Let n be a positive integer. A permutation a of the symmetric group of permutations of is called a derangement if for each . Suppose that x and y are two arbitrary permutations of . We say that...Let n be a positive integer. A permutation a of the symmetric group of permutations of is called a derangement if for each . Suppose that x and y are two arbitrary permutations of . We say that a permutation a is a double derangement with respect to x and y if and for each . In this paper, we give an explicit formula for , the number of double derangements with respect to x and y. Let and let and be two subsets of with and . Suppose that denotes the number of derangements x such that . As the main result, we show that if and z is a permutation such that for and for , then where .展开更多
Purpose Boarding is a common problem in the emergency department(ED)and is associated with poor health care and outcome.Imam Khomeini Hospital is the main healthcare center in Urmia,a metropolis in the northwest of Ir...Purpose Boarding is a common problem in the emergency department(ED)and is associated with poor health care and outcome.Imam Khomeini Hospital is the main healthcare center in Urmia,a metropolis in the northwest of Iran.Due to the overcrowding and high patient load,we aim to characterize the rate,cause and consequence of boarding in the ED of this center.Methods All medical records of patients who presented to the ED of Imam Khomeini Hospital from August 1,2017 to August 1,2018 were retrospectively analyzed.Patients with uncompleted records were excluded.Boarding was defined as the inability to transfer the admitted ED patients to a downstream ward in≥2 h after the admission order.Demographic data,boarding rate,mortality and triage levels(1–5)assessed by emergency severity index were collected and analyzed.The first present time of patients was classified into 4 ranges as 0:00–5:59,6:00–11:59,12:00–17:59 and 18:00–23:59.Descriptive,parametric and non-parametric statistical tests were performed and the risk of boarding was determined by Pearson Chi-square test.Results Demographic data analysis showed that 941(58.5%)male and 667(41.5%)female,altogether 1608 patients were included in this study.Five patients(0.3%)died.The distribution of patients with the triage levels 1–5 was respectively 79(4.9%),1150(71.5%),374(23.3%),4(0.2%)and 0(0%).Most patients were of level 2.Only 75(4.7%)patients required intensive care.The majority of patients(84.2%)were presented at weekdays.The maximum patient load was observed between 12:00–17:59.Of the 1608 patients,340(21.1%)experienced boarding within a mean admission time of 13.70 h.Among the 340-boarded patients,20.1%belonged to surgery,12.1%to orthopedics,10.9%to neurosurgery and 10.3%to neurology.The boarding rate was higher in females,patients requiring intensive care and those with low triage levels.Compared with the non-boarded,the boarded patients had a higher mean age.Conclusion The boarding rate is higher in the older and female patients.Moreover,boarding is dependent on the downstream ward sections:patients requiring surgical management experience the maximum boarding rate.展开更多
文摘Let n be a positive integer. A permutation a of the symmetric group of permutations of is called a derangement if for each . Suppose that x and y are two arbitrary permutations of . We say that a permutation a is a double derangement with respect to x and y if and for each . In this paper, we give an explicit formula for , the number of double derangements with respect to x and y. Let and let and be two subsets of with and . Suppose that denotes the number of derangements x such that . As the main result, we show that if and z is a permutation such that for and for , then where .
文摘Purpose Boarding is a common problem in the emergency department(ED)and is associated with poor health care and outcome.Imam Khomeini Hospital is the main healthcare center in Urmia,a metropolis in the northwest of Iran.Due to the overcrowding and high patient load,we aim to characterize the rate,cause and consequence of boarding in the ED of this center.Methods All medical records of patients who presented to the ED of Imam Khomeini Hospital from August 1,2017 to August 1,2018 were retrospectively analyzed.Patients with uncompleted records were excluded.Boarding was defined as the inability to transfer the admitted ED patients to a downstream ward in≥2 h after the admission order.Demographic data,boarding rate,mortality and triage levels(1–5)assessed by emergency severity index were collected and analyzed.The first present time of patients was classified into 4 ranges as 0:00–5:59,6:00–11:59,12:00–17:59 and 18:00–23:59.Descriptive,parametric and non-parametric statistical tests were performed and the risk of boarding was determined by Pearson Chi-square test.Results Demographic data analysis showed that 941(58.5%)male and 667(41.5%)female,altogether 1608 patients were included in this study.Five patients(0.3%)died.The distribution of patients with the triage levels 1–5 was respectively 79(4.9%),1150(71.5%),374(23.3%),4(0.2%)and 0(0%).Most patients were of level 2.Only 75(4.7%)patients required intensive care.The majority of patients(84.2%)were presented at weekdays.The maximum patient load was observed between 12:00–17:59.Of the 1608 patients,340(21.1%)experienced boarding within a mean admission time of 13.70 h.Among the 340-boarded patients,20.1%belonged to surgery,12.1%to orthopedics,10.9%to neurosurgery and 10.3%to neurology.The boarding rate was higher in females,patients requiring intensive care and those with low triage levels.Compared with the non-boarded,the boarded patients had a higher mean age.Conclusion The boarding rate is higher in the older and female patients.Moreover,boarding is dependent on the downstream ward sections:patients requiring surgical management experience the maximum boarding rate.
