Nanofiber-based sorbents: Current status and applications in extraction methods.

Advanced sorbents gradually become a research hotspot on account of the increasing attention paid to environmental problems. Due to the prominent physicochemical features of nanofibers (NFs), such as high porosity, large surface area, favorable interconnectivity, high adsorption capacity, wettability, and the possibility of surface modification using functional groups, these nanostructures are regarded as excellent candidates for extraction applications. Therefore, the research in the field of NFs and their nanocomposites has been increasing in recent years. In the present review, we summarize the most recent studies on NFs-based sorbents focusing on strategies for preparation, characterization, and their unique capabilities as porous sorbents in various sorbent-based extraction methods. Moreover, we further described the performance and selectivity of sorbents to achieve improved extraction efficiency. Finally, some perspectives on the challenges and outlook are provided to aid future investigations related to this topic.

A critical review of covalent organic frameworks-based sorbents in extraction methods.

Recently, covalent organic frameworks (COFs) as an important class of porous frameworks have been employed in analytical applications owing to their significant inherent properties such as a high specific surface area with modifiable pore size and a robust nature that leads to great stabilities. Also, COFs are flexible in design to deliberate changes in their physical or chemical properties by generating functionalized COFs or COF-based composites. Here, we summarize some important categories of COFs from the point of view of their design and synthetic strategies. Subsequently, the synergistic combination aspects of COFs with other materials such as different types of magnetic, metal/metal oxide nanoparticles, silica, carbon nanomaterials, polymers, polyoxometalates (POMs), metal-organic frameworks (MOFs), and COFs are reviewed. Finally, the recent applications of COFs as efficient sorbents in analytical sample preparation methods including solid-phase extraction (SPE), dispersive solid-phase extraction (dSPE), magnetic solid-phase extraction (MSPE), and solid-phase microextraction (SPME) will be surveyed with emphasis on important factors that lead to increase extraction efficiency. In addition, challenges and obstacles in these approaches are discussed with perspective highlights.

Antigenic and Substrate Preference Differences between Scorpion and Spider Dermonecrotic Toxins, a Comparative Investigation.

The Hemiscorpius lepturus scorpion and brown spider Loxosceles intermedia represent a public health problem in Asia and America, respectively. Although distinct, these organisms contain similar toxins responsible for the principal clinical signs of envenomation. To better understand the properties of these toxins, we designed a study to compare recombinant Heminecrolysin (rHNC) and rLiD1, the major phospholipase D toxins of scorpion and spider venom, respectively. Using a competitive ELISA and a hemolytic inhibition test, we come to spot a cross reaction between scorpion and spider venoms along with an epitopic similarity between rHNC and rLiD1 associated with neutralizing antibodies. Results show that the ability of the rHNC to hydrolyze lysophosphatidylcholine (LPC) is equivalent to that of rLiD1 to hydrolyze sphingomyelin and vice-versa. rHNC exclusively catalyze transphosphatidylation of LPC producing cyclic phosphatidic acid (cPA). The in-silico analysis of hydrogen bonds between LPC and toxins provides a possible explanation for the higher transphosphatidylase activity of rHNC. Interestingly, for the first time, we reveal that lysophosphatidic acid (LPA) can be a substrate for both enzymes using cellular and enzymatic assays. The finding of the usage of LPA as a substrate as well as the formation of cPA as an end product could shed more light on the molecular basis of Hemiscorpius lepturus envenomation as well as on loxoscelism.

FASStR: a framework for ensuring high-quality operational metrics in health care.

OBJECTIVES: Poorly defined measurement impairs interinstitutional comparison, interpretation of results, and process improvement in health care operations. We sought to develop a unifying framework that could be used by administrators, practitioners, and investigators to help define and document operational performance measures that are comparable and reproducible. STUDY DESIGN: Retrospective analysis. METHODS: Health care operations and clinical investigators used an iterative process consisting of (1) literature review, (2) expert assessment and collaborative design, and (3) end-user feedback. We sampled the literature from the medical, health systems research, and health care operations (business and engineering) disciplines to assemble a representative sample of studies in which outpatient health care performance metrics were used to describe the primary or secondary outcome of the research. RESULTS: We identified 2 primary deficiencies in outpatient performance metric definitions: incompletion and inconsistency. From our review of performance metrics, we propose the FASStR framework for the Focus, Activity, Statistic, Scale type, and Reference dimensions of a performance metric. The FASStR framework is a method by which performance metrics can be developed and examined from a multidimensional perspective to evaluate their comprehensiveness and clarity. The framework was tested and revised in an iterative process with both practitioners and investigators. CONCLUSIONS: The FASStR framework can guide the design, development, and implementation of operational metrics in outpatient health care settings. Further, this framework can assist investigators in the evaluation of the metrics that they are using. Overall, the FASStR framework can result in clearer, more consistent use and evaluation of outpatient performance metrics.

Complete neutralization of the lethality of Hemiscorpius lepturus crude venom by a novel anti-recombinant phospholipase D1 IgGs.

Treatment of scorpion envenomation is a challenging issue since serotherapy is implemented by administration of polyvalent equine antisera. In our previous study we discovered that recombinant phospholipase D1 (Hl-RecPLD1) is responsible for the lethality of Hemiscorpius lepturus (H. lepturus) venom in mice. Accordingly, this study was aimed to investigate the protectivity of purified anti-Hl-RecPLD1 IgG against the lethality or major complications of H. lepturus venom. The neutralization efficiency of purified anti-Hl-RecPLD1 IgGs against sphingomyelinase activities of the crude venom and Hl-RecPLD1 was also assessed. Anti-Hl-RecPLD1 IgGs at optimum amount of 3.7 mg completely neutralized one Lethal Dose 100 (LD100) of crude venom in mice. The anti-Hl-RecPLD1 IgGs remarkably reduced the necrosis area from 6.5 to 1 cm2 in rabbit derma, induced by the crude venom. The anti-Hl-RecPLD1 IgGs remarkably reduced the sphingomyelinase and hemolytic activities of crude venom as well. In conclusion, a novel rabbit monovalent IgG against Hl-RecPLD1 was able to completely protect the mice against the lethality of H. lepturus crude venom and reduced its toxicity as well. Such monovalent anti-Hl-RecPLD1 IgGs may have potential applications in serotherapy of H. lepturus envenomation.

The effect of quitting water pipe during pregnancy on anthropometric measurements at birth: a population-based prospective cohort study in the south of Iran.

BACKGROUND: Evidence regarding health effects of tobacco cessation during pregnancy is mainly restricted to cigarette while water pipe is the preferred method of tobacco smoking among women in the Middle-East. The present study aimed to assess the effects of cessation of water pipe during pregnancy on birth anthropometric measures in the south of Iran. METHODS: Data on 1120 singleton pregnancies (response rate = 93.4%) from a population-based prospective cohort study in suburban communities in Bandar Abbas city was used. Based on water pipe smoking status, the study subjects were categorized into: 1) those who never smoke water pipe (never smoker); 2) those who stopped water pipe during pregnancy and resumed it postpartum (quitters); 3) those who continued smoking water pipe during their pregnancy (always smokers). The Generalized Linear Models (GLMs) were utilized for the analyses. RESULTS: Compared to never smokers, quitting water pipe in pregnancy decreased mean birthweight of infants by 99.30 g (ß:-99.30, 95%CI:-204.35,-5.75) and an additional decrease of 37.83 g occurred in infants of always smokers (ß:-137.13;95%CI:- 262.21,-12.05). Means of birth length did not significantly differ among the three water pipe groups. Means of head circumference, however, significantly increased by 0.79 cm in infants of always smokers (ß:079,95%CI:0.13,1.45). CONCLUSION: Quitting water pipe during pregnancy had positive effects on infant growth, especially birth weight. Awareness campaigns about health benefits of quitting water pipe during routine prenatal checkups and integration of active follow-up visits into prenatal care protocols for smoking mothers are provided.

Developing recombinant phospholipase D1 (rPLD1) toxoid from Iranian Hemiscorpius lepturus scorpion and its protective effects in BALB/c mice.

Hemiscorpius lepturus (H. lepturus) is one of the most dangerous scorpions and the most medically important scorpion in Iran. The clinical signs of H. lepturus envenomation, including dermonecrosis, hematuria, renal failure and early death, are attributed to phospholipase D activity. This study was conducted to develop a novel recombinant phospholipase D1 (rPLD1) toxoid and investigate its immunogenicity and protective effects against the lethality of H. lepturus venom. The lethal protein recombinant phospholipase D1 was expressed from PLD H. lepturus venom gland. The rPLD1 toxin was converted into toxoid (the first toxoid of H. lepturus PLD) with a 0.25% concentration of formalin and stored for ten days at room temperature. In the toxicity test, the lethal activity of recombinant phospholipase D1 was fully inhibited. When it reached up to 3 times higher than the maximal effective concentration of the purified toxin (11.1 µg), rPLD1 toxoid was used. The sphingomyelinase activity was inhibited when up to 5.4 times of the LD100 of the purified toxin (20 µg), toxoid was used. It was then used to produce an antibody in BALB/c as an antigen and the mice were then challenged with rPLD1 toxin and the whole venom. The immunogenicity of rPLD1 toxoid was evaluated and the maximum titer of the raised antibodies was determined by ELISA assay. The optimum titer for anti-rPLD1 toxoid sera was obtained at the third intraperitoneal injection of rPLD1 toxoid, and a high titer was reached at the fourth injection in the mice. This toxoid increased the amount of antibodies and produced a protective antiserum against the whole venom of H. lepturus and rPLD1 toxin. The in-vivo test results showed that the mice were completely resistant against 200 times the LD100 of recombinant phospholipase D1 and the whole venom of H. lepturus. To conclude, rPLD1 can be used in toxoid form as an immunogen in the production of a new generation of neutralizing antibodies against the lethality and toxicity of H. lepturus whole venom.

A Population-based Prospective Study to Identify Contributors to Mother and Child Health in Suburban Communities: The Cohort Profile.

BACKGROUND: Following community health assessment Project (CHAP) in suburbs of Bandar Abbas city, health problems in women and children such as pregnancy complications and infant/child impaired growth are highly prevalent. Therefore, the present population-based prospective cohort study investigated the effects of a wide range of modifiable exposures during pregnancy and postpartum on mother and child health. METHODS: The sample comprised of 1000 pregnant women in their first gestational trimester, who live in the three most socially and economically vulnerable neighborhoods of Bandar Abbas, are under recruitment during Feb 2016-18. Four structured questionnaires are being carried out from pregnancy to 30 d, 6 months, and 12 months postpartum. Biologic and ultrasound results are also gathered through hospital and health center records. The study is currently close to the end of the recruitment phase. CONCLUSION: The results of the interim and final analyses are being translated into applicable preventive action plans aiming to reduce and control modifiable risk factors for ill-health in mothers and children in suburb communities in South of Iran.

Understanding Emergency Care Delivery Through Computer Simulation Modeling.

In 2017, Academic Emergency Medicine convened a consensus conference entitled, "Catalyzing System Change through Health Care Simulation: Systems, Competency, and Outcomes." This article, a product of the breakout session on "understanding complex interactions through systems modeling," explores the role that computer simulation modeling can and should play in research and development of emergency care delivery systems. This article discusses areas central to the use of computer simulation modeling in emergency care research. The four central approaches to computer simulation modeling are described (Monte Carlo simulation, system dynamics modeling, discrete-event simulation, and agent-based simulation), along with problems amenable to their use and relevant examples to emergency care. Also discussed is an introduction to available software modeling platforms and how to explore their use for research, along with a research agenda for computer simulation modeling. Through this article, our goal is to enhance adoption of computer simulation, a set of methods that hold great promise in addressing emergency care organization and design challenges.

Characteristics and Lethality of a Novel Recombinant Dermonecrotic Venom Phospholipase D from Hemiscorpius lepturus.

Hemoscorpius lepturus is the most medically important scorpion in Iran. The clinical signs of H. lepturus envenomation are remarkably similar to those reported for brown spiders, including dermonecrosis, hematuria, renal failure and even death. The lethality and toxicity of brown spiders' venom have been attributed to its phospholipase D activity. This study aims to identify a phospholipase D with possible lethality and dermonecrotic activity in H. lepturus venom. In this study, a cDNA library of the venom glands was generated by Illumina RNA sequencing. Phospholipase D (PLD) from H. lepturus was characterized according to its significant similarity with PLDs from brown spiders. The main chain designated as Hl-RecPLD1 (the first recombinant isoform of H. lepturus PLD) was cloned, expressed and purified. Sphingomyelinase, dermonecrotic and lethal activities were examined. Hl-PLD1 showed remarkable sequence similarity and structural homology with PLDs of brown spiders. The conformation of Hl-PLD1 was predicted as a "TIM beta/alpha-barrel". The lethal dose 50 (LD50) and dermonecrotic activities of Hl-RecPLD1 were determined as 3.1 µg/mouse and 0.7 cm2 at 1 µg respectively. It is the first report indicating that a similar molecular evolutionary mechanism has occurred in both American brown spiders and this Iranian scorpion. In conclusion, Hl-RecPLD1 is a highly active phospholipase D, which would be considered as the lethal dermonecrotic toxin in H. lepturus venom.

Monte Carlo Simulation Modeling of a Regional Stroke Team's Use of Telemedicine.

OBJECTIVES: The objective of this study was to evaluate operational policies that may improve the proportion of eligible stroke patients within a population who would receive intravenous recombinant tissue plasminogen activator (rt-PA) and minimize time to treatment in eligible patients. METHODS: In the context of a regional stroke team, the authors examined the effects of staff location and telemedicine deployment policies on the timeliness of thrombolytic treatment, and estimated the efficacy and cost-effectiveness of six different policies. A process map comprising the steps from recognition of stroke symptoms to intravenous administration of rt-PA was constructed using data from published literature combined with expert opinion. Six scenarios were investigated: telemedicine deployment (none, all, or outer-ring hospitals only) and staff location (center of region or anywhere in region). Physician locations were randomly generated based on their zip codes of residence and work. The outcomes of interest were onset-to-treatment (OTT) time, door-to-needle (DTN) time, and the proportion of patients treated within 3 hours. A Monte Carlo simulation of the stroke team care-delivery system was constructed based on a primary data set of 121 ischemic stroke patients who were potentially eligible for treatment with rt-PA. RESULTS: With the physician located randomly in the region, deploying telemedicine at all hospitals in the region (compared with partial or no telemedicine) would result in the highest rates of treatment within 3 hours (80% vs. 75% vs. 70%) and the shortest OTT (148 vs. 164 vs. 176 minutes) and DTN (45 vs. 61 vs. 73 minutes) times. However, locating the on-call physician centrally coupled with partial telemedicine deployment (five of the 17 hospitals) would be most cost-effective with comparable eligibility and treatment times. CONCLUSIONS: Given the potential societal benefits, continued efforts to deploy telemedicine appear warranted. Aligning the incentives between those who would have to fund the up-front technology investments and those who will benefit over time from reduced ongoing health care expenses will be necessary to fully realize the benefits of telemedicine for stroke care.

Identification and characterization of class 1 integrons among atypical enteropathogenic Escherichia coli isolated from children under 5 years of age.

BACKGROUND AND OBJECTIVES: The therapeutic options for diseases caused by Escherichia coli are limited. In this study we investigated the presence of virulence factors among Enteropathogenic Escherichia coli (EPEC) strains and their antibiotic resistance patterns. The isolates were also checked for the presence of class1 integrons and gene cassettes. MATERIALS AND METHODS: This study included 70 EPEC strains isolated from children. Antimicrobial resistance patterns were determined using diffusion methods. The broth microdilution methods was used to determine the minimum inhibitory concentration. PCR was used to detect eaeA, bfpA genes. The 5' and 3' conserved sequences (CSs) of class 1 integrons and intI gene were amplified to investigate the presence of integrons and gene cassettes. RESULTS: Antimicrobial susceptibility testing showed that 4 (5.7%), 3 (4.2%), and 2 (2.8 %) isolates were resistant to ampicillin, trimethoprim-sulfamethoxazole, and ceftazidime, respectively. Resistance rates to ciprofloxacin and aztreonam were 1.4%. Thirteen (18.5%) isolates showed resistance to tetracycline, and 4 (5.7%) were kanamycin resistant. Class I integron detected in 22 (31.4%) isolates. All the gene cassettes found in class I integrons corresponded to different variants of dfr and aadA genes. CONCLUSION: Prevalence of class I integrons in EPEC strains was high. Presence of aadA and dfr gene cassettes in integrons represents high distribution of resistance determinants in EPEC strains.

Preoperative fasting protects mice against hepatic ischemia/reperfusion injury: mechanisms and effects on liver regeneration.

We show that brief periods of fasting induce functional changes similar to those induced by long-term dietary restriction in mice, and these changes include protection from ischemia/reperfusion (I/R) injury. In this study, we investigated the mechanisms of protection induced by fasting, and we determined the effect on liver regeneration after partial hepatectomy. Partial hepatic ischemia (75 minutes) was induced in ad libitum fed mice and in 1- to 3-day-fasted mice, and one-third or two-thirds hepatectomy was performed in ad libitum fed mice and 3-day-fasted mice. Preoperative fasting for 2 or 3 days significantly decreased hepatocellular I/R injury. Hepatic gene expression of heme oxygenase 1 (HO-1), superoxide dismutase 2 (SOD2), glutathione peroxidase 1 (Gpx1), and glutathione reductase (GSR) was significantly up-regulated in 3-day-fasted mice at the baseline and 6 hours after reperfusion. After reperfusion, p-selectin and interleukin-6 (IL-6) levels were significantly lower, and superoxide radical generation, lipid peroxidation, and neutrophil influx were significantly attenuated in 3-day-fasted mice. Preoperative fasting did not affect liver regeneration after one-third hepatectomy. Hepatic gene expression of IL-6 and transforming growth factor ß1 was significantly higher in 3-day-fasted mice before and after one-third hepatectomy. Tumor necrosis factor α expression significantly increased after one-third hepatectomy in 3-day-fasted mice. After a 3-day fast and two-thirds hepatectomy, liver regeneration and subsequent postoperative recovery were compromised. In conclusion, up-regulation of the stress response gene HO-1 and the antioxidant enzymes SOD2, Gpx1, and GSR at the baseline and a better response after reperfusion likely underlie the protection induced by fasting against hepatic I/R injury. Preoperative fasting may be a promising new strategy for protecting the liver against I/R injury during liver transplantation and minor liver resections, although its effect on extended hepatectomy warrants further exploration.