8 research outputs found
BASE OIL BLENDS - A GREAT OPPORTUNITY FOR GREASE FORMULATORS
Mineral oils used by grease manufacturers can be divided into two major groups, naphthenic oils and paraffinic oils. These categories of base oils have their own advantages and disadvantages depending on the applications and conditions. The most important advantages of the naphthenic oils over the paraffinic oils, with the same viscosity and similar aromatic content, are better low-temperature flowability and better solvency. The contribution of having base oils with good solvency towards the thickener is that less thickener is needed to obtain a certain consistency of the finished product. For instance, a typical NLGI grade 2 lithium based grease, based on a solvent neutral 500, group one (Gr I) oil, may contain 9-14 wt% thickener; while 6-8% thickener is required for an equivalent viscosity oil of naphthenic nature. Using blends of naphthenic oil and paraffinic group one oil have successfully been used during the past decade in India. However, the author believes that the surplus of paraffinic Gr II and Gr III base oils is one among a number of market trends that brings some great opportunities to the grease formulators, if they look for blends where naphthenic oils are regarded as part of the solution for a sustainable formulation. A number of key parameters important for the performance of the finished product could be obtained within reasonable cost.
The purpose of this work was to compare “side by side” three base oil blends where paraffinic Gr I, Gr II and Gr III, in combination with naphthenic, were used for preparation of lubricating greases. Since the target viscosity was 150 mm2/s at 40ºC, a naphthenic oil was used in order to reach this viscosity.
The overall results obtained, reveal some interesting aspects of the use of Gr II as a substitute to Gr I for preparation of greases. The outcome of this work emphasizes that blends should be regarded as a great opportunity for grease formulators who are looking for some further development of their current formulations and furthermore, the lubricating grease based on the blend of paraffinic Gr II and naphthenic oil performs better than others
Improvement of Mouse Preantral Follicle Survival and Development following Co-Culture with Ovarian Parenchyma Cell Suspension
Background: The parallel and continued improvements in both infertility treatment and the management of malignancycases have brought to the forefront the potential for fertility preservation. Using ovarian follicular resourcescan effectively improve reproductive capacity and prevent infertility. The primary aim of this research was to try togenerate an appropriate in vivo environment for the growth of the mouse follicles. Hence, the possible effects of theovarian parenchyma cell suspension were explored on the growth and maturation of preantral follicles in vitro.Materials and Methods: In this experimental study, ovarian parenchymal cells were mechanically dissociated frompreantral follicles of 12-14 days-old NMRI mice and then divided into 5 experimental groups (G1: Control, G2: Freshfollicle with fresh parenchyma cell suspension, G3: Vitrified-warmed follicle with fresh parenchyma cell suspension,G4: Fresh follicle with frozen-thawed parenchyma cell suspension, and G5: Vitrified-warmed follicle with frozen-thawedparenchyma cell suspension). The diameter of the follicles and immature oocytes, viability, antrum formation,resumption of meiosis, in vitro fertilization (IVF), and Gdf9, Bmp6, and Bmp15 gene expression were examined ondifferent periods.Results: The diameter of the follicles and the oocytes on days 4 and 8, as well as the survival rate of the follicles upto day 12, were significantly higher in G2 and G4 compared to the Ctrl group (G1: 73.66%, G2:87.99%, G3: 82.70%,G4: 94.37%, and G5: 78.59%). Expression of growth marker genes for G3, and G5 groups was significantly higherthan other groups, which indicated the protective effects of parenchyma cell suspension on follicles damaged by vitrificationsolutions.Conclusion: The growth, survival, and maturation of preantral follicles could be enhanced by co-culturing them withovarian parenchyma cells. Further studies are needed to optimize the conditions for a successful parenchyma cellsuspension-induced in vitro maturation (IVM) to occur in infertility clinics
Global, regional, and national burden of disorders affecting the nervous system, 1990–2021: a systematic analysis for the Global Burden of Disease Study 2021
BackgroundDisorders affecting the nervous system are diverse and include neurodevelopmental disorders, late-life neurodegeneration, and newly emergent conditions, such as cognitive impairment following COVID-19. Previous publications from the Global Burden of Disease, Injuries, and Risk Factor Study estimated the burden of 15 neurological conditions in 2015 and 2016, but these analyses did not include neurodevelopmental disorders, as defined by the International Classification of Diseases (ICD)-11, or a subset of cases of congenital, neonatal, and infectious conditions that cause neurological damage. Here, we estimate nervous system health loss caused by 37 unique conditions and their associated risk factors globally, regionally, and nationally from 1990 to 2021.MethodsWe estimated mortality, prevalence, years lived with disability (YLDs), years of life lost (YLLs), and disability-adjusted life-years (DALYs), with corresponding 95% uncertainty intervals (UIs), by age and sex in 204 countries and territories, from 1990 to 2021. We included morbidity and deaths due to neurological conditions, for which health loss is directly due to damage to the CNS or peripheral nervous system. We also isolated neurological health loss from conditions for which nervous system morbidity is a consequence, but not the primary feature, including a subset of congenital conditions (ie, chromosomal anomalies and congenital birth defects), neonatal conditions (ie, jaundice, preterm birth, and sepsis), infectious diseases (ie, COVID-19, cystic echinococcosis, malaria, syphilis, and Zika virus disease), and diabetic neuropathy. By conducting a sequela-level analysis of the health outcomes for these conditions, only cases where nervous system damage occurred were included, and YLDs were recalculated to isolate the non-fatal burden directly attributable to nervous system health loss. A comorbidity correction was used to calculate total prevalence of all conditions that affect the nervous system combined.FindingsGlobally, the 37 conditions affecting the nervous system were collectively ranked as the leading group cause of DALYs in 2021 (443 million, 95% UI 378–521), affecting 3·40 billion (3·20–3·62) individuals (43·1%, 40·5–45·9 of the global population); global DALY counts attributed to these conditions increased by 18·2% (8·7–26·7) between 1990 and 2021. Age-standardised rates of deaths per 100 000 people attributed to these conditions decreased from 1990 to 2021 by 33·6% (27·6–38·8), and age-standardised rates of DALYs attributed to these conditions decreased by 27·0% (21·5–32·4). Age-standardised prevalence was almost stable, with a change of 1·5% (0·7–2·4). The ten conditions with the highest age-standardised DALYs in 2021 were stroke, neonatal encephalopathy, migraine, Alzheimer's disease and other dementias, diabetic neuropathy, meningitis, epilepsy, neurological complications due to preterm birth, autism spectrum disorder, and nervous system cancer.InterpretationAs the leading cause of overall disease burden in the world, with increasing global DALY counts, effective prevention, treatment, and rehabilitation strategies for disorders affecting the nervous system are needed
Equity or Equality? Which Approach Brings More Satisfaction in a Kidney-Exchange Chain?
In United States (U.S.), government-funded organizations, such as NLDAC, reimburse travel and subsistence expenses incurred during living-organ donation process. However, in Iran, there is a non-governmental organization called Iranian Kidney Foundation (IKF) that funds the direct and indirect costs of donors through charitable donations and contributions from participants in the exchange program. In this article, for countries outside the U.S. that currently use an equality approach, we propose a potential new compensation-apportionment approach (equitable approach) for kidney-exchange chains and compare it with the currently available system (equality approach) in terms of the apportionment of compensation in a kidney-exchange chain to cover the expenses incurred by the initiating living donor of the chain in the act of donation. To this end, we propose a mechanism to apportion compensation among all participating pairs based on the equity approach by utilizing a prediction model to calculate the probability of graft survival in each transplant operation. These probabilities are then used to define the utility of any transplantation, considering the quality of each pair’s donated and received kidney in the chain. Afterward, the corresponding cost is apportioned by a mechanism based on the normalized differences between the utility of donated and received kidneys for each incompatible pair of the chain. In summary, we demonstrate that by utilizing the equitable approach, there is more fairness and equity in the allocation of resources in organ-procurement systems, which results in more satisfaction among incompatible pairs. Additional future prospective studies are needed to assess this proposed equitable approach for kidney-exchange chains in countries outside the U.S., such as Iran, that currently use an equality approach