The effects of exoskeleton use on human response to simulated overhead tasks with vibration.

The use of occupational exoskeletons has grown fast in manufacturing industries in recent years. One major scenario of exoskeleton use in manufacturing is to assist overhead, power hand tool operations. This preliminary work aimed to determine the effects of arm-supporting exoskeletons on shoulder muscle activity and human-hand tool coupling in simulated overhead tasks with axially applied vibration. An electromagnetic shaker capable of producing the random vibration spectrum specified in ISO 10819 was hung overhead to deliver vibrations. Two passive, arm-supporting exoskeletons, with one (ExoVest) transferring load to both the shoulder and pelvic region while the second one (ExoStrap) transferring load primarily to the pelvic region, were used in testing. Testing was also done with the shaker placed in front of the body to better understand the posture and exoskeleton engagement effects. The results collected from 6 healthy male subjects demonstrate the dominating effects of the overhead working posture on increased shoulder muscle activities. Vibration led to higher muscle activities in both agonist and antagonist shoulder muscles to a less extent. Exoskeleton use reduced the anterior deltoid and serratus anterior activities by 27% to 43%. However, wearing the ExoStrap increased the upper trapezius activities by 23% to 38% in the overhead posture. Furthermore, an increased human-shaker handle coupling was observed in the OH posture when wearing the ExoVest, indicating a more demanding neuromuscular control.

The current work sought to understand exoskeleton use in overhead tasks with power hand tools. The study findings demonstrate that vibration didn't alter the effects of arm-supporting exoskeletons on shoulder muscle activities in overhead tasks with vibration, though exoskeleton use may complicate human-hand tool coupling and corresponding neuromuscular control.

Unlocking Quercetin's Neuroprotective Potential: A Focus on Bee-Collected Pollen.

In the quest to evade side effects associated with synthetic drugs, mankind is continually exploring natural sources. In recent decades, neurodegenerative disorders (NDDs) have surged dramatically compared to other human diseases. Flavonoids, naturally occurring compounds, have emerged as potential preventers of NDD development. Notably, quercetin and its derivatives demonstrated excellent antioxidant properties in the fight against NDDs. Recognizing bee-collected pollen (BP) as a well-established excellent source of quercetin and its derivatives, this review seeks to consolidate available data on the prevalence of this flavonoid in BP, contingent upon its botanical and geographical origins. It aims to advocate for BP as a superb natural source of "drugs" that could serve as preventative measures against NDDs. Examination of numerous published articles, detailing the phenolic profile of BP, suggests that it can be a great source of quercetin, with an average range of up to 1000 mg/kg. In addition to quercetin, 24 derivatives (with rutin being the most predominant) have been identified. Theoretical calculations, based on the recommended dietary intake for quercetin, indicate that BP can fulfil from 0.1 to over 100 % of the requirement, depending on BP's origin and bioaccessibility/bioavailability during digestion.

Do Physicians Overestimate Radiographic Findings in Patients Undergoing Knee Arthroplasty?

Background: Total knee arthroplasty (TKA) is 1 of the top 2 most common and expensive surgical procedures among Medicare beneficiaries. Due to the procedure's high annual cost, overdiagnosis and subsequent overutilization of TKA has substantial health-policy implications. Concerns regarding the overexaggeration of radiographic findings and overutilization of TKA have been expressed by medical insurers. Currently, the standard of care for assessing potential knee arthroplasty candidates includes assigning a Kellgren-Lawrence (KL) radiographic score. Our study investigated the accuracy of reported preoperative KL scores in patients undergoing TKA. Material and methods: Records of 277 patients who had underwent TKA at our institution for knee osteoarthritis were randomly selected from a large patient data registry and retrospectively reviewed. Two blinded raters assigned KL scores to the radiographs obtained during the preoperative assessment, which were compared to the scores reported by the operative surgeon. An intraclass correlation coefficient (ICC) was calculated to determine inter-rater reliability. Results: Between blinded raters, ICC3k = 0.88 (95% confidence interval: 0.86-0.90, P < .001), demonstrating good reliability. Between all raters, ICC2k = 0.89 (95% confidence interval: 0.86-0.90, P < .001), also demonstrating good agreement. Raters fully agreed on the KL classification for 196 patients (70.76%). Compared with blinded raters, the operative surgeon assigned lower KL scores. Conclusion: Reporting of KL score is consistent between operative surgeons and independent reviewers. In cases of disagreement between reviewers, the operative surgeon was generally more conservative in their estimation of the extent of osteoarthritis present radiographically. Concerns regarding inflation of radiographic findings to support surgical preauthorization are unwarranted.

Increased urinary arsenic concentration in newly diagnosed type 2 diabetes mellitus: a gender-independent, smoking-dependent exposure biomarker in older adults in Tehran.

Arsenic is ranked in the top ten environmental toxicants but its impact on type 2 diabetes mellitus (T2DM) and its association with other human health effects is contradictory. We aimed in this study to compare the urinary arsenic concentration (u As) in older age adults (> 40 years) and their T2DM subgroup in an age and gender-matched case control study to find the association of u As with, diet, oxidative stress, smoking, anthropometric factors, and lifestyle in our study participants. Face-to-face interviews based on structured questionnaires were conducted on 200 female and male volunteers (100 cases and 100 control). Considering the exclusion criteria, u As concentration and serum biomarkers of oxidative stress (malondialdehyde, superoxide dismutase, catalase) of 30 newly diagnosed T2DM and 30 control were determined by ICP-mass analysis and ELISA reader respectively. Despite the similarities in sociodemographic, diet, and lifestyle factors in males and females and their T2DM subgroups, a 4 times difference in u As levels between T2DM (93.7 ng/L (32)) and their healthy counterparts (23.7 ng/L (2.3)) without meaningful associations with gender, age, BMI, diet, and lifestyle was observed. Mean u As concentration in total population of smokers was significantly higher than non-smokers ((119 ng/L vs. 22.5 ng/L (p = 0.03)) and oxidative stress markers were not significantly higher in T2DM smokers than non-smokers. Chronic arsenic exposure through smoking could be contributed to the incidence of T2DM in older age adults. Oxidative stress markers were not significantly increased in smoker subgroup compared with non-smokers but except smoking pattern, other variables did not affect u As concentration. Precautionary measure to reduce the exposure of people with this element is recommended to prevent the arsenic-induced T2DM in human populations.

The Texture of Psychoactive Illicit Drugs in Iran: Adulteration with Lead and other Active Pharmaceutical Ingredients.

Psychoactive illicit drugs are widely used all over the world. Due to the high demand for illicit drugs, adulteration of substances with poisonous and active pharmaceutical ingredients is a common phenomenon in some countries. Lead and other active pharmaceutical ingredients are among adulterants added to illicit drugs intentionally. In the present study, we analyzed four major abused street drugs in Iran's drug black market (opium, Iranian crack, ecstasy tablets, and crystal methamphetamine) to assess active pharmaceutical ingredients and determine a quantitative assay of lead. A total of 40 psychoactive drugs were analyzed using high-performance liquid chromatography, gas chromatography/mass spectrometry, and flame atomic absorption spectroscopy. The results demonstrated that psychoactive drugs were adulterated with different drug categories, such as tramadol, ketamine, methadone, acetaminophen, and caffeine. Lead was found in all analyzed samples, ranging from 9-90 ppm. The smallest lead level was detected in methamphetamine samples. Iranian crack samples contained the highest amount of lead. Psychoactive illicit drugs were adulterated with different drug classes and also lead. Lead-adulterated psychoactive drugs are among the new sources of exposure to lead, while illicit drugs' contamination with different drugs may present a health hazard for drug-abusing patients.

The concentration and probabilistic health risk assessment of pesticide residues in commercially available olive oils in Iran.

This study was undertaken to analyze 29 pesticides residues in 37 commercially olive oil collected samples from Iran's markets using Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) approach along with acetonitrile for the extraction, surface adsorbents for clean-up procedure, following with a gas chromatography-mass spectroscopy (GC-MS). In order to eliminate the matrix effect, the calibration curves were drawn using spiked samples with the Area under curve (AUC) portion calculation of pesticide residue to AUC internal standard (Triphenyl Methane (TPM)). Moreover, the probabilistic health risk assessment includes non-carcinogenic and carcinogenic risk were estimated by target hazard quotient (THQ), total target hazard quotient (TTHQ) and cancer risk (CR) using the Monte Carlo Simulation (MCS) method. The calibration curves were linear in the range of 10-1500 ng/g, and R2 was higher than 0.994. All pesticides recoveries as average were in the range of 77.97-112.65%. The respective numbers attributed to LOD and LOQ were 3-5 ng/g and 8-15 ng/g. Results showed that 29.7% of samples were contaminated by pesticides which according to Iranian regulation, while in 7 cases banned pesticides were detected. Only 4 samples are noncompliant with EU regulation. The rank order of pesticides based on THQ was Heptachlor > DDT > Pretilachlor. Also, TTHQ for adults was 0.139; and children 0.467. The rank order of pesticides based on CR was Heptachlor > DDT. Consumers (adults and children) are not at non-carcinogenic risk due to ingestion of oil olive content (THQ and TTHQ < 1 value) but are at considerable carcinogenic (CR > 1E-6). According to the observed profile of pesticide in olive oil samples, which are mostly banned according to Iranian regulation, further improvements in agriculture procedures of cultivated olive in Iran, as well as required assessments of imported olive oil, was recommended.

Mutagenicity Assessment of Drinking Water in Combination with Flavored Black Tea Bags: a Cross Sectional Study in Tehran.

Diseases related to water impurities may present as major public health burdens. The present study aimed to assess the mutagenicity of drinking water from different zones of Tehran, and evaluate possible health risks through making tea with tea bags, by Ames mutagenicity test using TA 100, TA 98 and YG1029 strains. For this purpose, 450 water samples were collected over the period of July to December 2014 from 5 different zones of Tehran. Except for one sample, no mutagenic potential was detected during these two seasons and the MI scores were almost normal (≤ 1-1.6) in TA 100, TA 98 and YG1029 strains. Although no mutagenic effects were considered in TA 98 and TA 100 in the test samples of our three evaluated tea bag brands, one sample from a local company showed mutagenic effects in the YG1029 strain (MI=1.7-1.9 and 2) after prolonged (10-15 min.) steeping. Despite the mild mutagenic effect discovered for one of the brand, this cross sectional study showed relative safety of water samples and black tea bags in Tehran. According to the sensitivity of YG1029 to the mutagenic potential of water and black tea, even without metabolic activation by s9 fraction, this metabolizer strain could be considered as sensitive and applicable to food samples for quantitative analysis of mutagens.

Trace elements and heavy metals in mineral and bottled drinking waters on the Iranian market.

A survey of Iranian waters, sampled from 2010 to 2013, is presented. A total of 128 water samples from 42 different brands of bottled mineral and drinking water were collected and analysed for contamination levels of lead (Pb), cadmium (Cd), copper (Cu), arsenic (As) and mercury (Hg). Determinations were performed using a graphite furnace atomic absorption spectrophotometer for Pb, Cd and Cu, a hydride vapour generation as well as an Arsenator digital kit (Wagtech WTD, Tyne and Wear, UK) for As and a direct mercury analyser for Hg. Arsenic concentration in six bottled gaseous mineral samples was higher than the related limit. Regardless of these, mean concentrations of Pb, Cd, Cu, As and Hg in all types of water samples were 4.50 ± 0.49, 1.08 ± 0.09, 16.11 ± 2.77, 5.80 ± 1.63 and 0.52 ± 0.03 µg L⁻¹, respectively. Values obtained for analysed heavy metals in all samples were permissible according to the limits of national and international standards.

Toxicity assessment of nanosilver wound dressing in Wistar rat.

Antibiotic resistance to microorganisms is one of the major problems faced in the field of wound care in burns patients. Silver nanoparticles have come up as potent antimicrobial agent and are being evaluated in diverse medical applications ranging from silver based dressings to silver coated medical devices. We aimed in present study to test the release of nanosilver from nanosilver wound dressing and compare the dermal and systemic toxicity of nanosilver dressings in a repeated dose (21 days) model. Under general anesthesia, a limited standard 2nd degree burns were provided on the back of each rat in all treatment, negative control (simple dressing) and 5% silver nitrate groups, each contained 5 male wistar rats. According to the analysis made by atomic absorption spectrometry, the wound dressings released 0.599 ± 0.083 ppm of nanosilver during first 24 hrs of study. Daily observations were recoded and wounds were covered with new dressings each 24 hrs. Burn healing was observed in nanosilver wound dressing group in shorter time periods than the control groups. In toxicity assessment, this dressing didn't cause any hematological and histopathological abnormalities in treatment group but biochemical studies showed significant rise of plasma transaminase (ALT) at the endpoint (21 days) of the study (P=0.027). Portal mononuclear lymphoid and polymorphonuclear leukocyte infiltrations in three to four adjacent foci were recognized around the central hepatic vein in treatment group. Mild hepatotoxic effects of nanosilver wound dressing in wistar rat emphasize the necessity of more studies on toxicity potentials of low dose nanosilver by dermal applications.

Association between glycodelin and aryl hydrocarbon receptor in Iranian breast cancer patients: impact of environmental endocrine disrupting chemicals.

Breast cancer affects Iranian women one decade younger than their counterparts in other countries and the underlying risk factors have remained controversial. The aryl hydrocarbon receptor (AhR) mediates the effects of many environmental endocrine disruptors and contributes to the many other genes and Gd is an endocrine-regulated glycoprotein which may induce by AhR ligands in endometrium. This study has aimed to compare the interactions between Gd and AhR and other fundamental genes (p53, K-Ras, ER, PgR, AR) between pre and post menopausal Iranian breast cancer patients. To conduct immunohistochemical studies with appropriate monoclonal antibodies, 25 premenopausal invasive ductal carcinomas and 29 postmenopausal invasive ductal carcinomas were selected retrospectively in 2008-2010 from the pathology department of Imam Khomeini hospital complex of Tehran. Higher levels of AhR in epithelial cells of premenopausal patients and breast fibroadenoma emphasized the susceptibility of these cells to environmental induced tumors. Current study demonstrated a significant association between tumoral levels of Gd and AhR (p=0.002) in breast cancers which confirms the preliminary hypothesis about the role of TCDD exposure on Gd biosynthesis and secretion in TCDD-treated endometrial epithelial cells. In summary this study showed the dual prognostic role of Gd especially in premenopausal breast cancer which could be induced by AhR overexpression. Further studies are necessary to find the direct role of breast carcinogens as well as endocrine disrupting chemicals on the differential levels of Gd in breast tumors.