Airborne and aerosol pathogen transmission modeling of respiratory events in buildings: An overview of computational fluid dynamics.

Pathogen droplets released from respiratory events are the primary means of dispersion and transmission of the recent pandemic of COVID-19. Computational fluid dynamics (CFD) has been widely employed as a fast, reliable, and inexpensive technique to support decision-making and to envisage mitigatory protocols. Nonetheless, the airborne pathogen droplet CFD modeling encounters limitations due to the oversimplification of involved physics and the intensive computational demand. Moreover, uncertainties in the collected clinical data required to simulate airborne and aerosol transport such as droplets' initial velocities, tempo-spatial profiles, release angle, and size distributions are broadly reported in the literature. There is a noticeable inconsistency around these collected data amongst many reported studies. This study aims to review the capabilities and limitations associated with CFD modeling. Setting the CFD models needs experimental data of respiratory flows such as velocity, particle size, and number distribution. Therefore, this paper briefly reviews the experimental techniques used to measure the characteristics of airborne pathogen droplet transmissions together with their limitations and reported uncertainties. The relevant clinical data related to pathogen transmission needed for postprocessing of CFD data and translating them to safety measures are also reviewed. Eventually, the uncertainty and inconsistency of the existing clinical data available for airborne pathogen CFD analysis are scurtinized to pave a pathway toward future studies ensuing these identified gaps and limitations.

CFD modeling of airborne pathogen transmission of COVID-19 in confined spaces under different ventilation strategies.

Airborne transmission is an important route of spread of viral diseases (e.g., COVID-19) inside the confined spaces. In this respect, computational fluid dynamics (CFD) emerged as a reliable and fast tool to understand the complex flow patterns in such spaces. Most of the recent studies, nonetheless, focused on the spatial distribution of airborne pathogens to identify the infection probability without considering the exposure time. This research proposes a framework to evaluate the infection probability related to both spatial and temporal parameters. A validated Eulerian-Lagrangian CFD model of exhaled droplets is first developed and then evaluated with an office case study impacted by different ventilation strategies (i.e., cross- (CV), single- (SV), mechanical- (MV) and no-ventilation (NV)). CFD results were analyzed in a bespoke code to calculate the tempo-spatial distribution of accumulated airborne pathogens. Furthermore, two indices of local and general infection risks were used to evaluate the infection probability of the ventilation scenarios. The results suggest that SV has the highest infection probability while SV and NO result in higher dispersions of airborne pathogens inside the room. Eventually, the time history of indices reveals that the efficiency of CV and MV can be poor in certain regions of the room.

Mineral Oil for in vitro Embryo Production: What We Should Know?

Mineral oil as a barrier can minimize temperature, osmolality, and pH fluctuation of the media in the in vitro embryo production system (IVP). Regardless of these advantages, mineral oil quality is varied and may deteriorate during storage or transport conditions. So, it can affect the IVP outcome by absorbing the essentials factors or realizing the toxic components into the media. Although, some methods have already been developed to reduce these side effects, still there is a big concern about the safety and use of mineral oil in the IVP system. In this review, we provided an overview of the advantages and disadvantages of using mineral oil in the IVP system. We also reviewed available methods for its quality control and finally, we introduced some methods for reducing the side effects of mineral oil.

Polycystic Ovary Syndrome Develops the Complications of Assisted Reproductive Technologies.

Ovarian hyperstimulation syndrome (OHSS) is a serious complication that remains a threat to every patient experiencing stimulation of ovulation. Polycystic ovary syndrome (PCOS) appears to be the most important predisposing factor for OHSS. The severity of OHSS is associated with the degree of the follicular response to the ovulation inducing agents. The objective of this study was to investigate the relationship between PCOS with the risk of moderate-to-severe OHSS in intracytoplasmic sperm injection treatment patients. Sixty patients in the reproductive ages (20-38), including OHSS patients and age-matched normoresponders were included in this study. Patients who had larger follicle counts on the day of hCG injection were considered at risk for developing moderate-to-severe OHSS. In addition, oocyte quality was assessed about 20-30 min after oocyte pickup. The incidence of OHSS in PCOS patients increased significantly up to 13.9 times higher than in patients without PCOS (OR=13.900; P=0.007). Moreover, moderate-to-severe OHSS increased significantly (OR=3.860; P=0.043) in patients with primary infertility than those with secondary infertility. In addition, oocyte quality was not affected with the severity of OHSS. In conclusion, the risk of moderate-to-severe OHSS is correlated with PCOS and primary infertility without affecting oocyte quality.

Interaction of neuropeptide Y receptors (NPY1, NPY2 and NPY5) with somatostatin on somatostatin-induced feeding behaviour in neonatal chicken.

1. The present study was conducted to investigate whether brain somatostatin increases feed intake in neonatal chickens. The mediating role of neuropeptide Y receptors on feed intake induced by somatostatin was investigated. 2. In this study, seven experiments were designed, each with four treatment groups (n = 44 in each experiment). In Experiment 1, chicks received control solution and 0.5, 1 and 2 nmol of somatostatin through intracerebroventricular (ICV) injection. In experiments 2, 3 and 4, chickens were ICV injected with control solution and 1.25, 2.5 and 5 µg of B5063 (NPY1 receptor antagonist), SF22 (NPY2 receptor antagonist) and SML0891 (NPY5 receptor antagonist), respectively. In experiment 5, 6 and 7 chickens received ICV injection of B5063, SF22, SML0891, with a co-injection of + somatostatin, control solution and somatostatin. The cumulative feed intake was measured until 120 min post injection. 3. Somatostatin significantly increased feed intake in FD3 chicks. Both B5063 and SML0891 dose-dependently decreased feed intake compared with the control group, while SF22 led to a dose-dependent increase in feed intake. In addition, the hyperphagic effect of somatostatin significantly decreased with co-injection of B560 plus somatostatin (p < 0.05), but SF22 and SML0891 had no effect on feed intake induced by somatostatin in chicks (p > 0.05). 4. Based on the results of this study, it is likely that somatostatin increased feed intake and NPY1 receptor acts as a mediator in hyperphagic effect of somatostatin in neonatal chicks.

Alveolar fractal box dimension inversely correlates with mean linear intercept in mice with elastase-induced emphysema.

RATIONALE: A widely applicable model of emphysema that allows efficient and sensitive quantification of injury is needed to compare potential therapies. OBJECTIVES: To establish such a model, we studied the relationship between elastase dose and the severity of emphysema in female C57BL/6J mice. We compared alveolar fractal box dimension (D(B)), a new measure which is an assessment of the complexity of the tissue, with mean linear intercept (L(m)), which is commonly used to estimate airspace size, for sensitivity and efficiency of measurement. METHODS: Emphysema was induced in female C57BL/6J mice by administering increasing intratracheal doses of porcine pancreatic elastase (PPE). Changes in morphology and static lung compliance (C(L)) were examined 21 days later. Correlation of D(B) with L(m) was determined in histological sections of lungs exposed to PPE. The inverse relationship between D(B) and L(m) was supported by examining similar morphological sections from another experiment where the development of emphysema was studied 1 to 3 weeks after instillation of human neutrophil elastase (HNE). RESULTS: L(m) increased with PPE dose in a sigmoidal curve. C(L) increased after 80 or 120 U/kg body weight (P < 0.05), but not after 40 U/kg, compared with the control. D(B) progressively declined from 1.66 ± 0.002 (standard error of the mean) in controls, to 1.47 ± 0.006 after 120 U PPE/kg (P < 0.0001). After PPE or HNE instillation, D(B) was inversely related to L(m) (R = -0.95, P < 0.0001 and R = -0.84, P = 0.01, respectively), with a more negative slope of the relationship using HNE (P < 0.0001). CONCLUSION: Intratracheal instillation of increasing doses of PPE yields a scale of progression from mild to severe emphysema. D(B) correlates inversely with L(m) after instillation of either PPE or HNE and yields a rapid, sensitive measure of emphysema after elastase instillation.

CYP2E1-catalyzed oxidation contributes to the sperm toxicity of 1-bromopropane in mice.

1-bromopropane (1-BrP) induces dose- and time-dependent reproductive organ toxicity and reduced sperm motility in rodents. The contribution of cytochrome P4502E1 (CYP2E1) to both 1-BrP metabolism and the induction of male reproductive toxicity was investigated using wild-type (WT) and Cyp2e1-/- mice. In gas uptake inhalation studies, the elimination half-life of [1,2,3-(13)C]-1-BrP was longer in Cyp2e1-/- mice relative to WT (3.2 vs. 1.3 h). Urinary metabolites were identified by 13C nuclear magnetic resonance. The mercapturic acid of 1-bromo-2-hydroxypropane (2OHBrP) was the major urinary metabolite in WT mice, and products of conjugation of 1-BrP with glutathione (GSH) were insignificant. The ratio of GSH conjugation to 2-hydroxylation increased 5-fold in Cyp2e1-/- mice relative to WT. After 1-BrP exposure, hepatic GSH was decreased by 76% in WT mice vs. 47% in Cyp2e1-/- mice. Despite a 170% increase in 1-BrP exposure in Cyp2e1-/- vs. WT mice, sperm motility in exposed Cyp2e1-/- mice did not change relative to unexposed matched controls. This suggests that metabolites produced through CYP2E1-mediated oxidation may be responsible for 1-BrP-induced sperm toxicity. Both 1-BrP and 2OHBrP inhibited the motility of sperm obtained from WT mice in vitro. However, only 2OHBrP reduced the motility of sperm obtained from Cyp2e1-/- mice in vitro, suggesting that conversion of parent compound to 2OHBrP within the spermatozoa may contribute, at least in part, to reduced motility. Overall, these data suggest that metabolism of 1-BrP is mediated in part by CYP2E1, and activation of 1BrP via this enzyme may contribute to the male reproductive toxicity of this chemical.

Oral anticoagulation in a pediatric hospital: impact of a quality improvement initiative on warfarin management strategies.

BACKGROUND: There are potential risks associated with the use of warfarin in children, particularly as the dosing requirements may decrease as patients get older. CONTEXT: Our facility is a 715-bed freestanding pediatric tertiary care center with a large cardiac surgery center. A significant number of patients receive warfarin for treatment or prophylaxis of thromboembolic events while in hospital. KEY MEASURES FOR IMPROVEMENT: Initial dose of warfarin and time taken to achieve goal therapeutic international normalized ratio (INR). STRATEGIES FOR CHANGE: The intervention included: (1) revision of hospital drug formulary so that warfarin dosing was in accordance with the most recent guidelines; (2) warfarin administration restricted to one time of the day (12.00 noon); (3) target therapeutic INR level documented with each warfarin order; and (4) pharmacy computer system mandated that the pharmacist confirmed the target INR, documented the most current INR, and compared the dose with the formulary guidelines. If the warfarin dose was not in accordance with the formulary guidelines, the pharmacist contacted the physician and made dosing recommendations according to the guidelines. EFFECTS OF CHANGE: The number of patients with supratherapeutic INR values during the hospital admission was decreased by more than 50% and goal INR values were documented more frequently in the medical record. There was also an increase in subtherapeutic INR values. The intervention had no effect on the time taken to achieve the goal therapeutic INR. LESSONS LEARNED: Instituting changes in a number of aspects of anticoagulation management and incorporating an intensive educational effort across a breadth of healthcare providers can improve anticoagulation management with warfarin in challenging patient populations such as children. Similar methods could possibly improve anticoagulation with other agents such as unfractionated heparin or low molecular weight heparin.

Efficacy and cost-effectiveness of a high-powered parallel waterjet for wound debridement.

Current concepts of wound healing acknowledge the essential role of wound bed preparation in achieving a wound with good healing potential. Critical to wound bed preparation is the removal of necrosis, unhealthy tissue, foreign matter, and infection. One of the accepted methods of wound bed preparation is surgery. The high-power parallel waterjet is a new surgical device, which allows the operator to remove very precisely undesirable tissue and debris with maximal preservation of viable tissue. A retrospective study was performed to evaluate the efficacy, safety, and economic impact of using this technique of surgical debridement. Forty patients who had waterjet debridements were compared with 22 patients with matched wounds who had conventional surgical debridement. The waterjet group had significantly fewer procedures (p<0.002) than the conventional group. Based on these outcomes, the use of the new device in appropriate patients is expected to lead to cost savings of approximately 1,900 dollars per patient.

First successful replantation of face and scalp with single-artery repair: model for face and scalp transplantation.

Successful replantation of the scalp with microanastomosis of a single artery and vein has been reported to produce reliable results. In fact, there have been several reports of scalp replantations based on one-artery and vein repair. There has been a face and scalp replantation reported in the literature, but this was as two separate parts and was based on several arterial and venous repairs. The authors performed the first successful replantation of a face and scalp with repair of a single artery and, of course, two veins. A 21-year-old man presented after his face and scalp were completely severed. The patient's long hair was caught in a conveyor belt at work. The face and scalp underwent replantation, with repair of the right superficial temporal artery with an interposition vein graft. A multiteam approach allowed for minimization of overall ischemic time and simultaneous preparation of the vessels on the patient and amputated part as well as vein graft harvest from the arm. Also critical to the success of the procedure, the small portions of the vessels of the amputated part were sent for frozen section to differentiate artery from vein. Initially, only the right superficial temporal vein was repaired. One week after replantation, the patient returned for treatment of venous congestion of an area to the opposite side of the forehead partial transection, with repair of the left superficial temporal vein, also. This saved the entire part that underwent replantation, and the entire part survived. The face and scalp can undergo replantation based on single-artery repair.

Rated casemix of general practitioner referrals to practice counsellors and clinical psychologists: a retrospective survey of a year's caseload.

Although evidence-based guidelines are beginning to be produced as to which psychological therapies might be appropriate for which patients, little is known about how general medical practitioners (GPs) in practice distribute referrals between different psychological therapy services. In a retrospective survey, 19 practice counsellors and 10 clinical psychologists from the same geographical area rated a year's caseload of GP referrals using identical data collection methods. Rated casemix was found to be broadly similar, although practice counsellors rated relationship and bereavement problems as more common in their caseloads (totalling 986 patients), and clinical psychologists rated panic disorder, phobias, and obsessive-compulsive problems as more common in their caseloads (totalling 320 patients). Depression and anxiety reactions were the most common problems rated in both groups, but the clinical psychologist cases of depression were rated as more severe and complex. Where differences were found, they may have reflected the different ways that counsellors and clinical psychologists conceptualize cases rather than actual differences in casemix. The results are discussed in relation to evidence-based guideline recommendations about cases appropriate to be seen by practice counsellors and by clinical psychologists in primary and secondary care, and the need to adapt such guidance to local services and skills of practitioners.

Mental health training needs of primary health care nurses.

The primary health care team (PHCT) has a critical role to play in the care of people with mental health problems. However, little attention has been paid to the mental health training and preparation required by primary health care nurses. This paper reports on a training needs assessment undertaken in one London health authority area. The findings indicate that primary health care nurses are undertaking a wide range and increasing volume of mental health work with little preparation and training. Specific training needs include time and space to identify training gaps; basic training in mental health, safe working practices and management of role boundaries; and multidisciplinary training. In addition, NHS trusts, primary care groups and health authorities need to clarify which aspects of nurses' mental health workloads are appropriate to their role and develop policies, procedures and training to support them in undertaking that role.

Relationship between practice counselling and referral to outpatient psychiatry and clinical psychology.

BACKGROUND: Although reduction in the use of secondary care mental health services is a suggested benefit of counselling in general practice, there has been little empirical investigation of this relationship. AIM: To investigate the relationship between the provision of counselling in general practice and the use of outpatient psychiatry and clinical psychology services across a geographical area. METHOD: Information on referrals to outpatient psychiatry and clinical psychology from all general practices in the London Borough of Islington over one year (October 1993 to September 1994) was collected from the routine information systems of the main hospital departments serving this area. Referral rates per 1000 practice population were compared for practices with and without a practice-based counsellor. RESULTS: Fifteen (35%) of the 43 practices had a counsellor based in the practice. The median referral rate to clinical psychology was higher in practices with a counsellor (4.1 per 1000) than in practices without a counsellor (0.8 per 1000). There was no relationship between the provision of practice counselling and median referral rates to outpatient psychiatry (1.8 per 1000 with a counsellor, 1.7 per 1000 without a counsellor). CONCLUSION: Provision of practice counselling in the study was associated with higher referral rates to clinical psychology and no difference in referral rates to outpatient psychiatry. This is in contrast to the hypothesis that counselling reduces the use of secondary care mental health services.

Transluminal angioplasty of the iliac artery combined with femorofemoral bypass.

Significant aortoiliac occlusive disease commonly occurs in patients who are not acceptable risks for conventional aortoiliac or aortofemoral bypass reconstruction. We propose that, in suitable candidates, the lower extremities can be revascularized by combining intraluminal angioplasty of stenotic iliofemoral segments with femorofemoral bypass graft. We present three patients who have been managed in this fashion with satisfactory results. This method is proposed as an alternative to, not a substitute for, conventional, time-proven aortic grafting.