Prediction of the aggregation rate of nanoparticles in porous media in the diffusion-controlled regime.

The fate and aggregation of nanoparticles (NPs) in the subsurface are important due to potentially harmful impacts on the environment and human health. This study aims to investigate the effects of flow velocity, particle size, and particle concentration on the aggregation rate of NPs in a diffusion-limited regime and build an equation to predict the aggregation rate when NPs move in the pore space between randomly packed spheres (including mono-disperse, bi-disperse, and tri-disperse spheres). The flow of 0.

Aggregation of nanoparticles and morphology of aggregates in porous media with computations.

Hypothesis: The main hypothesis is that the aggregation process for nanoparticles (NPs) propagating in porous media is affected by the structure of the flow field as well as by the properties of the primary NPs. If this were true, then the aggregation could be predicted and controlled. However, to obtain reliable results from computations, one needs to account for the interactions between the NPs as well as the details of the fluid velocity, thus making advances over prior efforts that either ignored the aggregation of NPs, or used probabilistic methods to model aggregation.

Climate Change Imperils Pediatric Health: Child Advocacy Through Fossil Fuel Divestment.

Climate change poses an existential threat to children's health. Divestment of ownership stakes in fossil fuel companies is one tool available to pediatricians to address climate change. Pediatricians are trusted messengers regarding children's health and therefore bear a unique responsibility to advocate for climate and health policies that affect children.

The Role of Physician Advocacy in Supporting Policy Change That Reduces Leaded Aviation Gasoline Emissions.

Background: Leaded aviation gasoline (AvGas) accounts for 70%, or 935,082 pounds, of total lead emissions in the United States and has been repeatedly linked to elevated blood lead levels (BLLs) in those living in the vicinity of airports using AvGas. The well-established link between lead exposure and adverse health outcomes provided a platform ripe for environmental health advocates and pediatric health experts to assist a local environmental health organization in addressing lead waste from a local airport, Montgomery-Gibbs Executive Airport (MYF).

Method: We detail the steps we took, as a physician clean-air advocacy group.

Do premenopausal women with major depression have low bone mineral density? A 36-month prospective study.

Background: An inverse relationship between major depressive disorder (MDD) and bone mineral density (BMD) has been suggested, but prospective evaluation in premenopausal women is lacking.

Methods: Participants of this prospective study were 21 to 45 year-old premenopausal women with MDD (n = 92) and healthy controls (n = 44). We measured BMD at the anteroposterior lumbar spine, femoral neck, total hip, mid-distal radius, trochanter, and Ward's triangle, as well as serum intact parathyroid hormone (iPTH), ionized calcium, plasma adrenocorticotropic hormone (ACTH), serum cortisol, and 24-hour urinary-free cortisol levels at 0, 6, 12, 24, and 36 months.

Quantification of pH gradients and implications in insulator-based dielectrophoresis of biomolecules.

Direct current (DC) insulator-based dielectrophoretic (iDEP) microdevices have the potential to replace traditional alternating current dielectrophoretic devices for many cellular and biomolecular separation applications. The use of large DC fields suggest that electrode reactions and ion transport mechanisms can become important and impact ion distributions in the nanoliters of fluid in iDEP microchannels. This work tracked natural pH gradient formation in a 100 μm wide, 1 cm-long microchannel under applicable iDEP protein manipulation conditions.

Appropriate use of endoscopy in the diagnosis and treatment of gastrointestinal diseases: up-to-date indications for primary care providers.

The field of endoscopy has revolutionized the diagnosis and treatment of gastrointestinal (GI) diseases in recent years. Besides the 'traditional' endoscopic procedures (esophagogastroduodenoscopy, colonoscopy, flexible sigmoidoscopy, and endoscopic retrograde cholangiopancreatography), advances in imaging technology (endoscopic ultrasonography, wireless capsule endoscopy, and double balloon enteroscopy) have allowed GI specialists to detect and manage disorders throughout the digestive system. This article reviews various endoscopic procedures and provides up-to-date endoscopic indications based on the recommendations of American Society for Gastrointestinal Endoscopy and American Cancer Society for primary care providers in order to achieve high-quality and cost-effective care.

Low 24-hour adiponectin and high nocturnal leptin concentrations in a case-control study of community-dwelling premenopausal women with major depressive disorder: the Premenopausal, Osteopenia/Osteoporosis, Women, Alendronate, Depression (POWER) study.

Objective: Major depressive disorder (MDD) is associated with immune system dysfunction and disruption of multiple circadian systems. Adiponectin is an adipocytokine with anti-inflammatory and antiatherogenic effects. Circulating concentrations are inversely related to adiposity and risks of metabolic syndrome and diabetes mellitus.

Re-emergence of another vaccine-preventable disease?-Two cases of rubella in older adults.

Unlike its devastating teratogenic effects, post-natal infection with rubella typically causes subclinical or inapparent illness. While rubella has been largely eliminated from the United States following the introduction of an efficacious live-attenuated vaccine in 1969, a small proportion of the population remains susceptible. Recent declining vaccination rates have resulted in a rising incidence of sporadic and outbreak-associated measles, reminding us that an increasing proportion of the population is also susceptible to, and may be reservoirs of transmission for, rubella.

(1R*,2R*,4S*,5R*,6R*,8S*)-4,8-Dimethyl-2,6-diphenyl-bicyclo-[3.3.1]nonane-2,6-diol.

The racemic title compound, C(23)H(28)O(2), crystallizes in the space group C2/c as a layered structure in which a centrosymmetric three hydrogen bond sequence links four molecules. Both hydroxy groups are involved in this arrangement, but they differ in that one participates in two hydrogen bonds while the other takes part in only one. Between layers, the aromatic rings take part in edge-face interactions [shortest C-H⋯C distances 3.

Preventing aggression in persons with dementia.

Persons with dementia often present with non-cognitive clinical symptoms, such as aggression, which can be distressing and dangerous to both caregiver and patient. Depression, pain, caregiver burden, and the quality of the caregiver-patient relationship can contribute to the onset of aggression. Given the risks involved with medication, there is a strong need for preventive and nonpharmacological interventions before such behaviors occur.

Transitioning of children with GH deficiency to adult dosing: changes in body composition.

As more evidence gathers regarding the beneficial effect of growth hormone replacement therapy (GHRT) on body composition and other parameters in adults with childhood-onset growth hormone deficiency (GHD), questions emerge regarding whether or not GHRT should be discontinued following cessation of statural growth, and the effect of GHRT during the transition period on body composition and related parameters. This review discusses the effect of discontinuation of GHRT following attainment of adult stature, and the treatment and dose effect when GHRT is reinstated. We also review data regarding who should receive GHRT, the criteria for diagnosing persistent GHD, dosing of GHRT and the possibility of a GH 'holiday'.