Ammonium fluoride's analogy to ice: Possibilities and limitations.

Ammonium fluoride, NH4F, is often seen as an analog to ice, with several of its solid phases closely resembling known ice phases. While its ionic and hydrogen-ordered nature puts topological constraints on the ice-like network structures it can form, it is not clear what consequences these constraints have for NH4F compound formation and evolution. Here, we explore computationally the reach and eventual limits of the ice analogy for ammonium fluoride. By combining data mining of known and hypothetical ice networks with crystal structure prediction and density functional calculations, we explore the high-pressure phase diagram of NH4F and host-guest compounds of its hydrides. Pure NH4F departs from ice-like behavior above 80 GPa with the emergence of close-packed ionic structures. The predicted stability of NH4F hydrides shows that NH4F can act as a host to small guest species, albeit in a topologically severely constraint configuration space. Finally, we explore the binary NH3-HF chemical space, where we find candidate structures for several unsolved polyfluoride phases; among them is the chemical analog to H2O2 dihydrate.

On a new nitrogen sX hydrate from ice XVII.

Recently, a new gas hydrate structure has been discovered. This structure, sX, is unique in a sense that it is so far the only gas hydrate with chiral channels. It is formed by hydrogen-water or carbon dioxide-water mixtures at pressures above 0.300 GPa, and it has been shown that it is the only clathrate hydrate that is refillable with hydrogen. This property makes it a possible storage material for gases. By analyzing neutron diffraction data and calculations based on density-functional theory, we show that sX is also refillable with nitrogen; the guest:host ratio will be shown to be 2.6(3). Furthermore, we report sX's decomposition behavior and give evidence that it undergoes several transitions into the exotic hydrates sH and sIII that have not been observed at these pressure and temperature conditions-before forming the stable nitrogen hydrate sII.

Increased recurrence in Scarf osteotomy for mild & moderate hallux valgus with Meary's line disruption.

BACKGROUND: Scarf osteotomy for hallux valgus is a successful procedure. Neverthless recurrence of deformity is reported as 5-8%. First ray instability is a recognised risk factor for recurrence. We investigate whether a radiographic marker such as Meary's line can be used to predict recurrence. This paper aims to test the null hypothesis that there is no difference in recurrence for mild and moderate hallux valgus treated with Scarf osteotomy in the presence of a disrupted Meary's line compared to an intact line. METHODS: At a minimum of 3 months follow up we retrospectively analysed radiographs, theatre and clinic notes of 74 (n=74) consecutive patients treated with Scarf osteotomy for mild and moderate hallux valgus at a single centre. The patients were divided into Group A (n=30) - patients who on pre-operative weight bearing radiographs had a disrupted Meary's line, and Group B (n=44) - those with a normal Meary's line on pre-operative weight bearing radiographs. RESULTS: Our results demonstrate statistically significant five times higher odds of recurrence in Group A compared to Group B with an odds ratio of 5.2 p=0.006 [95% CI 1.6-17]. On this basis we reject the Null hypothesis. CONCLUSION: In this paper, we link a disrupted Meary's line with risk of recurrence of deformity. We demonstrate that, when Scarf osteotomy is used to correct mild and moderate hallux valgus in the presence of a broken Meary's line, the odds of recurrence as compared to the same procedure being performed with an intact line are 5.2 times higher. Alternative corrective techniques such as the Lapidus procedure warrant further investigation for the treatment of mild and moderate hallux valgus in the presence of Meary's line disruption.

The role of joint engagement in the development of language in a community-derived sample of slow-to-talk children.

We explored whether supported (SJE) or coordinated joint engagement (CJE) between mothers recruited from the community and their 24-month-old children who were slow-to-talk at 18 months old were associated with child language scores at ages 24, 36, and 48 months (n = 197). We further explored whether SJE or CJE modified the concurrent positive associations between maternal responsive behaviours and language scores. Previous research has shown that SJE, maternal expansions, imitations, and responsive questions were associated with better language scores. Our main finding was that SJE but not CJE was consistently positively associated with 24- and 36-month-old expressive and receptive language scores, but not with 48-month-old language scores. SJE modified how expansions and imitations, but not responsive questions, were associated with language scores; the associations were evident in all but the highest levels of SJE. Further research is necessary to test these findings in other samples before clinical recommendations can be made.

Assessing the stability and sporicidal efficacy of oxidizing disinfectants.

BACKGROUND: The role of the healthcare environment in the transmission of clinical pathogens is well established. EN 17126:2018 was developed to address the need for regulated sporicidal product testing and includes a realistic medical soil to enable validation of products that claim combined cleaning and disinfection efficacy. AIM: To investigate the chemical stability and sporicidal efficacy of oxidizing disinfectant products in the presence of simulated clean and medical dirty conditions. METHODS: Disinfectant stability and sporicidal efficacy were evaluated in like-for-like ratios of soil:product. Disinfectants were exposed to simulated test soils and free chlorine, chlorine dioxide or peracetic acid concentrations were measured using standard colorimetric methods. Efficacy of disinfectants against C. difficile R027 endospores was assessed as per EN 17126:2018. Comparisons of performance between clean and medical dirty conditions were performed using one-way analysis of variance. Correlation analysis was performed using Pearson product-moment correlation. FINDINGS: Performance of chlorine-releasing agents (sodium dichloroisocyanurate, chlorine dioxide and hypochlorous acid) was concentration dependent, with 1000 ppm chlorine showing reduced stability and efficacy in dirty conditions. By contrast, peracetic acid product demonstrated stability and consistently achieved efficacy in dirty conditions. CONCLUSION: These results have implications for clinical practice, as ineffective environmental decontamination may increase the risk of transmission of pathogens that can cause healthcare-associated infections.

What the COVID pandemic taught us about the management of pediatric minor trauma.

The COVID-19 pandemic necessitated a change in our practice in the management of pediatric soft-tissue injuries. Patients were managed conservatively whenever possible. Our aim in this study was to see whether this more conservative approach adversely affected clinical, and patient-reported outcomes, including scarring. A prospective record of children presenting to the plastic surgery "Early Bird" clinic for pediatric trauma between 01.04.2020 and 30.06.2020 was kept. Electronic patient records were reviewed. An outpatient telephone clinic was scheduled for all patients. Parents were asked about complications and what they thought about the scar and to rate it as either: "poor," "satisfactory," "good," or "excellent." There were 240 patients, including 136 (57%) males and 104 (43%) females. The most frequent type of injury was a facial laceration in 123 patients (51.3%), followed by hand lacerations in 43 (17.9%), fingertip injuries in 31 (12.9%), and others. Ninety out of 240 (37.5%) were offered surgery. Follow-up times ranged from 17 to 20 months. Most parents (86.2%) were happy with the scarring and reported it as "good" or "excellent." The proportion rating the scar "excellent" or "good" was similar in the non-operated cohort (i.e., 85.5%) versus the operated cohort (88.5%) (p-value 0.16). The overall complication rate of patients seen during this time was 5.9%; 7.4% in the conservatively managed and 4.9% of those who went to the theater. Despite managing more wounds, including some dog bites, conservatively, patients and parents reported low complication rates and high levels of satisfaction with the final scarring.

Profiles of language development in pre-school children: a longitudinal latent class analysis of data from the Early Language in Victoria Study.

BACKGROUND: Pre-school language impairment is common and greatly reduces educational performance. Population attempts to identify children who would benefit from appropriately timed intervention might be improved by greater knowledge about the typical profiles of language development. Specifically, this could be used to help with the early identification of children who will be impaired on school entry. METHODS: This study applied longitudinal latent class analysis to assessments at 8, 12, 24, 36 and 48 months on 1113 children from a population-based study, in order to identify classes exhibiting distinct communicative developmental profiles. RESULTS: Five substantive classes were identified: Typical, i.e. development in the typical range at each age; Precocious (late), i.e. typical development in infancy followed by high probabilities of precocity from 24 months onwards; Impaired (early), i.e. high probabilities of impairment up to 12 months followed by typical language development thereafter; Impaired (late), i.e. typical development in infancy but impairment from 24 months onwards; Precocious (early), i.e. high probabilities of precocity in early life followed by typical language by 48 months. The entropy statistic (0.84) suggested classes were fairly well defined, although there was a non-trivial degree of uncertainty in classification of children. That half of the Impaired (late) class was expected to have typical language at 4 years and 6% of the numerically large Typical class was expected to be impaired at 4 years illustrates this. Characteristics indicative of social advantage were more commonly found in the classes with improving profiles. CONCLUSIONS: Developmental profiles show that some pre-schoolers' language is characterized by periods of accelerated development, slow development and catch-up growth. Given the uncertainty in classifying children into these profiles, use of this knowledge for identifying children who will be impaired on school entry is not straightforward. The findings do, however, indicate greater need for language enrichment programmes among disadvantaged children.

Epinephrine induced leucocytosis in a non-infective exacerbation of asthma.

In life-threatening cases of Acute Asthma the administration of epinephrine may be given as part of the initial management by paramedics. Concurrent infection is a frequent precipitant of an asthma exacerbation and consequently a leucocytosis is often found in such a situation. This case illustrates that marked leucocytosis can occur without an underlying infective process following epinphrine use.

Control of carbapenemase-producing Enterobacteriaceae outbreaks in acute settings: an evidence review.

BACKGROUND: In recent years, infections with carbapenemase-producing Enterobacteriaceae (CPE) have been increasing globally and present a major public health challenge. AIM: To review the international literature: (i) to describe CPE outbreaks in acute hospital settings globally; and (ii) to identify the control measures used during these outbreaks and report on their effectiveness. METHODS: A systematic search of MEDLINE and EMBASE databases, abstract lists for key conferences and reference lists of key reviews was undertaken, and information on unpublished outbreaks was sought for 2000-2015. Where relevant, risk of bias was assessed using the Newcastle-Ottawa scale. A narrative synthesis of the evidence was conducted. FINDINGS: Ninety-eight outbreaks were eligible. These occurred worldwide, with 53 reports from Europe. The number of cases (CPE infection or colonization) involved in outbreaks varied widely, from two to 803. In the vast majority of outbreaks, multi-component infection control measures were used, commonly including: patient screening; contact precautions (e.g. gowns, gloves); handwashing interventions; staff education or monitoring; enhanced environmental cleaning/decontamination; cohorting of patients and/or staff; and patient isolation. Seven studies were identified as providing the best-available evidence on the effectiveness of control measures. These demonstrated that CPE outbreaks can be controlled successfully using a range of appropriate, commonly used, infection control measures. However, risk of bias was considered relatively high for these studies. CONCLUSION: The findings indicate that CPE outbreaks can be controlled using combinations of existing measures. However, the quality of the evidence base is weak and further high-quality research is needed, particularly on the effectiveness of individual infection control measures.

Acute oxalate nephropathy after massive ascorbic acid administration.

A single 45-g dose of intravenous ascorbic acid, a metabolic precursor of oxalate, was administered to a patient as adjuvant therapy for primary amyloidosis and the nephrotic syndrome. Acute oliguric renal failure occurred. Postmortem histopathologic examination of renal tissue revealed extensive intratubular deposition of crystalline material, which was confirmed as calcium oxalate by a microincineration technique. There were no extrarenal deposits of calcium oxalate. Plasma oxalate and ascorbic acid concentrations were increased. We conclude that therapy with high-dose ascorbic acid is a potential cause of oxalate nephropathy.

Natural history of primary autoimmune neutropenia in infancy.

Five patients with primary autoimmune neutropenia were evaluated during their first 2 years of life. Their illness resolved spontaneously after 6 to 41 months (median 13 months), and the patients were subsequently followed for 13 to 73 months (median 28 months). None required immunosuppressive therapy to induce remission, and routine antibiotic therapy adequately controlled all infectious episodes. An increased rate of infection, particularly otitis media and upper respiratory tract infection, occurred during the neutropenic period. No other noninfectious illnesses, particularly no other autoimmune diseases, were reported in any of these patients at any time. In each case, resolution of neutropenia paralleled the disappearance of neutrophil autoantibodies which were specific for the NA1 antigen. This report describes the clinical and laboratory findings and the long-term history of primary autoimmune neutropenia in these five patients.

Comparison of transthoracic impedance/heart rate monitoring and pulse oximetry for patients using diaphragm pacemakers.

Patients using diaphragm pacemakers have several respiratory-related problems placing them at high risk for death during sleep, including central hypoventilation, abnormal arousal responses, upper airway and/or tracheostomy obstruction, and, in the case of high quadriplegia, lack of motor response to airway obstruction. The recent death from airway obstruction of a patient using diaphragm pacemakers prompted us to re-evaluate both the need for home monitoring and the type of monitor to prescribe. We compared the performance of a transthoracic impedance/heart rate (TI/HR) monitor with that of a pulse oximeter in six patients with central hypoventilation syndrome whose treatment included diaphragm pacing. Polygraphic recordings of airflow, ECG, SaO2, transthoracic impedance, heart rate, and breath detection were obtained during brief tracheostomy occlusion during patient sleep. Although none of 13 occlusions was detected by the TI/HR monitor, the pulse oximeter identified 13 of 13 occlusions. Three reasons for TI/HR monitor failure included 1) the breath detection circuit consistently registered a breath with each obstructed, paced diaphragmatic contraction; 2) bradycardia did not occur during any airway occlusion; and 3) pacemaker stimuli were misinterpreted as additional heart beats, increasing apparent heart rate. Thus, pulse oximetry, but not TI/HR monitoring, can detect life-threatening airway obstruction in children using diaphragm pacemakers.

Energy metabolism during CAPD: a controlled study.

Abnormalities of energy metabolism may exacerbate the high prevalence of protein-calorie malnutrition and inadequate calorie intake in continuous ambulatory peritoneal dialysis (CAPD) patients, leading to further nutritional depletion. In a controlled study, using indirect calorimetry, we evaluated oxygen consumption (VO2), CO2 production, resting energy expenditure, and respiratory exchange ratio (RER) in 12 CAPD patients at rest and during a standard CAPD exchange and in 11 healthy nonuremic control patients. In addition, we investigated the influence of nutritional status and dialysis adequacy on energy metabolism in the CAPD group. There was no significant difference in resting energy parameters between the two groups. Unlike the control group, blood glucose and RER were maintained during prolonged fasting in the CAPD patients. This observation indicates that all the absorbed glucose was used as a metabolic fuel preventing fat oxidation. There was no significant relationship between energy expenditure and dialysis adequacy. There was no significant relationship between nutritional state (including energy intake) and energy expenditure despite evidence of malnutrition in 41% of the patients. If maintenance of "normal levels" of energy expenditure occurs in dialysis patients with suboptimal calorie intake (especially with evidence of protein-calorie malnutrition), this inability to conserve energy may act as an additional risk factor for ongoing malnutrition.

Marketing strategies of nurse practitioners in New York State.

As competition within the health care field increases, marketing strategies are becoming more important for all members of the health care team, including nurse practitioners. The purpose of this research was to identify marketing strategies being used by nurse practitioners in New York state. A total of 285 practitioners responded to a survey containing questions related to marketing techniques traditionally used in the business world: service differentiation, market segmentation and practice promotion. A majority of respondents did not report using many of the marketing strategies contained in the survey, although most nurse practitioners did report identifying themselves as primary care providers in one-on-one interactions with clients. Significantly higher marketing scores were found for nurse practitioners who attended a workshop or seminar on marketing strategies, had three or more years of experience, or who practiced in private outpatient settings.