosis, jaundice, respiratory distress, renal insufficiency, coagulation anomalies, and hyperparasitemia. Using a combined in vivo/in vitro metabolic-based approach, we investigated the putative pathogenic effects of Plasmodium berghei ANKA on brain, in a mouse strain developing malaria but resistant to cerebral malaria. The purpose was to determine whether the infection could cause a brain dysfunction distinct from the classic cerebral syndrome. Mice resistant to cerebral malaria were infected with P. berghei ANKA and explored during both the symptomless and the severe stage of the disease by using in vivo brain magnetic resonance imaging and spectroscopy. The infected mice did not present the lesional and metabolic hallmarks of cerebral malaria. However, brain dysfunction caused by anemia, parasite burden, and hepatic damage was evidenced. We report an increase in cerebral blood flow, a process allowing temporary maintenance of oxygen supply to brain despite anemia. Besides, we document metabolic anomalies affecting choline-derived compounds, myo-inositol, glutamine, glycine, and alanine. The choline decrease appears related to parasite proliferation. Glutamine, myo-inositol, glycine, and alanine variations together indicate a hepatic encephalopathy, a finding in agreement with the liver damage detected in mice, which is also a feature of the human disease. These results reveal the vulnerability of brain to malaria infection at the severe stage of the disease even in the absence of cerebral malaria.

Clinical predictors of cardiac events in patients with isolated syncope and negative electrophysiologic study.

BACKGROUND: Patients with syncope or near syncope of unknown etiology represent a great challenge to cardiologists. An initial symptomatic episode triggers a series of diagnostic analysis which remain unsatisfactory when negative. More invasive tools such as electrophysiologic testing yield only partial answers to risk stratification while the complementary implantable holter diagnostics are not usually considered until a recurrent episode is documented. OBJECTIVE: This study targets predictors of significant cardiac rhythmic events in patients with a reported episode of syncope or near syncope presenting with negative diagnostics and electrophysiologic study results (EPS). A significant cardiac rhythmic event was defined as a combined end-point of (1) symptomatic AV block; (2) symptomatic conduction abnormalities requiring pacemaker therapy; (3) symptomatic sustained ventricular arrhythmia; and (4) sudden death. METHODS: All patients undergoing EPS after a first episode of syncope or presyncope between January 1997 and December 2001 were included for analysis. The study population consisted of 329 pts (42.6% women), 21 to 96 years old (mean 70+/-15 years) referred for an EP study for syncope or near syncope. RESULTS: Of the 329 patients who underwent EPS, 305 (92.7%) had follow-up data. The population, mean age 70 (+/- 15 years) and composed of 42% women, presented with hypertension (51.5%), diabetes mellitus (14.4%), hypercholesterolemia (30%), tobacco use (35%), a familial history of coronary heart disease (22%), history of stroke (4%), history of MI (12%), history of atrial fibrillation (10%), structural heart disease (17.4%), left ventricular ejection fraction 61 (+/- 11%) and ECG abnormalities (37%). These anomalies included right (RBBB) or left (LBBB) bundle branch blocks, left anterior fascicular block (LAFB), left posterior fascicular block (LPFB), bifascicular block (RBBB+LAFB) and traces of myocardial infarction. The mean follow-up was 31+/-20 months with 5% of patients recording significant cardiac rhythmic events (15/305): AV block requiring pacemaker therapy in 7 patients, sinus dysfunction in 4, sudden death in 3 and ventricular tachycardia in 1. Univariate analysis reveals structural heart disease, ECG abnormalities and LVEF associated with the risk of significant cardiac rhythmic events defined by the combined end-point. Multivariate analysis using a Cox model found that the only independent predictor of events was an ECG abnormality. The long-term risk of significant event in the subset with ECG abnormalities is of 10.6% (12/113). If unexplained syncope recurrence was included in the combined end-point, ECG abnormality and LVEF were both determinants with a 13.3% (15/113) risk of a arrhythmic events analysis in the subset of patients presenting with ECG abnormalities and Cox model found ECG abnormality as the only independent predictor of event. CONCLUSIONS: This study demonstrated that an ECG abnormality is the only predictive variable associated with a significant arrhythmic event in patients with a lone episode of syncope or near syncope and a negative EPS.

Antioxidant status of neonates exposed in utero to tobacco smoke.

To investigate the influence of maternal smoke exposure on neonatal and maternal antioxidant status, 39 mothers who were active smokers, 14 mothers exposed to environmental tobacco smoke (ETS), 17 controls, and their newborns were included in a prospective, controlled study. Plasma total antioxidant capacity, measured as total radical-trapping antioxidant parameter (TRAP) and ferric reducing antioxidant power (FRAP), and concentrations of specific antioxidants were measured in cord and in maternal blood. A similar, significant increase in ceruloplasmin concentration was observed in neonates born to actively smoking mothers and in those born to ETS exposed mothers. Uric acid and TRAP concentrations were significantly increased in ETS-exposed newborns and their mothers, compared to newborns and mothers from the active smoking and no-exposure groups with a trend towards increased uric acid, TRAP and FRAP concentrations being observed in the active smokers group. Neonatal and maternal antioxidant concentrations correlated significantly, except for ceruloplasmin. Cord blood vitamin A, E and C concentrations were unaffected by smoke exposure. These results show that maternal active smoking as well as ETS exposure significantly affect neonatal and maternal antioxidant status.

Clinical study of the effect of calcium hydroxide on root canal disinfection / 第三军医大学学报

Objective To compare the disinfectant effects of calcium hydroxide and traditional formaldehyde and cresol(FC) on the intracanal medicament in infected single rooted teeth. Methods A total of 84 single rooted teeth with chronic apical periodontits were randomly selected for the disinfection with calcium hydroxide or FC in root canal after the root canals were cleared routinely. Samples were taken before and after root canal disinfection a week later. The number and species of bacteria in the root canal and the change of clinic signs and symptoms were observed. All the patients were followed up for one year. Results The number and species of bacteria in the root canal decreased significantly and there was significant difference between the two groups ( P 0.05). Conclusion Calcium hydroxide is an effective disinfectant in root canal therapy.

Multivariate analysis of determinants of bacterial contamination of whole-blood donations.

BACKGROUND AND OBJECTIVES: Introduction of bacteria into blood components at the collection stage seems to be a frequent occurrence. We therefore assessed determinants of bacterial contamination of whole-blood donations to gain insight into contamination mechanisms and direct prevention. MATERIALS AND METHODS: A cross-sectional study was carried out on donors accepted for whole-blood donation in four French blood banks. Each blood bank used its own two-stage procedure for phlebotomy site preparation. Contamination was identified by culturing two 15-ml samples (collected aseptically at the outset of donation) in a BacT/Alert 240 system. Determinants were assessed by logistic regression analysis. RESULTS: Bacterial contamination, mainly by skin flora, occurred in 76 (2.2%) out of 3385 donations. Significant determinants were as follows: the blood bank (odds ratio [OR] range = 3.0-5.6, P < 0.001); lack of repetition of scrub (OR = 2.7, P = 0.032); and donor age > 35 years (OR = 1.8, P = 0.036). CONCLUSION: Systematic scrub repetition should be implemented to reduce bacterial contamination by skin flora at the collection stage. Further research is required to clarify the role of different antiseptic agents and of donor age.

[Methodology for the development of a program for following and maintaining the competency of human resources]. / Méthodologie de développement d'un programme de suivi et maintien des compétences des ressources humaines.

The progressive introduction of a management program for the maintenance and assessment of staff competence has also focussed attention on the human factor, a major consideration in risk management and quality control. This article has examined the relevant tools and practical means of application, and proposes a methodology combining a methodical analysis of processes with the determination of the minimal knowledge required for participation in the practical and theoretical training programs that provide a means of objective evaluation. The results obtained in terms of technical, organizational and cultural impact have also been analyzed.

Efficacy of a new collection procedure for preventing bacterial contamination of whole-blood donations.

BACKGROUND: Transfusion-related bacterial contamination is a serious problem. The introduction of bacteria into donations at the collection stage seems frequent, despite well-conducted phlebotomy site preparation. Additional preventive measures are required. STUDY DESIGN AND METHODS: The aim of this study was to assess the potential efficacy of excluding the first 15 mL of blood to reduce the bacterial contamination of donations. A special device allowed the aseptic collection of two samples at the beginning of donation: S1 (first 15 mL) and S2 (next 15 mL). Bacteriologic cultures of S1 and S2 were performed by using an automated system. The procedure's efficacy was measured by the proportion of positive donations in S1 that were then negative in S2. RESULTS: S1 and/or S2 were positive in 76 (2.2%) of 3385 donations. In about three-fourths of the culture-positive donations, contamination was detected in the first 15-mL sample only. Gram-positive cocci accounted for 81 percent of species, gram-positive bacilli for 14 percent, and gram-negative bacilli for 5 percent. The new procedure would have prevented the introduction of bacteria in 55 donations, reducing to 0.6 percent the risk of contamination from the first 15 mL collected. CONCLUSION: Although the final effect on blood component bacterial contamination rates cannot be derived from the study, excluding the first 15 mL of blood may reduce the rate of bacterial contamination in donations.

[The role of the thalamic ventrolateral nucleus in the cortical effect on the activity of vestibular neurons]. / Rol' ventrolateral'nogo iadra talamusa v realizatsii kortikofugal'nogo vliianiia na aktivnost' vestibuliarnykh neironov.

Electrocoagulation of lateral vestibular nucleus (NVL) reduces inhibitory effect of the motor and somatosensory areas and enhances the inhibitory effect of limbic, vestibular, and orbital cortical areas. Facilitating effect was enhanced by electrostimulation of the motor area and reduced by the stimulation of other cortical areas. Following the coagulation of the NVL, the ascending afferent flow to the cortex seems to be reduced. This results in diminishing of the cortical neurones tone and readjusts the descending influences upon the NVL neurones activity.

Pseudomonas aeruginosa endophthalmitis caused by contamination of the internal fluid pathways of a phacoemulsifier.

PURPOSE: To report 4 cases of Pseudomonas aeruginosa endophthalmitis caused by internal contamination of the internal pathways of a phacoemulsifier. SETTING: Ophthalmology Center, Perpignan, France. METHODS: Four clinical cases of postoperative endophthalmitis occurred after phacoemulsification. An investigation was necessary to prove the cause of the bacteriological contamination. RESULTS: Serotyping and ribotyping of the Pseudomonas aeruginosa strains obtained from the vitreous samples and from the phacoemulsifier showed that all these strains were identical and that the initial site of the contamination was the phacoemulsifier. CONCLUSIONS: The profession should be cognizant of this cause of endophthalmitis, although its occurrence is rare. Cataract surgeons should test samples from the collection bags of their phacoemulsifiers to ensure there is no bacteriological contamination.

Magnetic resonance spectroscopy of serum and acute-phase proteins revisited: a multiparametric statistical analysis of metabolite variations in inflammatory, infectious and miscellaneous diseases.

Proton MR spectra and biochemical assays have been recorded on the sera of 40 patients and ten controls in order to document the correlation between spectroscopic and biochemical variations in selected pathologies (cancer, inflammatory and infectious diseases, diabetes). N-acetyl proton resonances are essentially generated by the N-acetyl residues of the glucidic moieties borne by the most abundant acute-phase proteins (alpha1-acid glycoprotein, alpha1-antitrypsin and haptoglobin). These resonances are not correlated to immunoglobulins A, G and M levels. Principal component analysis shows that variations in spectroscopic and biochemical data are independent markers of the inflammatory status of patients but no additional sensitivity or specificity is obtained when the two sets of data are combined.