Metamaterial perfect absorber using elliptical nanoparticles in a multilayer metasurface structure with polarization independence.

A metamaterial perfect absorber (MPA) using elliptical silver nanoparticles is proposed and investigated to provide 100% absorption for both transverse electric and transverse magnetic polarizations with a wide range of incident angles and polarization independence. Metamaterial absorbers with narrow absorption performance over a wide frequency range are significantly desired in sensing applications. Incident angle insensitivity and polarization angle independence are key features of MPAs. The output characteristics are examined using the three-dimensional finite difference time domain method. The effective medium theory and transmission line theory are applied to investigate the simulation results. Here, the 100% absorption occurs at resonance wavelength of λres = 2290 nm, and maximum sensitivity and figure of merit become 200 nm/RIU and 720 RIU-1, respectively. The results show that an absorption spectrum is insensitive to the incident angle of 0°-60°. The proposed device can be used as a high-performance biosensor and photodetector.

Evaluation of the Impact of Handoff Based on the SBAR Technique on Quality of Nursing Care.

BACKGROUND: Effective communication, including the complete and accurate transfer of information and the prevention of misrepresentation and misinterpretation of patient-centered data during handoff, can enhance the quality of patient care and safety. PURPOSE: This study was aimed at evaluating the impact of bedside handoff using the Situation, Background, Assessment, Recommendation (SBAR) technique, on the quality of nursing care. METHODS: The Quality Patient Care Scale (QUALPACS) was completed by the patient while nurses performed a verbal bedside shift handoff and after receiving education on the purpose and proper use of the SBAR communication tool. RESULTS: The mean age of subjects was 51.29 ± 8.02 years. We found a significant increase in the mean score of QUALPACS dimensions, namely psychosocial (P < .001), physical (P < .001), and communication (P < .001) after SBAR implementation. CONCLUSIONS: Findings suggest that using the SBAR handoff technique increases the quality of nursing care in all QUALPACS dimensions.

Spatial distribution and health risk of exposure to BTEX in urban area: a comparison study of different land-use types and traffic volumes.

Many previous studies have investigated BTEX concentrations in urban areas; however, the available evidence on the association of different land-use types and BTEX concentrations is still scarce. In this study, the BTEX concentrations were measured and compared in different land-use types and traffic volumes of Mashhad metropolis, Iran. Sampling was conducted in summer and winter of 2018 based on NIOSH 1501 method in six land-use types, including Residential, Commercial/official, Industrial, Greenspace, Transportation, and Tourism. The spatial autocorrelation model was used to investigate the emission pattern. The Monte Carlo simulation technique and sensitivity analysis were used to assess the health risk of exposure to BTEX compounds. The median [interquartile range (IQR)] of benzene, toluene, ethylbenzene m-xylene, o-xylene and total BTEX concentrations based on overall mean were 4 (2.23), 8.37 (4.48), 1.2 (1.46), 0.89 (2.59), 0.8 (1.73) and 17.7 (8.19) µg/m3, respectively. Benzene and toluene had clustered emission patterns (z-score > 1.96). Exposure to benzene in the study area had a carcinogenic risk for inhabitants. The concentration of BTEX compounds was significantly different based on land-use type. The maximum and minimum concentrations of BTEX were observed in Transportation and Greenspace land uses, respectively. The BTEX concentrations in summer were significantly higher than in winter, and traffic had a significant effect on BTEX concentrations. Overall, our results supported a significant relationship between land-use type and BTEX concentrations in the urban area. Moreover, ambient benzene concentration had a carcinogenic risk potential for inhabitants of study area.

Effect of Nigella sativa oil supplement on risk factors for cardiovascular diseases in patients with type 2 diabetes mellitus.

This study aimed to evaluate the effects of Nigella sativa oil on serum level of systemic inflammation, oxidative stress, fasting blood glucose (FBG), and lipid profile in patients with type 2 diabetes mellitus (T2DM). This double-blind randomized clinical trial study was based on 50 patients with T2DM. Patients were allocated randomly to either N. sativa oil or placebo groups. The intervention group received 1,000 mg N. sativa oil as two capsules, daily for 8 weeks, whereas the placebo group received a corresponding placebo. At baseline and the end of the study, 5 ml blood was collected from each patient after 14-hour fasting for measuring serum C-reactive protein (hs-CRP), malondialdehyde (MDA), FBS, and lipid profile. Analyses covariance was performed to compare investigated parameters between two groups, controlled for relevant covariates. Using N. sativa supplement was significantly associated with decrease in FBS (p < .001), triglyceride (p < .001), total cholesterol (p < .001), low-density lipoprotein cholesterol (p < .001), serum hs-CRP, MDA (p < .001) and increase in serum level of high-density lipoprotein cholesterol (p < .001) in intervention group compared with placebo group. Nigella sativa oil supplement has cardiovascular protective effects in patients with T2DM, by improving the lipid profile and glycemia, by reducing the C-reactive protein level and the lipid peroxidation.

Evaluating the Use of a Modified Early Warning Score in Predicting Serious Adverse Events in Iranian Hospitalized Patients: A Prognostic Study.

INTRODUCTION: Assessment of early clinical warning signs and appropriate response can prevent serious adverse events in hospitalized patients. The Modified Early Warning Score (MEWS) is an applicable early warning sign system that can be used to predict serious adverse events. This study aimed to evaluate the predictive capacity of the MEWS to identify patients in an Iranian hospital who are at risk of developing serious adverse events. METHODS: In this prognostic study, 381 adult patients from the emergency department who were admitted to an inpatient hospital unit of an Iranian hospital from May 2018 to October 2018 were included. The MEWS tool was completed for each patient at the time of admission and then daily for a period of up to 30 continuous days after admission or until the development of a serious adverse event. Receiver operating characteristic, specificity, sensitivity, positive predictive values, and negative predictive values were calculated. RESULTS: In this study, a MEWS of ≥3 on admission was associated with an increased likelihood of developing serious adverse events within 30 days of admission with the area under the curve of 0.82 (95% confidence interval [CI]: 0.77-0.85), sensitivity of 82.81% (95% CI: 71.3-91.1), specificity of 75.39% (95% CI: 70.3-80), positive predictive value of 40.5% (95% CI: 35.2-45.9), and negative predictive value of 95.6% (95% CI: 92.7-97.4). DISCUSSION: A MEWS ≥3 on admission can predict the occurrence of serious averse events in patients admitted to an Iranian hospital for 30 continuous days.

Correction to: Metoclopramide role in preventing ileus after cesarean, a clinical trial.

The original publication of this paper contains an error.

Design of a plasmonic sensor based on a square array of nanorods and two slot cavities with a high figure of merit for glucose concentration monitoring.

In this paper, a plasmonic nanosensor, by using a nanorod array in a square resonator coupled with two slot cavities, with properties for the detection of glucose concentration in water, is proposed and analyzed. We investigated the sensing feature by changing the concentration of the glucose from 0 to 60%. Obtained results show that, by placing different water samples in a square resonator and two cavities, resonance wavelengths can be changed. These resonances demonstrate different dependence on the glucose concentration of water samples. Further, varying the physical parameters of the configuration can also change the resonance wavelength and can be simply tuned. These features recommend flexibility to propose the structure. Simulation results show that the values of sensitivity and figure of merit can be obtained as 892 nm/RIU and 3.5×106 RIU-1, respectively, which can help researchers to discover applications in the plasmonic sensor domain.

Metoclopramide role in preventing ileus after cesarean, a clinical trial.

PURPOSE: Ileus is a common event following cesarean section. Early post-cesarean recovery is very important not only for the mother but also for the baby who is dependent on breastfeeding. This article aims to demonstrate the efficacy of metoclopramide for the prevention of ileus after cesarean. METHODS: In this randomized controlled trial, 696 women scheduled for cesarean were randomized in two groups. Three hundred fifty-three persons settled in control group and 343 were assigned in intervention group who received an injection of 10-mg intramuscular metoclopramide prior to operation. After cesarean, the participants recorded the first flatus, defecation, feeling of hunger, feeding and ambulation in a questionnaire, and also their sense of bloating in a visual analog scale under supervision of a research assistant. The data was analyzed by SPSS 17, t test, and chi-square, while p < 0.05 was considered significant. RESULTS: The interval between cesarean and the first flatus (p < 0.0001), defecation (p < 0.0001), feeling of hunger (p < 0.0001), feeding (p = 0.007), and ambulation (p < 0.0001) were significantly shorter in the metoclopramide group. In addition, polytomous logistic regression analysis showed the metoclopramide group had less bloating with significant difference (OR = 2.83 and CI 1.91-4.21). CONCLUSIONS: Our study proved the functionality of metoclopramide in preventing ileus. As this drug is safe, tolerable, harmless, inexpensive and available, and also no definite method has been developed to prevent ileus after cesarean; yet, metoclopramide could be considered as a suitable option. Certainly with regard to some limitations in our study, further comprehensive studies are still required to ensure validity of the obtained results.

Aloe vera supplementation improves cardiovascular risk factors in hemodialysis patients: A randomized, double-blind, placebo-controlled trial.

Objective: This study assessed the effects of Aloe vera supplementation on serum inflammatory factors, blood sugar and lipid profiles in hemodialysis patients. Materials and Methods: Totally, 50 hemodialysis patients were allocated randomly to either Aloe vera or placebo groups. The Aloe vera group received 2 Aloe vera capsules daily for 8 weeks (500 mg/day). Serum C-reactive protein (hs- CRP), Fasting blood glucose (FBS), and lipid profiles levels were evaluated at the baseline and the end of the eighth week. Results: Aloe vera supplementation for 8 weeks was associated with a significant reduction of serum hs- CRP (p=0.004), total cholesterol (p=0.01), low density lipoprotein (LDL) (p=0.02) leves and increased high density lipoprotein (HDL) (p=0.002) concentration in the hemodialysis patients. Conclusion: Aloe vera supplementation is beneficial in improvement of cardiovascular risk factors in hemodialysis patients.

The effect of web-based family-centered empowerment program in preventing the risk factors of substance abuse in students' parents; application of the health promotion model.

BACKGROUND: The age of onset of substance abuse among adolescents has recently decreased worldwide. Parents play an important role in preventing their children from drug abuse. This study aimed to investigate the effect of web-based family-centered empowerment program in preventing the risk factors of substance abuse in students' parents, using the health promotion model (HPM). MATERIAL AND METHODS: This interventional study was based on 118 parents of high school students in Sabzevar, Iran (2019). Multi-stage random sampling was used to divide the participants into the experimental (n = 65) and control (n = 65) groups. The data were collected through a researcher-made questionnaire based on Pender's HPM. A website was designed to perform all stages of the study. The web-based educational intervention was performed for the experimental group. Both groups completed the questionnaires 2 months after the educational intervention. The data were analyzed using t-test, paired t-test, regression, correlation, and analysis of covariance. RESULTS: There was a significant difference between the scores of prior related behavior, perceived benefits of action, activity-related effect, situational influences, competitors, and commitment in the parents of the experimental group compared to the control group after the educational intervention (P-value < 0.05). Moreover, a significant difference was observed between preventive behaviors of substance abuse and the mean score of perceived barriers to action, perceived self-efficacy, interpersonal influences, and role model in the parents of the experimental group compared to the control group after the educational intervention (P-value < 0.05). CONCLUSION: Overall, designing an educational intervention based on the constructs of Pender's HPM could be an effective strategy for promoting preventive behaviors of substance abuse in parents.

Comparison of Nebulized Lidocaine and Intratracheally Injected (Spray-as-you-go) Lidocaine in Pain and Cough Reduction during Bronchoscopy.

Background: Patients undergoing bronchoscopy often suffer from pain, coughing, and suffocation. Therefore, lidocaine is prescribed through various methods to induce local anesthesia. This study aimed to compare nebulized lidocaine and intratracheally injected lidocaine in pain and cough reduction during bronchoscopy. Materials and Methods: This clinical trial was performed on 96 patients, divided into two groups of intervention (receiving lidocaine via a nebulizer before bronchoscopy) and control (receiving lidocaine through the working channel of bronchoscope). Then, the patientsá¾½ cough frequency was recorded during the procedure, and the pain level was measured using a numerical rating scale at the end of the procedure. The data were analyzed with SPSS software (version 16) using the chi-square and Fisher's exact tests. Moreover, the linear and Poisson regression tests were applied to analyze the main variables in this study. Results: There was no significant difference between the two groups regarding demographic characteristics (P>0.05). Moreover, the linear regression test revealed that the intervention (nebulized lidocaine) group had significantly lower pain scores (1.54±0.08) than the control (intratracheally injected lidocaine) group (2.5±0.26) (P=0.013). In addition, the Poisson regression test showed a statistically significant difference between the intervention (35.22±2.93) and control (48.85±5.96) groups in terms of cough frequency (P<0.0001). Conclusion: This study indicated that nebulized lidocaine has higher efficacy in reducing the patientsá¾½ pain and cough during bronchoscopy than intratracheally injected lidocaine.

Evaluating the effects of telenursing on patients' activities of daily living and instrumental activities of daily living after myocardial infarction: A randomized controlled trial study.

AIM: This study aimed to assess the effects of telenursing on patients' activities of daily living and instrumental activities of daily living (ADLs and IADLs) following a myocardial infarction (MI). METHODS: This randomized, parallel-group, controlled trial was conducted on 95 patients post-MI from 2018 to 2019. Patients were randomly assigned to the intervention (telenursing) and control groups using permuted block randomization. Through telephone calls, telenursing was performed twice a week during the first six consecutive weeks, then once a week until week 12. ADL and IADL questionnaires were completed by both groups before intervention and 12 weeks later. The CONSORT 2010 checklist was used to report the study protocol. RESULTS: The mean age of patients was 56.8 ± 11.07 and 54.2 ± 9.8 years in the telenursing and control group, respectively. The mean ADL and IADL scores in the telenursing group were substantially greater than in the control group [4.57 (3.18, 5.97); P < 0.001 and 4.40 (3.06, 5.75); P < 0.001, respectively]. The odds of a higher degree of independence (no disabilities vs. mild disabilities and disability as well as no disabilities and mild disabilities vs. disability) regarding ADLs and IADLs were significantly greater in the telenursing group as compared with the control group (P < 0.001 and P < 0.001, respectively). CONCLUSIONS: Our findings suggest that the use of telenursing intervention may increase patients' ADLs and IADLs after an MI and may enhance their independence. Geriatr Gerontol Int 2022; 22: 616-622.

Local Usage of Nigella sativa Oil as an Innovative Method to Attenuate Primary Dysmenorrhea: A Randomized Double-blind Clinical Trial.

OBJECTIVES: We sought to determine the effect of topical application of Nigella sativa (black seed) oil, on the primary dysmenorrhea intensity. METHODS: We conducted a randomized, double-blind clinical trial on 124 female students, 18-22 years old, living in the dormitories of Sabzevar Universities. After a primary assessment, participants were randomly divided into two groups. The first group rubbed two drops of N. sativa oil, and the second group rubbed liquid olive oil, as the placebo. Massage was performed on the fontanel lobe 3, at night, three days before menstruation, for eight consecutive days (about five days after menses). This procedure was repeated for three menstrual cycles. After three cycles, pain severity was measured by the visual analog scale. Data analysis was carried out using the Mann-Whitney U test and analysis of covariance (ANCOVA). RESULTS: This study was conducted on 124 female students. The mean age of students, mean age of first menarche, body mass index, and pain severity were not significantly different in the two groups (p > 0.050). No adverse effects were observed during the study. The results of ANCOVA showed that pain intensity in N. sativa oil group was significantly decreased compared to that of the placebo group (0.6 score; p < 0.050). CONCLUSIONS: N. sativa could be a promising, safe, and easily available analgesic supplement in women suffering from primary dysmenorrhea.

The effects of Benson relaxation technique on activities of daily living in hemodialysis patients; A single-blind, randomized, parallel-group, controlled trial study.

BACKGROUND AND PURPOSE: Many patients with renal failure due to the chronic nature of the disease and prolonged dialysis treatment experience dramatically reduced ability to perform daily living activities (ADLs). This study was aimed at evaluating the effects of Benson relaxation technique (BRT) on ADLs in hemodialysis (HD) patients. MATERIALS AND METHODS: This single-blind, randomized, parallel-group, controlled trial study was conducted among 65 hemodialysis patients. They were randomly divided into intervention (n = 33) and control (n = 32) groups. In the intervention group, BRT was performed twice daily for 20 min in a month. The control group received no intervention except for usual care. Data were assessed using the Nottingham Extended Activities of Daily Living (NEADL) scale. RESULTS: The mean age of the subjects was 50.32 ± 7.23 years and 78.4% (n = 51) were male. The odds of higher degree of independence regarding NEADLS was about 25% greater in the intervention group as compared to the control one (OR: 1.24; 95% CI: 1.07, 1.44; P = 0.001). CONCLUSION: Findings suggest that using BRT as a non-pharmacological intervention may effectively enhance the ADLs of HD patients.

Development and Validation of an Instrument to Measure Parental Factors Related to Substance Use Prevention in Adolescents.

BACKGROUND: The average age of using illicit drugs for the first time in adolescents has decreased in Iran over the past years. Studies show that family and environment play a notable role in keeping adolescents away from substances. AIMS: The present study is an attempt to develop and validate a model-based questionnaire to measure parental factors related to substance use prevention in adolescents. METHODS: This methodological study was carried out on 336 parents of high school students in Sabzevar- Iran, in 2018. The first draft of the questionnaire, including 136 items, was developed based on the constructs of the Health Promotion Model (HPM) using similar questionnaires, literature review, and interviewing 9 qualified experts. The validity of the questionnaire was measured through face validity (qualitative and quantitative), content validity (qualitative and quantitative), and construct validity (confirmatory factor analysis). The reliability of the questionnaire was measured by internal consistency and test-retest reliability. SPSS ver. 16 and LISREL ver. 8.2 software was used for statistical analysis. RESULTS: Throughout the validation process, 35 items were omitted, and the final version of the questionnaire consisting of 101 items was developed. The overall content validity ratio was 0.81, which indicates the proper and understandable content of the items. The overall content validity index was 0.96, which indicates excellent expert validity. The Cronbach's alpha coefficient of the questionnaire was 0.85 (constructs range= 0.73-0.96), and the intraclass correlation coefficient of the questionnaire was 0.78 (constructs range= 0.46-0.91), which indicates that the questionnaire has good internal consistency and test-retest reliability. Further, the confirmatory factor analysis yielded an appropriate fit for the model (RMSEA= 0.069, χ2/df= 2.77, GFI= 0.60, AGFI= 0.83, CFI= 0.83, NNFI= 0.83). CONCLUSION: The validity and reliability of the HPM-based questionnaire were supported. Therefore, the questionnaire can be used by health educators and health policymakers in empowerment programs for parents to improve their behavioral skills concerning the prevention of substance use in their adolescents.

The effects of two types of renin-angiotensin system inhibitors on the hypertension induced by new pressor protein associated with beta-factor XIIa in rats.

BACKGROUND AND PURPOSE: New pressor protein (NPP) is a human plasma enzyme, which is structurally related to the beta-fragment of activated factor XII. The present study aimed to compare the effects of angiotensin converting enzyme inhibitors (captopril) and angiotensin type 1 receptor blocker (losartan) on the hypertension induced by NPP injection in normal (sham-2NX) and bilaterally nephrectomized rats (2NX). EXPERIMENTAL APPROACH: In total, 60 male Wistar rats were sham operated or bilaterally nephrectomized under anesthesia. After 24 h of anesthesia with Inactin® (100 mg/kg), their systolic blood pressure (SBP), diastolic blood pressure (DBP), and heart rate (HR) were measured before and after the intravenous administration of captopril, losartan, and NPP. FINDINGS / RESULTS: In the sham-2NX group, after NPP injection, changes were observed in SBP (145.99 ± 3.6 mmHg), DBP (93.9 ± 3.87 mmHg), and HR (400.29 ± 12.78 bpm). In the captopril group, SBP and DBP had no significant changes, while HR increased significantly (P = 0.001). In the losartan group, SBP and DBP decreased (P = 0.001 and P = 0.000, respectively), while HR had no significant changes. In the 2NX group, after NPP injection, changes were denoted in SBP (127.89 ± 9.03 mmHg), DBP (65.86 ± 5.69 mmHg), and HR (333.35 ± 11.47 bpm). In addition, captopril injection increased DBP (P = 0.016) and HR (P = 0.036) in response to NPP injection, while losartan injection had no significant effects in this regard. CONCLUSION AND IMPLICATIONS: It could be concluded that losartan could improve hypertension in normal rats, while captopril deteriorated hypertension in bilaterally nephrectomized rats in this hypertension model.

Designing and Evaluating Educational Intervention to Improve Preventive Behavior Against Cutaneous Leishmaniasis in Endemic Areas in Iran.

OBJECTIVES: Health education programs are one of the most important strategies for controlling cutaneous leishmaniasis (CL) in endemic areas such as Neshabur city. This study aimed to develop and evaluate a comprehensive health education program to improve preventive behaviors for CL. METHODS: This was an interventional study conducted on 136 high school students in Neishabur city. Data collection instruments included a demographic questionnaire and a researcher-made questionnaire based on the "Health Belief Model" and "Beliefs, Attitudes, Subjective Norms and Enabling Factors Model" constructs. The control and intervention groups completed the questionnaires before and 2 months after the intervention. The intervention was conducted in 6, 1-hour educational sessions for the intervention group students and 2, 1-hour sessions for school administrators, teachers, and students' parents. RESULTS: There was no significant difference between the 2 groups in the pre-intervention phase. However, in the post-intervention phase, there were significant differences between the 2 groups for mean scores of knowledge, perceived susceptibility, perceived severity, perceived benefits, cues to action, self-efficacy, attitude, subjective norms, behavioral intention, enabling factors, and behavior associated with CL. CONCLUSION: Health education program based on the "Health Belief Model" and the "Beliefs, Attitudes, Subjective Norms and Enabling Factors Model" model constructs may be a comprehensive and effective educational program to improve preventive behaviors against CL in students.

The effects of cool dialysate on quality of sleep among patients undergoing hemodialysis: A randomized clinical trial.

INTRODUCTION: Low quality of sleep is a common problem among hemodialysis patients. This study was conducted to evaluate the effect of a cold dialysis solution on the quality of sleep in patients undergoing hemodialysis. METHODOLOGY: This double-blind clinical trial was performed on 26 hemodialysis patients with chronic renal failure and sleep disorders in the dialysis center of Sabzevar, Iran, in 2016-2017. Of the 26 patients, 13 each were allocated to the intervention and control groups. The patients in both groups received 4 weeks of hemodialysis (3 sessions per week) using a standard solution with a temperature of 37°C. In the next stage, the control group continued to receive the standard-temperature dialysis, while the intervention group received dialysis using a solution with a temperature of 35.5°C for 4 weeks (3 sessions per week). The Pittsburgh Sleep Quality Index was used to assess and compare the quality of sleep before and after the intervention in the two groups. Data were analyzed using R 1.2.3 software, at 95% confidence level. RESULTS: Although the mean scores of sleep quality were not significantly different between the intervention (9.53 ± 3.12) and control (11.23 ± 3.37) groups at baseline, postintervention, significant differences were observed (intervention group: 4.7 ± 4.55; control group: 10.61 ± 2.69; P < 0.001). CONCLUSION: This study showed that dialysis with cold solution is a simple, cost-effective, and nonpharmacological method that can be used to improve sleep quality in patients undergoing hemodialysis.

Dengue Fever as an Emerging Infection in Southeast Iran.

Dengue fever (DF) is a mosquito-borne acute viral disease presenting with hemorrhagic manifestations in severe cases. Southeast Iran is in close proximity to Pakistan, an endemic country for DF. This cross-sectional study was conducted in the Sistan and Baluchestan province in the southeast of Iran to investigate possibility of DF (immunoglobulin M [IgM], immunoglobulin G [IgG], and nonstructural protein 1 [NS1] antigen tests) in 60 clinically suspected patients (April 2013 to August 2015). NS1 protein was detected in 5% (N = 3), at least one of the antibodies (IgM and/ or IgG) was detected in 11% (N = 7) of the samples. Five patients identified as of acutely infected. There was a simultaneous presence of NS1 protein and IgG or IgM antibodies in 4% (N = 2) of patients. Previous studies show establishment of potential vectors in this area. These evidences support the hypothesis that DF can be a health concern in Southeast Iran with potential future outbreaks.

Effect of Topical Application of Nigella Sativa Oil and Oral Acetaminophen on Pain in Elderly with Knee Osteoarthritis: A Crossover Clinical Trial.

BACKGROUND: Limited evidence supports Nigella sativa's role as an effective complementary and alternative medicine and the anti-inflammatory effects of Nigella sativa on patients with allergic rhinitis. OBJECTIVE: The aim of this study was to investigate the effect of topical application of Nigella sativa oil and oral acetaminophen on pain in the elderly with knee osteoarthritis residing in a parents' home in Sabzevar. METHODS: This study is done as a crossover clinical trial. After obtaining written consent of elderly patients with osteoarthritis of the knee, they were randomly divided into two groups. In step 1, in group 1, 1 cc of Nigella sativa oil was applied on the knee joint every 8 hours for 3 weeks; for the second group, every 8 hours for 3 weeks, patients were given 1 tablet of 325 mg acetaminophen. After a period of 1 month without medication to wash out each group, in step 2, each treatment group received the drug interaction in the same way as above. Pain was determined using a visual scale (VAS) before and after the first and second stages. Treatment response was defined as a decrease in pain scores over 1.5. Data analysis was performed with an R software mixed model. RESULTS: This study was done on 40 elderly patients: 18 (45%) men and 22 (55%) women. Their mean year and weight were 75.66±8.9 years and 69.67±14.33 kg, respectively. Study results showed that topical application of Nigella sativa oil and oral acetaminophen reduced pain in elderly with knee osteoarthritis; after using Nigella sativa oil, the reduction of pain was higher (p=0.01). CONCLUSION: The results of this study showed that topical application of Nigella sativa oil was effective in reducing pain in patients with knee osteoarthritis; therefore, it is recommended as a safe supplement for these elderly. TRIAL REGISTRATION: The trial was registered at TCTR (http://www.clinicaltrials.in.th/) with the ID: TCTR20160125003. FUNDING: This study was approved and supported by the Sabzevar University of Medical Sciences.