Tolerable Limits Research Articles

Hot-Cracking Mechanism of Laser Welding of Aluminum Alloy 6061 in Lap Joint Configuration.

Laser welding, known for its distinctive advantages, has become significantly valuable in the automotive industry. However, in this context, the frequent occurrence of hot cracking necessitates further investigation into this phenomenon. This research aims to understand the hot-cracking mechanism in aluminum alloy (AA) 6061, welded using a laser beam in a lap joint setup. We used an array of material characterization methods to study the effects of processing parameters on the cracking susceptibility and to elucidate the hot-cracking mechanism. A laser power of 2000 W generated large hot cracks crossing the whole weld zone for all welding speed conditions. Our findings suggest that using a heat input of 30 J/mm significantly mitigates the likelihood of hot cracking. Furthermore, we observed that the concentrations of the alloying elements in the cracked region markedly surpassed the tolerable limits of some elements (silicon: 2.3 times, chromium: 8.1 times, and iron: 2.7 times, on average) in AA6061. The hot-cracking mechanism shows that the crack initiates from the weld root at the interface between the two welded plates and then extends along the columnar dendrite growth direction. Once the crack reaches the central region of the fusion zone, it veers upward, following the cooling direction in this area. Our comprehensive investigation indicates that the onset and propagation of hot cracks are influenced by a combination of factors, such as stress, strain, and the concentration of alloying elements within the intergranular region.

Understanding the Effect of Different Glucose Concentrations in the Oligotrophic Bacterium Bacillus subtilis BS-G1 through Transcriptomics Analysis.

Glucose is an important carbon source for microbial growth, and its content in infertile soils is essential for the growth of bacteria. Since the mechanism of oligotrophic bacterium adaptation in barren soils is unclear, this research employed RNA-seq technology to examine the impact of glucose concentration on the oligotrophic bacterium B. subtilis BS-G1 in soil affected by desertification. A global transcriptome analysis (RNA-Seq) revealed that the significantly differentially expressed genes (DEGs) histidine metabolism, glutamate synthesis, the HIF-1 signaling pathway, sporulation, and the TCA cycle pathway of B. subtilis BS-G1 were significantly enriched with a 0.015 g/L glucose concentration (L group), compared to a 10 g/L glucose concentration (H group). The DEGs amino acid system, two-component system, metal ion transport, and nitrogen metabolism system of B. subtilis BS-G1 were significantly enriched in the 5 g/L glucose concentration (M group), compared with the H group. In addition, the present study identified the regulation pattern and key genes under a low-glucose environment (7 mRNAs and 16 sRNAs). This study primarily investigates the variances in the regulatory pathways of the oligotrophic B. subtilis BS-G1, which holds substantial importance in comprehending the mechanism underlying the limited sugar tolerance of oligotrophic bacteria.

Management policies impact fishers’ income beyond tolerable limits: The case of the Chilean TURFs in Central Chile

Fish trade worldwide seeks sustainable fishery production which right-based-fisheries should provide. However, fisheries managed in TURF system (Territorial Use Rights for Fisheries), as occurs for loco (Concholepas concholepas) and kelp fisheries in central Chile, can turn out to be highly fluctuating. This can pose a challenge to fisher’s livelihood depending on the income variability this type of management produces. This work analyzes temporal variations of loco and kelp abundances and landings at increasing spatial scales, investigating which would be a TURF size that could dampen the influence of natural variations on fishers’ income enough for it to be tolerable. We analyzed loco and kelp abundance and landings data from hard bottom TURFs in Atacama (n = 22) and Coquimbo (n = 61) regions of Central Chile, which represent 81.4% of the total TURFs in these regions. Income variations less than 39% were considered tolerable, according to a study conducted by the National Consumer Service, where 61% of a person’s salary is necessary to cover essential needs in Chilean family. Loco and kelp landings variations exceeded that criterion at all analyzed spatial scales, suggesting that they cannot rely solely on those fisheries within a TURF. Even increasing the size of TURF including the coast of an entire region, does not dampen variability to a tolerable value. This explains the reason for former fisher migrations within these fisheries, something present regulations prevent, generating a complex situation which is necessary to revise in order not to maintain an incentive to side step regulations.

Energy management of fault-tolerant real-time embedded systems through switching-activity-based techniques

Energy management and fault tolerance are essential aspects in designing most real-time embedded systems, and dynamic voltage and frequency scaling (DVFS) is a fundamental approach in energy management. Using DVFS can lead to a considerable decrease in the system's reliability as the rate of transient faults increases due to low voltage and frequency. This study focuses on finding and implementing methods that address the following three issues in hard real-time embedded systems: energy consumption, fault tolerance, and time limitations. Switching activity depends on the nature of tasks. Since the switching activity is task-specific, the energy consumption of a task can be significantly greater than that of other tasks. As far as we know, previous studies on the power management of fault-tolerant real-time systems have not considered switching activity, so the impact of this factor is considered in this study. Multiple heuristic methods are proposed based on the switching activity factor to minimize energy consumption while sustaining the system's original reliability. In the proposed methods, the order of task execution is determined based on task switching activities. The methods are developed for both periodic and frame-based task models. The results show that the proposed methods can decrease the energy consumption by 12.7 %∼35.5 % for the periodic task model and 17.4 %∼45.2 % for the frame-based task model while preserving the system's reliability.

Occurrence of zearalenone in maize and millet grains and their derived porridges marketed in Abidjan (Côte d’Ivoire)

Zearalenone is an endocrine-disrupting mycotoxin commonly found in cereals. The objective of this work was to evaluate zearalenone levels in maize and millet grains, and their porridges to measure the impact of the preparation processes of these porridges on the occurrence of zearalenone. The sampling was realized according to the regulation (EC) No 401/2006 of the European commission. Zearalenone concentration in commodities was determined using HPLC/UV. Zearalenone concentrations were compared with the Maximum Tolerable Limits (MTLs) of zearalenone established by European Union (EC) No1881/2006. The average zearalenone levels in the grains were 82.83 µg/Kg (maize) and 141.88 µg/Kg (millet). These levels were below the MTL in the case of maize, and above the MTL concerning millet. Average zearalenone levels in porridges were 11.70 µg/Kg < MTLs (maize) and 36.16 µg/Kg > Infant Maximum Tolerable Limit (IMTL) of millet. Zearalenone concentrations in millet grains were higher than in maize grains. Zearalenone levels in maize and millet-based porridges were low compared with their respective basic commodities. The processing techniques used for porridges, removed 85.88-93.67% of zearalenone from maize, and 74.51-76.66% of zearalenone from millet. Despite this significant reduction, the average zearalenone content in millet-based porridge was above the IMTL (20 µg/Kg). 

Evaluation of Koga irrigation water in Mecha district, Amhara Region, as an example of irrigation water quality in Northwestern Ethiopia

Irrigation water quality impacts plant growth, crop production, and public health. Thus, understanding the trends in irrigation water quality is important to manage public health, and optimize crop production. The Koga region in Ethiopia is a developing area where crops are an important food source for a growing population, and irrigation is critical to supply additional food crops and secure food insecurity issues. This study measures physiochemical and biological parameters to assess the suitability of Koga irrigation water for crops intended for human consumption. In March 2022, irrigation water samples were collected and analyzed for physicochemical and biological qualities. Kelley’s ratio, magnesium danger, and sodium absorption ratio were calculated from the data obtained. Results showed that the turbidity (174.33–259.00 NTU), total suspended solids (80.33–175.00 mg/L), total alkalinity (143.33–195.33 mg/L), total hardness (150.67–224.6 mg/L), SO42−(43.96–73.00 mg/L), PO43−(56.27–87.43 mg/L), and BOD5 (63.23–95.40 mg/L) levels surpassed the recommended limit of FAO(35 NTU,50 mg/L,100 mg/L,100–150 mg/L,20 mg/L,3 mg/L and 30 mg/L, respectively). BOD5 levels of the tested water samples exceeded the permissible limit set by the EU (10 mg/L). The coliform and fecal coliform levels in all sampled waters were higher than the zero/100 mL limits of the EU and WHO set for irrigation water. The studied water samples were found to be unsuitable for the cultivation of crops and vegetables since TA, PO4−3, and NO3− levels exceeded the tolerance limit of the crops and vegetables cultivated in the site, while the coliform and BOD5 levels surpassed their tolerable limits. Consequently, it is not recommended to eat crops and vegetables without first properly preparing them. The results showed improper ratio of Mg2+:Ca2+ and Na+:Ca+2, and a magnesium hazard was foreseen. This study showed that the turbidity, total suspended solids, total alkalinity, total hardness, SO42−, PO43−, BOD5, and the coliform levels of the studied irrigation water samples of the Koga irrigation project were not found within the safe limits of FAO, WHO, EU, and irrigation water quality limits of different nations, even though additional samples evaluating seasonal fluctuations are needed to fully assess the water quality.

Structural and functional impairments of skeletal muscle in patients with postacute sequelae of SARS-CoV-2 infection.

Following acute coronavirus disease 2019 (COVID-19), a substantial proportion of patients showed symptoms and sequelae for several months, namely the postacute sequelae of COVID-19 (PASC) syndrome. Major phenomena are exercise intolerance, muscle weakness, and fatigue. We aimed to investigate the physiopathology of exercise intolerance in patients with PASC syndrome by structural and functional analyses of skeletal muscle. At least 3 mo after infection, nonhospitalized patients with PASC (n = 11, age: 54 ± 11 yr; PASC) and patients without long-term symptoms (n = 12, age: 49 ± 9 yr; CTRL) visited the laboratory on four nonconsecutive days. Spirometry, lung diffusion capacity, and quality of life were assessed at rest. A cardiopulmonary incremental exercise test was performed. Oxygen consumption (V̇o2) kinetics were determined by moderate-intensity exercises. Muscle oxidative capacity (k) was assessed by near-infrared spectroscopy. Histochemical analysis, O2 flux (JO2) by high-resolution respirometry, and quantification of key molecular markers of mitochondrial biogenesis and dynamics were performed in vastus lateralis biopsies. Pulmonary and cardiac functions were within normal range in all patients. V̇o2peak was lower in PASC than CTRL (24.7 ± 5.0 vs. 32.9 ± 7.4 mL·min-1·kg-1, respectively, P < 0.05). V̇o2 kinetics was slower in PASC than CTRL (41 ± 12 vs. 30 ± 9 s-1, P < 0.05). k was lower in PASC than CTRL (1.54 ± 0.49 vs. 2.07 ± 0.51 min-1, P < 0.05). Citrate synthase, peroxisome proliferator-activated receptor-γ coactivator (PGC)1α, and JO2 for mitochondrial complex II were significantly lower in PASC vs. CTRL (all P values <0.05). In our cohort of patients with PASC, we showed limited exercise tolerance mainly due to "peripheral" determinants. Substantial reductions were observed for biomarkers of mitochondrial function, content, and biogenesis. PASC syndrome, therefore, appears to negatively impact skeletal muscle function, although the disease is a heterogeneous condition.NEW & NOTEWORTHY Several months after mild acute SARS-CoV-2 infection, a substantial proportion of patients present persisting, and often debilitating, symptoms and sequelae. These patients show reduced quality of life due to exercise intolerance, muscle weakness, and fatigue. The present study supports the hypothesis that "peripheral" impairments at skeletal muscle level, namely, reduced mitochondrial function and markers of mitochondrial biogenesis, are major determinants of exercise intolerance and fatigue, "central" phenomena at respiratory, and cardiac level being less relevant.

Study of Proximate Composition and Storage Stability of Selected Bakery Products from Developed Wheat-Sologold Sweet Potato Flour

The proximate composition and storage stability of selected bakery products from composite wheat-sologold sweet potato flour (40:60) were investigated. This is crucial to harness the beneficial attributes of the composite flour coupled with the quality of its baked products. Results of the proximate composition of the baked products (bread, biscuit and cake) from composite wheat-sologold sweet potato flour were as follows: moisture content (10.60, 8.20, 6.80%), crude fiber (0.42, 0.38, 0.40%), ash content (1.20, 1.40, 1.30%), protein content (17.10, 16.50, 18.40%), oil extract (5.83, 5.33, 5.30%) and nitrogen free extract (64.85, 66.79, 67.80%) respectively. These values are within the range of good quality marketable baked products. During storage under room temperature, the total bacterial and fungi count of the baked products were found to be within was within the tolerable limit of edible food. The wheat-sologold sweet potato is therefore, a potential composite flour in the baking industry for improved quality and safety of baked products.

Effect of cylindrical heat pipes on electrochemical hydrogen adsorption within a carbon electrode employed in a modified reversible PEM fuel cell

The presented work is a maiden experimental attempt on thermal management of a modified reversible polymer electrolyte membrane fuel cell (MRPEMFC) using a passive cooling approach to enhance the hydrogen (H)-adsorption capacity of an integrated activated carbon (aC) electrode. In the current study, cylindrical heat pipes (CHPs) are installed on the hydrogen side (H-side) and oxygen side (O-side) bi-polar end plates (BEPs) of the developed cell to maintain a temperature within tolerable limits during the charging operation. The noteworthy achievement with the integration of a CHP on the H-side of the MRPEMFC is a 12 °C reduction in the operating temperature. While, the highest obtained gravimetric H-storage density is recorded 1.52 wt percent (wt%) with the integration of CHPs on H- and O-side BEPs, which is 40% higher than without CHPs. Furthermore, CHPs assisted-MPEMFC is able to supply 0.4 mA constant current for the first 3 min during the discharging operation.

Mitigating biomass recalcitrance for plant‐based bioenergy production

AbstractThe emission of greenhouse gases, particularly carbon dioxide, predominantly from fossil fuel combustion has received critical warnings several times as their levels exceed the tolerable limits in view of global warming. This calls for a paradigm shift from a fossil fuel‐based source to a less hazardous bioenergy source. Plant feedstock is an attractive source of raw materials for bioenergy production; however, chemical or enzymatic digestion of the feedstock is expensive owing to the supramolecular lignocellulosic barrier, indicating the need for better alternatives. Several attempts have been made towards reducing the biomass recalcitrance of straw using genetic transformations. We present a review highlighting potential plant candidates for bioenergy production, the lignocellulose composition of the feedstock, how the composition can impede enzymatic degradation, the regulation of lignocellulose polymer biosynthesis, and the influence of genetic transformation on biomass saccharification. Moreover, the review also discusses conflicting research interests in biomass recalcitrance and suggests a common ground. The review findings suggest that bioenergy production from crop straws will drastically reduce over‐dependence on fossil fuels and consequently pollution levels.

Environmental impact assessment of abattoirs in Rivers State, Nigeria

Abattoir waste discharged randomly into a recipient ecosystem can have a serious ecological impact. This study aimed to assess the environmental impact of abattoir operations, looking at the physicochemical and microbiological quality of air, soil and wastewater within the vicinity of operations. Physicochemical parameters of air, soil and water were found to differ across locations, though not significant (p&gt;0.05). BOD and COD exceeded the tolerable limits of 30-100 mg/l and 250 mg/l respectively, for all samples. Only the pH (10.62) of wastewater from the Mbodo-Aluu abattoir exceeded the tolerable limit of 5.5-9.0. All heavy metals were within tolerable limits, except Zn, which exceeded 0.2 mg/l. Microbiological parameters of air, soil and water were also found to differ across locations, though not significant (p&gt;0.05). Abattoir operations impact the physicochemical characteristics of wastewater, soil, and air in the abattoir environment. Microbes associated with wastewater, soil impacted by abattoir wastewater, and air from the abattoir environment were found to include pathogenic species of bacteria and fungi. Proper waste management should be encouraged among abattoir operators and should include treatment of wastewater.

SDS-capped 1-pyrenecarboxaldehyde nanoprobe for selective detection of Cu2+ ion from water samples: Spectroscopic approach.

Sodium dodecyl sulfate (SDS)-capped 1-pyrenecarboxaldehyde nanoparticles (PyalNPs) were prepared using a reprecipitation method in an aqueous medium and exhibited red-shifted aggregation-induced enhanced emission (AIEE). The dynamic light scattering (DLS) examination showed narrower particle size distribution with an average particle size of 41 nm, whereas -34.5mV zeta potential value indicate the negative surface charge and good stability of nanoparticles (NPs) in an aqueous medium. The AIEE was seen at λmax = 473 nm in a fluorescence spectrum of a PyalNP suspension. In the presence of Cu2+ ions, the fluorescence of PyalNPs quenches very significantly, even in the presence of other metal ions like Ba2+ , Ca2+ , Cd2+ , Co2+ , Al3+ , Fe2+ , Hg2+ , Ni2+ and Mg2+ . The changes in the fluorescence lifetime of PyalNPs in the presence of Cu2+ ions suggested that the type of quenching was dynamic. The fluorescence quenching data for the NPs suspension fitted well into a typical Stern-Volmer relationship in the concentration range 1.0-25 μg/ml of Cu2+ ions. The estimated value of the correlation coefficient R2 = 0.9877 was close to 1 and showed the linear relationship between quenching data and Cu2+ ion concentration. The limit of detection (LOD) was found to be 0.94 ng/ml and is far below the tolerable intake limit value of 1.3μg/ml accepted by the World Health Organization for Cu2+ ions in drinking water. The fluorescence quenching approach for a SDS-capped Pyal nanosuspension for copper ion quantification is of high specificity and coexisting ions were found to interfere very negligibly. The developed method was successfully applied for the estimation of copper ions in river water samples.

Radical Pathway Glycosylation Empowered by Bench-Stable Glycosyl Donors.

ConspectusThe study of carbohydrates has emerged as a crucial research area in various disciplines due to their pivotal roles in cellular processes. To facilitate in-depth exploration of their biological functions, chemical glycosylation reactions that allow facile access of glycoconjugates to a broad research community are highly needed. In classical glycosylation reactions, a glycosyl donor is activated by an acid to generate a reactive electrophilic intermediate, which subsequently forms a glycosidic bond upon reaction with a nucleophilic acceptor. Such an ionic pathway glycosylation has been the mainstay technique for glycoconjugate synthesis and allowed the synthesis of numerous intricate structures. Nevertheless, limitations still exist. For instance, when labile glycosyl donors or harsh activating conditions are required, these methods show limited tolerance to hydroxyl groups that are abundant on sugar rings. In addition, achieving good stereocontrol represents another longstanding obstacle. In recent years, new modes of donor activation have been sought to tackle the above challenges.We noted that glycosylation methods passing through the intermediacy of glycosyl radicals via a cascade of single-electron transfer steps possess significant but underexplored potential. Progress in this area has been slow due in large part to a dearth of handy methods to generate and maneuver glycosyl radicals. Most existing methods call for either forcing conditions or unstable/inconvenient starting materials. In order to better exploit the power of the radical pathway glycosylation, we have developed a range of glycosyl donors─namely, glycosyl sulfoxides, glycosyl sulfones, and glycosyl sulfinates─that are bench stable and can be readily prepared from simple starting materials. These donors can be activated to form glycosyl radicals under mild conditions. Enabled by the use of these donors, we have developed a series of glycosylation methods that could be used for making O-, S-, or C-glycosides, some of which were previously difficult to access. In many cases, no protecting group on glycosyl donors is required. As an illustration of their potential utility, our methods have been adopted in the preparation of sugar-drug conjugates, sugar-DNA conjugates, glycopeptides, and even glycoproteins. While in most cases the intrinsic reactivity of glycosyl radical intermediates can be explored to access axially configured products, some of the methods also allow the utilization of external, delicate reagents, or catalysts to override such innate preference and achieve catalyst-controlled stereoselectivity.We believe that radical pathway glycosylation has enormous potential and can inspire the development of novel methods for glycoside synthesis. In this Account, we highlight the design principles for the development of our glycosyl donors, summarize our recent advancements in radical pathway glycosylation enabled by their use, and provide an outlook on the future directions of this field.

Tolerable treatment of glioblastoma with redox-cycling ‘mitocans': a comparative study in vivo

ABSTRACTObjectives: The present study describes a pharmacological strategy for the treatment of glioblastoma by redoxcycling ‘mitocans’ such as quinone/ascorbate combination drugs, based on their tumor-selective redox-modulating effects and tolerance to normal cells and tissues.Methods: Experiments were performed on glioblastoma mice (orthotopic model) treated with coenzyme Q0/ascorbate (Q0/A). The drug was injected intracranially in a single dose. The following parameters were analyzed in vivo using MRI orex vivo using conventional assays: tumor growth, survival, cerebral and tumor perfusion, tumor cell density, tissue redox-state, and expression of tumor-associated NADH oxidase (tNOX).Results: Q0/A markedly suppressed tumor growth and significantly increased survival of glioblastoma mice. This was accompanied by increased oxidative stress in the tumor but not in non-cancerous tissues, increased tumor blood flow, and downregulation of tNOX. The redox-modulating and anticancer effects of Q0/A were more pronounced than those of menadione/ascorbate (M/A) obtained in our previous study. No adverse drug-related side-effects were observed in glioblastoma mice treated with Q0/A.Discussion: Q0/A differentiated cancer cells and tissues, particularly glioblastoma, from normal ones by redox targeting, causing a severe oxidative stress in the tumor but not in non-cancerous tissues. Q0/A had a pronounced anticancer activity and could be considered safe for the organism within certain concentration limits. The results suggest that the rate of tumor resorption and metabolism of toxic residues must be controlled and maintained within tolerable limits to achieve longer survival, especially at intracranial drug administration.

Optimization of land management measures for soil erosion risk using GIS in agricultural landscape of western Hararghe highlands, Ethiopia

Soil loss through water is one of the major environmental problems leading to land degradation worldwide. Though soil erosion is an inevitable natural phenomenon, it is possible to reverse and minimize the rate at a local level. This requires spatially unambiguous evidence on rate of soil loss so as to implement site specific land management decisions. The aim of this study was to estimate the mean annual soil loss and optimize land management measures in the Midhagdu watershed of western Hararghe highlands, Ethiopia. The study used five soil loss factors as input variables to estimate the soil loss. A thematic layer map was generated for each factor with spatial resolution of 30 m using Geographical Information System (GIS), and combined them with revised universal soil loss equation (RUSLE) model to estimate soil loss and identify erosion risky area in the watershed. According to the results, the distribution of annual soil loss varied between 0 and 179 t ha−1 yr−1, with a mean annual loss rate of 44.24 t ha−1 yr−1. The total annual soil loss in the entire watershed was 240,250 tons. Of this, 93.48% (224,593 tons) of the loss occurred in 49% (2,674 ha) of the catchment area,which was above the maximum tolerable soil loss limits. Most of the soil erosion affected areas are spatially situated in the upper and hillsides of the watershed. This is due to factors attributed to the steepness of the slope, dominance of Leptosols with shallow soil depth, coupled with absence of supporting practice in these parts of the watershed. Thus, slope length and slope steepness (LS) factor was the primary RUSLE parameters that controlled the soil loss in the studied watershed followed by soil erodibility (K) and support practice (P) factor. Hence, this study optimized land management options for future intervention based on the inherent limitation of the biophysical environment, socioeconomic and cultural conditions of the watershed community.

Elemental, phytochemical, and toxicological assessment of Cissus rotundifolia (Forssk.) Vahl

Cissus rotundifolia (Forssk.) Vahl. (Vitaceae) is a wild plant that is commonly used by communities from rural areas as a food and medicine. There are limited studies on the phytochemical composition and the impact of soil quality on the elemental distribution in this plant. In this study, we report a phytochemical analysis to identify the phytocompounds responsible for the reported biological activities of C. rotundifolia. We also examined the impact of soil quality on elemental uptake by the edible parts of C. rotundifolia collected from eight geographical locations in KwaZulu-Natal (South Africa) to assess the nutritional benefits and potential heavy metal toxicities. Three secondary metabolites (stigmasterol, β-sitosterol, and pheophytin a) were isolated, and their structures were characterised by high-resolution mass spectrometry and nuclear magnetic resonance data. The plant was found to contribute adequately to the recommended dietary allowances for essential nutrients without exceeding tolerable upper intake limits and with low concentrations of toxic heavy metals. The average concentrations of microelements in the edible parts were found to be in decreasing order of Fe&gt;Mn&gt;Se&gt;Zn&gt;Cu&gt;Cr&gt;Ni&gt;Co. The bioaccumulation factors indicate that the plant controls the uptake of metals from the soil and would make a good indicator and biological monitor for cadmium toxicity. However, a health risk assessment exposed carcinogenic risks on regular consumption of the plant obtained from sites close to pollution sources, such as roads and landfills. The findings from this study show the synergies when consuming medicinal plants and provide evidence for C. rotundifolia as a nutraceutical. Significance: This study provides additional scientific knowledge on the phytochemical composition of C. rotundifolia. Three phytocompounds (stigmasterol, β-sitosterol, and pheophytin a) were isolated, and their presence may be correlated to this plant’s antidiabetic, anti-inflammatory, and antibacterial properties. This study shows that C. rotundifolia contributes adequately to the recommended dietary allowances for essential elements, and the plant is safe for human consumption if collected from non-polluted sites. The carcinogenic and non-carcinogenic estimates for the toxic metals due to consumption of the plant signify the possibility of developing cancer over time if the plant is consumed frequently from polluted sites.

Overstuffing the patellofemoral compartment in total knee arthroplasty: a systematic review.

To systematically review and analyze the data available in the literature to evaluate the role of patellofemoral overstuffing in affecting clinical outcomes following primary total knee arthroplasty. A systematic literature review was conducted following the PRISMA guidelines. Only studies including primary total knee arthroplasty in the setting of osteoarthritis with a quantifiable method of measuring patellofemoral overstuffing using pre- and post-operative x-rays or advanced imaging, as well as reported subjective and/or objective patient outcomes in relation to patellofemoral overstuffing were included. Extracted data included patellofemoral overstuffing quantitative measurement method, outcome measurements, follow-up, patient demographics, author, and publication details. Descriptive analysis was provided for the available literature. There were six included articles with a total of 2325 TKAs assessed. All papers found no significant effect on clinical outcomes when the amount of PFJ overstuffing was within reason. The amount of overstuffing that routinely takes place seems to be within tolerable limits and does not create a significant difference in clinical outcomes. Nevertheless, it is recommended to recreate the anatomic dimensions of the PFJ in order to best obtain a joint that is within this safe margin of error.

Health Risk Assessment of Some Heavy Metals Contamination in Vegetables Sold at Bichi Local Government Area, Kano State – Nigeria

Vegetables are the source of essential nutrients for health maintenance and treatment of various diseases. However, they are a major source of heavy metals contamination. This study evaluates the levels of heavy metals in selected vegetables sold in Bichi and their potential health risks. The collected samples were ashed using concentrated HNO3 and analyzed using AAS. The concentrations of the heavy metals detected were in the range of 0.18 to 0.04; 1.64 to 0.63; 0.01; 3.44 to 0.67, and 0.17 to 0.06 mg/kg, for Cu, Fe, Cd, Pb, and Zn respectively. The concentrations of heavy metals were below WHO/FAO recommended levels except Pb, which is above the tolerable limit. The highest concentration of Pb (3.44 mg/kg) where detected in pepper, and the least in carrots (0.67 mg/kg). The Estimated Daily Intake values of individual heavy metals from the consumption of vegetables were 1.08 × 10−3, 1.66 × 10−2, 1.42 × 10−, 3.52 × 10−2, and 1.36×10−3mg/kg body weight/day for Cu, Fe, Cd, Pb, and Zn respectively which were less than the Maximum tolerable daily intake. The Hazard Index of all vegetables is 6.83 × 10−2 which is less than 1, indicating that, the consumption of these vegetables may result in non- carcinogenic health risks. The Target Cancer Risks value of Pb was 2.99 × 10−7, which is less than the standard risk limit (10−6). This shows that, despite the high concentration of Pb in the samples, the calculated parameters have clearly indicated that, there are no carcinogenic health risks to consumers.

Investigating the current trend of selected heavy metal pollution with possible ecological and human health effects along the uMgeni River of KwaZulu-Natal, South Africa

ABSTRACT This study aims to evaluate the concentrations, water quality analysis and health risk assessment of metals contained in water, soil and sediment samples along the uMgeni River, Durban, South Africa. Eleven heavy metals were studied and analysed using Inductively Coupled Plasma Optical Emission Spectrometer (ICP-OES). The concentrations of the heavy metal in water samples were in the order of As > Mn > Cd > Cr > Mo > Zn > Cu > Co > Ag > Ni with Pb not been detected in the water samples. All the heavy metals were found to be higher than the tolerable limits for safe drinking water as provided by the WHO and USEPA except for the Zn and Pb which were lower. The water quality index, heavy metal environmental index, and heavy metal toxicity index revealed that the quality of the water is poor and unfit for both domestic and irrigation uses. Similarly, the health risk assessment revealed that both carcinogenic-non-carcinogenic risk values for the heavy metals were higher than the threshold values provided by the USEPA and were more prevalent for children than adults.

Hybrid Vibration Control of Hospital Buildings against Earthquake Excitations Using Unbonded Fiber-Reinforced Elastomeric Isolator and Tuned Mass Damper

Lifeline structures such as hospital buildings need to be specifically designed such that they experience reduced vibrations when subjected to earthquake excitations because it will be difficult to vacate hospital buildings under the event of any earthquake. Therefore, to ensure operational condition under earthquake excitations in an existing hospital building, the present study utilizes flexible unbonded fiber-reinforced elastomeric isolators (UFREIs) for its seismic isolation. The UFREI-based isolation system is designed to restrict the structural acceleration within the tolerable limits for the building inhabitants even during earthquake hazards. However, the use of such flexible isolators results in excessively large bearing displacements, which either may not be practical and/or pose several serviceability issues. Therefore, tuned mass damper (TMD) is attached to the base floor of the UFREI-isolated hospital building to reduce the large isolator displacements. Properties of the hybrid vibration control system are designed according to the site-specific scenario in New Delhi, India. Further, nonlinear time-history analyses of the UFREI-isolated hospital building with the TMD are carried out, and responses are compared with its uncontrolled response. Results show that the peak bearing displacement response of the UFREI-isolated hospital building is reduced by 9% to 27%, due to the addition of the TMD. Importantly, the required design displacement of the UFREI-based isolation system is decreased by 27%, without compromising the effectiveness of base isolation. In fact, the performance of the hybrid vibration control system is superior to the base isolation system alone.