Effects of wearing medical gowns at different temperatures on the physiological responses of female healthcare workers during the COVID-19 pandemic.

BACKGROUND: Using medical gowns with high protection against COVID-19 among healthcare workers (HCWs) may limit heat exchange, resulting in physiological challenges. OBJECTIVE: This study aimed to compare the physiological and neurophysiological responses of female HCWs when using two typical medical gowns at different temperatures during the COVID-19 pandemic. METHODS: Twenty healthy female HCWs participated in this study. Participants wore two types of medical gowns: Spunbond gown (SG) and laminate gown (LG). They walked on a treadmill in a controlled climate chamber for 30 minutes at three different temperatures (24, 28, and 32°C). Heart rate (HR), skin surface temperature (ST), clothing surface temperature (CT), ear temperature (ET), blood oxygen percentage (SaO2), galvanic skin response (GSR), and blood pressure were measured before and after walking on a treadmill. The study's results were analyzed using SPSS26. RESULTS: The study found that LG led to an average increase of 0.575°C in CT compared to SG at the same temperatures (P < 0.03). The average HR increased by 6.5 bpm in LG at 28°C compared to SG at a comfortable temperature (P = 0.01). The average ET in SG and GSR in LG at 32°C increased by 0.39°C and 0.25µS, respectively, compared to the comfortable temperature (P < 0.02). CONCLUSION: The study recommends maintaining a comfortable temperature range in hospitals to prevent physiological challenges among HCWs wearing medical gowns with high protection against COVID-19. This is important because using LG, compared to SG, at high temperatures can increase HR, ET, CT, and GSR.

Novel biogenic preparation of gold nanoparticles decorated on sepiolite clay and evaluation of anti-cancer effect on gastric cancer cell and electrochemical sensing of nitrite.

An environmentally friendly strategy was used in this study to synthesize gold nanoparticles decorated on sepiolite clay (GNPs-SC) using Heracleum persicum grass extract. The physicochemical characters of the prepared composite were characterized using transmission electron microscopy (TEM), scanning electron microscopy (SEM), and X-ray diffraction (XRD). A GNPs-SC modified carbon pate electrode (CPE) was used to study the electrochemical oxidation of nitrite. The proposed nitrite sensor exhibits excellent performance, including a broad linear range (1.0-150 µM), a low limit of detection (0.4 µM), and acceptable reproducibility (RSD = 2.6%). As well, the prepared GNPs-SC was tested for its effectiveness against human gastric adenocarcinoma (AGS) cell line. The MTT assay protocol revealed that the bio-synthesized product displayed significant cytotoxic activity against gastric cancer in human subjects. The findings of this study indicate that GNPs-SC, synthesized using environmentally friendly protocol, exhibit great potential for use in electrochemical sensing and treatment of human cancer.

Staffs' physiological responses to irrelevant background speech and mental workload in open-plan bank office workspaces.

BACKGROUND: Acoustic comfort is one of the most critical challenges in the open-plan workspace. OBJECTIVE: This study was aimed to assess the effect of irrelevant background speech (IBS) and mental workload (MWL) on staffs' physiological parameters in open-plan bank office workspaces. METHODS: In this study, 109 male cashier staff of the banks were randomly selected. The 30-minute equivalent noise level (LAeq) of the participants was measured in three intervals at the beginning (section A), middle (section B), and end of working hours (section C). The heart rate (HR) and heart rate variability (HRV): low frequency (LF), high frequency (HF), and LF/HF of the staff were also recorded in sections A, B, and C. Moreover, staff was asked to rate the MWL using the NASA-Task load. RESULTS: The dominant frequency of the LAeq was 500 Hz, and the LAeq in the frequency range of 250 to 2000 was higher than other frequencies. The LAeq (500 Hz) was 55.82, 69.35, and 69.64 dB(A) in sections A, B, and C, respectively. The results show that the IBS affects staffs' physiological responses so that with increasing in IBS, the HF power decreases. Moreover, with higher MWL, increasing noise exposure, especially IBS, causes more increases in LF power and LF/HF ratio. CONCLUSION: It seems that the IBS can affect physiological responses and increase staff stress in open-plan bank office workspaces. Moreover, the mental workload can intensify these consequences in these working settings.

Analysis of body heat tolerance of workers in a simulated warm environment based on linear mixed model.

Workers' heat tolerance plays a crucial role in maintaining their health and performance in hot environments. This study aimed to empirically analyze the body heat tolerance of workers under a simulated warm environment. Twenty healthy male workers from the typical light metal industry (age: 23.15±2.45 years) were participated in the experimental study. Workers were exposed to two thermal environments (Ta = 22°C, RH = 35%, and Ta = 35°C, RH = 35%) in a simulated moderate workload in a climate-controlled room. The maximal aerobic capacity (VO2 max) and body fat mass of workers were determined. The heat tolerance indicators were determined based on heart rate (HR) and ear temperature (ET) before and after each experiment. A linear mixed model was employed to analyze body heat tolerance indicators using the SPSS statistical package. All physiological responses significantly increased in the warm air condition compared to the thermoneutral condition. The HR and ET increased by an average of 14 bpm and 0.75°C, respectively (p<0.05). The mixed model could accurately predict heat tolerance indicators (r = 0.95 and r = 0.97) so that the VO2 max and body fat mass were identified as the main individual influential factors. The VO2 max showed significant correlation with urinary specific gravity (r = -0.55, p<0.05), HR (r = -0.59, p<0.05), and ET (r = -0.57, p<0.05) in warm environment. The model confirmed that physical fitness is critical in increasing heat tolerance in warm environments. It can be a helpful screening tool for properly selecting workers in occupational medical examinations for working in warm air conditions. It is proposed that workers' regular exercise and lifestyle modifications can strengthen their heat tolerance.

The simultaneous exposure to heat and whole-body vibration on some motor skill functions of city taxi drivers.

BACKGROUND: Driving requires sensory-motor abilities in unpredictable and complex driving scenarios. This experimental study aimed to investigate the combined effects of exposure to whole-body vibration and heat on motor skill functions of city taxi drivers. METHODS: This study was conducted using a driving simulator on 30 male taxi drivers. The drivers were exposed to five exposure conditions set by a single or combined exposure of two air temperatures (24 and 30 °C) and two vibration levels (0.5, 1 m/s2). Motor skill functions, including body balance, hand grip strength, and perceived fatigue, were measured using a force plate, dynamometer, and Borg CR-10 questionnaire. RESULTS: The separate exposure to heat did not modify balance and hand grip strength, but its combined exposure to vibration affected balance and grip strength. The effect sizes of heat, vibration, and heat + vibration on balance were respectively 0.003, 0.23, and 0.441. Vibration exposure made the most significant mean differences in hand grip strength compared with the other scenarios. The separate effect of heat on drivers' perceived fatigue was comparable to vibration. The combined exposure to heat and vibration aggravated the perceived fatigue associated with exposure to heat and vibration alone. CONCLUSION: Vibration mainly affects the driver's postural equilibrium, handgrip strength, and fatigue. The heat exposure alone did not have any remarkable effects on the balance responses and handgrip strength; however, it significantly increased the drivers' perceived fatigue. Exposure to heat can aggravate the effects of vibration on motor skills with a synergistic interaction.

The Influence of Face Masks on Verbal Communication in Persian in the Presence of Background Noise in Healthcare Staff.

Wearing face masks has resulted in verbal communication being more challenging during the COVID-19 pandemic. This study aimed to investigate the effect of face masks on the speech comprehensibility of Persian nurses in healthcare settings. Twenty female nurses from the governmental hospitals randomly participated in an experiment on seven typical commercial face masks at two background noise levels. Nurses' speech intelligibility from a human talker when wearing each face mask was determined based on the speech discrimination score. The vocal effort of nurses wearing each face mask was determined based on the Borg CR10 scale. Based on the linear mixed model, the speech intelligibility of nurses from a human speaker wearing surgical masks, N95 masks, and a shield with face masks were approximately 10%, 20%, and 40-50% lower, respectively, than no-mask conditions (p < 0.01). The background noise decreased the speech intelligibility of nurses by approximately 22% (p < 0.01). The use of a face shield further decreased speech intelligibility up to 30% compared to using a face mask alone (p < 0.01). The vocal efforts of nurses when wearing surgical masks were not significant compared with the baseline vocal efforts (p > 0.05); however, vocal efforts of nurses when wearing N95 and N99 respirators were at an unacceptable level. The face masks had no considerable effect on the speech spectrum below 2.5 kHz; however, they reduced high frequencies by different values. Wearing face masks has a considerable impact on the verbal communication of nurses in Persian. The level of background noise in the healthcare setting can aggravate the effect sizes of face masks on speech comprehensibility.

Prediction of occupational exposure limits for noise-induced non-auditory effects.

There is a recent trend to place more emphasis on noise non-auditory effects. Despite its implications on health, there is a lack of recommendations for noise in occupational settings. This study aimed to present occupational exposure limits for noise-induced non-auditory effects in healthy males using empirical exposure-response regression models based on the data of laboratory and field considering the effective variables. To this end, the equivalent noise level was measured and recorded in four working settings including closed offices, open-plan offices, control rooms, and industrial workplaces during a normal working day. They were 65, 68, 73, and 80dB(A), respectively. In the laboratory, 31 healthy males were exposed to five noise conditions (four noisy conditions and one quiet) during 8 h and they were asked to perform the cognitive tests. In the field phase, 124 healthy males were also examined from four working settings in their workstations for 8 h. The psychophysiological parameters of the participants were recorded in both lab and field. The results indicated variations in mental responses at levels above 55dBA, and psychophysiological variations at levels above 70dB(A) in both phases. The findings also showed that the developed regression models could plausibly predict the noise-induced psychophysiological responses during exposure to noise levels; thus, they can be presented the likely exposure limits. Based on the results of the models, the levels <55dB(A) are likelihood of the acoustic comfort limit, and the levels ranged from 55 to 65dB(A) are the acoustic safe limits. The acoustic caution limit is the likelihood of the levels ranged from 65 to 75dB(A). The levels ranged from 75 to 80dB(A) are likely the action levels or control limits, and the occupational exposure limit are the probability of levels> 80dB(A).

Enhanced performance of adsorptive removal of dibenzothiophene from model fuel over copper(II)-alginate beads containing polyethyleneterephthalate derived activated carbon.

In this research, copper(II)-alginate (Cu(II)-A) beads containing polyethyleneterephthalate derived activated carbon (PET-AC) with porous structure were prepared by a feasible cross-linking technology. The composition and structure of the beads were thoroughly analyzed by X-ray diffraction, Fourier transform infrared spectroscopy, Brunauer-Emmett-Teller adsorption, scanning electron microscopy and energy dispersive X-ray methods. The desulfurization activity of the adsorbent for dibenzothiophene (DBT) in the model oil was investigated. The influence of mass ratio of PET-AC on the features of the prepared Cu(II)-A beads was studied. According to experimental results, higher adsorption capacity was acquired from PET-AC/Cu(II)-A at 4:1 mass ratio due to its high porosity and available Cu(II) adsorption centers. The adsorption isotherms could be correlated by the Langmuir isotherm and the maximum adsorption capacity reached up to 62.9 mg g-1. The adsorption data showed better fitting (R2 greater than 0.99) to the pseudo-second-order rate equation. Lewis acid-base and π-π interactions might be the driving force of the DBT adsorption. The adsorbent could be also reused for 4 successive runs with negligible loss in desulfurization capability. All of these features make the PET-AC/Cu(II)-A as a potential adsorbent towards desulfurization from fuels.

Application of graphene/zinc-based metal-organic framework nanocomposite for electrochemical sensing of As(III) in water resources.

In this study, a novel nanocomposite of graphene oxide/zinc based metal-organic framework (GO/MOF) was prepared through a simple solvothermal method. The electrochemical As(III) sensing capability of the nanocomposite was explored by casting the GO/MOF on a glassy carbon electrode (GCE), followed by an electrochemically reduction of GO. As(III) detection was performed by the differential pulse anodic stripping voltammetry (DPASV) method after closed-circuit mode. The present sensor showed excellent electrochemical performance such as a wide linear range from 0.2 to 25 ppb (µg/L), low detection limit (S/N = 3) of 0.06 ppb and good reproducibility with a relative standard deviation (RSD) value of 2.1%. The detection limit of As(III) is lower than the threshold value set by the Environmental Protection Agency (EPA) in drinking water. A good selectivity for As(III) detection by the proposed Gr/MOF-GCE was also demonstrated. Finally, this platform was employed for the As(III) monitoring in environmental water samples, and the accuracy of obtained results were confirmed by inductively coupled plasma-optical emission spectrometer (ICP-OES) system.

A novel electrochemical sensor based on silver/halloysite nanotube/molybdenum disulfide nanocomposite for efficient nitrite sensing.

In the present study, the silver/halloysite nanotube/molybdenum disulfide (Ag/HNT/MoS2) nanocomposite was successfully synthesized. For this purpose, the lumen of HNTs was firstly modified by silver to generate Ag nanorods via chemical process and then the MoS2 layers deposited on the Ag/HNT nanocomposite by hydrothermal method. The characterization of Ag/HNT/MoS2 nanocomposite were investigated by field emission scanning electron microscopy (FE-SEM), Fourier transform infrared (FT-IR) spectroscopy, transmission electron microscopy (TEM), X-ray photoelectron spectra (XPS), energy dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD) analyses. The nanocomposite modified carbon paste electrode (CPE) was applied for the electrocatalytic detection of nitrite in aqueous solutions. It was demonstrated that the treatment of HNTs with Ag and MoS2 materials enhanced the catalytic performance of modified CPE. At optimal experimental conditions, the designed sensor displayed remarkable sensing ability toward nitrite oxidation, offering a good linearity from 2 to 425 µM. The limit of detection (LOD) of the proposed strategy was estimated to be 0.7 µM based S/N = 3. The good reproducibility, acceptable stability, fast response time and anti-interference performance of the proposed assay suggests that the modified CPE has great potential working as a nitrite electrochemical sensor for environmental applications.

Bone Allograft: An Option for Total Mandibular Reconstruction.

Total mandibular reconstruction is one of the most challenging modalities in maxillofacial surgery. In this article, we try to introduce a method of total mandible reconstruction. We report a 25-year-old male patient with complete involvement of the mandible by Langerhans cell tumor. The patient underwent total mandibulectomy and reconstruction with bone allograft harvested from a donor who had died the day before. The patient has good functional and aesthetic results in a long time. It seems that bone allograft can be a good alternative to other methods in total mandibular reconstruction.

Primary Orbital Hydatid Cyst: A Case Report.

Hydatid cyst is a rare parasitic infection that involved all organs. It caused by the larval stage of Echinococcus tapeworms. Hydatid cyst of the head and neck is a very rare condition, even in areas where Echinococcus infestation is endemic. Orbital hydatid cyst is extremely rare and accounts for less than 1% of all hydatid cysts. Herein a 24-year-old man with primary orbital hydatid cyst is introduced. He complained from proptosis and diplopia. MRI images revealed a lesion with low signal intensity on T1-weighted images and high signal intensity on T2-weighted images, which displaced the optic nerve inferiorly and the globe inferolateral. The cyst was enucleated via frontotemporal craniotomy and superior orbitotomy approach. Histopathological examination of the fluid confirmed the diagnosis of hydatid cyst. Treatment of the orbital hydatid cyst is surgical excision followed by the systemic use of albendazole.

A novel voltammetric sensor for sensitive detection of mercury(II) ions using glassy carbon electrode modified with graphene-based ion imprinted polymer.

In this paper, a novel strategy was proposed to prepare ion-imprinted polymer (IIP) on the surface of reduced graphene oxide (RGO). Polymerization was performed using methacrylic acid (MAA) as the functional monomer, ethylene glycol dimethacrylate (EGDMA) as the cross-linker, 2,2'-((9E,10E)-1,4-dihydroxyanthracene-9,10-diylidene) bis(hydrazine-1-carbothioamide) (DDBHCT) as the chelating agent and ammonium persulfate (APS) as initiator, via surface imprinted technique. The RGO-IIP was characterized by means of Fourier transform infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM) and thermogravimetric analysis (TGA). The electrochemical procedure was based on the accumulation of Hg(II) ions at the surface of a modified glassy carbon electrode (GCE) with RGO-IIP. The prepared RGO-IIP sensor has higher voltammetric response compared to the non-imprinted polymer (NIP), traditional IIP and RGO. The RGO-IIP modified electrode exhibited a linear relationship toward Hg(II) concentrations ranging from 0.07 to 80 µg L(-1). The limit of detection (LOD) was found to be 0.02 µg L(-1) (S/N=3), below the guideline value from the World Health Organization (WHO). The applicability of the proposed electrochemical sensor to determination of mercury(II) ions in different water samples was reported.

Synthesis and application of novel ion-imprinted polymer coated magnetic multi-walled carbon nanotubes for selective solid phase extraction of lead(II) ions.

In this study, novel magnetic ion-imprinted polymer (MIIP) nanoparticles were utilized for the sensitive and selective detection of Pb(II) ions by graphite furnace atomic absorption spectrometry (GFAAS). The Pb(II)-imprinted polymer was synthesized by using 4-vinylpyridine (4VP) as the functional monomer, ethylene glycol dimethacrylate (EGDMA) as the cross-linker, 2,3,5,6-tetra(2-pyridyl) pyrazine (TPPZ) as the chelating agent and magnetic multi-walled carbon nanotubes (MMWCNTs) as the carrier. The synthesized MIIP materials were characterized by field emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and vibrating sample magnetometer (VSM). Various analytical parameters such as extraction and desorption time, eluent type and concentration, pH and sample volume were systematically examined. The selectivity of MIIP sorbent for Pb(II) ions in the presence of some cations was also evaluated. The limit of detection (LOD, 3S(b)) and the relative standard deviation (RSD, n=8, c=25 ng L(-1)) were found to be 2.4 ng L(-1) and 5.6%, respectively. The maximum sorption capacity of the MIIP for Pb(II) was found to be 48.1 mg g(-1). Finally, the proposed analytical procedure was successfully applied to monitoring lead in human hair and water samples with satisfactory results for the spiked samples.