Cysteine-Induced Hybridization of 2D Molybdenum Disulfide Films for Efficient and Stable Hydrogen Evolution Reaction

The noble, metal-free materials capable of efficiently catalyzing water splitting reactions currently hold a great deal of promise. In this study, we reported the structure and electrochemical performance of new MoS₂-based material synthesized with L-cysteine. For this, a facile one-pot hydrothermal process was developed and an array of densely packed nanoplatelet-shaped hybrid species directly on a conductive substrate were obtained. The crucial role of L-cysteine was determined by numerous methods on the structure and composition of the synthesized material and its activity and stability for hydrogen evolution reaction (HER) from the acidic water. A low Tafel slope of 32.6 mV dec⁻¹, close to a Pt cathode, was registered for the first time. The unique HER performance at the surface of this hybrid material in comparison with recently reported MoS₂-based electrocatalysts was attributed to the formation of more defective 1T, 2H-MoS₂/MoO_x, C nanostructures with the dominant 1T-MoS₂ phase and thermally degraded cysteine residues entrapped. Numerous stacks of metallic (1T-MoS₂ and MoO₂) and semiconducting (2H-MoS₂ and MoO₃) fragments relayed the formation of highly active layered nanosheets possessing a low hydrogen adsorption free energy and much greater durability, whereas intercalated cysteine fragments had a low Tafel slope of the HER reaction. X-ray photoelectron spectroscopy, scanning electron microscopy, thermography with mass spectrometry, high-resolution transmission electron microscopy, Raman spectroscopy techniques, and linear sweep voltammetry were applied to verify our findings.     

Surgical lengthening of the clinical tooth crown

To understand why the crown lengthening may be desirable, a review of periodontal anatomy is in order. The odontologists know, but often underestimate importance of periodontal tissues health to restoration of defected teeth or dental arches. In order to avoid pathological changes, to predict treatment results more precisely, it is necessary to keep gingival biological width unaltered during teeth restoration. If there are less than 2 mm from restoration's margin to marginal bone clinical crown lengthening possibility should be considered in dental treatment plan. The choice depends on relationship of crown-root-alveolar bone and esthetical expectations. In order to keep margins of restoration supragingivally the distance from marginal bone to margins of restoration should not be less than 3 mm. Ideally the margins of restoration should be supragingivally or in the same level as marginal gingiva. When the margins of restoration are prepared subgingivally, the distance from marginal gingiva to margins of restoration should not be more than 0.7 mm. To continue dental treatment in operated area is recommended not earlier than in 4 weeks, and making restorations in esthetical area--not earlier than in 6 weeks.     

Cost-effective adenosine dosing for the treatment of PSVT

We reviewed our experience with adenosine for the conversion of paroxysmal supraventricular tachycardia (PSVT) to determine whether the recommended dosing strategy of 6 mg, followed by 12 mg, is cost-effective in actual practice. We observed a 65% conversion rate to sinus rhythm with the initial dosage of 6 mg adenosine (95% CI, 54% to 75%), and, based on subsequent cost analysis, conclude that the current strategy should not be replaced by a 12-mg-first strategy. If the packaging of adenosine was changed so that 12 mg cost less than twice 6 mg, this analysis should be revisited.     

Spontaneous esophageal rupture: a frequently missed diagnosis

The objective of this study was to determine the diagnostic features of spontaneous esophageal rupture and compare them with those traditionally applied in making this diagnosis. A retrospective 15-year chart review was performed on all cases listing esophageal rupture as a diagnosis. Only those cases diagnosed by contrast studies or direct visual confirmation were included. Facets of the history, physical examination, laboratory results, and X-ray procedures were examined and compared with the "classic" presentation of this diagnosis as noted in current medical texts. Fourteen cases of confirmed esophageal rupture were found. Only a small minority of cases presented in a fashion resembling a classic case. Esophageal rupture was the admitting diagnosis in 29 per cent of the cases. Laboratory values associated with esophageal rupture included elevated white blood cell count and hypoxia. The chest X-ray was abnormal in all but one patient, with findings of pneumothorax and/or pleural effusion in the majority. We conclude that reliance on classic findings will lead to misdiagnosis in the vast majority of cases presenting to the Emergency Department. Conversely, toxic appearance, pleural effusion, pneumothorax, elevated white blood cell count, azotemia, and hypoxia are all positively associated with this disease. In toxic-appearing patients with pleural effusions and/or pneumothoraces, spontaneous esophageal rupture should be considered.     

Hydrothermal synthesis and characterization of nanostructured titanium monoxide films

At the present time, the formation of titanium monoxide (TiO_x) two dimensional (2D) species with distinct composition, size, shape, and a significantly reduced bandgap (E_g) value compared to TiO₂ is of great scientific and practical importance. This paper describes our findings investigating Ti surface oxidation for the formation of TiO_x films possessing a densely-packed nanoplatelet morphology and a low bandgap value. This goal was herein achieved by the hydrothermal treatment of the Ti surface in selenious acid solution kept at a slightly alkaline pH. Furthermore, the nanoplatelet design not typical for TiO₂ porous films was created by this method for the first time. The formation of titanium monoxide, particularly TiO_0.84, as a major crystalline phase, was verified by XRD and confirmed by EPR investigations. It is worth noting that these nanoplatelet-shaped films with a thickness of 0.1–0.25 μm exhibited a very large shift of their light absorption threshold, down to 1.29 eV, compared to the E_g of anatase TiO₂ and a surprising 70% porosity determined via simulation of experimental reflection plots. It is anticipated that this unique TiO_x nanomaterial will pave the way for new investigations and applications.

At the present time, the formation of titanium monoxide (TiO_x) two dimensional (2D) species with distinct composition, size, shape, and a significantly reduced bandgap (E_g) value compared to TiO₂ is of great scientific and practical importance.     

Frightening dreams and spells: a case of ventricular asystole from Lyme disease.

We present a case of a 20-year-old woman who presented with a febrile illness, frightening dreams and repeated short episodes of apparent seizure activity. Third degree heart block and ventricular asystole were noted on the monitor when the patient experienced a spell during conscious sedation for a lumbar puncture. The combination of heart block and a predominantly lymphocytic cerebrospinal fluid led to the diagnosis of Lyme disease. Lyme titres were strongly positive and subsequently confirmed by Western Blot analysis. Cardiac aetiologies and specifically heart block associated with Lyme disease should be considered in patients from endemic areas presenting with fever and unexplained spells or seizure-like activity.     

Emergency medical services in the reconstruction phase following a major earthquake: a case study of the 1988 Armenia earthquake

STUDY OBJECTIVE: To use the clinical activities of an ambulance service as a tool to assess the residual and unmet medical needs of a city in the aftermath of a major earthquake and to apply that assessment to the development of a training curriculum for the prehospital personnel. METHODS: The researchers conducted structured interviews with health care workers at all levels of the emergency health care delivery system in Gyumrii, Armenia, and carried out a retrospective frequency analysis of 29,010 ambulance runs for an 11-month period from February through December 1992. Runs first were assigned into the broad categories of: 1) Adult Medical; 2) Pediatric Medical; or 3) Trauma, and then, according to diagnosis. The runs then were classified further as: 1) Primary Care; 2) Basic Life Support (BLS); or 3) Advanced Life Support (ALS). RESULTS: Adult Medical calls represented 24,684 (85%), Pediatric Medical calls 459 (1.6%), and Trauma calls 3,867 (13%). Only 12% of all ambulance calls resulted in transport to a medical facility, although this percentage was higher in children. Thirty percent of Adult Medical patients were diagnosed by the emergency medical providers as having exclusively a psychiatric problem. CONCLUSION: In the late aftermath of a devastating earthquake, the ambulance service in Gyumrii, Armenia has been delivering a substantial proportion of non-emergency, primary care services. They have adopted this unconventional role to compensate for the deficit in health care facilities and personnel created by the disaster. The training program that the investigators developed reflected the actual work activities of the prehospital personnel demonstrated in their assessment.     

Simulation based teamwork training for emergency department staff: does it improve clinical team performance when added to an existing didactic teamwork curriculum?

Objective: To determine if high fidelity simulation based team training can improve clinical team performance when added to an existing didactic teamwork curriculum.

Setting: Level 1 trauma center and academic emergency medicine training program.

Participants: Emergency department (ED) staff including nurses, technicians, emergency medicine residents, and attending physicians.

Intervention: : ED staff who had recently received didactic training in the Emergency Team Coordination Course (ETCC®) also received an 8 hour intensive experience in an ED simulator in which three scenarios of graduated difficulty were encountered. A comparison group, also ETCC trained, was assigned to work together in the ED for one 8 hour shift. Experimental and comparison teams were observed in the ED before and after the intervention.

Design: Single, crossover, prospective, blinded and controlled observational study. Teamwork ratings using previously validated behaviorally anchored rating scales (BARS) were completed by outside trained observers in the ED. Observers were blinded to the identification of the teams.

Results: There were no significant differences between experimental and comparison groups at baseline. The experimental team showed a trend towards improvement in the quality of team behavior (p = 0.07); the comparison group showed no change in team behavior during the two observation periods (p = 0.55). Members of the experimental team rated simulation based training as a useful educational method.

Conclusion: High fidelity medical simulation appears to be a promising method for enhancing didactic teamwork training. This approach, using a number of patients, is more representative of clinical care and is therefore the proper paradigm in which to perform teamwork training. It is, however, unclear how much simulator based training must augment didactic teamwork training for clinically meaningful differences to become apparent.